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30 Cards in this Set
- Front
- Back
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What is the role of nucleotides?
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1. Energy metabolism
2. Build nucleic acids 3. Physiological mediators 4. Precursor functions 5. Supercharge the reaction 6. Regulate enzymes 7. Carry electrons |
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What is a nucleoside?
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A nucleic acid minus the phosphate
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Purines are ?
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A G
(Pure As Gold) |
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Pyrimidines are ?
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C U T
(CUT the PY) |
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Deoxy -ribonucleic acid means what?
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No oxygen at the 2'
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What makes up the backbone of the DNA?
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Phosphate bonds on the 3' and 5'
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A binds with G T or C? Why?
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It bonds with T because they both form 2 hydrogen bonds.
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C binds with A T or G? Why?
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It bonds with G because they both form 3 hydrogen bonds.
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Why is DNA a double helix structure?
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Van der Walls forces cause the twisting. this also accounts for the major and minor groove.
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What causes DNA to denature?
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Heat
Salt concentration pH |
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What are important physical properties of water?
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1. Very high boiling point
2. Also high freezing point 3. High heat capacity |
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what are important chemical properties of water?
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1. Dipolar
2. Hydrogen bonds between the partially positive hydrogen and partially negative oxygen 3. It has a tendency to dissociate |
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what is the equilibrium constant?
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K'eq = [H+] [A-] / [HA]
This expression describes the extent of dissociation of HA to H+ and A- |
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What is the concentration of H+ in pure water?
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[H+] = 1x10^-7
These dissociated ions are very important in biological systems. |
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What (biological) can be affected by changes in [H+] ?
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1. Rates of enzyme catalyzed reactions
2. Permeability of membranes 3. Stability of protiens 4. Rates of molocule transport through membranes 5. Absorption and metabolism of drugs 6. If something is hydrophobic or hydrophilic |
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What is pH (how is it calculated) and why is it used?
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pH = -log [H+]
it is used to simplify the small numbers in [H+]. i.e. instead of 1x10^-8 we just say pH of 8 (which is smaller than 7 - counterintuative) |
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What is pK' ?
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pK' = -log K'eq
this again is a simplification method to write and compare K'eq |
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Henderson-Hasselbalch eq is:
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pH = pK' + log ( [base]/[acid] )
thus, with the two concentrations of conjugate base and acid you can figure the pH. A physician could increase either base or acid in order to move the pH. |
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When will the pH = pK' ?
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When [base] = [acid]
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Which two acid base systems are the best physiological buffers?
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Phosphate (pK' 6.7)
& Bicarbonate (pK' 6.1) -this one manages most buffering in the blood. more important. |
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What are carbohydrates?
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Polyhydroxy aldehydes, Polyhydroxy ketones, or compounds that can by hydrolyzed to give these as a product.
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What is the most important monosaccharide?
What polysaccharides does it make up? Is it a pentose, hexos, trios, etc & is it an aldehyde or ketone? |
-Glucose
-starch, cellulose, glycogen -aldohexose |
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furanose and pyranose have how many members in their rings respectively?
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furanose 5
pyranose 6 |
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What are two conformation possibilities for 6 membered rings?
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boat & chair
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What is mutarotation?
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changes in configuration from alpha to beta forms. These changes are at the anomeric carbon and only happen when the ring opens and recloses.
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What denotes an alpha and beta carb?
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alpha is when the hydroxy is pointing down at the anomeric carbon. Beta is pointing up.
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How do you determine the chirality of a carbohydrate?
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By the chirality of the group furthest from the functional group.
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What is a glycoside? an aglycone?
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A glycoside is a compound formed when the anomeric hydroxyl group of a sugar reacts with another hydroxy compound. The other sugar not providing its anomeric hydroxy group is called the aglycone.
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what are the most important disaccharides? what are they made up of?
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Maltose - 2 glucoses
Lactose - galactose and glucose sucrose - glucose and fructose |
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What is a glycosaminoglycan? Name 2
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Unbranched polysaccharides made up of repeating disaccharides where one is an amino sugar and one is a uronic acid.
1. Heparin (inhibits blood clotting) 2. Hyaluronic acid ( bottlebrush structure) |
