Bioenergetics Flashcards
(13 cards)
What is photosynthesis?
A process where plants use light energy to produce glucose and oxygen from carbon dioxide and water.
Equation for photosynthesis?
Word: Carbon dioxide + water → glucose + oxygen.
Where does photosynthesis occur?
In the chloroplasts of plant cells, which contain chlorophyll to absorb light.
What factors affect the rate of photosynthesis?
- Light intensity (more light → faster photosynthesis).
- CO₂ concentration (higher concentration → faster photosynthesis).
- Temperature (too high → enzymes denature).
What is the inverse square law in photosynthesis?
Light intensity is inversely proportional to the square of the distance from the light source:
How do plants use glucose?
- Respiration (to release energy).
- Starch (storage).
- Cellulose (cell walls).
- Amino acids (combine with nitrates).
- Fats and oils (energy storage).
What is respiration?
The process of releasing energy from glucose. It happens in every cell.
What is the difference between aerobic and anaerobic respiration?
• Aerobic: Uses oxygen; releases lots of energy.
Equation: Glucose + oxygen → carbon dioxide + water (+ energy).
• Anaerobic: No oxygen; less energy released.
Human equation: Glucose → lactic acid (+ energy).
Plant/yeast equation: Glucose → ethanol + CO₂ (+ energy).
What is fermentation?
Anaerobic respiration in yeast cells. Used in making bread (CO₂ makes dough rise) and alcohol (ethanol production).
What is oxygen debt?
The amount of oxygen needed to break down lactic acid after anaerobic respiration.
Why do organisms need energy from respiration?
- To build larger molecules (e.g., proteins).
- For muscle contraction.
- To maintain body temperature.
How do you measure the rate of photosynthesis?
By counting bubbles of oxygen released by pondweed in water, or by measuring the volume of oxygen produced.
What is metabolism?
The sum of all chemical reactions in the body, including respiration, photosynthesis, and breaking down excess proteins.
