SAC 1B revision - Enzymes Flashcards
Metabolism
All reactions that occur in a cell.
The require enzymes and many of the reactions are dependent on one another.
Anabolic reaction:
The building up of more complex molecules from simple ones.
Energy is REQUIRED and therefore the reaction is ENDERGONIC.
e.g. Photosynthesis
Catabolic reactions:
The breaking down of more complex molecules from simple ones.
Energy is PRODUCED therefore it is EXERGONIC.
e.g. Cellular respiration
Enzymes
They are made up of proteins (amino acids).
They have a tertiary structure
They are made at the ribosomes or the rough endoplasmic reticulum.
They speed up chemical reactions by lowering the activation energy.
Biological catalyst:
They speed up the rate of specific reactions by lowering the activation energy.
Activation energy
is the energy required to initiate a reaction.
Active site
they are specific spaces that are there for reactions to catalyse.
Specific substrate
the substrate is the molecule that binds to an enzyme.
Lock and Key
Enzymes bind to a substrate just like a key fits into a lock.
It has to be a perfect fit or the ‘door’ won’t open (the reaction will not occur).
Cofactor
they are a non-protein, additional component required for the functioning of some enzymes.
Control metabolic pathways
they are a series of linked reactions.
One reaction will go on to form another.
Coenzymes
an organic compound that acts with an enzyme to alter the rate of reaction.
Denaturing
high temperatures and extreme pH’s can alter the tertiary structure of an enzyme.
This means that the active site is permanently altered and therefore, the enzyme cannot bind to the substrate.
The reaction can no longer take place and the enzyme is no longer functional.
General
Enzymes are involved with the CONSTRUCTION and BREAKDOWN of biomolecules.
