Enzymes/proteins Flashcards
What make up proteins?
Amino acids
What is the structure of an amino acid?
Central carbon, amino group, carboxyl group, hydrogen atom and r group
What’s the chemical symbol for an amino group?
NH2
What’s the chemical symbol for a carboxyl group?
COOH
What do amino acids join to make?
Do peptide or polypeptide
By what reaction do amino acids join to form a dipeptide?
Condensation reaction
What’s the bond between amino acids?
Peptide bond between amino and carboxyl group
How can peptide bonds be broken?
By hydrolysis reaction
What’s the primary structure of a protein?
Sequence of amino acids in a polypeptide chain
What’s the secondary structure of a protein?
The way the chain of amino acids of the polypeptide chain is folded and held by hydrogen bonds between NH group and CO group
What’s the tertiary structure of a protein?
Way the whole molecule is folded and held by ionic and disulphides bonds
What’s the quaternary structure of a protein?
Number of polypeptide chains linked together
What’s the test for a protein?
- add biuret
- turns purple
What are enzymes?
Globular proteins, biological catalysts
What do enzymes do?
Speed up reactions and lower the activation energy needed to start reactions by weakening bonds when enzyme substrate complex is formed
What is an active site?
Place where substrate binds to
What does it mean that active sites are specific shapes?
Only substrates that are the right shape will fit into the active site and form enzyme substrate complexes
What is the lock and key model?
Active Site does not change shape it’s fixed and is complementary to the substrate
What is the induced fit model?
Active site is not complementary; active site changes shape slightly when substrate binds to it
What happens if the temp is too high for the enzyme?
Enzyme becomes denatured and the hydrogen bonds are broken meaning the shape of the active site changes
What is the effect of the active site changing shape?
Fewer enzyme substrate complexes formed
What is competitive inhibition?
Inhibitor is a similar shape to the substrate meaning it binds to the active site but prevents substrate binding so fewer enzyme substrate complexes formed
What is non-competitive inhibition?
Inhibitor attaches to the enzyme so the shape of the active site changes so the substrate is no longer complementary so fewer enzyme substrate complexes formed
