Bioenergetics Biology Paper 1 Higher

Bioenergetics Revision Notes

Photosynthesis: 6H2O+6CO2 -> C6H12O6+6O2

Epidermis tissue: secretes a waxy cuticle which waterproofs the plant but lets more light in for photosynthesis, can be described as translucent. 

Palisade Mesophyll Tissue: contains many chloroplasts to maximise the rate of photosynthesis and some air space for gas diffusion to occur.

Spongy Mesophyll Tissue: contains some chloroplasts and lots of air space to maximise gas diffusion.

Guard Cells: they are located at the underside of the leaf and control stomata openings as well as containing some chloroplasts for photosynthesis. 

Stomata: opening at the bottom of the leaf, where gas diffusion occurs and water is also lost through transpiration.

Limiting Factors

In order for photosynthesis to happen; light, CO2 and heat are needed. As light intensity increases, the rate of photosynthesis increases and the same happens for CO2 concentration. However, when experiments are conducted, it is shown that some factors can affect the increase of the rate of photosynthesis (despite light intensity and CO2 concentration still increasing.) These factors are called Limiting Factors.  These seem to suggest that all factors need to be in perfect proportion in order to maximise the rate of photosynthesis. For temperature, on the other hand, it is rather different. If the…