Cellular Respiration

Cellular Respiration

Assessment Statements

Topic 3.7

3.7.1
Q: Define cell respiration.
A: Cell respiration is the controlled release of energy from organic compounds in cells to form ATP.

3.7.2
Q: State what happens to glucose in cell respiration.
A: Glucose in the cytoplasm is broken down by glycolysis into pyruvate, with a small yield of ATP.

3.7.3
Q: Explain what happens during anaerobic cell respiration.
A: During anaerobic cell respiration, pyruvate can be converted in the cytoplasm into lactate, or ethanol and carbon dioxide, with no further yield of ATP. Ethanol and carbon dioxide are produced in yeast, whereas lactate is produced in humans.

3.7.4
Q: Explain what happens during aerobic cell respiration.
A: During aerobic cell respiration, pyruvate can be broken down in the mitochondrion into carbon dioxide and water with a large yield of ATP. The two process that extract the chemical energy contained in pyruvate are citric acid cycle and oxidative phosphorylation.

Topic 8.1

8.1.1
Q: State what oxidation and reduction involve in terms of electron transfer and what they frequently involve in terms of oxygen and hydrogen.
A: Oxidation involves the loss of electrons from an element, whereas reduction involves a gain of electrons. Oxidation frequently involves gaining oxygen or losing hydrogen, whereas reduction frequently involves losing oxygen or gaining hydrogen.

8.1.2
Q: Outline the process of glycolysis, including phosphorylation, lysis, oxidation and ATP formation.
A: Two phosphate groups, provided by two molecules of ATP, are added to a molecule of glucose to form hexose biphosphate, adding of phosphate group is called phosphorylation. Phosphorylation raises the energy level of hexose and this makes the subsequent reactions possible. Hexose biphosphate undergoes lysis, splitting it into two molecules of triose phosphate. Each triose phosphate molecule is oxidized, removing two atoms of hydrogen. The energy released by this oxidation is used...