- 161 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about 'Enzymes, cont.' - debbie

**An Image/Link below is provided (as is) to download presentation**

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

### Enzyme kinetics

### Proteolytic cleavage

Substrate Activation(catalytic mechanisms)

- Strain on substrate
- Weakens bonds
- Makes more accessible for reaction

- Acid/base catalysis
- Covalent (nucleophilic/electrophilic) catalysis

Study of reaction rates—can tell lots about reaction mechanisms

Michaelis-Menton Kinetics(saturation kinetics)

Simplifying assumptions

- No back reaction
- k3 is rate limiting
- [ES] is constant (steady state assumption)

- Km
- Measure of binding affinity (roughly)
- The lower the Km, the tighter the binding

- Vmax
- Maximum rate of enzyme
- Determined by turnover number (kcat)

How best to calculate them?

Double-reciprocal plot(Lineweaver-Burk)

Regulation

- Irreversible inhibitors—generally not natural part of cell
- Drugs and toxins
- Covalent modification
- Aspirin

- Reversible
- Substrate level regulation
- Competitive inhibitors
- Noncompetitive inhibitors
- Allosteric regulation (activators and inhibitors)
- Covalent modification (reversible)
- Proteolytic cleavage

Regulation

Reversible

- Substrate level regulation
- Competitive inhibitors
- Noncompetitive inhibitors
- Allosteric regulation (activators and inhibitors)
- Covalent modification (reversible)
- Proteolytic cleavage

Only extracellular

Download Presentation

Connecting to Server..