Starter quiz
- Which of the following are reactants for photosynthesis?
- Carbon dioxide, water, and energy
- Oxygen, glucose, and energy
- Carbon dioxide and water ✓
- Carbon dioxide and oxygen
-
- What is the correct summary word equation for photosynthesis?
- carbon dioxide + oxygen → glucose + water
- carbon dioxide + water → glucose + oxygen ✓
- glucose + oxygen → carbon dioxide + water
- water + glucose → carbon dioxide + oxygen
-
- Where in the plant cell does photosynthesis occur?
- Chloroplasts ✓
- Mitochondria
- Nucleus
- Ribosomes
-
- What is the correct summary symbol equation for photosynthesis?
- 6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O
- 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ ✓
- C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
- CO₂ + H₂O → O₂ + C₆H₁₂O₆
-
- How is light energy absorbed by plants?
- By chlorophyll in the chloroplasts. ✓
- By the cell wall.
- By the mitochondria.
- By the nucleus.
-
- What effect does temperature have on enzyme activity?
- It always increases activity.
- It decreases activity.
- It has no effect.
- It increases activity up to an optimum point. ✓
-
Exit quiz
- What are the products of photosynthesis?
- carbon dioxide and water
- glucose and carbon dioxide
- glucose and oxygen ✓
- oxygen and water
-
- What is a limiting factor in photosynthesis?
- a condition that has no effect on the rate of photosynthesis
- a condition that slows down the rate of photosynthesis when in short supply ✓
- a condition that speeds up photosynthesis
- a factor that always increases the rate of photosynthesis
-
- What happens to the rate of photosynthesis at very high temperatures?
- it decreases ✓
- it increases continuously
- it increases slightly
- it remains constant
-
Why does the rate of photosynthesis decrease at high temperatures?- Enzymes involved in photosynthesis become more effective at high temperatures.
- High temperatures increase the availability of water to the plant.
- Enzymes involved in photosynthesis can denature, reducing their effectiveness. ✓
- High temperatures increase the rate of photosynthesis.
-
- How does carbon dioxide concentration affect the rate of photosynthesis?
- it decreases the rate
- it decreases the rate after a certain point
- it has no effect
- it increases the rate until an optimum level is reached ✓
-
At carbon dioxide concentrations above the optimum, what limits the rate of photosynthesis?- light intensity ✓
- water availability ✓
- temperature ✓
- nutrient supply
- oxygen concentration
-
Worksheet
Loading worksheet ...
Presentation
Loading presentation ...
Video
Lesson Details
Key learning points
- The rate of photosynthesis depends on factors including light, chlorophyll, water, temperature and carbon dioxide.
- A factor that when in short supply slows down or limits the rate of photosynthesis is called a limiting factor.
- Increased temperature increases photosynthesis rate up to the optimum (due to increased enzyme-substrate collisions).
- Above the optimum temperature, enzymes are denatured and rate of photosynthesis decreases.
- Increased CO2 concentration increases rate of photosynthesis up to the optimum, when all enzyme active sites are full.
Common misconception
Students may mistakenly believe that only one factor can limit the rate of photosynthesis at any given time.
The lesson teaches that multiple factors, such as light intensity, carbon dioxide concentration, and temperature, can simultaneously influence the rate of photosynthesis.
Keywords
Photosynthesis - The process used by producers to make their own food via a series of chemical reactions.
Rate - A measure of how much change occurs per unit of time.
Limiting factor - A condition that when in short supply slows down or limits the rate of photosynthesis.
Enzyme - A biological catalyst that speeds up a chemical reaction without itself being used up.
Optimum - The conditions where maximum rate of reaction occurs.
+