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.

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!

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