Biochem Chapter 6 Mechanisms Of Enzymes

Front 1

Diffusion Controlled RXN

Back 1

A reaction that occurs with every collison between reactant molecules

Front 2

Triose Phosphate Isomerase

Back 2

catalyzes the rapid interconversion of DHAP and G3P in the glycolysis pathway

Front 3

Superoxide Dismutase as a catalyst

Back 3

Fast catalyst b/c of its negatively charged substrate is attracted to positively charged electric field near the active sit and because the reaction itself is very fast

Front 4

Superoxide Dismutase

Back 4

-Reacts wtih first thing it comes into contact with
-Does alot of damage
-Why Anti-Oxidants are so important
-Lou Gehring's less then normal Superoxide Dimutase
-concentration at any given time is very low, probability of 2 together is very low because they react slowly.

Front 5

Superoxide Dismutase catalyzes the very rapid removal of ..........

Back 5

the toxic superoxide radical anion, O2- a by product of oxidative metabolism, The enzyme catalyzes the conversion of superoxide to molecular oxygen and H2O2, which is rapidly removed by the subsequent action of enzymes suc as catalase.

Front 6

Proximity Effect

Back 6

The increase in the rate of a nonenzymatic or enzymatic reaction attributable to high effective concentrations of reactants, which result in more frequent formation of transitition states.

Front 7

Proximity Effect- observed rates

Back 7

The most restricted compound, rigid bicyclic has no rotational freedom so is therefore more likely to react because less entropy is lost during transition state.

Front 8

Lysozyme

Back 8

catalyzes the hydrolysis of polysaccharides that make up the cell walls of bacteria.
- in tears, saliva, and nasal mucus to prevent bacterial infection.
- In Egg white

Front 9

Substrate of Lysozyme

Back 9

Is a polysaccharide composed of alternating residues of N-acetyl-glucosamine and N-acetylmuramic acid connected glycosidic bonds

Front 10

Stabilizes Lysozyme

Back 10

4 disulfide bonds cross linked

Front 11

Models of Lysozyme and it's complexes can be obtained by

Back 11

X-Ray Crystallographic analysis.

Front 12

Substate binding cleft of lysozyme accommodates

Back 12

six saccharide residues at six sites.

Front 13

Two ionic amino acid residues present

Back 13

Glu-35 and Asp 52, are located close to C-1 of the distorted sugar molecule in the D binding site

Front 14

Glu-35

Back 14

is in the nonpolar region of the cleft and has a perturbed pka near 6.2

Front 15

Asp-52

Back 15

more polar enviroment, has a pka near 3.5
found in crevices

Front 16

Optimum pH of lysozyme

Back 16

5

Front 17

pH affects Enzymatic Rates

Back 17

The effect of pH on the reaction rate of an enzyme can suggest which ionizable amino acid residues are in its active site. Sensitivity to pH usually reflects an alteration in the ionizable state of one or more residues involved in catalysis and occasionally in substrate binding. Provided the enzyme in not denatured when the pH is altered, a plot of reaction velocity versus pH most often yields a bell-shaped curve.

Front 18

Diffusion controlled rxn

Back 18

A reaction that occurs with every collison between reactant molecules