Bio Lab 1210 Enzymes

Front 1

active site

Back 1

the site of attachment and the surrounding parts of the enzyme that stress the substrate’s bonds

Front 2

biocatalyst

Back 2

they accelerate metabolic reactions to biologically useful rates.

they are not used in the chemical reaction

(lower activation energy)

Front 3

Catalase

Back 3

an enzyme in plants and animals that speeds the breakdown of hydrogen peroxide, toxic to cells

Front 4

catechol oxidase

Back 4

a plant enzyme that converts catechol to benzoquinone

Front 5

what is the source of catechol oxidase in this experiment

Back 5

the potato extract

Front 6

what happens when fruit is bruised

Back 6

injured cells release catechol and catechol oxidase which react to form benzoquinone a brownish product.

Front 7

What does benzoquinone do

Back 7

prevents decay in damaged cells

Front 8

competitive inhibition

Back 8

when molecules are structurally similar to the substrate that competes for the a position at the active site of an enzyme. Example hydroxylamine and hydrogen peroxide competing for peroxidase. And coffee stirs in toothpickase

Front 9

denature

Back 9

structural changes in the enzyme that destroys its effectiveness by altering the active site and slowing down the reaction

Front 10

Causes of denature

Back 10

extreme temperature, extreme pH, salt concentration, or any other environmental condition that alters protein structure

Front 11

energy of activation

Back 11

energy required to form the transition state. It is lowered by the enzyme

Front 12

enzyme

Back 12

biological catalysts. They catalyze reactions by lowering activation energy

Front 13

enzyme substrate complex

Back 13

enzyme and substrate together. It stresses or distorts chemical bonds to form a transition state

Front 14

optimal condition

Back 14

the range of values for environmental factors in which the enzyme functions best

Front 15

peroxidase

Back 15

an enzyme in plants (such as turnips) and some bacteria that turns hydrogen peroxide into water and O2. It is a large protein with a reactive iron atom at its active site

Front 16

substrate

Back 16

thing enzyme binds to. The reacting molecules

Front 17

transition state

Back 17

the substrate becomes more reactive and the metabolic reaction accelerates. Requires activation energy

Front 18

During the procedure using the potato extract demonstrating the affect of temperature, what was the enzyme studied?

Back 18

Catechol oxidase

Front 19

During the procedure using the meat extract demonstrating the affect of pH, what was the substrate of the reaction?

Back 19

Hydrogen peroxide

Front 20

During the procedure using the turnip extract demonstrating the affect of inhibitors, what was the enzyme studied?

Back 20

peroxidase

Front 21

Where does the energy for a reaction come from

Back 21

energy comes form the environment- it may take a long time

Front 22

How do enzymes work?

Back 22

enzymes destabilize the bond on order to lower activation energy

the complex distorts chemical bonds to a transition state in which substrate becomes more reactive and metabolic reactions accelerates.

Front 23

Adding catalyst speed up the reaction because

Back 23

at a given temperature more molecules have sufficient energy to go over the "energy hump" because the activation energy is lowered

Front 24

The enzyme lock and key model explains the exquisite specificity of enzymes because

Back 24

the 3D shape of the enzyme is compatible with the 3D shape of the substrate

the 3D shape of the active site holds specific reactive parts of the protein next to specific reactive parts of the substrate

Front 25

Why does heat increase the rate of most reactions

Back 25

faster molecular motion, increase probability that enzymes molecules will contact substrate

Front 26

How does the rate change with temperture

Back 26

rate of chemical reaction doubles with a 10 degree C in temperature

Front 27

why do Competitive inhibitors work

Back 27

they usually have a greater strength than the substrate

Front 28

example of enzyme inhibitors

Back 28

anti depressant drugs

like Vioxx

Front 29

Amylase

Back 29

breaks foe starch into simple sugar

use I2 to detect when starch disappears

Front 30

name a human organ that secretes enzymes

Back 30

pancreas

salivary glands

Front 31

pH is a measure of

Back 31

H+ concentration

Front 32

You have probably observed the enzyme-driven reaction in whichcatechol, a compound often found in plant tissue, is converted intobenzoquinone, which is a brown product. Where would you have seen thisreaction outside of the lab?

Back 32

When you cut up fruit, such as apples, they turn brown when this reaction occurs. Catechol oxidase (the enzyme) is exposed to oxygen, it converts catechol to benzoquinone. This is when you see that brown color occur.

Front 33

copper effects on amylase

Back 33

non-competitive inhibitor

It is a non-competitive inhibitorbecause it does not look similar to the substrate. Therefore, it is not competing withthe substrate for the active site of the enzyme like a competitive inhibitor does.Instead, it reduces enzyme activity by altering the ability of the active site to bind thesubstrate. You can tell that copper is an inhibitor because the enzyme activity in thecopper treated test tubes is slower than the control test tube containing only distilledwater, buffer, enzyme and starch.