B1.2
What happens in cells

Description of DNA
-made up of two strands that form a DOUBLE HELIX.
-have complimentary base pair of A and T, C and G.
-has strong covalent bonds and a sugar phosphate backbone.

Genes
-these are small sections of DNA
-they code for a specific sequence of amino acids to make a specific protein.
-they can be copied and can be passed on to the next generation.

Enzymes
-each enzyme has a specific active sit so it can bond to a specific substrate or substrates.

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Amino acids.
-amino acid chains can form enzymes
-they have strong forces to hold it together and create its shape.
High temperatures break the forces. Causing it to change shape.

Affects of pH
-each enzyme works best at a certain pH.
-e.g enzymes in digestive system work best at 7.0pH-7.4pH.
-amino acids have charges and changing pH affects the charge.
- cashing it’s shape to change

Substrate concentration.
-enzymes work best when there are plenty of substrates available. Increased concentration= increased enzyme activity.
Enzyme concentration.
- Increased activity= more substrates broken down.

Rate of reaction
=amount of reactant used or product formed divided by time taken
- the time it takes for a reaction to take place.
-every reaction has different speeds.