Question

The transformation of pyruvate to lactate is: A. a decarboxylation B. an oxidation C. a reduction D. hydration

Short answer

C. a reduction

Step-by-step solution

- Understand Pyruvate to Lactate Transformation

The transformation of pyruvate to lactate occurs in anaerobic conditions, typically in muscles during intense exercise where oxygen is limited.

- Identify Type of Reaction

In this reaction, pyruvate is reduced to lactate. Reduction is a chemical reaction that involves the gain of electrons. Lactate is produced by the addition of electrons (and a proton) to pyruvate.

- Compare with Given Options

Compare the characteristics of reduction with other options:A. Decarboxylation - loss of a carbon dioxide molecule (not applicable here).B. Oxidation - loss of electrons (opposite of what happens here).C. Reduction - gain of electrons (matches here).D. Hydration - addition of water (not applicable here).

- Conclude the Correct Answer

Based on the analysis, the correct answer for the transformation of pyruvate to lactate is C. a reduction.

Key concepts

Reduction Reaction

In chemistry, a reduction reaction is a process where a molecule gains electrons. This is the opposite of an oxidation reaction.
During the transformation of pyruvate to lactate, pyruvate gains electrons. This gain makes the reaction a reduction.
Additionally, a proton (H+) is added to pyruvate to form lactate. This combined gain of electrons and proton is what defines a reduction.
Reduction reactions are essential in many biological processes because they allow molecules to store energy in their bonds.

Anaerobic Conditions

Anaerobic conditions are environments where oxygen is absent. Many cells, especially muscle cells, can still produce energy in these conditions.
During intense exercise, the oxygen supply to muscles can be insufficient for their energy needs. Cells then switch to anaerobic respiration.
In anaerobic respiration, pyruvate is converted to lactate. This conversion helps regenerate NAD+, crucial for glycolysis, allowing the cell to continue producing energy.
Without anaerobic conditions, the cell would run out of NAD+ and energy production would halt.

Electron Transfer

Electron transfer is a fundamental process in reduction and oxidation reactions, often called redox reactions.
In the context of pyruvate-to-lactate transformation, NADH transfers electrons to pyruvate. This electron transfer reduces pyruvate to lactate.
The overall reaction can be summarized as follows:
NADH + H+ + pyruvate → NAD+ + lactate
This reaction is critical as it ensures the continuation of energy production in anaerobic conditions.
The conversion of NADH back to NAD+ enables ongoing glycolysis, which is why electron transfer is vital in this process.