Which organelle breaks down sugar molecules that supply energy to the cell?
a. golgi apparatus
b. nucleus
c. endoplasmic reticulum
d. mitochondrion

d. mitochondrion

Explanation: In eukaryotic organisms the mitochondria is the organelle which is involved in the release of energy from the sugar molecules present in the food. Glycolysis is the process which occur in the mitochondria in which glucose breaks down into two carbon fragments. In further breakdown process the carbon dioxide is produced and energy is trapped in the high energy electrons. The energy in these electrons is used in an electron transport chain to produce ATP molecules, these are the sources of energy.

Mitochondrion or mitochondria facilitates the breakdown of sugar molecules to supply energy to the cell. Mitochondria are defined as a cell organelles that are found in all aerobic eukaryotes. It is absent in prokaryotes and anaerobic eukaryotes. It is involved in the process of oxidative phosphorylation and citric acid cycle for carried out aerobic respiration.

Further Explanation:

Mitochondria is a cell organelle that plays an essential role in the formation of metabolic energy in aerobic eukaryotic cells. The energy is obtained from the breakdown of carbohydrates and fatty acids. This is further converted into ATP by the process of oxidative phosphorylation. The breakdown of glucose and fatty acids in the presence of oxygen is serves as the principle source of metabolic energy.

The first stage of glucose breakdown takes place in the cytosol of the cell and this process is called glycolysis. In this process, the glucose is converted into molecules of pyruvate which is then transported into mitochondria. In mitochondria, the pyruvic acid is oxidized into carbon dioxide.

The oxidation of pyruvic acid releases a large amount of energy in the form of ATP. This process involves the oxidation of pyruvic acid into acetyl-CoA which is further breaks down into carbon dioxide by Kreb’s cycle.

The complete oxidation of carbohydrates takes place in the matrix of mitochondria. The process of oxidative phosphorylation takes place in the inner mitochondrial membrane. The oxidation of acetyl CoA into carbon dioxide is related with the reduction of NAD+ into NADH2 and FAD into FADH2. The energy produced from such electron transfer reactions are transformed into potential energy stored in the proton gradient located across the membrane and is further used for synthesis of ATP.

Learn more:

1. Learn more about aerobic and anaerobic respiration

2. Learn more about cellular respiration

3. Learn more about alcoholic

Answer Details:

Grade: High School

Subject: Biology

Chapter: Respiration in plants

Keywords:

Carbon dioxide, oxygen, pyruvate, acetyl CoA, ATP, energy, mitochondria, cell, phosphorylation, cytosol.