QUESTION: Which vitamins work as coenzyme?
ANS: Vitamins that function as coenzymes include:
Vitamin B1 (Thiamine):
- Thiamine acts as a coenzyme in the form of thiamine pyrophosphate.
- It facilitates the conversion of pyruvate to acetyl CoA and plays a vital role in the citric acid cycle (Krebs cycle).
Vitamin B2 (Riboflavin):
- Riboflavin serves as a precursor for two coenzymes FMN and FAD.
- FMN and FAD participate in various redox reactions within cells.
Vitamin B3 (Niacin):
- Niacin is a precursor for two coenzymes NAD and NADP.
- NAD and NADP are involved in processes such as glycolysis and the citric acid cycle.
Vitamin B5 (Pantothenic Acid):
- Pantothenic acid is a component of coenzyme A (CoA).
- CoA is essential for the synthesis of certain molecules, such as cholesterol and acetylcholine.
Vitamin B6 (Pyridoxine):
- Pyridoxal phosphate (PLP) is the active form of vitamin B6 and serves as a coenzyme.
- It participates in processes such as the synthesis of neurotransmitters and metabolism of glycogen and other sugars.
Vitamin B7 (Biotin):
- Biotin acts as a coenzyme for several carboxylase enzymes.
- These enzymes are involved in important metabolic pathways, such as the metabolism of carbohydrates, fats, and amino acids.
Vitamin | Role as Coenzyme |
Vitamin B1 | · Thiamine acts as a coenzyme in various enzymatic reactions involved in energy metabolism, particularly carbohydrate metabolism.
· It helps convert pyruvate to acetyl CoA and plays a role in the citric acid cycle. |
Vitamin B2 | · Riboflavin serves as a precursor for coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD).
· FMN and FAD participate in redox reactions, particularly in energy metabolism, including the oxidation of fatty acids, glucose, and amino acids. |
Vitamin B3 | · Niacin is a precursor for coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP).
· NAD and NADP play essential roles in energy metabolism and redox reactions, including glycolysis, the citric acid cycle, and oxidative phosphorylation. |
Vitamin B5 | · Pantothenic acid is a component of coenzyme A (CoA), which is involved in numerous metabolic reactions.
· CoA plays a critical role in the synthesis and oxidation of fatty acids, the citric acid cycle, and the metabolism of carbohydrates and amino acids. · It also contributes to the synthesis of cholesterol and acetylcholine. |
Vitamin B6 | · Pyridoxal phosphate (PLP), the active form of vitamin B6, acts as a coenzyme in over 100 enzymatic reactions.
· PLP is primarily involved in amino acid metabolism, including neurotransmitter synthesis, tryptophan to niacin conversion, and glycogen and sugar metabolism. |
Vitamin B7 | · Biotin serves as a coenzyme for carboxylase enzymes involved in the metabolism of carbohydrates, fats, and amino acids.
· It assists in the activation of these enzymes, allowing them to catalyze carboxylation reactions necessary for various cellular processes. |
- Vitamin B1 (Thiamine):
- Thiamine acts as a coenzyme in the form of thiamine pyrophosphate (TPP).
- TPP is involved in several enzymatic reactions related to energy metabolism, particularly carbohydrate metabolism.
- It facilitates the conversion of pyruvate to acetyl CoA and plays a vital role in the citric acid cycle (Krebs cycle).
- Vitamin B2 (Riboflavin):
- Riboflavin serves as a precursor for two coenzymes: flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD).
- FMN and FAD participate in various redox reactions within cells.
- They are involved in energy metabolism, including the oxidation of fatty acids, glucose, and amino acids.
- Vitamin B3 (Niacin):
- Niacin is a precursor for two coenzymes: nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP).
- NAD and NADP play crucial roles in energy metabolism and redox reactions.
- They are involved in processes such as glycolysis, the citric acid cycle, and oxidative phosphorylation.
- Vitamin B5 (Pantothenic Acid):
- Pantothenic acid is a component of coenzyme A (CoA).
- CoA is essential for various metabolic reactions, including the synthesis and oxidation of fatty acids, the citric acid cycle, and the metabolism of carbohydrates and amino acids.
- It also plays a role in the synthesis of certain molecules, such as cholesterol and acetylcholine.
- Vitamin B6 (Pyridoxine):
- Pyridoxal phosphate (PLP) is the active form of vitamin B6 and serves as a coenzyme.
- PLP is involved in over 100 enzymatic reactions, primarily related to amino acid metabolism.
- It participates in processes such as the synthesis of neurotransmitters, the conversion of tryptophan to niacin, and the metabolism of glycogen and other sugars.
- Biotin:
- Biotin acts as a coenzyme for several carboxylase enzymes.
- These enzymes are involved in important metabolic pathways, such as the metabolism of carbohydrates, fats, and amino acids.
- Biotin helps activate these enzymes, allowing them to catalyze carboxylation reactions necessary for various cellular processes.
Important Questions about Enzymes
- Enzymes MCQs
- Inhibition in enzymes
- Which enzyme digests starch?
- Which enzyme digests protein?
- which enzyme is present in saliva?
- Which enzyme is not present in succus entericus?
- Which enzyme breaks down protein in the stomach?
- Which enzyme converts fibrinogen to fibrin?
- Which enzyme converts glucose into alcohol?
- Which enzyme digests fat?
- Which enzyme digests milk protein?
- Which enzyme is used in PCR?
- Which enzyme unzips the DNA double helix?
- Which liver enzyme increases with alcohol?
- Which enzyme cuts DNA?
- Which enzyme catalyzes the first step of glycolysis?
- Which enzyme binds DNA fragments together?
- Which enzyme transcribes DNA into RNA?
- which enzyme adds new nucleotides?
- Which enzyme digests cellulose?
- Which enzyme separates the two strands of DNA?
- Which enzyme converts carbohydrates into glucose?
- Which enzyme removes RNA primer?
- Which enzymes help in digestion?
- Which enzyme works best in acidic conditions?
- Which enzyme synthesizes tRNA?
- Which enzyme secreted by pancreas?
- Which enzyme converts maltose into glucose?
- Which vitamins work as coenzyme?