C: Cellular Control Processes

Question 1

control processes include:

Answer 1

control enzyme turnover rate
-coordination: time + sequence
-regulation: amount

Question 2

coordination:
what is it?
substrate availability?

Answer 2

-Making the right kinds of enzymes IN THE PROPER SEQUENCE AND TIME: Glucose break down for energy which Need at least 6 different enzymes which occur in 6 different steps
* ENZYMES NEEDED IN THE RIGHT ORDER

-Substrate availability: substrate isn’t available very often and the cell shouldn’t waste energy and building materials so…
-“When” Solution: Enzyme is made occasionally, not all the time

Question 3

regulation:
what is it?
substrate concentration

Answer 3

Making the right amount of enzyme
–Proper rate: Regulation deals with rate and Have enough enzymes to do the job

-Substrate concentration: If substrate concentration is very large all the time then system will Make a lot of enzymes all the time
–If the substrate concentration is low all the time then Very few enzyme molecules will be needed, because they are recycled
– “How Much” Solution: Enzyme is made in amounts that correspond to the [substrate] needed

Question 4

homeostasis:
what is it?
messengers?
methods? aka?
types of inhibitors?

Answer 4

-homeostasis is slow methods to control enzymes

–Messengers:
-Small molecules called repressors can turn down the production of new, enzyme, protein molecules. That way they are only made when necessary
-Small molecules called activators can turn up the production of new, enzyme, protein molecules

-Fast methods to control enzymes: Inhibition
-inhibitor: Molecule that attaches to the enzyme and interferes with its ability to do its job

-Types of inhibition:
– Product inhibition
– Competitive inhibition
– Allosteric inhibition: Feedback inhibition

Question 5

Regulation: production inhibition

Answer 5

Product of enzyme catalyzed reaction inhibits the enzyme from working by clogging the active site, reducing the turnover rate
* Concentration of product will fall, because it is no longer being made
* Lowered products = no clogging = increase turnover rate

Question 6

Regulation: Competitive inhibition

Answer 6

Different substrate binds to active site, preventing
normal substrate from binding, so no normal
product is made

Question 7

Regulation: Allosteric inhibition

Answer 7

-Binding of inhibitor (not substrate or product) to another {allosteric} site (not the active site)
–Changes the shape of the active site so the enzyme can no longer do its job.
**Allosteric activation is possible as well feedback inhibition

Question 8

Regulation: Feedback inhibition

Answer 8

-Products of a series of reactions allosterically bind to the first enzyme in the pathway to shut off production if product builds up
-Ex. Products of glucose break down block enzymes to stop glycolysis reactions from continuing if not necessary

Question 9

enzymes in real life: inhibitors function

Answer 9

-Enzyme inhibition is used to control disease:
– Resembling substrates/Allosteric inhibitors.
– Bacterial death due to starvation of necessary components
* Problem: Drug resistance by natural selection
» → Life properties: Evolution

Question 10

four ways to help drug resistance

Answer 10

-Stop the production of enzyme-target of drug
– Modify the enzyme-target of the drug
– Select the drug out: impermeability
– Inactivation of drug by other enzymes