Master GCSE Biology

MS1.

- Photosynthesis is the process by which plants use sunlight to convert carbon dioxide and water into glucose and oxygen. (1)

MS2.

- Chlorophyll absorbs sunlight energy and uses it to split water molecules. (1)

- The energy from sunlight is stored in glucose. (1)

MS3.

- Glycolysis: Glucose is broken down into pyruvate. (1)

- Krebs cycle: Pyruvate is further broken down to release carbon dioxide and energy. (1)

- Electron transport chain: Energy is used to pump protons across a membrane, creating a proton gradient. Oxygen combines with protons and electrons to form water. (1)

MS4.

MS5.

- A limiting factor is an environmental condition that restricts the rate of photosynthesis. (1)

- Examples include light intensity, temperature, carbon dioxide concentration, and water availability. (1)

MS6.

- Aerobic respiration: Uses oxygen, produces carbon dioxide and water, releases more energy. (1)

- Anaerobic respiration: Does not use oxygen, produces lactic acid or ethanol, releases less energy. (1)

MS7.

- Metabolism is the sum of all chemical reactions that occur in an organism. (1)

MS8.

- Oxygen debt is the amount of oxygen required to restore body tissues to their pre-exercise state. (1)

- During exercise, anaerobic respiration occurs, producing lactic acid. After exercise, oxygen is used to convert lactic acid back to glucose. (1)

MS9.

- Fermentation is a type of anaerobic respiration that produces either lactic acid (lactic acid fermentation) or ethanol (alcoholic fermentation). (1)

- Allows bacteria and yeasts to produce food and beverages like cheese, yogurt, and beer. (1)

MS10.

- Lactic acid (1)