Final Review - Biochemistry Flashcards
Where does the synthesis of fatty
acids take place in a eukaryotic cell?
Cytoplasm
What is the type of enzyme that catalyzes the
hydrolysis of triglycerides to yield free fatty acids and
glycerol?
Lipase
The activation of a fatty acid to acyl adenylate
requires the equivalent of how many ATP?
2
Which molecule is not required in the activation
and transport of a fatty acid into the mitochondria?
NADH
Which of the following is not a co-
substrate in the beta-oxidation of a
fatty acid?
NADPH
The beta-oxidation of a C24 fatty acid would
yield how many molecules of acetyl-CoA?
12
he beta-oxidation of a C18 fatty acid would yield
how many molecules of (i) NADH and (ii) FADH2?
8 NADH, 8 FADH2
beta-oxidation of a cis-
unsaturated fatty acid requires what
additional enzyme?
isomerase
What are the three major ketone
bodies produced in the body?
acetoacetate, acetone and beta-hydroxybutyrate
The activation of acetyl CoA to malonyl CoA in
fatty acid synthesis requires what two molecules?
ATP and CO2
Fatty acid synthase can only synthesize
___(i)___ fatty acids up to ___(ii)___ carbons long.
(i) saturated (ii) 16
Amino acids generated from the breakdown of
digested dietary proteins, or the degradation of
cellular proteins can be:
- used for synthesis of new proteins
- used for energy
Can amino acids be stored for later use like fats and carbs?
No they cannot
The first step in the degradation of amino acids is
the transfer of the ___(i)___ to alpha-ketoglutarate by
a(n) ___(ii)___.
i) amino group (ii) aminotransferase
In uricotelic organisms, like
birds, excess ammonia is excreted
as:
uric acid
In the first step of the urea cycle, bicarbonate
(HCO3-) and NH4+ are converted to ________
carbamoyl phosphate
Where do the 2 nitrogen atoms in urea come from?
NH4
aspartate
An amino acid is found to be broken down to form
acetyl CoA. What would be the best classification of
this amino acid?
ketogenic
Nitrogen can be fixed from N2 to
NH3 by _____.
the Haber-Bosch process
some bacteria and archaea
Can nitrogen be fixed by plants?
No
Approximately how many ATP molecules are
required to biologically fix one N2 to two NH3?
16
Nitrogen is incorporated into amino acids by
specific aminotransferases. What cofactor do
aminotransferases contain?
PLP (pyridoxal phosphate)
If DNA was replicated conservatively, how many different DNA
bands would have appeared in the CsCl gradient after centrifugation
in the Meselson-Stahl experiment after one round of replication?
2
Which of the following is not an
enzyme involved in DNA replication?
DNA synthase
Which of the following statements is true
regarding how DNA is synthesized during DNA
replication?
a. The leading strand is synthesized continuously, while the lagging
strand is synthesized in short fragments.
b. The lagging strand is synthesized continuously, while the leading
strand is synthesized in short fragments.
c. Both the leading and lagging strands are synthesized continuously.
d. Both the leading and lagging strands are synthesized in short
fragments.
e. DNA polymerase synthesizes the leading strand in the 5’ 3’
direction and synthesizes the lagging strand in the 3’ 5’ direction.
a. The leading strand is synthesized continuously, while the lagging
strand is synthesized in short fragments.
What are the short fragments on the lagging strand called?
Okazaki fragments
How are okazaki fragments joined together?
DNA ligase
T/F DNA replication is semi-discontinuous
True
Which of the following below are involved in
stabilizing the single strands of the separated DNA
double helix?
single stranded binding proteins
The error rate in the selection efficiency (tendency
to choose the correct nucleotide initially) of DNA
polymerase is approximately ________.
1 in 10^4-10^5