Energy transfers between organisms

• leafs have a large surface area that absorbs as much sunlight as possible
• as arrangement of leafs on the plant that minimises overlapping and so avoids the shadowing of one leaf to another
• leaves are thin so there is a short diffusion distance
• leaves have a transparent cuticle and epidermis that let light through to the mesophyll cells
• leaves are packed with chloroplasts that collect sunlight
• leaves have numerous stomata for gas exchange
• leaves have many air spaces to allow rapid diffusion in the gas exchange of CO2 and O2
• in leaves there is a network of xylem vessels that bring water to the leaf and phloem that carry sugars away
• light dependent reaction occurs in the thylakoid membrane of chloroplasts
• light independent reaction occurs in the stroma of the chloroplasts
• Photoionisation: light energy is absorbed by the chlorophyll and this excites the electrons causing them to jump up a level of energy ignorer for them to leave the chlorophyll
• limiting factor: something that determines the maximum rate of reaction even if the other factors change to become more favourable
• lipids and proteins can also be used as alternative respiratory substrates
• lipids are broken down into glycerol and fatty acids. The glycerol is phosphorylated and converted to triode phosphate which enters the glycolysis pathway and the into the Krebs cycle. The fact acid is broken down into 2 carbon fragments which are converted to acetyl co a which then enters the Krebs cycle.