L4

Question 1

What three factors determine of a chemical reaction? And how does this effect it’s rate?

Answer 1

1. Activation energy - energy that must be overcome for chemical reaction to continue
2. Concentration - substrate increases = increase reaction until enzyme hits saturation

Increase enzyme = increase rate of reaction

3. Temperature - increase temp = speed up molecule movement ; slow down = low temp

Question 2

What does activation energy mean?

Answer 2

The kinetic energy required for 2 colliding molecules to react

Question 3

How to enzymes increase the rate of reactions?

Answer 3

Lower activation energy

Question 4

How do enzymes differ from Catalyst? What do enzymes names tend to end with?

Answer 4

Enzymes = biological catalyst found w/in cells of the body

• names end in “ase”.

Question 5

Describe the characteristics of an enzyme (6)

Answer 5

• increase reaction rate (lowering activation energy)
• Not chemically altered
  Can be reused
• doesn’t change chemical reaction.
• made of protein
• regulate cellular metabolism

Question 6

Specificity

Answer 6

Each unique enzyme has one unique substrate

Question 7

Saturation

Answer 7

Maximal rate of substantiate converted to product ( reaching its max amount)

Question 8

Cofactors

Answer 8

Metals (cu+, zn+)

Question 9

Coenzymes

Answer 9

Organic molecules
- derived from water soluble vitamins (b’s)

Question 10

Function of an enzyme and its mechanism

Answer 10

Function = chemical reaction speeds up

Mechanism = decrease activation energy for Chemical reaction

Question 11

How are enzymes regulated. And why is regulation important

Answer 11

1. Allosteric regulation - regulation of enzyme by binding substrate to site other than active site
2. Covalent Modulation - (phosphorylation) adding of phosphate
3. Proteolytic cleavage - enzyme is released in an inactive form (zymogen)
4. Genetic control of synthesis - cells make enzymes that are not currently present

Question 12

Allosteric regulation

Answer 12

regulation of enzyme by binding substrate to site other than active site

Activation + inhibition

Able to turn on/off

Question 13

Covalent modulation

Answer 13

Aka phosphorylation ( adding of phosphate)

• turns protein on

Question 14

Proteolytic cleavage

Answer 14

enzyme is released in an inactive form (zymogen)

Question 15

Genetic control of synthesis

Answer 15

Cells make enzymes that are not currently present

Ex) pregnancy = lactation ( producing milk)

Males during puberty

Question 16

Isoenzyme

Answer 16

Enzyme with same active site & substrate

Question 17

How are isoenzymes the same and how are they different?

Answer 17

Same - same active site & substrate

Different - have a few different amino acids (which help distinguish which organ)

Question 18

Describe how enzymes are used in diagnosis

Answer 18

They have different amino acids therefore, if you took a sample of each and compared it to the “diseased” one you will find the correct enzyme it belongs to and organ

Question 19

Where is the defect when an enzyme is lacking/ dysfunctional?

Answer 19

End product ( excessive accumulation of intermediates)

Question 20

Significance in pH optimum? What happens at extremes?

Answer 20

Enzymes have maximum activity at specific pH

On either side of that enzyme activity deceases ( not at its optimum or favorable amount)

Question 21

Significance of Temperature optima? What happens if it’s at extremes?

Answer 21

• temperature optima = favorable temperature (98..6)

If above optima, enzymes will denature (unfold) slowing enzyme activity until fully denatured

If optima is below optima, molecules will slow down movement decreasing collision rate, therefore decreasing enzyme activity

Question 22

Explain how an enzyme can cause 2 substrates to join creating only one product

Answer 22

Substrates bind to enzyme ➡️ shape change bringing molecules closer together (electrons interact) ➡️ electrons interacting = covalent bond / new Chemical (product) formed

Question 23

Explain how an enzyme with one substrate can produce 2 products

Answer 23

Degradation- strain / breakdown of a chemical

Substrate binds to enzyme➡️ cause shape change putting stress onto covalent bond ➡️ breaking bond due to extreme stress