BCH 451 EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
GRADED A++
Relevance of H-bonds in the structures of DNA and proteins
makes certain structures possible
proton hopping
the covalent and H-bonds are interchangeable of protons in water . Allows for fast movement of protons.
physiological pH. what do the amino acids look like in this pH?
7-7.4. the amino acids are deprotonated
buffering capacity
the ability of a buffered solution to absorb protons or hydroxide ions without a significant change in pH;
+-pH 1
buffer
pH range over which they can maintain a more or less constant pH.
Titration of amino acids
-starts at pH=0 so all the amino acids are positive and the hydroxyl groups are neutral
-x axis= conc. OH added
-y axis= pH
,when is the buffering capacity of acid/base at its max?
pH=pKa
equivalence point
where pH of base=pH of acid
Pepsin pH
stomach acid -1.5-3.5
what does changing pH do ?
-affect H-bond donors/acceptors
-change solubility of polar molecules
-change the active site
-destabilize the structure
buffer systems in vivo (in living organism)
mainly based on phosphate ( conc. in mmol range), bicarbonate (important for blood plasma), and
histidine (efficient buffer @ neutral pH)
buffer system in vito (outside of living organism)
mainly based on sulfonic acids of cyclic amines (HEPES, PIPES< Tris, phosphate)
acidosis
pH below 7.4
-metabolic= diabetes via fatty acid dependence/breakdown which produces carboxylic acid, lactic
, buildup, fasting, kidney failure
-respiratory= CO2 buildup due to pulmonary problems brain injury
Alkosis
pH above 7.4
-metabolic= vomiting, dehydration
-respiratory= loss of CO2 (hyperventilation)
Glycine
only amino acid that is not chiral , very flexible
aliphatic
c-atoms form open chains; not rings
DNA is what charged?
negatively charged due to sugar phosphate backbone
pI
the average pKa values around the net 0 amino acid
alpha-carboxyl group is more ____ than in carboxylic acids
acidic
alpha-amino group is more ____ than in amines
basic
peptide
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
GRADED A++
Relevance of H-bonds in the structures of DNA and proteins
makes certain structures possible
proton hopping
the covalent and H-bonds are interchangeable of protons in water . Allows for fast movement of protons.
physiological pH. what do the amino acids look like in this pH?
7-7.4. the amino acids are deprotonated
buffering capacity
the ability of a buffered solution to absorb protons or hydroxide ions without a significant change in pH;
+-pH 1
buffer
pH range over which they can maintain a more or less constant pH.
Titration of amino acids
-starts at pH=0 so all the amino acids are positive and the hydroxyl groups are neutral
-x axis= conc. OH added
-y axis= pH
,when is the buffering capacity of acid/base at its max?
pH=pKa
equivalence point
where pH of base=pH of acid
Pepsin pH
stomach acid -1.5-3.5
what does changing pH do ?
-affect H-bond donors/acceptors
-change solubility of polar molecules
-change the active site
-destabilize the structure
buffer systems in vivo (in living organism)
mainly based on phosphate ( conc. in mmol range), bicarbonate (important for blood plasma), and
histidine (efficient buffer @ neutral pH)
buffer system in vito (outside of living organism)
mainly based on sulfonic acids of cyclic amines (HEPES, PIPES< Tris, phosphate)
acidosis
pH below 7.4
-metabolic= diabetes via fatty acid dependence/breakdown which produces carboxylic acid, lactic
, buildup, fasting, kidney failure
-respiratory= CO2 buildup due to pulmonary problems brain injury
Alkosis
pH above 7.4
-metabolic= vomiting, dehydration
-respiratory= loss of CO2 (hyperventilation)
Glycine
only amino acid that is not chiral , very flexible
aliphatic
c-atoms form open chains; not rings
DNA is what charged?
negatively charged due to sugar phosphate backbone
pI
the average pKa values around the net 0 amino acid
alpha-carboxyl group is more ____ than in carboxylic acids
acidic
alpha-amino group is more ____ than in amines
basic
peptide
