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Flashcards in 2014 biochem endterm Deck (41)
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1

Which of the following is used in the oxidation of odd chain fatty acids?
A) Carnitine
B) Succinyl CoA
C) Vitamin B12

C) Vitamin B12

2

What is the role of ATP-binding cassette transporter (ABCA-1)?
A) removal of excess cholesterol from cell
B) transport cholesterol between LDL and HDL
C) activate LPL

A) removal of excess cholesterol from cell

3

What is the component used directly to make 2’ deoxy compound in DNA synthesis?
A) GTP
B) GDP
C) GMP
D) cAMP

B) GDP

4

high concentration in which amino acid will activate the urea cycle?
A) ornithine
B) cetruline
C) aspartate
D) arginine

D) arginine

5

Where are ketone bodies formed?
A) liver
B) blood
C) bones

A) liver

6

What prevents glucose, synthesized in the liver by Gluconeogenesis, from being converted back to glucose-6-phosphate?
A) High Km of Glucokinase
B) lack of glucose-6-phosphatase

A) High Km of Glucokinase

7

What is the main body system that is affected in cystic fibrosis?
A) Circulatory system
B) Respiratory system
C) Musculoskeletal system
D) nervous system

B) Respiratory system

8

What is the consequence of prolonged consumption of trans-unsaturated fatty acid?
A) unable to absorb essential fatty acid
B) Reduced LDL receptors
C) decreased bile synthesis

B) Reduced LDL receptors

(trans fat increases LDL, so they would produce less receptors)

9

What activated carbohydrate is required for de-novo synthesis of purine ring?
A) phosphoribosylpyrophosphate
B) Ribose-5-phosphate
C) glucose-6-phosphate

A) phosphoribosylpyrophosphate (PRPP)

10

What substrate leads to the polymerization of the inactive Acetyl CoA Carboxylase (AAC)?
A) Citrate
B) Malonyl CoA
C) Acetyl CoA

A) Citrate

11

Whats the oxidative stage product of pentose phosphate pathway?
A) ATP
B) NADPH
C) NADH

B) NADPH

12

Patients with a deficiency in which enzyme should avoid prolonged fasting?
A) Acyl CoA dehydrogenase
B) Acyl CoA decarboxylase

A) Acyl CoA dehydrogenase

13

What reaction is deactivated if the Sprechers shunt is blocked by a drug?
A) Oxidation of branched fatty acids
B) Transfer of acetyl CoA from mitochondria to cytosol
C) Retro inversion of fatty acid C: 24:6 to C: 22:6
D) Mitochondrial recycling of carnitine

C) Retro inversion of fatty acid C: 24:6 to C: 22:6

(DPA to DHA)

14

Through which of the following are amino acids transported from the intestine cell to the interstitial fluid?
A) Facilitated transporter
B) K transporter
C) Na transporter

A) Facilitated transporter

15

fructose-> fructose-1-phosphate (via fructose kinase (1))-> DHAP (via aldolase B (2))

If fructose was consumed, a deficiency in which enzyme would lead to severe problems in liver metabolism and why?
A) 1 due to rapid consumption of ATP
B) 2 due to lack of inorganic phosphate
C) 1 due to metabolism of fructose by hexokinase
D) 2 due to lack of DHAP

no answer given

16

Which of the following zymogens is activated by autocatalysis?
A) Trypsinogen
B) Pepsinogen

B) Pepsinogen

17

What is the main purpose of the non-oxidative stage of pentose phosphate pathway?
A) Production of ribose-5-phosphate
B) Reduction of NAD into NADH

A) Production of ribose-5-phosphate

18

peroxinitrite is cell-damaging oxidant. Which reaction is the main source of peroxinitrite in humans?
A) O2- + NO >> ONOO-
B) 2NO+O2 >> 2NO2
C) NO+NO2 >> N2O3
D) NO- +NO >> ONNO-

A) O2- + NO >> ONOO-

19

Oxidation and decarboxylation of metabolites in the Krebs cycle release energy. What is the main portion of this energy used for?
A) Synthesis of GTP
B) Production of NADH
C) Generation of heat
D) Oxidation of NADH to NAD+
E) Production of H2O2

B) Production of NADH

20

What does the enzyme colipase assist?
A) Pancreatic Lipase
B) Ceramide
C) Sphingomyelin

A) Pancreatic Lipase

21

What physiological process will be affected by the inhibition of the mutant RAS protein prenylation which is the attachment of farnesyl?
A) cholesterol synthesis
B) Beta oxidation

A) cholesterol synthesis

22

PDH kinase phosphorylates PDH, what stimulates this step and how it affects PDH activity?
A) cAMP, inactivation
B) Acetyl-coA, inhibition
C) Pyruvate, inhibition

B) Acetyl-coA, inhibition

23

What does a normal phosphatase defect in glucose translocase lead to?
A) accumulation of limit dextrin
B) hypoglycemia

B) hypoglycemia

24

Which enzyme catalyzes the oxidative deamination?
a) glutamate dehydrogenase
b) glutamate lyase

a) glutamate dehydrogenase

25

What is the effect of protein kinase on glycogen phosphorylase?
A) PKA, activates it
B) phosphoprotein phosphatase, activates it

A) PKA, activates it

26

How does our body appose ketoacidosis during prolonged starvation?
A) increase the production of ketone bodies
B) increase activity of urea cycle
C) increase release of ammonia from glutamine by the kidneys
D) Increase lipogenesis

C) increase release of ammonia from glutamine by the kidneys

27

What is a general characteristic of membrane lipid?
A) amphipathic
B) unsaturated fatty acids
C) covalent bonding with proteins

A) amphipathic

28

What increases the fluidity in the plasma membrane?
A) Cis-unsaturated fatty acids
B) Trans-unsaturated fatty acids
C) Integral proteins

A) Cis-unsaturated fatty acids

29

What is the function of Acyl CoA synthase?

Activate fatty acids for metabolic reactions

30

Mr.Hamad visited his Dr. and found out that he was hyperglycemia. The doctor found normal levels of Apo CII, so what is the next thing he would need to check?
A) lipoprotein lipase
B) hormone-sensitive lipase
C) HDL level

A) lipoprotein lipase (LPL)