Regulation Of Metabolism Flashcards
In order to purify proteins, what has to occur to the cell?
It has to be split open to release the protein from the cell.
Define specific activity.
Moles of product formed per mg of protein per unit of time.
State six methods to study metabolism?
- Subcellular fractionation.
- In vivo: use of radioisotopes.
- Purification.
- Amino acid sequence (Edman degradation).
- Location (using antibodies).
- 3D structure: X-Ray crystallography.
Define homeostasis.
Maintaining a constant internal environment.
The activity of enzymes has to be regulated so that metabolic pathways function when required. Why is this?
To avoid wasting energy.
State four features of allosteric control as a regulatory strategy.
- Distinct regulatory sites.
- Multiple functional sites.
- Activity at one site affects other sites (cooperativity).
- Information transducers (feedback mechanisms).
State three features of multiple forms of enzymes as a regulatory strategy.
- Isoenzymes - Slightly different in structure and have different Km and Vmax values.
- Different tissue or organelle or at different development stage.
- Fine-tuning metabolism.
State four features of covalent modifications as a regulatory strategy.
- Most of them are reversible.
- Activation/inhibition through phosphorylation/dephosphorylation which is an irreversible reaction.
- Localisation.
- Degradation.
State two features of proteolytic activation as a regulatory strategy.
- Zymogen or proenzyme.
2. Occurs just once.
Give three examples of proteolytic activation as a regulatory strategy.
- Blood clotting.
- Digestive enzymes.
- Programmed cell death.
What are two regulatory strategies?
- Control of the amount of enzyme present.
2. Control of the activity of the enzyme present.
