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221 Cards in this Set
- Front
- Back
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subunits of nucleic acids?
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nucleotides
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basic structure of a nucleotide?
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base + sugar + phosphate
the sugar is 5 Carbon ...AKA "PENTOSE"....common example is Ribose |
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the 2 types of BASES of nucleic acids?
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purines
and pyrimidines |
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What are the PURINES?
What is their structure? |
A -adenine & G -guanine
2 ring structure |
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what are the PYRIMIDINES?
What is their structure? |
C- cytosine, T -thymine & U - uracil
1 ring structure (memory: 1 C-U-T-e pyramid) |
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What are the 2 types of sugars of a nucleic acid?
-These are __ carbon sugars. |
Ribose- with on OH- on carbon #2
Deoxyribose with an H+ on carbon #2. (remember: Deoxy= Not oxygen) 5 carbon sugars. |
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5 Carbon sugars are called ______.
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pentose
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another way to say "Carbon #" 1,2,3,4, or 5?
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prime!
1',2',3' etc. |
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What is a Phosphodiester Linkage?
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Joins nucleotides (via dehydration) together to form nucleic acids.
C'3 - PO3 - O - C'5 Joins C'3 - PO3 - O |
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What are the functions of nucleotides & site an example for each function.
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1. carrying chemical energy. Eg. ATP
2. combine with other groups to form coenzymes. Eg. CoA (Coenzyme A) 3. Signaling withing the cell. Eg. Cyclic AMP |
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What make ATP such a good carrier for cellular energy?
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Easily hydrolyzed phosphoanhydride bonds.
Phosphate broken off with water, but added with energy from sunlight or food. |
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What is the difference between a nucleotide and a nucleoside?
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A nucleoside is like a nucleotide without the phosphate.
Just a Base + Sugar. |
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in the DNA sequence G-A-T-T-A-C-A
in standard notation which end is 5'? |
G
*always start with 5' on the left |
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What can always be found attached to the 3' end of a DNA?
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a hydroxyl group
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What is ATP??
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Adenosine triphosphate
A nucleotide that carries cellular energy. |
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What is AMP?
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Adenosine monophosphate: a nucleotide
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What is UDP?
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Uridine diphosphate: a nucleotide
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What is cAMP?
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cyclic adenosine monophosphate
A nucleotide formed from ATP. cAMP plays an important role in intracellular signaling |
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Nomenclature: What is the name for the base indicated by "A"?
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adenine
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Nomenclature: What is the name for the base indicated by "G"?
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guanine
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Nomenclature: What is the name for the base indicated by "C"?
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cytidine
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Nomenclature: What is the name for the base indicated by "U"?
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uridine
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Nomenclature: What is the name for the base indicated by "T"?
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thymidine
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Nomenclature: What is the name for the NUCLEOSIDE indicated by "A"?
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AdenOSINE
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Nomenclature: What is the name for the NUCLEOSIDE indicated by "G"?
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GuanOSINE
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Nomenclature: What is the name for the NUCLEOSIDE indicated by "C"?
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CytiDINE
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Nomenclature: What is the name for the NUCLEOSIDE indicated by "U"?
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UriDINE
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Nomenclature: What is the name for the NUCLEOSIDE indicated by "T"?
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ThymiDINE
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How is ATP converted to ADP?
Then how is ADP converted back to ATP? |
ATP--> ADP : hydrolysis (water releases a phosphate for cellular use)
ADP --> ATP : energy from sunlight of food |
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How many hydrogen bonds formed between A&T?
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2
(looser hold) |
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How many hydrogen bonds form between C&G?
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3
(tighter hold) |
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3 Questions:
1. Length between base pairs on a DNA molecule? 2. How many base pairs per helical turn? 3. Length of a helical turn? |
1. .34 nm
2. 10 3. 3.4 nm |
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DNA has a __________backbone.
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sugar phosphate
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DNA grows in the __' direction.
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3'
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the 5' end and the 3' end replicating in opposite directions is called _____.
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antiparallel
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Summarize the 1920's experiment by Fred Griffith and its conclusions.
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Mice injected with "S" and "R" strains of Strep.
S kills mouse R doesn't. Heated S strain doesn't kill mouse. Heated S strain + R strain DOES kill mouse. Conclusion: Proteins are NOT the HERITABLE MATERIAL!! |
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Summarize the 1940's experiment by Avery, MacLeod, McCarty and its conclusions.
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They found the "TRANSFORMATION PRINCIPLE"
They mixed homogenates of S-strain RNA, protein, lipid, carbohydrate, and DNA with the R strain and found that only DNA transformed the cells to S strain. Conclusion: DNA is the molecule that carries the heritable material! |
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Summarize the 1950's experiment by Hershey & Chase and its conclusions.
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Phage protein coats and DNA had different labels then allowed to infect bacteria. When the heads were shaved of in a blender, only the DNA labels were left in the infected bacteria, not the protein labels.
Conclusion: DNA is the heritable material |
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DNA replication which produces two copies that each contained one of the original template strands and one new strand
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Semiconservative
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5 basic steps in the REPLICATION process?
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1. Opening DNA double helix
2. Building a primer 3. Assembling complementary strands 4. Removing the primer 5. Joining Okazaki fragments |
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What is a primer?
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A strand of RNA that serves as a starting point for DNA synthesis on the LAGGING STRAND.
They are required for DNA replication because DNA polymerases can only add new nucleotides to an existing strand of DNA. |
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What is ORI?
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REPILCATION ORIGIN: a particular sequence in a genome at which replication is initiated.
-It attracts INITIATOR PROTEINS. -A&T rich: fewer hydrogen bonds - numerous in humans (46 chromosomes) but only 1 in bacteria. |
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How many base pairs in ORI?
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100 bp
(ORI initiates DNA replication) |
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What is an Okazaki fragment?
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a relatively short fragment of DNA created on the lagging strand during DNA replication.
About 100-200 bp long. * the lagging strand must be constructed in fragments because it can only build in the 3' direction! |
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What are the relatively short fragments of DNA created on the lagging strand during DNA replication?
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Okazaki fragments
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What is a primer?
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A strand of nucleic acid that serves as a starting point for DNA synthesis in the LAGGING STRAND.
They are required for DNA replication because the enzymes that catalyze this process, DNA polymerases, can only add new nucleotides to an existing strand of DNA. |
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What is ORI?
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REPILCATION ORIGON: a particular sequence in a genome at which replication is initiated.
-It attracts INITIATOR PROTEINS. -A&T rich: fewer hydrogen bonds - numerous in humans (46 chromosomes) but only 1 in bacteria. |
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How many base pairs in ORI?
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100 bp
(ORI initiates DNA REPLICATION) A&T rich (like TATA, but TATA is for TRANSCRIPTION!!) |
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What is an Okazaki fragment?
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a relatively short fragment of DNA created on the lagging strand during DNA replication.
About 100-200 bp long. * the lagging strand must be constructed in fragments because it can only build in the 3' direction! |
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What are the relatively short fragments of DNA (with no RNA primer at the 5' terminus) created on the lagging strand during DNA replication?
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Okazaki fragments
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What aids the opening of the double helix for replication? (at the ORI)
*attracts helicase which unwinds DNA |
initiator proteins
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What enzyme synthesizes (replicates) DNA?
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DNA polymerase III
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What does DNA polymerase III do?
used in replication, translation or transcription? |
enzyyme that synthesizes DNA (in replication)
(connects C's to G's and A's to T's) |
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What enzyme "unwinds" DNA for replication?
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DNA helicase
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IS the lagging strand left "naked" during replication?
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no- it's bound by a "single strand DNA binding protein"
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What is DNA primase?
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It synthesizes RNA primers for DNA replication in the LAGGING STRAND.
*They are needed because DNA polymerases can only add new nucleotides to an existing strand of DNA. |
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Function of DNA polymerase I?
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It replaces the RNA primer (on the lagging strand) with DNA during DNA replication.
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Which enzyme replaces the RNA primer (on the lagging strand) with DNA during DNA replication?
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DNA polymerase I
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After the RNA primer has been replaced by DNA polymerase I, ______ seals the nicks between the Okazaki fragments.
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DNA ligase
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What does DNA ligase do?
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seals the nicks between the Okazaki fragments after the RNA primer has been replaced by DNA polymerase I
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What is the region of repetitive DNA sequence at the end of a chromosome?
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telomeres
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the length of the _____decreases with the age of the cell.
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telomere
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What does telomerase do?
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synthesizes DNA to elongate the telomere to make the Okazaki fragment fit.
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What synthesizes DNA to elongate the telomere to make the ozaki fragment fit?
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telomerase
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The activity of DNA polymerase which works by cleaving nucleotides one at a time from the end of DNA allowing the incorrect base pair to be excised during proofreading.
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exo-nuclease
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In which direction does exo-nuclease work?
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3' ---> 5'
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The activity of the DNA polymerase that allows the incorrect base pair to be excised during proofreading.
Which direction does this work? |
exonuclease
3' ----> 5' (DNA polymerase reverses its direction by one base pair) |
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When DNA polymerase comes across mis-paired DNA it has what 3 options?
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Fix the wrong one, fix the right one, or leave both.
-/- mutate both strands (alter template) -/+ Mutate synthesized strand, but keep correct template stand +/+ repair synthesized strand |
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Single nucleotide changes can cause disease & malformed prteins. What is 1 example of a sickness caused by this kind of mutatation?
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Sickle cell anemia
A glutamic acid is changed to a valine. |
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A damage to DNA in which the purine base (adenine or guanine) is removed from the deoxyribose sugar?
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depurination
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What is depurination?
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A damage to DNA in which the purine base (adenine or guanine) is removed from the deoxyribose sugar
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DNA damage: an amino group is removed. ?
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deamination
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What is an example of deamination (molecular)?
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In cytosine, an amino group is lost and cytosine becomes uracil.
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Deamination causes what kind of mutation?
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point mutation (single base substitution)
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depurination causes what kind of mutation?
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deletion (position skipped)
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2 ways UV radiation does damage to our DNA?
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1. causes thymine dimers (forms covalent bonds between thymines)
2. DNA break Repair (must know): -NUCLEASE enzyme recognizes and excises the damaged DNA -DNA POLYMERASE fills the gap -DNA LIGASE seals the nick |
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What is the generalized term for an enzyme capable of cleaving the phosphodiester bonds between the nucleotide subunits of nucleic acid?
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nuclease
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CENTRAL DOGMA?
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gene ------- transcription-----> RNA -----translation-----> protein
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the coding strand: sense or antisense?
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sense (+)
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the template strand: sense or antisense?
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antisense (-)
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which strand makes Proteins (via RNA)?
coding (+) or template (-) |
Coding (+)
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U pairs with ??
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A
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Why is RNA short lived?
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IT is unstable and is chewed up by RNase. RNase is vigorous stable and prolific!
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Intramolecular base pairing (H bonds) between RNA molecule give it what structure?
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secondary structure.
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Subunits of RNA polymerase:
BETA subunit binds _________. |
RNA nucleoside
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Subunits of RNA polymerase:
ALPHA subunit binds _________ |
regulatory proteins
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Subunits of RNA polymerase:
BETA PRIME subunit binds _________ |
DNA template
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Subunits of RNA polymerase:
SIGMA subunit binds _________ |
promoter
MOST IMPORTANT SUBUNIT! |
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A stretch of GC that forms into a hair-pin structure in DNA would be a _____.
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transcription terminator
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The Sigma subunit of RNA polymerase positions itself -10 to -35 units from the 3' end ...this region of DNA is called.....
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the promoter
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Which subunit dissociates from RNA polymerase shortly after transcription begins and then rebinds after transcription?
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sigma
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What is polycistronic?
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1 RNA can make multiple proteins
only in prokaryotes |
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RNA polymerase I is for...
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rRNA
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RNA polymerase II is for...
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mRNA and small nuclear RNA
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RNA polymerase III is for...
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tRNA and small RNA
*involved in splicing |
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What is TBP ?
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TATA-box binding protein
contained by TFIID complex and binds to the promoter |
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A fully processed mRNA that codes for a single protein is said to be _____.
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monocistronic
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RNA processing steps
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1. 5’ cap (7-methylguanosine, 5’-5’ triphosphate bridge)
2. 3’ poly-A tail (150-250 As) 3. splicing a. certain splicing sequences needed for intron removal..especially a special "A" (to form the laria)t b. spliceosome contains small nuclear RNAs and proteins (snRNP) c. intermediate structure called LARIAT |
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Nucleic acid sequence that is represented in the mature form of an RNA molecule after portions of a primary RNA have been removed by cis-splicing
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exons
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the nucleotide sequences that are cut out of mature RNA?
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introns
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a modification of an RNA after transcription, in which introns are removed and exons are joined
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splicing
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What is snRNA?
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Small nuclear RNA.
contained in splicosome |
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What is snRNP?
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Small nuclear Ribonucleic proteins.
contained in splicosome |
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What is unique about alpha tropomyosin?
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It is a gene that can express different proteins in different types of cells: an example of alternative splicing!
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What is the term for when a gene is able to generate different proteins( using different combinations of exons) for different cells (such as in alpha tropomyosin)?
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Alternative splicing.
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Regulatory DNA sequences:
for general transcription initiation in Prokaryotes? |
-35 & -10 sequences= promoter
In prokaryotes, the promoter consists of two short sequences at -10 and -35 positions upstream from the transcription start site. |
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Regulatory DNA sequences:
operon specific; bound by activator or repressor (proteins that activate /repress DNA) in Prokaryotes? |
Operator
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Regulatory DNA sequences:
for general transcription initiation in Eukaryotes? |
TATA box
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Regulatory DNA sequences:
gene specific regulatory element in Eukaryotes? |
enhancer
(enhance transcription) |
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What is a Transcription Factor?
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A sequence-specific DNA-binding factor.
*Only EUKARYOTES! A protein that binds to specific DNA sequences, thereby controlling the flow (or transcription) of genetic information from DNA to mRNA. |
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What is an Activator
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A DNA-binding PROTEIN that regulates one or more genes by INCREASING the rate of transcription in both Eukaryotes and Prokaryotes.
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What is a Repressor?
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A DNA-binding protein that regulates the expression of genes by binding to the operator and BLOCKING the attachment of RNA polymerase to the promoter, thus PREVENTING transcription of the genes in both Eukaryotes and Prokaryotes.
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What are the 3 Gene regulatory Proteins in Prokaryotes and Eukaryotes?
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Pro & Eu:
activators and repressors Only Eu: Transcription factors |
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What is an operon?
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A functioning unit of genomic material containing a cluster of genes under the control of a single regulatory signal or promoter.
Only in Prokaryotes (polycistronic). |
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What is the Lac operon and How does it work?
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An operon required for the transport and metabolism of lactose in prokaryotes.
Regulated by the availability of glucose and lactose: no lactose: Lac1 repressor ON no glucose: CAP activator ON So to turn the operon ON, there must be lactose but no glucose. |
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What is a homeodomain?
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A protein structural motif that binds DNA or RNA (commonly found in transcription factors) composed of 3 α- helices.
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What is a Zinc finger?
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A protein structural motif that can coordinate one or more zinc ions to help stabilize its folds.
Composed of 1 α- helix and 1 β-sheet. |
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What is a Leucine Zipper?
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Composed of 2 α- helices.
A motif usually found as part of a DNA-binding domain in various transcription factors, and therefore involved in regulating gene expression. |
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What is the tryptophan (trp) operon?
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An operon that codes for the enzyme that produces tryptophan in PROkaryotes.
Tryptophan activates a repressor, so that the the tryptophan-producing enzyme can't bind to operon. So... if tryptophan is high, the genes are off, if tryptophan is low, the genes are on! |
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TFI family and Polymerase I work for what kind of RNA?
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rRNA
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TFII and Polymerase II work for what kind of RNA?
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mRNA
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TFIII family and Polymerase III work for what kind of RNA?
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tRNA
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Sequence for mRNA Transcription initiation in Eukaryotes?
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Start @ TATA box
Then TFII: D-A-B-E-H, H phosphorylates Polymerase II (which is bound by TFIIF) Then TRANSCRIPTION can occur! |
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what 2 things bind to an activator (Protein)?
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Enhancer (DNA binding site)
& Mediator (protein COMPLEX which binds the TFII's and the polymerase) |
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How many base pairs between transcription (TATA box) and enhancer
(binding site for activating protein) |
could be 50 K base pairs between enhancer and TATA.
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______form a preinitiation complex, which, together with RNA polymerase II, bind to and read the single-stranded DNA gene template
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general transcription factors
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what is attached to the 3' end of tRNA?
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covalently bonded amino acids
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how many enhancers per gene?
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multiple
(ENHANCERS ARE Regulatory DNA sequences) |
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ribosomes are composed of ____ and _____.
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proteins
RNA * always! for prokaryotes & eukaryotes. |
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what's the function of peptidyl tranferase?
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forms peptide bonds between amino acids during translation (in ribosome)
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function of a tRNA?
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carry amino acids to mRNA
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the non- amino acid end of a tRNA is the _______.
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anticodon
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shape of tRNA?
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cloverleaf
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How does "Chromatin remodeling complex" work?
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It moves histones around to make "remodeled nucleosomes": DNA available for transcription.
(Chromatin= DNA + histones) |
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Explain Translation.
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Messenger RNA (mRNA) produced by TRANSCRIPTION is decoded by the RIBOSOME to produce a specific AMINO ACID chain, or polypeptide, that will later fold into an active PROTEIN.
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Explain Transcription
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the process of creating a complementary RNA copy of a sequence of DNA
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structure of a histone?
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made of core of 8 histone proteins
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What is a nucleosome?
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A segment of DNA wound around a histone protein core.
* histone proteins & 147 base pairs of DNA wrapped around |
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How can an excess of Chromatin remodeling complex be a bad thing?
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Too much of this causes accelerated transcription & CANCER!!!
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What is Even-skipped (Eve)?
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a transcriptional REPRESSOR (protein) involved in segment formation in Drosophila (fruit fly).
When eve gene is replaced, (by LacZ gene) all segments except for #2 do not form properly. |
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What is a repressor?
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proteins that bind to specific sites on DNA and prevent transcription of nearby genes.
eg. EVE (even skipped) |
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What is the difference between a hormone receptor in the absence of the hormone and in juxtaposition with the hormone?
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level of gene expression
Although genes are expressed without the hormone, they can express at higher level in a (hormone receptor) complex. |
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Term for when a hormone receptor complex enhances gene expression?
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Combinatorial control
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what is ey?
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eyeless gene, a MASTER TRANSCRIPTION FACTOR (one gene for the whole eye)
Activating ey induces formation of full-fledged eyes in fruit fly wings, legs, and other tissues. |
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significance of a "master transcription factor"?
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it's a single gene that gives rise to something complicated, eg. eyeless gene (ey)
determines the development of an organ or a large body structure |
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Term for a single gene that gives rise to something complicated, eg. eyeless gene (ey)?
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master transcription factor
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What does RISC stand for in a RISC protein, and what is a RISC protein's function?
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RNA Induced Silencing Complex
It bonds with 1 strand of mRNA to slow protein synthesis and regulate gene expression. |
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What is dicer?
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An enzyme in the RNase III family that cleaves double-stranded RNA (dsRNA) and microRNA (miRNA) into short double-stranded RNA fragments called small interfering RNA (siRNA) about 20-25 nucleotides long, usually with a two-base overhang on the 3' end.
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example of combinatorial control?
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GLUCOCORTICOID hormone activates different genes by working with different transcription factors in a complex
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what happens: loss of function of eyeless gene?
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no eye!
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What is ectopic expression of eyeless gene?
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ectopic eye
Ectopic expression is the expression of a gene in an abnormal place, so an ectopic eye would be an eye on the leg, antenna, etc. |
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what is dsRNA?
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double-stranded RNA ...AKA viruses
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What is miRNA?
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micro- RNA, about 22 nucleotides long
post-transcriptional regulators that bind to complementary sequences on target mRNAs, usually resulting in translational repression (no protein translated) and gene silencing. Uses RISC protein. |
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Sequence of events in post-transcriptional control using miRNA?
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1. miRNA synthesized in NUCLEUS.
2. Cleaved into single strand by dicer. 3. Forms complex with RISC. 4. Search for complimentary TARGET mRNA 5. mRNA is rapidly degraded by RISC and unable to make proteins. |
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Sequence of events in post-transcriptional control using siRNA?
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1. dsRNA (virus) cleaved into siRNA's by dicer.
2. Half of siRNA forms complex with RISC 3. RISC searches for complimentary foreign RNA, then degrades it. |
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what is siRNA?
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Small interference RNA;
cleaved fragments of a foreign dsRNA which form a complex with RISC in order to seek out and destroy other foreign dsRNA (viruses) |
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siRNA: prokaryotes or eukaryotes?
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Prokaryotes...
maybe some eukaryotes too but not found yet. |
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miRNA: prokaryotes or eukaryotes?
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Eukaryotes (animals)
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What is the purpose of Anti-sense RNA?
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Antisense RNA is introduced into a cell to INHIBIT TRANSLATION of a complementary mRNA by base pairing to it and physically obstructing the translation machinery.
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What is "reverse genetics" and what example were we given?
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Knocking out the gene expression without changing the gene itself.
Eg. Antisense RNA It binds to sense RNA to inhibit translation. |
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what is "forward genetics"?
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knocking out a gene by changing the DNA sequence.
eg. a mutation in the gene |
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what is the alternative to reverse genetics?
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forward genetics.
*reverse alters expression without changing genes, forward changes the genes (DNA) |
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in a tRNA a ___is covalently bonded to the __' end.
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amino acid
3' |
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What are the 3 stop codons?
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UAA
UAG UGA |
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What is the start codon?
What does is code for? |
AUG
Methionine |
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a codon is made of ______.
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3 nucleotides.
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What is the function of Aminoacyl tRNA synthetase?
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an enzyme with specific binding sites that connects a specific amino acid to a tRNA.
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What enzyme has specific binding sites that connects specific amino acids to tRNA.
|
Aminoacyl tRNA synthetase
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How is translation initiated?
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Initiator tRNA with methionine moves along RNA searching for AUG.
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What is the "Redundancy" in the genetic code?
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some amino acids are coded by multiple codons.
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How many reading frames per mRNA potentially?
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3
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The subunits of a ribosome consist of...?
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Large subunit: 49 proteins + 3 rRNAs
Small subunit: 33 proteins + 1 rRNAs |
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incoming amino acids bind to what part of a ribosome?
Peptide chain leaves though which part? |
enter: A site
Exit : E site (E for Exit) |
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what is translation elongation?
|
-new aminoacyl-tRNA binds to A site
-peptide bond forms -large subunit translocates, then small subunit translocates |
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How does translation termination work?
|
"A site" of ribosome meets a stop codon, RELEASE FACTOR (protein) binds to A site
---> dissociation of the translation machinery. |
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5 steps in translation initiation?
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1. small unit of ribosome loaded with Met-tRNAmet and initiation factors.
2. initiator tRNA moves along RNA searching for the first AUG codon 3. large subunit binds 4. elongation 5. termination |
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Which protein allows for the termination of translation by recognizing the termination codon or stop codon in a mRNA sequence?
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Release factor
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What is tetracycline?
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Antibiotic that inhibits protein synthesis
blocks binding of aminoacyl-tRNA to A site in bacteria |
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What is cycloheximide?
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Antibiotic that inhibits protein synthesis
blocks translocation of ribosome inhibiting bacterial growth |
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Antibiotics that inhibit protein synthesis:
Which one blocks binding of aminoacyl-tRNA to A site in bacteria |
tetracycline
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Antibiotics that inhibit protein synthesis:
Which one blocks the translocation of ribosome inhibiting bacterial growth? |
cycloheximide
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How do proteins know where to go within the cell?
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there is a SIGNAL SEQUENCE within the amino acid sequence!
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What is a signal sequence?
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Sequence which determines the destination of the protein and directs it through the nucleus, golgi, endosome, lysosomes, or to the cell surface.
15-60 amino acids long & usually removed after transport |
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What kind of Signal sequence would be good for getting through the ER?
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nonpolar, hydrophobic aminos.
eg, Leucine, valine, Glutamic acid |
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What kind of Signal sequence would be good for importation to the nucleus?
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aqueous positively charged aminos
eg. lysine and arginine |
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How are proteins transported into the nucleus via nuclear pore?
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the protein uses a nuclear localization signal (lysines / arginines: aqueous positively charged aminos).
sequence is recognized by nuclear transport receptor which binds and helps push protein though |
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2 components which aid proteins in transversing the ER translocation channel?
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-signal recognition particle (SRP) in cytosol
-SRP receptor embedded in ER membrane (then sequence functions to open the translocation channel, and is then cleaved after transport!) |
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vesicles are ____coated during formation.
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clathrin
Clathrin dissociates after formation leaving "naked" vesicle |
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What binds the cargo receptor molecules to the clathrin in vesicles?
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adaptin
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______coated vesicles transport molecules from ER to Golgi and between Golgi compartments
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COP (coated proteins)
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What on transport vesicle binds to tethering protein on target organelle ?
How is the vesicle then enveloped? |
Rab ("ID")
2 "T" snare proteins (Target) bind to 2 "V" snares (vesicle) and pull vesicle to fuse & release cargo |
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What is endocytosis?
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a cell takes in molecules from outside
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What is phagocytosis?
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(cellular eating), autophagy—remove old organelles (eats own organelles)
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What is pinocytosis?
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(cellular drinking) – fluid and macromolecules
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What is transcytosis?
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transport from one extracellular (EC) space to another EC.
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what are the main sorting stations in the inward endocytic pathways?
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endosomes
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degradation center containing acid hydrolases, pH= 5
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lysosomes
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what is glycosylation and where does it occur?
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adding carbs to a protein, occurs in ER
makes glycoproteins |
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what are the 2 kinds of cellular secretions?
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regulated (by signal molecule)
and constitutive (Work all the time, eg: making ECM) |
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What is important about Restriction Enzyme?
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Important for genetic engineering!
Recognizes "palindromic sequences" and cleaves double stranded DNA leaving sticky or blunt ends (usually sticky) Sticky: from zig zag cut Blunt: from straight cut |
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a plasmid needs 3 things to be a cloning vector:
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a. ori (replication origin)
b. selection marker , e.g. ampicillin resistance gene; a gene that confers a trait suitable for artificial selection c. multiple restriction enzyme sites (for cutting) also...3k-4k bp long |
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What purpose does the bacterial host serve in "cloning"?
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store, amplify and express plasmid by making proteins!
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what is Transformation?
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DNA uptake by bacteria (can be in form of plasmid)
* transformation occurred in +pGLO bacteria. |
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What is transfection?
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DNA uptake by animal (eukaryotic) cells
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what is Transduction?
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injection of DNA into host cells by virus
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What is Conjugation?
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DNA transfer between two cells via direct contact
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What are some applications of cloning?
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contructing reporters, like GFP (Green fluorescent protein) or pGLO or insulin
genomic library & genome sequencing project |
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How were restriction enzymes and genetic engineering used to sequence the human genome?
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it was sequenced in fragments ...a homogenate could be made of each fragment
...so there was lots of homogeneous genome fragments, then they could daisy-chain to reconstruct the sequence. |
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What is the cDNA library?
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cDNA is COMPLIMENTARY to MATURE RNA, not DNA!
smaller DNA is much easier to clone & express cDNA is made with reverse transcriptase...normally RNA doesn't make DNA. |
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What is reverse transcriptase?
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a DNA polymerase enzyme that transcribes single-stranded RNA into double-stranded DNA.
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the total genetic information (or sequences) carried by a cell or an organism ?
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genome
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comparative analyses of the complete genomic sequences from different organisms and determination of global patterns of gene expression?
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genomics
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What is transcriptome?
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the entire complement of RNAs produced by a cell
(like genome, but streamlined for transcription) |
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The entire complement of proteins produced by a cell is termed the _____.
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proteome
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the systematic study of the amounts, modifications,
interactions, localization, and functions of all or subsets of proteins at the whole-organisms, tissue, cellular and sub-cellular levels is called......? |
proteomics
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How is broekn DNA repaired?
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-NUCLEASE enzyme recognizes and excises the damaged DNA
-DNA POLYMERASE fills the gap -DNA LIGASE seals the nick |
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What does DNA polymerase do?
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helps catalyze in the polymerization of deoxyribonucleotides into a DNA strand. DNA polymerases are best-known for their feedback role in DNA replication, in which the polymerase "reads" an intact DNA strand as a template and uses it to synthesize the new strand
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What is an operator?
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a segment between the promoter and the genes of the operon to which a repressor binds
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what is splicosome?
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a complex of snRNA and snRNP (protein) subunits that removes introns from a transcribed pre-mRNA (hnRNA) segment.
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What is the complex of specialized RNA and protein subunits that removes introns from a transcribed pre-mRNA (hnRNA) segment.
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splicosome
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What is attracted to ORI?
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initiator proteins
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