Question

RuBP carboxylase, PEP carboxylase, Pyruvate dehydrogenase, ATPase, cytochrome oxidase, Hexokinase, Lactate dehydrogenase.
Select/choose enzymes from the list above which are involved in

a. Photosynthesis

b. Respiration

c. Both in photosynthesis and respiration

Answer 1

RuBP carboxylase:

RuBP carboxylase is an enzyme involved in the calvin cycle of photosynthesis. It fixes atmospheric carbon dioxide with Ribulose 1,5 bisphosphate (RuBP) to form the first stable 3-carbon product, 3-phosphoglyceric acid.

PEP carboxylase:

Oxaloacetate.
PEP carboxylase is an enzyme found in C4 plants and is involved in photosynthesis.
It fixes atmospheric $C{O}_2$ with phosphoenol pyruvate (PEP) to form the first stable $4$-carbon compound,

Final answer:
a) Enzymes involved in photosynthesis: RuBP carboxylase, PEP carboxylase

Pyruvate dehydrogenase:

Pyruvate dehydrogenase is the enzyme involved in respiration.
It catalyzes the oxidative decarboxylation of pyruvate to acetyl CoA followed by the oxidation of NAD+ to NADH.

Cytochrome oxidase:

Cytochrome oxidase is also involved in respiration.

$\bullet$ It is the enzyme in the electron transport chain present in the inner mitochondrial membrane.

$\bullet$ It accepts electrons from cytochrome $a^3$ to the final electron acceptor, that is, the $O_2$ molecule.

Hexokinase:

Hexokinase is the enzyme involved in the glycolysis, which is one of the respiratory pathways.
It catalyzes the conversion of glucose to glucose-$6$-phosphate.

Lactate dehydrogenase:

Lactate dehydrogenase is the enzyme involved in anaerobic respiration in bacteria and animal skeletal muscles.
It catalyses the conversion of pyruvic acid to lactic acid under the anaerobic conditions.

Final answer:
b) Enzymes involved in respiration: Pyruvate dehydrogenase, Cytochrome oxidase, Hexokinase, Lactate dehydrogenase

ATPase:

ATPase is the enzyme that is involved in the breakdown of phosphate bond of ATP to form ADP and Pi.

$\bullet$ This enzyme is involved in both photosynthesis and respiration.
$\bullet$ In photosynthesis, it is involved in the dark reaction for the reduction of $C{O}_2$.

$\bullet$ In respiration, it is required during the initial steps of glycolysis.


Final answer:
c) Enzyme involved both in photosynthesis and respiration:
ATPase