Question

Substrate phosphorylation is the formation of
a. ATP
b. AMP
c. ADP
d. Pyruvic acid

Answer 1

Substrate level phosphorylation is a metabolic reaction that involves the conversion of higher energy substrate into lower energy product. It uses some chemical energy. Fermentation that is defined as breakdown of glucose into lactic acid also involves substrate level phosphorylation.

Complete answer:
Arnon used the term assimilatory powers to refer to ATP and NADPH. The process of reduction of NADP into ${NADPH}^{+}$, $H^{+}$ may be denoted as electron transport system ETS) in photosynthesis. The flow of electrons through ETS is linked to photophosphorylation.

ATP :- the process of formation of ATP from ADP and inorganic phosphate (P) utilising light energy is called photophosphorylation. ATP formed during this process is used as an energy source .

AMP :- AMP also called as adenosine monophosphate is produced during the process of ATP synthesis by the enzyme adenylate kinase by combining two ADP molecules. Thus this option is not correct.

ADP :- in the process when one phosphate group is removed by breaking and utilising a phosphoanhydride bond in a process called hydrolysis, that involves removal of hydrogen energy is released, and ATP is converted to adenosine diphosphate (ADP).

Pyruvic acid :- the pyruvic acid is formed during a commonly known as pathway glycolysis . When glycogen is broken down the end product formed is known as pyruvic acid.

Hence, the correct answer is option (A).

Note: ATP is defined as the energy currency that the cell uses. The substrate level phosphorylation differs from that of oxidative phosphorylation. Oxidative phosphorylation uses the enzymes oxidises nutrients and releases a large amount of energy.