Enzymes Pt 1 Flashcards
What is any substance that binds to a protein non covalently called?
They are called ligands
How can a binding site be formed to join a ligand?
The AA side chains form a cavity (like lock and key site)
What are enzymes?
Most are proteins with a globular shape and responsible for nearly all chemical equation within a cell
Main function of enzyme
A biological catalyst that speeds up specific reactions by binding to ligands and converting them to products
What is a ligand also known as?
Substrate
Do enzymes work in chains with other enzymes or not?
Enzymes usually work in tandem and only small amounts are required
Are enzymes specific?
Enzymes are specific as they catalyse one type of reaction and grouped into functional classes such as hydrolase or protease
What do proteolytic enzymes do?
Hydrolyse peptide bonds in protein
Do enzymes recognise stereochemistry?
Yes they do for example:
L-amino acid oxidase will only go for L amino acids
DNA polymerase is a very specific enzyme, what is the error rate of one wrong nucleotide?
One in 10^8 base pairs during replication of DNA
What do lysozyme break?
Breaks polysaccharide chains in cell walls of bacteria via hydrolysis
What is the part of the enzyme called that binds to substrate?
And what does lysozyme active site hold?
Active site
long groove holds polysaccharide chain
What is the lock and key theory and how did it change?
1894 Fischer believed the active site would match with a substrate perfectly however induced fit in 1958 by Koshland says the active site shape changes while binding
Can exams force energetically unfavourable reactions
No enzymes cannot force energetically unfavourable reactions and do not alter equilibrium of reaction
How do enzymes catalyse reactions (activation energy)?
They lower activation energy required
However cannot change the change in gibbs free energy
