Questions & Answers

Describe the process of various biochemical reactions that occur during glycolysis.

Answer Verified Verified
Hint: Glycolysis is a series of reactions that extract energy from glucose by splitting it into two three-carbon molecules called pyruvates.

Complete Answer:
The glycolysis is a multistep process, the steps of glycolysis are,
 Step 1: Hexokinaseis added to glucose, creating a 6-phosphate. That is active sugar.
\[~a-D-Glucose\text{ }+\text{ }ATP~\grave{a}~Glucose-6-phosphate\text{ }\left( G6P \right)\text{ }+\text{ }ADP\]

Step 2: The Glucose 6-phosphate is converted into its isomer, fructose 6-phosphate. This reaction is catalyzed by Phosphoglucose isomerase.
\[Glucose-6-phosphate\text{ }\left( G6P \right)~\grave{a}~Fructose-6-phosphate\text{ }\left( F6P \right)\]

Step 3: Phospho Fructose HK then uses another ATP molecule to transfer a Phosphate G to Fructose 6-phosphate, which makes it Fructose 1,6-bisphosphate.
\[~Fructose-6-phosphate\text{ }\left( F6P \right)\text{ }+\text{ }ATP~\grave{a}~Fructose-1,6-bisphosphate\text{ }\left( F1,6PP \right)\text{ }+\text{ }ADP\]

Step 4: Fructose-bisphosphate aldolase then splits Fructose 1,6-bisphosphate into 2 sugars, di & glyceraldehyde.
  & Fructose-1,6-bisphosphate\text{ }\left( F1,6PP \right)~\grave{a}~dihydroxyacetone phosphate\text{ }\left( DHAP \right)\text{ } \\
 & +\text{ }Glyceraldehyde-3-phosphate\text{ }\left( G3P \right) \\

Step 5: Triosephosphate isomerase the inter-converts and takes Glyceraldehyde away.
\[Dihydroxyacetone\text{ }phosphate\text{ }\left( DHAP \right)~\grave{a}~Glyceraldehyde-3-phosphate\text{ }\left( G3P \right)\]

Step 6: Glyceraldehyde 3-phosphate dehydrogenase
 serves 2 functions in this step. The first, a Hydrogen atom is stripped from Glyceraldehyde to NAD+ to create NADP. Next, Triose adds a phosphate group to Glyceraldehyde to make it 1,3-diphosphoglycerate.
  & Glyceraldehyde-3-phosphate\text{ }\left( G3P \right)\text{ }+NA{{D}^{+}}~ \\
 & +\text{ }Pi~\grave{a}~1,3-Bisphosphoglycerate\text{ }\left( 1,3BPG \right)\text{ }+\text{ }NADH\text{ }+\text{ }{{H}^{+}} \\

Step 7: Phosphoglycerate kinase takes a phosphate group from 1,3-diphosphoglycerate and gives it to ADP to form ATP.
\[~1,3-Bisphosphoglycerate\text{ }\left( 1,3BPG \right)\text{ }+\text{ }ADP~\grave{a}~3-Phosphoglycerate\text{ }\left( 3PG \right)\text{ }+\text{ }ATP\]

Step 8: Phosphoglycerate mutase then relocates the phosphate group from 3-Carbon to 2-Carbon.
\[3-Phosphoglycerate\text{ }\left( 3PG \right)~\grave{a}~2-Phosphoglycerate\text{ }\left( 2PG \right)\]

Step 9: Enolase then removes a molecule of water from 2-phosphate to form PEP.
\[2-Phosphoglycerate\text{ }\left( 2PG \right)~\grave{a}~Phosphoenolpyruvate\text{ }\left( PEP \right)\text{ }+\text{ }H2O\]

Step 10: Pyruvate kinase takes a phosphate group from PEP and gives it to ADP, and this forms pyruvic acid & ATP.
\[Phosphoenolpyruvate\text{ }\left( PEP \right)\text{ }+\text{ }ADP~\grave{a}~Pyruvate\text{ }+\text{ }ATP\]

Note: Glycolysis, gluconeogenesis, glycogenesis, and glycogenolysis are similar terms but their meanings are different.