Proteins And Enzymes

Question 1

Explain how a competitive inhibitor works

Answer 1

•Inhibitor is a similar shape to substrate
•Inhibitor binds to the active site
•Fewer enzyme_substrate complexes because less substrate can bind
•So less (named product) is produced
~Inhibition can be overcome by adding more substrate/ max product will eventually form

Question 2

Explain how a non-competitive inhibitor works

Answer 2

•Inhibitor is not a similar shape to substrate
•Inhibitor binds to allosteric site
•Changes the shape of active site so no longer complementary to substrate
•Fewer enzyme-substrate complexes as substrate cannot bind
•Less named product formed
~Inhibition cannot be overcome by adding more substrate/max product will never be produced

Question 3

Describe how a peptide bond is formed between two amino acids

Answer 3

•Condensation
•Between amine and carboxyl groups of separate amino acids
•Forming peptide bond between amino acids

Question 4

What is the primary structure of a protein?

Answer 4

Number and sequence of amino acids (that are joined by peptide bonds from condensation reactions)

Question 5

What is the secondary structure of a protein?

Answer 5

Hydrogen bonding between amino acids form beta pleated sheets or alpha helix

Question 6

What is the tertiary structure of a protein?

Answer 6

The 3D shape determined by the placement of ionic,hydrogen and disulphide bonds between different R groups from amino acids in the polypeptide chain

Question 7

What is the quaternary structure of a protein?

Answer 7

Two or more polypeptide chains bonded together

Question 8

What happens if you change the sequence or number of amino acids?

Answer 8

Different sequence of amino acids forms ionic/hydrogen/disulphide bonds, between R groups, in different places