cofactors

Question 1

The need of microorganisms for trace elements arises from their roles as cofactors for enzymes: Give some examples

Answer 1

Iron, copper, magnesium, manganese, zinc, cobalt, selenium, etc

Question 2

Participate in precise functions between the enzyme and substrate:
- Help bring the active site and substrate close together
- Participate directly in chemical reactions with the enzyme-substrate complex

Answer 2

enzymes

Question 3

Organic compounds that work in conjunction with an apoenzyme

Answer 3

coenzymes

Question 4

General function of coenzymes

Answer 4

• remove a chemical group from one substrate molecule and add it to another substrate molecule
• Carry and transfer hydrogen atoms, electrons, carbon dioxide, and amino groups

Question 5

coenymes are derived from

Answer 5

vitamins

Question 6

:transfer electrons from one substrate to another, dehydrogenases transfer a hydrogen from one compound to another

Answer 6

Oxidoreductases

Question 7

Always present in relatively constant amounts regardless of substrate

Answer 7

constitutive enzymes

Question 8

Production is turned on (induced) or turned off(repressed) in responded to changes in concentration of the substrate

Answer 8

regulated enzymes

Question 9

Activity of enzymes influenced by the cell’s environment such as

Answer 9

• Natural temperature, pH, osmotic pressure

-Changes in the normal conditions cause enzymes to be unstable or labile.

Question 10

What happens to the bonds during denaturation, what does it cause and prevent?

Answer 10

-Weak bonds that maintain the native shape of the apoenzyme are broken

• This causes disruption of the enzyme’s shape

-Prevents the substrate from attaching to the active site

Question 11

What does competitive inhibition do to an enzyme and site?

Answer 11

• Inhibits enzyme activity by supplying a molecule that resembles the enzyme’s normal substrate

-“Mimic” occupies the active site, preventing the actual substrate from binding.

Question 12

What happens in noncompetitive inhibition

Answer 12

-Enzymes have two binding sites: the active site and a regulatory site.
-Molecules bind to the regulatory site.
-Slows down enzymatic activity once a certain concentration of product is reached.

Question 13

Do enzymes last for a long time

Answer 13

Enzymes do not last indefinitely; some wear out, some are degraded deliberately, and some are diluted with each cell division
Replacement of enzymes can be regulated according to cell demand

Question 14

Genetic apparatus responsible for replacing enzymes is repressed
Response time is longer than for feedback inhibition

Answer 14

Enzyme repression

Question 15

Enzymes appear (are induced) only when suitable substrates are present

Answer 15

enzyme induction