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39 Cards in this Set
- Front
- Back
Describe two features of an atom. |
It is the smallest unit into which matter can be divided without the release of electrically charged particles. The smallest unit of matter that has the characteristic properties of a chemical element. (elementary particle) |
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Name the positively charged part of the atom? What subatomic particles reside within this. |
Nucleus Proton and neutron. |
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Name the subatomic particle which moves around in shells. |
Electron |
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When the substances in a covalent bond have equal affinity for electrons it is called? |
Non-Polar |
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Define polar and name the two domains. |
when one nucleus has a higher affinity for the shared electrons in a covalent bond and the electrons are distributed unevenly. They have positive and negative domains. |
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What is electrostatic interaction? |
When ionic substances are attracted by oppositely charged domains of polar substances. |
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Name and explain the two principals of diffusion. |
Brownians Motion A dissolved molecule or small particle suspended in fluid is constantly struck at random by molecules of the fluid in its neighbourhood as a result of which it wanders erratically. Ficks Law The random wandering causes an average drift from regions where they are denser to regions where they are rarer and the mean drift rate is proportional to the gradient of density. |
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Name the two parts of the biological membrane and say which is polar/nonpolar and which is hydrophylic/hydrophobic. |
Head - polar - hydrophilic Tails - nonpolar - hydrophobic |
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What is a biological membrane |
A very thin boundary that both separates and links the living cells with the external environment. It permits cellular function by regulating transport, flow of information, nutrients and metabolites. |
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Name four components of the memebrane |
channel proteins surface proteins trans membrane proteins receptor rafts |
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Name the three types of membrane transport |
Passive transport Facilitated transport Active transport |
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Name the three types of passive transport |
diffusion osmosis dialysis |
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Name the three types of facilitated transport |
Uniport Symport Antiport |
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Define diffusion |
Process resulting from the random motion of molecules by which there is a net flow of matter from a region of high concentration to low concentration. -Down a concentration gradient |
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When is diffusion unreliable |
over long distances |
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what is diffusion through a semipermiable membrane called |
osmosis |
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What is oncotic pressure? |
form of osmotic pressure exerted by proteins. |
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Compare the freshwater teleost and the marine teleost? |
Skin Freshwater - the water diffuses in through the skin and ions diffuse out through the skin. Marine - Ions diffuse in through the skin while water diffuses out. Gills Freshwater - actively uptake ions. Diffusion of water in through the gills and ions out through the gills. Marine - active secretion of ions. Diffusion of ions in through the gills and water out through the gills. Dialysis Freshwater - Dilute urine with a mix of water and ions. Marine - concentrated urine of ions and water. |
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Define dialysis |
Separation of suspended colloidal particles from dissolved ions or molecules of small dimensions by means of their unequal rates of diffusion through the pores of a semipermiable membrane. |
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Give an example of dialysis |
glomerular filtration |
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is Uniport transport up or down a concentration gradient |
down |
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give two examples of uniport |
aquaporin potassium channels |
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Give another name for symport |
Co-transport |
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Is symport up or down the concentration gradient |
down |
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How does symport work? |
two substrates normally an ion and a molecule must bind simultaneously to the same side of the transporter. There is conformational change and conductivity and both substrates are transported together. |
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Give an example of Symport |
Absorption of sugars and amino acids. Absorbed by enterocytes by cotrasport with sodium ions. |
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Is Antiport up or down the concentration gradient? |
Down |
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Define Antiport |
Two substrates, normally an ion and a molecule bind to opposite sides of the transporter before its conformational change and conductivity. One substrate is absorbed and the other secreted. |
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Give an example of antiport |
Sodium-proton exchanger in the proximal convoluted tube of the kidneys. |
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What is the function of active transport? |
To accumulate a high concentration of molecules that the cell needs such as ions, glucose, amino acids. It is against the concentration gradient. |
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Name the two types of active transport and give an example of each. |
Primary active transport - Na-K ion pump Secondary active transport - Symport/Antiport |
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Name the type of active transport which uses high energy phosphage bonds. |
Primary active transport - Na-K pump |
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Name the type of active transport that uses electrochemical gradient. |
secondary active transport - Symport/Antiport |
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Define electrochemical gradient. |
a spatial variation of both electrical potential and chemical concentration across a membrane resulting in a type of potential energy available for work in a cell. |
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How do proteins work? |
They change the structural organisation or shape of their subunits. |
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Name two types of proteins and give an example of each. |
Dynamic proteins - enzymes/membrane channels Strucutral proteins - Actin filaments, B-Keratin |
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What state do proteins tend to maintain? |
The lowest possible energy state |
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Where does energy shaping of protein come from? |
interactions between its components (from subunit to amino acid to atoms) and interactions with surrounding water molecules. |
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Where do dynamic proteins get sufficient energy for a change of shape or structure? |
interactions with other substances |