Lesson 10 : EXTRACTION AND EFFECTS OF PH AND TEMPERATURE

Question 1

protein polymers that catalyze chemical reactions to maintain operating rate to sustain life.

Answer 1

Enzymes

Question 2

a substance the enzymes act on to produce a final product

Answer 2

Substrate

Question 3

Factors affecting enzymes

Answer 3

substrate and enzyme concentration, pH, temperature, and presence of inhibitor.

Question 4

proposes a specific substrate for a specific enzyme shape.

Answer 4

Lock & Key Model

Question 5

proposes that in order to achieve optimal binding upon conformational shape changes of the enzyme and substrate.

Answer 5

Induced Fit Model

Question 6

optimal temperature for peak enzyme function is at _______; average: _______. If temperature exceeds, enzymes become _________.

Answer 6

35 - 40C
37C
denatured

Question 7

optimal pH for peak enzyme function is at ___________.

Answer 7

neutral pH: 7

Question 8

EXTRACTION OF INVERTASE FROM YEAST

● Weigh _____ of ________. Dissolve in ___________
● Let the solution stand for ________ at ____________
● Decant the supernatant if _________ occurs/ Dilute the supernatant to _________ using distilled water
● The resultant supernatant will be used as __________ in the succeeding experiments.

Answer 8

10g of baker’s yeast
30mL of 0.1M NaHCO3

24 hours
room temperature

sedimentation
1:100

enzyme solution

Question 9

What is the objective of extraction of invertase from yeast

Answer 9

To isolate invertase from yeast

Question 10

__________ is the enzyme produced by ___________ that hydrolyzes the glycosidic bond of sucrose producing ___________ and ________.

Answer 10

Invertase
Saccharomyces cerevisiae
glucose and fructose

Question 11

PREPARATION OF DENATURED INVERTASE

● Incubate ______ of __________ in ______ for ___________.
● Let the solution cool
● Collect only ___________ if __________ occurs. Resultant supernatant is used as _________________ in succeeding experiments.

Answer 11

25 mL of enzyme stock solution
boiling water bath for 10 minutes.

supernatants
frothing
denatured enzyme stock solution

Question 12

EFFECTS OF TEMPERATURE

● Set up __,__,__,__,__,__ and __ water baths
● Prepare six test tubes with __, __, and __ of __, __ . Incubate test tubes separately for _____ in each water bath
● Add ____ to the tubes, incubate test tubes for another ______
● Add ___ of ____. Immerse test tubes in a ___ water bath for ____ to develop a characteristic _____ color.
● Cool test tubes in an ice water bath. Add ____ of ___ to each tube. Mix well.
● Prepare another test tube for the reagent blank containing ____, ___, ___, and ___, ____. Incubate for _____ at ________.
● Repeat steps 4-5
● Measure the absorbance at _____
● Determine the amount of invert sugar produced in each test tube reaction using the invert sugar standard curve constructed in the first experiment.
● Plot the temperature against the amount of the invert sugar

Answer 12

20°C, 30°C, 40°C, 50°C, 60°C,70°C, and 90°C

1mL 0.03M sucrose, 1.4mL distilled water, and 0.5 mL of 0.05M acetate buffer, pH 4.7
5 minutes

0.1mL enzyme solution
5 minutes

2mL of DNS reagent
95°C
10 minutes
red-brown

5mL of distilled water

0.1mL of denatured enzyme, 1mL of the 0.03M sucrose, 1.4mL of distilled water, and 0.5mL of the 0.05M acetate buffer solution, pH 4.7
5 minutes
room temperature

540 nm

Question 13

PROCEDURE: EFFECTS OF PH

● Prepare ___ numbered test tubes. Add ___ of appropriate ________ as described. Label accordingly.
● To each test tube, add _______ and ________. Mix thoroughly. Incubate all tubes in ___________ for _______
● Add ____ of _______ and incubate the reaction mixture in a ________ for ________
● Add _____ of ______. Immerse the test tube in a __________ for __________ to develop a characteristic __________ color
● Cool test tubes in an ice water bath. Add _____ of ______ to each tube. Mix well.
● Prepare another set of six test tubes for the reagent blank, each containing _____ of _____, ____, and ________. Mix thoroughly. Incubate tubes in ______ for _______
● Repeat steps 3-5
● Measure the absorbance at _________
● Determine the amount of invert sugar produced in each test tube reaction using the invert sugar standard curve constructed in the first experiment.
● Plot the pH against the amount of the invert sugar

Answer 13

six
0.5 mL
0.1M buffer solution

0.10mL enzyme solution
1.4mL of distilled water
60°C water bath
5 minutes

1mL
0.03M sucrose
60 °C water bath
5 minutes

2mL
DNS reagent
boiling water bath
10 minutes
red-brown

5mL of distilled water

0.10mL of denatured enzymes, 1.4mL distilled water, and 0.5mL of buffer.
60°C water bath
5 minutes

540 nm

Question 14

EFFECTS OF PH & TEMPERATURE ON INVERTASE OBJECTIVE

Answer 14

To determine invertase activity in varying pH and temperature using spectroscopy.

Question 15

study of absorption and emission of light.

Answer 15

Spectroscopy

Question 16

an instrument measuring the amount of light that a sample absorbs.

Answer 16

Spectrophotometer

Question 17

Spectrophotometer measures a substance using the principle of ________ which measures ___________ by its _____, ________ and ___________.

Answer 17

Beer-Lambert Law
absorbance of the substance
light absorptivity, concentration and optical path length

Question 18

reacts with a reducing sugar from the hydrolysis of invertase

Answer 18

DNS reagent with heat

Question 19

______, a product of DNS and a reducing sugar = ________ color detected at _____

Answer 19

ANSA
red-brow
540 nm

Question 20

amount and activity of reducing sugar directly proportional to activity of invertase

Answer 20

Absorbance of light

Question 21

Most enzymes are __________ that speed up chemical reactions. Some enzymes are RNA catalysts known as __________. Enzymes work by ____________

Answer 21

protein-based catalysts
Ribozymes
lowering the activation energy.

Question 22

Enzymes have an ________ with a unique __________ that is ______for the _________ that it binds with.

Answer 22

active site
3D shape
specific
substrate

Question 23

Factors that affect enzyme activity include

Answer 23

pH, temperature, concentration, inhibitors & activators

Question 24

○ _________- include inorganic metal ions.
○ __________ -include organic molecules like vitamins.

Answer 24

Cofactors
Coenzymes

Question 25

pH, temperature, concentration, inhibitors &activators. bind to the active site and block the substrate.

Answer 25

Competitive Inhibitors

Question 26

___________ also called as ____________. It binds into the _________ of the enzyme or somewhere away from the _______ and changes the enzyme’s _______.

Answer 26

Non-competitive Inhibitors
allosteric inhibitors
allosteric site
active site
shape

Question 27

breaks down proteins or polypeptides into amino acids.

Answer 27

Protease

Question 28

breaks down fats or lipids like triglycerides into glycerol and fatty acids.

Answer 28

Lipase

Question 29

catalyzes rearrangement reactions.

Answer 29

Isomerase

Question 30

catalyzes transfer of functional groups from one molecule to another.

Answer 30

Transferase

Question 31

transfers phosphate group (particularly from ATP) to another.

Answer 31

Kinase

Question 32

removes hydrogen atoms from a molecule.

Answer 32

Dehydrogenase

Question 33

breaks down starch into simple sugars.

Answer 33

Amylase

Question 34

catalyzes the transfer of electrons

Answer 34

Oxidoreductase

Question 35

catalyzes hydrolysis reactions.

Answer 35

Hydrolase