Two different enzymes catalyze the same reaction and both exhibit the same Vmax. When Enzyme A was run with a 40 uM substrate, the initial rate (Vo) was 10 uM/min, and when g it was run with a 4 mM substrate, the Vo was 20 uM/min. Estimate the approximate Vmax and Km of Enzyme A. When Enzyme B was run with 80 uM substrate, the initial rate (Vo) was 10 uM per minute. Estimate the Km of Enzyme B.

a) k_m = 4.08 uM

  V_{max} = 20.07 uM/min

b) k_m = 8.16 uM

Explanation:

Given that:

For Enzyme A:

the substrate concentration [S] = 40 uM

the initial velocity rate v = 10 uM/min

when it was 4mM, v = 20 uM/min

i.e.

at 4mM = 4000 uM;

Using Michealis -menten equation;

when v = 10

∴

when v= 20

equating equation (1) and (2):

let multiply equation (1) by 100 and equation (2) by 1

4000V_{max} - 1000K_m = 4000

4000V_{max} - 20 k_m = 8000    

  0        -980k_m = 4000

k_m = 4000/-980

k_m = 4.08 uM

replacing the value of k_m into equation (1)

40{V_max } - 10(4.08) = 400

40{V_max } - 40.8 = 400

40{V_max } = 400 +  40.8

40{V_max } = 440.8

V_{max} = 440.8/40

V_{max} = 11.02 uM/min

b)

Since V_{max} of A ie equivalent to that of B; then:

V_{max} of B = 11.02 uM/min

Here;

[S] = 80  uM

V = 10 uM/min

∴

10(k_m +80) = 881.6

10k_m = 881.6  - 800

10k_m = 81.6

k_m = 81.6/10

k_m = 8.16 uM

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.