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Biological Molecules
Carbohydrates à carbon, hydrogen, oxygen
Proteins à carbon, hydrogen, oxygen, nitrogen, [sulfur]
Lipids à carbon, hydrogen, oxygen [3 fatty acids + glycerol]
Enzymes à Biological catalysts that speed up the reaction without being used up.
- Amylase à digests starch to glucose [salivary glands, small intestine, pancreas]
- Protease à digests proteins to amino acids [salivary glands, small intestine, pancreas]
- Lipase à digests lipids to fatty acids + glycerol [small intestine, pancreas]
In IGCSE biology:
Effect of Temperature on enzyme activity
- At low temperatures, enzyme substrates have very little kinetic energy.
- Too high temperatures cause enzymes to denature and the active site has changed its shape
Effect of pH level on enzyme activity.
- Enzymes have different optimum pH levels.
Transport
In IGCSE biology, you need to understand that:
- Diffusion: Net movement of particles from an area of a high concentration to an area of low concentration.
- Osmosis: Net movement of water molecules from an area of high water potential to an area of low water potential.
- Active transportà Net movement of particles from an area of low concentration to area of high concentration using energy.
[Amoeba à single celled and has high surface area to volume ratio to increase diffusion rate.]
End of this topic!
Drafted by Gina (Biology)