Lesson 7 : Laboratory Tests for Enzymes

Question 1

Enzymes are ___________ responsible for ____________ many biological processes.

Answer 1

proteins
speeding up

Question 2

Enzymes act as _____________ by lowering the _______________ required for a reaction.

Answer 2

catalysts
activation energy

Question 3

Enzymes are also _________ in their action, it can act on one substrate or one class of related analogs of substrate because the _____________ of the enzymes complement to the __________ and _________ of the substrate.

Answer 3

specific
active site
geometry and polarity

Question 4

Factors that affect the enzyme activity such as ___________, ____________, ____________, and _______________ must be considered in characterizing the enzyme in its native form and inhibition activity of the test compound against the enzyme.

Answer 4

enzyme concentration, temperature, pH of the working buffer, and presence of the inhibitor compounds

Question 5

Reagents for Catalase Enzyme Activity

Answer 5

Hydrogen Peroxide (H2O2)
Distilled Water
Vinegar (Source of Acetic Acid)
Potato

Question 6

Reagents for Enzyme

Answer 6

Inhibition Assay
Urea Solution
Bromothymol Blue
Mercuric Chloride
Distilled Water
Urease

Question 7

What are the things we can learn from the Catalase Enzyme Activity

Answer 7

Enzyme activity of Catalase from Potato
Increase or Decrease in Surface Area
Changes in Temperature
Changes in pH

Question 8

A very common enzyme that is present in almost all organisms that are exposed to oxygen.

Answer 8

Catalase

Question 9

Catalase is also found in __________.

Answer 9

plants

Question 10

What Happens to Hydrogen Peroxide when Catalase is Added?

Answer 10

Catalase is an enzyme that catalyzes the reaction by which hydrogen peroxide is broken down to water and oxygen.

Question 11

This breaking down of hydrogen peroxide to water and oxygen is physically seen as ‘______________’ or _________________.

Answer 11

bubbling
formation of bubbles on the top of the solution

Question 12

Effect of Changes in temperature and pH to Enzymes

Answer 12

Recall that enzymes are protein in nature. Hence, the same factors that denature proteins also denature enzymes.

Question 13

Effect of Increase or Decrease in Surface Area

Answer 13

Increasing surface area also increases enzymatic activity.

Question 14

Catalase has an optimum temperature of ____. Going lower or above the optimum temperature may result in ____________ of the enzyme.

Answer 14

37C
denaturation

Question 15

If the pH level is lower than __ or higher than __, the enzyme becomes ___________ and loses its structure.

Answer 15

7, 11
denaturated

Question 16

Enzyme Inhibition Assay

In this experiment we used ___________ as the enzyme inhibitor for the enzyme ____________.

_______________ was used as the pH indicator for the solution.

Answer 16

Mercuric Chloride
urease

Bromothymol Blue

Question 17

What is Bromothymol Blue

Answer 17

This 0.1% aqueous bromothymol blue solution (also known as Bromothymol Blue)

Question 18

Bromothymol blue changes color to determine pH of a solution:

Yellow
Blue

Answer 18

Yellow - Acidic
Blue - Alkaline

Question 19

Mercury is a ____________ that has been used for centuries as a medicine and a poison.

Answer 19

heavy metal

Question 20

Mercury ions from mercuric chloride can produce its toxic effects by ____________, ____________, and _______________.

Answer 20

protein precipitation, generalized corrosive action, and enzyme inhibition

Question 21

Binding of mercury can change the ___________ of the enzyme and ___________ its activity.

Answer 21

shape
block

Question 22

What are some of the enzymes inhibited by mercury

Answer 22

urease,
acetylcholinesterase,
catalase,
dipeptidyl peptidase (CD26),
amylase,
lipase,
lactase and
glucose-6-phosphatase.

Question 23

Urea is the product of ______________ of _______________. Urease will ____________ the ___________of urea into _____________ and ______________. Ammonia has a pH of __-___-___. The formation of ammonia shifts the pH of the solution to __________.

Answer 23

decarboxylation
amino acids
catalyze the hydrolysis
ammonia and carbon dioxide
11-13
alkaline