Enzymes

Question 1

Enzyme is

Answer 1

A type of protein that is A biological catalyst that speeds up the rate of reaction but is not used up.

Question 2

Enzymes are specific

Answer 2

Only attach onto one type of substante

Question 3

Enzymes can

Answer 3

Break down a large substate into smaller molecules. Or help smaller chemicals join.

Question 4

Starch +

Answer 4

Amylase= glucose
Starch = polymer
Amylase = enzymes
Glucose= monomers

Question 5

Glycogen +

Answer 5

Glucase = glucose

Glycogen = polymer
Glucase= Enzymes
Glucose = monomers

Question 6

Protein +

Answer 6

Protease = amino acids

Protein= polymer
Protease = enzymes
Amino acids = monomers

Question 7

Lipids +

Answer 7

Lipase = glycerol and fatty acids

Lipids= Polymer
Lipase= Enzymes
Glycerol and fatty acids= Monomers

Question 8

Substate

Answer 8

A molecule that is changed in a reaction. Will fit into an active site of the enzyme. Must be complimentary.

Question 9

Active site

Answer 9

The part the substrate joins to the enzymes

Question 10

Lock and key model

Answer 10

Substrate fits into the enzymes just like a key fits into a lock and make it I into products.

Question 11

Metabolic reactions

Answer 11

Useful chemical reactions in the body.

Question 12

Temperature on enzymes: high

Answer 12

Higher temperature increases the kinetic energy of the particles and enzymes so there is a greater number of collisions and a higher reaction rate. Temperature too high and enzymes denature.

Question 13

Denaturing

Answer 13

Changes the shape of the active site because the bonds holding the enzyme together break and can no longer react so it stops. It is irreversible, can not function.

Question 14

Temperature of enzymes: cold

Answer 14

Less kinetic energy for movement of particles and enzymes, less collisions and slow reaction rate. Do not denature at low temperatures so will function again.

Question 15

Optimum temperature

Answer 15

Is the temperature at which the collisions rate is the greatest, work best at this temperature

Question 16

Practical : how temperature affects enzymes activity

Answer 16

Watch a video

1)
The enzyme catalase catalyses the breakdown
of hydrogen peroxide into water and oxugen.
2) You can collect the oxygen and measure
how much is produced in a set time.
3) Use a pipette to add a set
hydrogen peroxide to a boilins tube.
Put the tube in a water bath at 10 °C.
4) Set up the rest of the apparatus as shown.
Add a source of catalase (e.g. 1 cm}
of potato) to the hydrogen peroxide
and quickly attach the bung.
5) Record how much oxygen is produced in the first minute. Repeat three times and calculate the mean.
6) Repeat at 20 °C, 30 °C and 40 °C.
7) Control any variables (e.g. pH, the potato used, the size of potato pieces, etc.) to make it a fair test.

Question 17

Enzymes ph

Answer 17

Enzymes work at an optimum ph. Too high or two low the active site will denature.

Question 18

Practical: investigate how enzymes activity can affect changes in ph

Answer 18

Watch a video

1)You can adapt these experiments to investigate the effect of pH on enzyme activity.
2)
Follow the same method, but add a buffer solution with a different pH level to a series of
different tubes containing the enzyme-substrate mixture.
3) As before, control any variables
- use the water bath to keep the temperature of the reaction
mixture the same for each pH, and make sure volumes and concentrations are kept the same.