Control of metabolic pathways Flashcards
What is meant by cell metabolism?
All of the integrated enzyme-controlled reactions within a cell
What is a catabolic pathway?
A pathway which releases energy and involves breaking large complex molecules into small simple molecules.
What is an anabolic pathway?
A pathway which requires energy and involves building up small simple molecules into large complex molecules.
Why do membrane bound compartments help keep reaction rates high?
Create high surface area: volume ratios and keeps high concentrations of substrates
What are some of the roles of proteins in membranes?
Pores, pumps, enzymes
How are metabolic pathways controlled?
Presence, absence or activity of enzymes in the pathways
What is meant by induced fit model of enzyme action?
The active site changes shape slightly to fit more closely around the substrate.
What has a high affinity for the active site of an enzyme?
The substrate
What is a multi-enzyme complex?
A group of enzymes working together.
What is a competitive inhibitor?
Same shape as active site of enzyme, competes with substrate.
What is a non-competitive inhibitor?
Binds to enzyme away from active site, changes shape of active site.
What is feedback inhibition?
When the end-product of a metabolic pathway inhibits an earlier enzyme.
How can competitive inhibition be overcome?
By increasing substrate concentration
What can happen if the end product of a reaction gets high?
The reaction can reverse.
