Metabolism and Bioenergetics (GATE)
This is Topic Test for GATE
Questions
One of the products of PP pathway is erythrose-4-phosphate. It is used for the synthesis of
- fatty acids
- nucleotides
- aromatic amino acids
- nitrogenous bases
Most of the steps of pentose phosphate pathway occur in plants in
- cytoplasm
- plastids
- mitochondria
- glyxosomes
Which of the following statements about pentose phosphate pathway are correct?
a. It is an anabolic pathway.
b. NADPH produced in this pathway is required for the prevention of the oxidative stress.
c. The first step of PP pathway is a rate limiting step and is irreversible.
d. Epimerase converts ketose ribulose-5-phosphate to aldose ribose-5-phosphate.
- All of the above
- Only a, b and c
- Only b, c and d
- Only a and b
NADPH generated in PP pathway is used for which of the following?
a. Amino acid synthesis
b. Steroid synthesis
c. Fatty acid synthesis
d. Reduced glutathione synthesis
- All of the above
- Only c, b and a
- Only b, d and c
- Only a, b and c
Which of the following enzymes is not involved in TCA?
- Citrate synthase
- Fumarase
- Malate dehydrogenase
- Malate synthase
Which of the following products is not formed in non-oxidative PP pathway?
- Glyceraldehyde 3-phosphate
- Ribulose 5-phosphate
- Sedoheptulose 7-phosphate
- Erythrose 4-phosphate
Which of the following events occur in the oxidative phase of PP pathway?
a. Two molecules of NADP+ are reduced to NADPH.
b. 6-phosphogluconolactonase catalyses dehydrogenation reaction.
c. CO2 is generated in this phase.
d. The rate-limiting reaction of pentose phosphate pathway is catalysed by glucose-6-phosphatase.
- All of the above
- Only a, b and c
- Only a, c and d
- Only b, c and d
Which of the following is the significance of glyoxylate cycle in pathogenic fungi?
- It uses acetate as a carbon source.
- It increases affinity for the host.
- It synthesises chitin in the cell wall.
- It increases resistance to antifungals.
Glucose-6-phosphate dehydrogenase (G6PDH) is the first enzyme that is required for initiation of pentose phosphate pathway. Which of the following is/are the effects of mutation in glucose-6-phosphate dehydrogenase (G6PDH)?
a. Liver problems in neonates
b. Chronic granulomatous disease
c. Resistance to malarial parasite
d. Erythrocyte survival affected
- All of the above
- Only a, b and c
- Only b, c and d
- Only a, c and d
The variants with altered glucose-6-phosphate dehydrogenase activity have been classified into five classes by WHO. The variants with severe deficiency with intermittent haemolysis belong to
- Class I
- Class II
- Class III
- Class IV
Which of the following substrates leads to the synthesis of L-malate by malate synthase in glyoxylate pathway?
- Citrate
- Glyoxylate
- Succinate
- Fumarate
Several drugs and toxins inhibit oxidative phosphorylation. Even if a single enzyme is inhibited, the whole process comes to a halt. One such inhibitor is oligomycin, which is used as an antibiotic. It blocks which of the following enzymes?
- ATP synthase
- Cytochrome c oxidase
- Succinate dehydrogenase (complex II)
- Cytochrome c reductase
NAD specific isocitrate dehydrogenase oxidises isocitrate in citric acid cycle. Which of the following acts as an activator of this enzyme?
- Acetyl coA
- Oxaloacetate
- ADP
- ATP
Phosphoenolpyruvate carboxykinase reaction (an anaplerotic reaction) produces which of the following in animals?
- Acetyl CoA
- L-malate
- Oxaloacetate
- Aspartate
Phosphoenolpyruvate (PEP) is formed during glycolysis or gluconeogenesis metabolic pathway. It is used by bacteria for which of the following?
- Carbon fixation
- Chorismate synthesis
- Nitrogen fixation
- Carbon assimilation