AP BIOLOGY

CELL RESPIRATION

GLYCOLYSIS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
What molecule is glucose broken into during glycolysis?
A
pyruvic acid
B
citric acid
C
oxaloacetate
D
carbon dioxide
Explanation: 

Detailed explanation-1: -During glycolysis, glucose ultimately breaks down into pyruvate and energy; a total of 2 ATP is derived in the process (Glucose + 2 NAD+ + 2 ADP + 2 Pi–> 2 Pyruvate + 2 NADH + 2 H+ + 2 ATP + 2 H2O).

Detailed explanation-2: -Glycolysis is the process by which glucose is broken down within the cytoplasm of a cell to form pyruvate. Under aerobic conditions, pyruvate can diffuse into mitochondria, where it enters the citric acid cycle and generates reducing equivalents in the form of NADH and FADH2.

Detailed explanation-3: -In eukaryotic cells, the pyruvate molecules produced at the end of glycolysis are transported into mitochondria, which are the sites of cellular respiration. There, pyruvate will be transformed into an acetyl group that will be picked up and activated by a carrier compound called coenzyme A (CoA).

Detailed explanation-4: -During cellular respiration, a glucose molecule is gradually broken down into carbon dioxide and water. Along the way, some ATP is produced directly in the reactions that transform glucose. Much more ATP, however, is produced later in a process called oxidative phosphorylation.

Detailed explanation-5: -Enzymes split a molecule of glucose into two molecules of pyruvate (also known as pyruvic acid). This occurs in several steps, as shown in the Figure below. In glycolysis, glucose (C6) is split into two 3-carbon (C3) pyruvate molecules. This releases energy, which is transferred to ATP.

There is 1 question to complete.