Question

Anaerobic breakdown of glucose in our muscles produces:
A. Pyruvic acid
B. lactic acid
C. Ethyl alcohol
D. Oxalic acid

Answer 1

The metabolic mechanism that transforms glucose to pyruvic acid is known as glycolysis. The high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide are formed from the free energy released during this process (NADH). Glycolysis is a set of $10$ enzyme-catalysed processes. Glycolysis is the initial step in cellular respiration, when glucose molecules are oxidised.

Complete explanation:
Option A: Pyruvic acids are frequently produced from glucose and converted to carbohydrates (such as glucose) via gluconeogenesis or fatty acids via the acetyl-CoA pathway.
So, option A is incorrect.
Option B: When muscle cells run out of oxygen, they must convert to an anaerobic energy-processing pathway. Lactic acid is formed when glucose is broken down in the absence of oxygen.
So, option B is correct.
Option C: Pyruvic acid is produced when a glucose molecule is broken down into two molecules. The two pyruvic acid molecules are subsequently converted to two ethanol molecules and $2C{O_2}$.
So, option C is incorrect.
Option D: Oxalic acid is produced primarily by oxidising carbohydrates or glucose in the presence of vanadium pentoxide using nitric acid or air. Glycolic acid and ethylene glycol are two examples of precursors that can be employed.
So, option D is incorrect.

Therefore, Option B is the correct answer.

Note:
Pyruvic acid is often generated from glucose, transformed back to carbohydrates (such as glucose) via gluconeogenesis, or transformed to fatty acids via an acetyl-CoA process. It may also be used to make the amino acid alanine, and it may be fermented to produce ethanol or lactic acid. When oxygen is present (aerobic respiration), pyruvic acid delivers energy to cells via the citric acid cycle (also known as the Krebs cycle), and when oxygen is not present (anaerobic respiration), it ferments to form lactate (lactic acid).