What Are Limiting Factors?

A limiting factor is something that slows down the rate of photosynthesis when it is in short supply.

💡 Key Concept: If a factor is increased, the rate of photosynthesis will increase, but only up to a certain point.

The Three Main Limiting Factors

💡 Key Fact: A fourth factor, chlorophyll amount, can also limit photosynthesis if a plant lacks nutrients.

How Each Factor Affects Photosynthesis

1️. Light Intensity ☀️

✔ More light = faster photosynthesis, but only up to a point.
✔ After this, another factor (like CO₂ or temperature) becomes limiting.

2️. Carbon Dioxide Concentration 🌱

✔ More CO₂ = faster photosynthesis (as CO₂ is needed to make glucose).
✔ After a point, light or temperature becomes the limiting factor.

3️. Temperature 🌡

✔ Photosynthesis works best at 25-30°C.
✔ If too low, enzymes work too slowly.
✔ If too high, enzymes denature, stopping photosynthesis.

The Greenhouse Effect – Controlling Limiting Factors

Farmers use greenhouses to increase crop yields by:
✔ Using artificial lights to boost photosynthesis.
✔ Adding CO₂ to the air.
✔ Controlling temperature with heaters or ventilation.

💡 Why Is This Important? More photosynthesis = faster plant growth = higher crop yields = more food & profit.