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I/GCSE Biology - Photosynthesis and Limiting Factors

Photosynthesis and Limiting Factors

July 8, 2021

In I/GCSE Biology, photosynthesis is commonly asked in exam!

Photosynthesis

Do you remember the previous post regarding the structure of leaves in I/GCSE Biology?

Photosynthesis is the process that plants use to create glucose.

Carbon dioxide + water ➡️  (energy from light) glucose + oxygen

  • The glucose made during photosynthesis is used by the plant for respiration. This happens all the time, but photosynthesis only happens in the light.

Adaptions for photosynthesis:

  • Leaves have a large surface area to absorb more sunlight
  • Stomata allow carbon dioxide to diffuse into the leaf
  • Also allow oxygen and water produced to diffuse out of the leaf

Limiting Factors

In I/GCSE Biology, it's also important to memorize the limiting factors in photosynthesis!

  • Low temperature, dim light and low carbon dioxide levels all limit the rate of photosynthesis.
  • We can measure these by measuring the rate pondweed gives off oxygen.

This can test the effect of:

  • Temperature, using hot and cold water baths
  • Light intensity using bright and dim lights
  • CO2 concentration by adding different amounts of sodium hydrogen carbonate to the water

And we're done with this topic! Well Done!

Drafted by Alyssa (Biology)

References:

  1. "Photosynthesis", https://gosciencegirls.com/wp-content/uploads/2021/05/PHOTOSYNTHESIS.jpg
  2. "Adaptions for photosynthesis". Photo from the internet.
  3. "Pin on Biology", https://i.pinimg.com/originals/90/08/a7/9008a7fbad99c927e44397fc283fa6ff.jpg
  4. "Limiting factors in photosynthesis", https://i.ytimg.com/vi/eFhQ32uQFiI/maxresdefault.jpg?v=5fa54c1a