Biology 12: Unit 2 Test

~ Small unit molecule joined with others to form polymer

~ Ex) Amino acids, simple sugars, fatty acids, nucleotides

~ Large molecule which consists of repeating units or monomers

~ Ex) Proteins, Starch, Neutral Fat, DNA/RNA

~ A large molecule

~ Ex) Neutral fat, RNA/DNA

~ Contain C & H

~ Important biological molecules

~ Formed in dehydration synthesis reactions

~ Type of chemical reaction which occurs in cells

- Small molecules (monomers) are joined to form large molecules (polymers)

- Water is released in the process

~ The water molecule forms from a hydroxyl (-OH) group from the end of one molecule and a hydrogen atom from the end of the second molecule. Water is released in the process and a covalent (peptide) bond forms between the two monomers.

~ Dehydration synthesis reactions result in the formation of proteins, lipids, carbohydrates, and nucleic acids

- Specific enzymes are needed to catalyze each type of dehydration synthesis reaction

~ Reverse reactions of dehydration synthesis

- Large molecules (polymers) are broken down into the molecules (monomers) of which they are composed

- The addition of water leads to a disruption of the chemical bonds linking molecules together

~ The hydroxyl group from the water attaches to one side of the chemical bond and the hydrogen of water attaches to the other side

- This breaks the bond between the two monomers

~ Hydrolysis reactions result in the breakdown of proteins, lipids, carbohydrates and nucleic acids

- Specific enzymes are needed to catalyze each type of hydrolysis reaction

~ Characterized by the empirical formula (CH20)

~ Hydrates of carbon

- due to the ratio of hydrogen to oxygen within any carbohydrate molecule (2H: 1O)

~ Carbohydrates contain only carbon, oxygen,and hydrogen

~ Primary function: Energy Source

~ Monosaccarides, Disaccharides,Polysaccharides

~ Structure

- One sugar unit (monomer)

- Small number of carbon atoms (3-7C)

- Carbons may be organized linearly or in a ring

~ Examples

- 5 Carbon Sugars (pentose sugars): ribose and deoxyribose

- structural components of nucleic acids (RNA/ DNA)

- 6 Carbon Sugars (hexose sugars): glucose, fructose and galactose

~ Functions:

- Primary energy source for cells (especially glucose)

- Monomers for disaccarides and polysaccarides

~ The most common monosaccharide is glucose

~ Structure:

- consist of two monosaccharides covalently bonded through dehydration synthesis

- weak bond called "glycosidic or ester linkage"

- these bonds are broken without using too much energy

- primary function: energy storage

- only monosaccharides can be directly used by organisms for energy (must first be broken down to their monomers before they can be used for energy by a cell)

~ Examples: Maltose, Sucrose, Lactose

~ Formed when two glucose molecules combine

~ Function:

- Energy storage

~ Formed when one glucose molecules combines with one fructose molecule

~ Function:

- Energy storage in plants and energy transport in plants

- Sugars made in the leaves of green plants are transported to non photosynthetic regions for storage in the form of sucrose

~ Formed when one lactose molecule combines with one galactose molecule

~ Function:

- Energy storage

~ Structure:

- consist of many (3 or more) monosaccharides which are linked together through dehydration synthesis

- polysaccharides are fairly large molecules (macromolecules) and consist of many repeating units (monomers) and are described as polymers

~ Types: Starch (amylose), Glycogen, Cellulose,Chitin

~ Other Functions: Chains of carbohydrates are attached to the outside of the cell membrane. carbohydrates are attached to either proteins (glycoproteins) or fats (glycolipids)

- Carbohydrate chain function in

- cell-cell recognition: acts as a marker so the immune system recognizes the cell

- form receptor sites for specific molecules to attach to allow communication between cells

ie. protein hormones attach to specific receptor sites on the outside of their target cells

~ Structure

- polymer of glucose

- consists of a relatively straight chain of glucose molecules with few side branches

- glucose monomers in starch are joined by alpha 1-4 bonds (glycosidic bonds) formed in the process of dehydration synthesis

- found in plants

~ Function:

- energy storage in plants

~ Structure:

- Hexagonal

- polymer of glucose

- consists of highly branched chain of glucose molecules

- glucose monomers in glycogen are joined by alpha 1-4 bonds (glycosidic bonds) formed in the process of dehydration synthesis

- found in animals

~ Function:

- short term energy storage in animals (stored in the muscles and liver)

~ Structure:

- polymer of glucose

- straight/ linear chain of glucose molecules (no branching straight chains form cellulose fibres)

- glucose monomers in cellulose are joined by beta 1-4 bonds (glycosidic bonds) formed in the process of dehydration synthesis

- found in plants

~ Function:

- important structural component in plant cell walls. The presence of cellulose within the cell wall provides the plant cell with strength and support

~ Structure:

- polymer of glucose

- structure similar to cellulose, glucose monomers are joined by beta 1-4 bonds

- unique as this polysaccharide contains nitrogen*

- combines with calcium carbonate to form strong structural compound

~ Function:

- used make exoskeleton in arthropods and cell walls in fungi

~ Organic molecules which consist primarily of carbon, hydrogen, and oxygen atoms. Some contain small amounts of phosphorous and nitrogen

~ the ratio of H+ to O is higher, therefore insoluble in water

~ Three types: Neutral fats, phospholipids, and steroids

~ Nonpolar; water insoluble

~ Structure:

- consist of one molecule of glycerol and three fatty acids

- Fatty acids consist of a long hydrocarbon chain ending in a -COOH group (carboxylic acid)

- In cells, most fatty acids contain between 16-18 carbon atoms

~ Triglycerides are formed by 3 dehydration synthesis reactions; three fatty acid molecules combine with 1 glycerol molecule to form a triglyceride or neutral fat

~ Functions:

- Serve as long term energy storage in animals

- insulation for animals living in colder regions

~ Consist of saturated fatty acids

~ Typically solid at room temperature

~ Derived from animal sources

- Eg) butter, animal fats

~ Contain the maximum possible number of hydrogen atoms

~ No double bonds between the carbon atoms and hydrocarbon chain

~ Lack of a double bond produces a relatively straight molecule

~ As a result, saturated fatty acids tend to be packed tightly together

~ Consist of unsaturated fatty acids

~ Typically liquids are room temperature

~ Derived from plant sources

-Eg) oils (vegetable, etc)

~ Contain less than the maximum possible number of hydrogen atoms

~ Double bonds occur between the carbon in the hydrocarbon chain wherever there are fewer than two hydrogen atoms per carbon atom

~ Presence of double bond produce a bent molecule

~ As a result, unsaturated fatty acids are not packed tightly together

~ Structure:

- Similar to neutral fats

- Consist of one glycerol molecule joined to 2 fatty acids; the third fatty acid is replaced by a phosphate group

- The phosphate group is in turn, often attached to a nitrogen containing group

- The fatty acids and phosphate groups are attached to the glycerol molecule by 3 dehydration synthesis reactions

- Have both a polar and non polar region

- The phosphate end of the phospholipid can ionize and therefore is polar and soluble in water (the phosphate head)

A type of molecule that interacts with water by dissolving in water and/or forming hydrogen bonds

A type of molecule that does not interact with water; insoluble, non polar

~ Major structural component of the cell membrane

~ Arrange themselves into a phospholipid bilayer in the presence of water

- The polar phosphate heads face outward in contact with the watery cytoplasm or extracellular fluid. The nonpolar fatty acids face inward avoiding contact with water.

~ Structure

- Very different from other fats

- 4 fused carbon rights ( 3 six carbon rings and one 5 carbon ring)

- Different steroids have different functional groups attached to them

- Position of double bonds within the rings of the steroid may vary

~ Function

- Cholesterol is used to make other steroids

- Cholesterol helps stabilize the cell membrane

- The sex hormones: testosterone, estrogen and progesterone, are steroid hormones that all have effects on sexual characteristics and reproduction

- Aldosterone is a steroid hormone which helps control blood sodium levels and blood pressure

- Cortisol is a steroid hormone which helps in the recovery from physical injury and reduces the inflammatory response

A characteristic arrangement of atoms within a molecule that determine the important chemical and physical properties of the compound

A chemical messenger responsible for controlling specific body functions