The correct Answer is A-4, B-3, C-2, D-1
Explanation
Enzymes are biological catalysts that facilitate specific biochemical reactions. Their specificity arises from the unique three-dimensional structure of their active sites, which allows them to bind to particular substrates and catalyze specific transformations. This question assesses knowledge of the specific actions of several key enzymes involved in metabolic pathways.
Statement-wise Analysis
- A. Hexokinase: This enzyme is involved in the first step of glycolysis. It catalyzes the phosphorylation of glucose, converting it into glucose-6-phosphate. This reaction utilizes ATP. Therefore, Hexokinase phosphorylates Glucose.
- B. Invertase: Also known as sucrase, invertase is an enzyme that catalyzes the hydrolysis of sucrose (a disaccharide) into its constituent monosaccharides, glucose and fructose. Therefore, Invertase splits Sucrose into Glucose and Fructose.
- C. Lactate dehydrogenase: This enzyme plays a crucial role in anaerobic respiration. It catalyzes the reduction of pyruvate to lactate (lactic acid), regenerating NAD+ from NADH, which is essential for glycolysis to continue in the absence of oxygen. Therefore, Lactate dehydrogenase reduces Pyruvate to Lactic acid.
- D. Pyruvate dehydrogenase: This is a multi-enzyme complex that catalyzes the oxidative decarboxylation of pyruvate, converting it into acetyl-CoA. This reaction is a key link between glycolysis and the citric acid cycle. Therefore, Pyruvate dehydrogenase converts Pyruvate to Acetyl CoA.
Based on the analysis:
A matches with 4 (Phosphorylates Glucose)
B matches with 3 (Splits Sucrose into Glucose and Fructose)
C matches with 2 (Reduces Pyruvate to Lactic acid)
D matches with 1 (Converts Pyruvate to Acetyl CoA)
This corresponds to option B.
Key Takeaway: Enzymes exhibit high specificity for their substrates and catalyze distinct biochemical reactions, which are fundamental to metabolic pathways.