pH and Buffers
A COMMON BIOCHEMISTRY BUFFER, HEPES, HAS A PKA OF 7.5. WHAT IS THE USEFUL BUFFERING RANGE OF HEPES?
ABOUT 6.5-8.5
What is a secondary structure made of?
alpha helicies and beta sheets
Most enzymes ends in the suffix _____
-ase
What type of side chain is Alanin
non-polar
What is the set of metabolic pathways that breaks down molecules into smaller units to release energy.
Catabolism
WHAT IS THE PH OF A SOLUTION OF 0.1 M HCL?
1
Intrinsically disordered proteins have a high content of ______.
have a high content of charged residues
An enzyme-catalyzed reaction was carried out with [S] initially = (1000 x Km ) for that substrate. After 9 minutes, 1% of the substrate had been converted to product, and 12 mmol of product have been formed.
If, in a separate experiment, one-third as much enzyme and twice as much substrate is combined, how long will it take for the same amount (12 mmol) of product to be formed?
27min
What is the name of this tripeptide: N-K-P
What is asparagine-lysine-proline?
It is catalyzed by alcohol dehydrogenase.
AT WHAT POINT OF THE TITRATION DOES PKA = PH?
THE HALF-EQUIVALENCE POINT OR THE MIDPOINT
Mouse myoglobin is a(n) _______ of human myoglobin and a(n) ________ of mouse hemoglobin.
ortholog; paralog
Penicillin and related drugs inhibit the enzyme _____; this enzyme is produced by ______.
transpeptidase; bacteria
What are the three groups that amino acids consist of
What is an amino group, a carboxylic acid group and a side chain or R group
Glucose labeled with radioactive carbon (14C) at carbon C-1 and C-6 gives rise in glycolysis to pyruvate labeled in which of the carbons?
the methyl carbon
WHAT IS THE PH OF A SOLUTION OF 5*10^-4 M HCL?
3.3, PH = -LOG([H+])
What residues are not found in alpha helicies?
Proline and glycine
What do you need to know to calculate the turnover number of an enzyme?
the total enzyme concentration.
the vo of the catalyzed reaction at [S] >> Km.
Kcat
Which amino acid side chains will exist predominantly in their conjugate base form at neutral pH?
D, E
The reaction A + B ↔ C has a ΔG'° of –20 kJ/mol at 25° C. Starting under standard conditions, one can predict that at equillibrium the conc of ____ will be ____ than concentration of____
the concentration of C will be greater than the concentration of A or B.
ACETIC ACID HAS A PKA OF 4.8, WHAT IS THE PREDOMINANT FORM OF THE COMPOUND IN A SOLUTION AT PH 6.0?
ACETATE OR CONJUGATE BASE
What is a tetrameric structure with one type of protein called?
homooligomer
Consider the three enzymes below. Rank them from highest to lowest catalytic efficiency.
ENZYME KM (M) kcat (s-1)
A 5 x 10^-5 2.5 x 10^4
B 2 x 10^-2 4 x 10^5
C 1 x 10^-1 4 x 10^7
A, C, B
D
What is the code for Aspartic Acid
Which enzymes is used in both glycolysis and gluconeogenesis?
aldolase