Post Lab Act 1: The Cell

Question 1

What is the Objectives of 1A?

Answer 1

❏ To be able to isolate the components of cell
❏ To be able to perform homogenization and differential centrifugation
❏ To appreciate the biochemical systems that maintain life

Question 2

What is the objectives of 1B?

Answer 2

❏ To perform the different qualitative tests in the differentiated samples
in 1A
❏ To identify the biomolecules that are present in the samples
❏ To be acquainted on the different chemical tests that may be
encountered in biochemistry laboratory

Question 3

assemblages of a DNA or RNA strand wrapped in a protein
package

Answer 3

Viruses

Question 4

Fibrous protein structure

Answer 4

Cytoskeleton

Question 5

RNA/protein

Answer 5

Ribosomes

Question 6

DNA/protein

Answer 6

Chromatin

Question 7

proteins/nucleic acids

Answer 7

Mitochondria

Question 8

nucleic acid/proteins

Answer 8

Nucleus

Question 9

lipid/protein

Answer 9

Cell membranes

Question 10

Biomolecule components of organelles

Answer 10

Lvl 1: Monomeric Units

Lvl 2: Macromolecules

Lvl 3: Supramolecular Complexes

Lvl 4: The Cell and its organelles

Question 11

4 Common Procedures used in Homogenization

Answer 11

1. Break cells with high freq sound
2. Use mild detergent to make holes in the plasma membrane
3. Force cells through a small hole using high pressure
4. Shear cells between a close-fitting rotating plunger and the thick walls of a glass vessel

Question 12

What is the first step in purification?

Answer 12

Disrupt tissues and cells

Question 13

Using gentle mechanical procedures called ____ so that the plasma membranes of the cells can be ruptured and that the cell contents are released.

Answer 13

Homogenization

Question 14

The resulting thick soup from homogenization is called

Answer 14

Homogenate or an extract

Question 15

It contains large and small molecules from the cytosol, such as enzymes, ribosomes, and metabolites as well as all of the membrane- enclosed organelles

Answer 15

Homogenate

Question 16

Repeated centrifugation at progressively higher speeds will fractionate cell homogenate into their components.

Answer 16

Differential Centrifugation

Question 17

Separates cell components on the basis of size and density.

Answer 17

Centrifugation

Question 18

In Centrifugation the _____ will form a pellet at the bottom of the tube

Answer 18

Sediments

Question 19

It is the fluid and the remaining suspension above the test tube

Answer 19

Supernatant

Question 20

for DNA. Tests for the deoxyribose in DNA

Answer 20

Dische Diphenylamine Test

Question 21

What are the reagents for Dische Test

Answer 21

diphenylamine,
Sulfuric acid

Question 22

What is the positive result of Dische Test

Answer 22

light blue to
blue depending on the
amount of DNA

Question 23

What is the negative result for Dische test?

Answer 23

Clear

Question 24

What is the Diphenylamine solution

Answer 24

mixture of diphenylamine, glacial
acetic acid and sulfuric acid

Question 25

General test for carbohydrates

Answer 25

Molisch Test

Question 26

What is the Reagents of Molisch Test

Answer 26

α-naphthol in ethanol, Sulfuric Acid

Question 27

Positive result of Molisch Test

Answer 27

– purple ring

Question 28

In Dische test, the reaction is a ______ reaction forming a furfural compound

Answer 28

dehydration reaction

Question 29

In Molisch Test, The ______ forms a complex that gives the positive sample a purple ring

Answer 29

α-naphthol

Question 30

What is the Positive result of Biuret Test

Answer 30

Violet Solution

Question 31

What are the Reagents of Biuret Test

Answer 31

KOH, hydrated CuSO4 , Potassium sodium tartarate

Question 32

The reaction in Biuret Test is a formation of complex between copper and _____ and between copper and _____

Answer 32

oxygen; nitrogen

Question 33

General Test for Lipids

Answer 33

Sudan Test

Question 34

is non-polar and is soluble only to lipids and similar macromolecules

Answer 34

Sudan IV

Question 35

What is the reagent of Sudan Test?

Answer 35

Sudan IV (red brown crystals)

Question 36

What is the Positive result of Sudan Test?

Answer 36

– red globules/red layer

Question 37

is a fat-soluble dye that stains lipids red.

Answer 37

Sudan IV (Red)

Question 38

In Sudan Test what are the two expected result?

Answer 38

There must be 2 layers. The top should be red.