HOTSEAT 2022 Flashcards
Which of the following is true for redox reactions in biology?
A. They require the presence of oxygen
B. They are only involved in catabolism
C. The substrate donating electrons is reduced
D. The substrate accepting electrons also gains protons
E. Redox reactions only occur in the TCA cycle
D. The substrate accepting electrons also gains protons
Does not require O2, Not only involved in catabolism
Which of the following is the slowest process in regulation of enzyme activities compared with the others?
A. Phosphorylation
B. Allosteric activation
C. Allosteric inhibition
D. Protein degradation
E. Dephosphorylation
D. Protein degradation
Slowest process total due to the fact you have to induce gene expression through transcription
Regulation of PFK-1 by citrate is an example of:
A. Feedback activation
B. Feedforward activation
C. Feedback inhibition
D. Feedforward inhibition
E. Transcriptional regulation
C. Feedback inhibition
Which of the following is FALSE for gluconeogenesis?
A. It should be off when glycolysis is on
B. It can use several different carbon sources
C. Most of the enzymes used are the same as glycolysis
D. It is suppressed in the liver during fasting
E. It is negatively regulated by ADP
D. It is suppressed in the liver during fasting
no it is on during fasting contributing to adding blood glucose during fasting
Don’t want a futile cycle, can use pyruvate, amino acids and glucose, all but 3 irreversible enzymes are the same, it is negatively regulated by ADP
Which of the following is FALSE for coenzymes:
A. NADH is the reduced form
B. FAD is the oxidized form
C. Flavin coenzymes function as prostetic groups
D. Both NADH and FADH2 are produced in glycolysis
E. Both NADH and FADH2 are produced in the TCA cycle
D. Both NADH and FADH2 are produced in glycolysis
FADH2 is not produced in glycolysis
NADH is reduced as it has the H, FAD is oxidized as it doesn’t have the H, flavin group is hydrophobic, Both NADH and FADH are produced in glycolysis
Which of the following statements is INCORRECT about fatty acids?
A. Saturated fatty acids have higher melting temperature than unsaturated fatty acids.
B. Naturally occurring unsaturated fatty acids mostly have double bonds in trans configuration.
C. ω-3 and ω-6 fatty acids are nutritionally essential fatty acids.
D. Polyunsaturated fatty acids such as arachidonic acid
are used as precursors to make eicosanoids.
B. Naturally occurring unsaturated fatty acids mostly have double bonds in trans configuration.
They normally have cis bonds!
PLant fats are better than animal fats, humans can make but we need w-3 adn w-6.
Which of the following reactions is the regulation point of cholesterol synthesis?
A. Conversion of acetyl CoA to acetoacetyl CoA
B. Synthesis of HMG-CoA
C. Reduction of HMG-CoA to mevalonate
D. Conversion of mevalonate to isopentenyl
pyrophosphate
E. Ring closure of squalene 2,3-epoxide
C. Reduction of HMG-CoA to mevalonate
Complete the transamination reaction shown below. The structure of oxaloacetate is shown to help you.
Glutamate + Oxaloacetate ⇌ α-Ketoglutarate + ___________
A. Glutamine
B. Alanine
C. Serine
D. Aspartate
E. Pyruvate
D. Aspartate
Which of the following is NOT a nucleoside?
A. Adenosine
B. Uridine
C. Cytosine
D. Guanosine
E. Inosine
C. Cytosine is a nucleotide
Adenosine is a nucleoside (base is adenine)
Uridine is a nucleoside (base is urosine)
Guanosine is a nucleoside (base is guanine)
Inosine is a nucleoside (base is hypoxanthine)
Upon the release of glucagon, which of the following enzymes is repressed in the liver?
A. Protein kinase A
B. Glucokinase
C. PEP carboxykinase
D. Fructose 1,6-bisphosphatase
E. Glucose 6-phosphatase
B. Glucokinase (it catalyzed the first step of glycolysis)
F-1,6-BP could be confused with F-2,6,BP.
