Biochemistry

Learn the toughest concepts covered in Biochemistry with step-by-step video tutorials and practice problems by world-class tutors

6. Enzymes and Enzyme Kinetics
1

concept

Kcat

clock
6m
Play a video:
Was this helpful ?
0
2

concept

Kcat

clock
10m
Play a video:
Was this helpful ?
0
3

example

Kcat Example 1

clock
2m
Play a video:
Was this helpful ?
0
4
Problem

To calculate the turnover number of an enzyme, you need to know:

5
Problem

If 10 μg of an enzyme (MW = 50,000 g/mol) is added to a solution containing a [substrate] 100 times greater than the Km, it catalyzes the conversion of 75 μmol of substrate into product in 3 min. What is the enzyme’s turnover #?

a) 1.25 x 105 min-1

b) 2.5 x 104 min-1

c) 1.5 x 102 min-1

d) 3.5 x 106 min-1

6

concept

Kcat

clock
3m
Play a video:
Was this helpful ?
0
7
Problem

Studies with mutated forms of an enzyme show that changing some active-site amino acids decrease the enzyme’s turnover number (kcat) but do not affect the K m of the reaction. What is the best interpretation of these results?

8
Problem

The turnover number for an enzyme is known to be 5000 min -1. From the following set of data, determine both the Km and the total amount of enzyme ET.

A) What is the Km of the enzyme?

a) 1 mM. 

b) 2 mM. 

c) 4 mM. 

d) 1000 mM.

B) What is the total amount of enzyme?