September 20, 2022
In this chapter of AS/A-level Biology, we will study Protein Structure & Enzymes.
Proteins Structure
Mutation result of a non-functional protein. [4]
- A mutation causes a change in the sequence of amino acids
- The R groups will be different
- The bonding will be different
- This will change the folding into it’s tertiary structure so the 3D shape will be different under the AS/A-level Biology curriculum.
Compare and contrast the molecular structures of globular and fibrous proteins [5]
- In AS/A-level Biology, They are both chains of amino acids that are joined by peptide bonds
- They both contain hydrogen and ionic bonds and disulphide bridges
- In globular proteins they hydrophilic group is outside but in fibrous proteins they have hydrophobic groups on their outside
- Globular proteins are folded into compact shapes where as fibrous proteins are long chains
- globular have tertiary or quaternary structures whereas fibrous have little or no tertiary structure
Enzyme
What are enzymes?
- Temperature dependant
- Biological catalyst
- Proteins
What is meant by the term ‘biological catalyst’ in AS/A-level Biology? [4]
- Enzymes reduce activation energy
- Speed up the rate of reaction
- They do not get used up
- Produced by cells
What is meant by the term ‘activation energy’ ? [2]
- When it comes to AS/A-level Biology, it is the energy needed for a reaction to occur
- By increasing the number of collisions between enzymes and substrate
Why is it necessary to measure the initial rate of reaction? [3]
- To ensure that substrate is not the limiting factor
- It is the highest at this point
- The substrate gets used up in the reaction
Now you understand more about proteins and enzyme! Congratulations~