Respiration in Plants MCQs

Statement analysis regarding enzymes of glycolysis:

I. Hexokinase catalyzes phosphorylation of glucose using ATP.
II. Invertase converts sucrose into glucose and fructose in plants.
III. Pyruvate dehydrogenase catalyzes conversion of PEP to pyruvic acid.
IV. Triose phosphate isomerase interconverts DHAP and PGAL.

Which statements are correct?

Consider the stoichiometry of glycolysis starting from ONE molecule of Glucose:

I. Total ATP synthesized directly (gross gain) = 4 ATP.
II. Total ATP consumed in preparatory phase = 2 ATP.
III. Net gain of ATP directly from glycolysis = 2 ATP.
IV. Total NADH + H⁺ generated = 4 molecules.

Which of the above statements are correct?

Regarding the cleavage step of glycolysis:

I. Cleavage converts a 6-carbon molecule into two 3-carbon molecules.
II. Enzyme splits Fructose-1,6-bisphosphate into PGAL and DHAP.
III. DHAP directly enters the subsequent payoff reactions without conversion.
IV. Both triose phosphates eventually get oxidized to pyruvic acid.

Which statements are correct?

Consider the following statements about water release during glycolysis:

I. Water molecule (H₂O) is released during conversion of 2-phosphoglycerate to phosphoenolpyruvate.
II. Enolase catalyzes the dehydration step forming PEP.
III. Water is released during glucose phosphorylation by hexokinase.
IV. Water molecule is consumed when PGAL is converted to BPGA.

Which statements are correct?

Read the following statements regarding Pyruvic Acid:

I. Pyruvic acid is the key main end-product of glycolysis.
II. Its metabolic fate depends entirely on cellular needs and availability of O₂.
III. It contains 3 carbon atoms per molecule.
IV. In absence of O₂, pyruvic acid always enters the TCA cycle.

Which of the above statements are correct?

Statement analysis on initial sugar utilization in plants:

I. Plant sucrose originates as the end product of photosynthesis or storage starch breakdown.
II. Invertase hydrolyzes sucrose into glucose and galactose.
III. Glucose and fructose are phosphorylated by hexokinase.
IV. Phosphorylated glucose isomerizes to produce fructose-6-phosphate.

Which of the statements are correct?

Regarding oxidation of PGAL to BPGA during glycolysis:

I. Two redox-equivalents (2 hydrogen atoms) are removed from PGAL.
II. NAD⁺ acts as the electron/hydrogen acceptor forming NADH + H⁺.
III. Inorganic phosphate (P_i) is incorporated into the molecule without ATP expenditure.
IV. The step is catalyzed by an isomerase enzyme.

Which option lists the correct statements?

Which steps in glycolysis involve isomerization reactions?

I. Glucose-6-phosphate → Fructose-6-phosphate.
II. Dihydroxyacetone phosphate ⇌ Glyceraldehyde-3-phosphate.
III. 3-phosphoglyceric acid → 2-phosphoglyceric acid.
IV. Phosphoenolpyruvate → Pyruvic acid.

Select the option containing isomerization / mutase steps.

Consider the following statements about the total number of carbon atoms in glycolytic intermediates:

I. Glucose and Fructose-1,6-bisphosphate are 6-carbon compounds (6C).
II. BPGA, PGA, PEP, and Pyruvic acid are 3-carbon compounds (3C).
III. Acetyl CoA produced after glycolysis is a 3-carbon compound.
IV. Oxaloacetic acid is a 2-carbon compound.

Which statements are correct?

Statements regarding oxygen requirement of Glycolysis:

I. Glycolysis requires molecular O₂ to initiate glucose splitting.
II. It occurs in both presence and absence of molecular oxygen.
III. The pathway produces CO₂ gas as a byproduct at step 5.
IV. No CO₂ molecule is evolved during glycolysis.

Which statements are correct?