Question

The figure given below shows the steps in glycolysis. Fill in the missing steps $A,B,C,D$ and also indicate whether $ATP$ is being used up or released at step $E$?

Answer 1

Glycolysis

Glycolysis is the process of partial breakdown of glucose to pyruvic acid. It is a 10-step process

A

A- Fructose -6-phosphate.

Step 2: Conversion of glucose-6-phosphate $\to$fructose-6-phosphate

B

B - Fructose 1,6 bisphosphate

Step 3: Conversion of fructose-6-phosphate to fructose 1,6 bisphosphate.

C

C- Glyceraldehyde -3-phosphate

Step 4: Conversion of fructose 1,6 bisphosphate to Glyceraldehyde-3-phosphate and dihydroxyacetone-3-phosphate ($DHAP$).

D

D - 1,3 bisphosphoglyceric acid

Step 5: Conversion of Glyceraldehyde-3-phosphate to 1,3 bisphosphoglyceric acid along with the reduction of $NA{D}^{+}$ to $NADH+H^{+}$

E

E - $ATP$ to $ADP$

Step 3: Conversion of fructose-6-phosphate to fructose 1,6 bisphosphate requires the breakdown of $ATP$ to transfer phosphate group to fructose-6-phosphate to form a symmetrical molecule.

Conclusion

The missing steps are as follows

●A$\to$ fructose 6 - phosphate

●B $\to$ fructose 1, 6 bisphosphate

●C $\to$ triose phosphate

●D $\to$ triose bisphosphate

●At step E. energy is being used up.