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Flashcards in Enzymes Lab Deck (28)
1

ENZYMES

are globular proteins that catalyze reactions without being consumed themselves

2

Why are enzymes essential to life

Because they allow chemical reactions to occur rapidly and efficiently without having to increase the temperature in the system

3

Each reaction is catalyzed by

its own unique/ specific enzyme

4

SUBSTRATE

is a REACTANT acted upon by an enzyme is called the SUBSTRATE of that enzyme.

5

What does the activity or specific function of an enzyme dependent on

it depend on its 3D shape ( tertiary structure)

6

Generally, How is the name of an enzyme formed

by addidding " ase" to the name of its substrate

7

ACTIVE SITES

An enzyme molecule contains one more active sites where the SUBSTRATE fits

8

DENATURED

The shape of the enzyme is altered- it no longer is functional

9

EQUATION OF ENZYMATIC REACTIONS

ENZYME + SUBSTRATE ENZYME SUBSTRATE COMPLEX -----> ENZYME + PRODUCT

10

The variable that remains unchanged in a enzymatic ration is

THE ENZYME

11

What happens to the enzyme at the end of a reaction

The product is released and the enzyme returns to it original shape

12

Since all enzymes speed up the conversion of some substances(SUBSTRATE) into a product. How we study the activity of the enzyme

by detecting production of the product ( since only THAT enzyme can cause THAT PRODUCT to be produced

13

Why do some plants and vegetables turn burn if peeled or sliced

It is due to the formation of a class of compounds called QUINONES by the damaged plant.

14

The purpose of QUINONES in potatoes ( for example)

They protect the interior of the potato from invasion by soil microorganisms if the skin of the potato is damaged.

Molecules of quinones collect in the area of the damage and form a brown patch that
1. seals the break
2. is toxic to microorganisms

15

How does QUINONES protect the plant

Molecules of quinones collect in the area of the damage and form a brown patch that
1. seals the break
2. is toxic to microorganisms

16

High concentration of QUINONES is also toxic to plant cells. What mechanism do plants have that make quinone only after the plant skin is damaged.

In addition to cellulose the cell walls also contain CATECHOL

17

in its chemically reduced form ( gained electron) what does CATECHOL look like

It is colorless

18

What happens to CATECHOL in the presence of oxygen

It will oxidize to QUINONE

19

What is the purpose of POLYPHENOL OXIDASE (PPO)

It is an enzyme that catalyses the oxidization of CATECHOL to QUINONES

20

How does PPO work

1.In an undamaged potato PPO remains inside the cells (in the cytoplasm) with the CATECHOL outside.

2. When the potato cells are damaged the cytoplasm leaks out, allowing the PPO to come in contact with the CATECHOL on the outside and catalyze its conversion to QUINONE

21

What is the equation for the QUINONE PRODUCT

PPO( enzyme) + CATECHOL( substrate) ENZYME- SUBSTRATE COMPLEX ---> PPO (enzyme) + QUINONE ( product/ brown)

22

How can the activity of any enzyme be measured

by detecting the product of the reaction catalyzed by the enzyme

23

QUINONE is a yellow/ brown liquid, its formation indicates

a reaction has occurred. PPO catalyzed CATECHOl to produce QUINONE

24

Why is QUINONE in its entirety darker than its individual molecules that are a faint copper colored molecule

A solution of QUINONE is proportional to its concentration. The darker the solution, the more product present

25

In the experiment why are the potatoes blended

to open up lots of potato cells

26

Why is the blended potato poured through 4 layers of cheese cloth

To remove most of the starch

27

The extract turns brown why

1.once the cells are broken the PPO comes in contact with the CATECHOL and become QUINONE a brown color.

2. The CATECHOL is used up in the solution to make QUINONE but soon after this product is made PPO IS free to catalyze waiting for more CATECHOL

28

Why does increasing the amount of PPO not increase the rate of the reaction

There are specific amounts of active sites per substrate. Adding more PPO will not make a difference unless more substrate is added