Chapter 5 Enzyme Notes From Lipponcotts

Front 1

Cofactor vs Coenzyme

Back 1

Cofactor = non protein

Conezyme = organic molecule

Front 2

Coenzymes vs Cosubstrates

Back 2

Cosubstrates only transiently associate with an enzyme

They dissociate in an altered state

Front 3

Coenzymes frequently derived from what?

Back 3

Vitamins

Front 4

Enzymes are usually located where?

Back 4

In specific organelles within the cells.

Serves to isolate the substrate or product from competing reactions

Front 5

Enzymes work how?

Back 5

By providing an alternate reaction pathway with a lower free energy of activation

Front 6

Transition state stabilization option for enzyme to do its work how does this work?

Back 6

Active site of enzyme often acts as flexible template that binds the substrate in a geometric structure resembling the activated transition state of the molecule

By stabilizing the substrate in its transition state, the enzyme greatly increases the concentration of the reactive intermediate that can be converted to product and thus accelerates the reaction

Front 7

Mechanisms by which enzymes work

Back 7

1. Transition State Stabilization

2. Catalytic groups that enhance the probablity that the transition state is formed

3. Visualization of the transition state

Front 8

Maximal Velocity

Back 8

The rate of velocity of reaction (v) is teh number of substrate molecules converted to product per unit time. Enzyme rate of an enzymatic reaction increases with substrate concentration until maximal velocity Vmax.

Front 9

Leveling off of the reaction rate curve at high substrate concentration reflects what?

Back 9

The saturation with substrate of all available binding sites on the enzyme molecules present

Front 10

Allosteric enzymes show what kind of curve?

Back 10

Sigmoidal (S Shaped)

Front 11

Enzymes following Michaelis Menten Kinetics show what type of curve?

Back 11

Hyperbolic (like myoglobin O2 dissociation)

Front 12

Effect of pH on enzyme denaturization

Back 12

Extremes of pH can lead to denaturization of the enzyme, because structure of the catlytically active protein molecule depends on the ionic character of the amino acid side chains

Front 13

What is the meaning of a Zero order reaction for enzyme/substrates according to Michalies Menten?

Back 13

It means the rate is constant and INDEPENDENT of substrate concentration

Front 14

What is the meaning of First order Rctn according to M+M

Back 14

rate is proportional to substrate concentration