Biology Lab Exercise 6 Vocabulary

Front 1

Exercise 6

Back 1

Enzyme Activity

Front 2

Enzymes

Back 2

Biological catalysts that regulate the rate of chemical reaction.

Front 3

Catalase

Back 3

Decomposes hydrogen peroxide, a toxic compound, into water and oxygen. It is found in all living organisms other than obligate anaerobes.

Front 4

Optimum pH

Back 4

The best pH for reaction to occur.

Front 5

Know the name of the enzyme that breaks down hydrogen peroxide.

Back 5

Catalase

Front 6

What is the source of catalase for these experiments?

Back 6

Sheep Red Blood Cells

Front 7

What 2 products result from enzyme activity?

Back 7

Water and Oxygen

Front 8

Which of the products was measured in these experiments?

Back 8

oxygen gas pressure

Front 9

Know the optimum pH for enzyme activity.

Back 9

In the range of pH 6 - 8, but ph 7 is best.

Front 10

Why is the enzyme less active at very high or very low pH?

Back 10

Enzymes, like all proteins are folded into a three dimensional shape (called tertiary structure). This is determined by its amino acid sequence and the conditions of the solution it finds itself in. The acidity of a solution can affect the tertiary structure of the protein, making it more or less accessible to the substrates.

Front 11

Know the optimum temperature for enzyme activity.

Back 11

Room temperature (25 C)was best for the experiment. Most human enzymes have optimal temperatures of about 35 - 40 C (close to human body temperature). ????????????????

Front 12

Why do you see little or no gas production at low temperature?

Back 12

Particles move slower at cold temperatures. Therefore, less reactions are happening because the substrates collide with active sites less frequently.

Front 13

Why do you see little or no gas production at high temperature?

Back 13

The thermal agitation of the enzyme molecule disrupts the hydrogen bonds, ionic bonds, and other weak interactions that stabilize the active shape of the enzyme, and the protein molecules eventually denatures.

Front 14

Know the relationship between substrate concentration and reaction rate.

Back 14

The rate at which a particular amount of enzyme converts substrate to product is partly a function of the initial concentration of the substrate: The more substrate molecules that are available, the more frequently they access the active sites of the enzyme molecules. However, there is a limit to how fast the reaction can be pushed by adding more substrate to a fixed concentration of enzyme. At some point, the concentration of substrate will be high enough that all enzyme molecules have their active sites engaged. As soon as the product exits an active site, another substrate molecule enters. At this substrate concentration, the enzyme is said to be saturated, and the rate of the reaction is determined by the speed at which the active site converts substrate to product.

Front 15

What molecule is the substrate in this enzymatic reaction?

Back 15

H₂O₂, hydrogen peroxide

Front 16

What is the control in this experiment?

Back 16

0% concentration of substrate (H₂0₂)

Front 17

Is it a positive or negative control?

Back 17

Negative control, it give negative results.

Front 18

Know the relationship between enzyme concentration and reaction rate.

Back 18

When an enzyme population is saturated, the only way to increase the rate of product formation is to add more enzyme. Cells sometimes increase the rate of a reaction by producing more enzyme molecules.

Front 19

What is the control in this experiment?

Back 19

0% concentration of enzyme.

Front 20

Is it a positive or negative control?

Back 20

Negative control, it give negative results.

Front 21

Know the name and chemical formula of the inhibitor used in this experiment.

Back 21

CuSO₄, Copper Sulfate

Front 22

What is the expected result of adding this inhibitor?

Back 22

It will make the substrate either not be able to bond to the enzyme, competitive inhibition, or it will make the bond between the substrate and enzyme less effective, noncompetitive inhibitor.