Question

Which is true about the end products of glycolysis?
A. $2 \text{pyruvic acid}+ 2ATP + 2NADH_2$
B. $2 \text{pyruvic acid}+ 2NADH_2$
C. $1 \text{pyruvic acid}+ 2ATP + 2NADH_2$
D. $2 \text{pyruvic acid}+ 1ATP + 1NADH_2$

Answer 1

Hint: Glycolysis is a process which starts from glucose and there is breakdown of glucose into pyruvic acid and energy by the help of enzyme and the main purpose is to provide pyruvate for TCA cycle.

Complete answer:
First of all, you should know what glycolysis is. It is the process of breakdown of glucose into pyruvic acid and energy. There are two molecules of ATP which are consumed during two phosphorylation reactions in order to form fructose 1,6-bisphosphate and in return, there is production of four molecules of ATP by substrate-level phosphorylation where there is conversion of 1, 3-bisphosphoglycerate to 3-phosphoglycerate and phosphoenolpyruvate to pyruvate. For $NADH_2$, two molecules are formed at the time of oxidation of glyceraldehyde 3-phosphate to 1,3-diphosphoglycerate.

Net Reaction of glycolysis is-
$\text{Glucose}+2NAD^{+}+2ADP+2H_{3}PO_{4}​→2\text{Pyruvate}+2NADH+2H^{+}+2ATP$
In this reaction, each NADH is equivalent to 3 ATP which means that the net gain in glycolysis is 8ATP.
So, the end products in glycolysis are $2\text{pyruvic acid}+ 2ATP + 2NADH_2$

Thus, from the above reaction it is clear that 2pyruvic acid, 2NADH and 2ATP is formed in the reaction of glycolysis which means that we need to find that option where end products are $2\text{pyruvic acid}+ 2ATP + 2NADH_2$ and it is seen in the case of option A and in all the other options, the end products given are incorrect as in option B there is no ATP, in option C there is only 1 pyruvic acid and in option D there is only one ATP and NADH.

Hence, the correct answer is option (A).

Note: The main purpose of glycolysis is to provide pyruvate for TCA cycle and for this there is breakdown of glucose into pyruvic acid, ATP and NADH and the final end products of this cycle are $2\text{pyruvic acid}+ 2ATP + 2NADH_2$ . There are many steps in this cycle which leads to these end products and the net gain in this glycolysis is 8 ATP.