Key Concepts - Week 9 - Enzymes

Question 1

Enzymes are powerful _________

Answer 1

catalysts

Question 2

All reactions pass through a _____________ on the reaction pathway

Answer 2

transition state

Question 3

Enzyme active sites bind the…?

Answer 3

transition state of the reaction more tightly than the substrate

Question 4

Enzyme active sites bind the transition state of the reaction more tightly than the substrate.
By doing so, enzymes stabilize the ___________ & lower the…?

Answer 4

transition state

activation energy of the reaction

Question 5

What are enzymes? What do they do? (4 points)

Answer 5

Question 6

What are the Two basic types of enzyme-catalysed reactions?

Answer 6

Question 7

Essentially all enzyme-catalysed reactions are_______.

Answer 7

REVERSIBLE

Question 8

Label the cofactor, catalytic site, coenzyme, apoenzyme, and holoenzyme on a drawing of an enzyme

Answer 8

Question 9

Define COFACTORS

Answer 9

are non-protein components (e.g. metal ions)

Question 10

Define COENZYMES

Answer 10

1. Organic molecules (contain Carbon)
2. Commonly vitamins or derivatives
3. Involved in catalysis such as to assist in 4. chemical group transfer
4. Often at the active site and aide recognition, attracting or repelling a substrate or product
5. If the coenzyme is tightly bound to the protein such as through covalent interaction it is known as a PROSTHETIC GROUP

Question 11

Define APOENZYME

Answer 11

is a protein without a prosthetic group (inactive)

Question 12

Define HOLOENZYME

Answer 12

Enzyme with cofactors or coenzymes attached that is ready to catalyse a reaction (active)

Question 13

Activation energies are ALWAYS _________.

Answer 13

positive

Question 14

At a higher temperature, there are less molecules required to overcome…?

Answer 14

the activation energy compared to the lower temperature.

Question 15

In addition to temperature, the pH of a reaction can also…?

Answer 15

affect the enzyme catalysed reaction.

Question 16

T/F: Substrates bind to the enzyme via weak forces (non-covalent associations)

H-bonds, van der Waals and ionic interactions
Sometimes also by hydrophobic interactions

Answer 16

True

Question 17

What are other factors of enzyme regulation?

Answer 17

Question 18

Enzymes are __________ that are essential to our cells to facilitate…?

Answer 18

proteins (or ribozymes)

reactions fast enough to sustain life

Question 19

Enzymes often has the suffix “_____” and are classified into groupings based on what chemical reactions they faciliate

Answer 19

ase

Question 20

Enzymes have ___________, they are specific and can be regulated

Answer 20

catalytic power

Question 21

The reaction rate is proportional to the concentration of reactant molecules with the transition-state energy (3 points, 2 sub points)

Answer 21

Question 22

Selectivity of an enzyme is dependent on…? Grouping of selected amino acids in the ________ structure of the protein.

Answer 22

The active site of the protein

tertiary

Question 23

Regulation occurs in a variety of ways. List them:

Answer 23

Question 24

Label the type of reversible inhibition

Answer 24