Post Lab Act 1: The Cell Flashcards
What is the Objectives of 1A?
❏ 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
What is the objectives of 1B?
❏ 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
assemblages of a DNA or RNA strand wrapped in a protein
package
Viruses
Fibrous protein structure
Cytoskeleton
RNA/protein
Ribosomes
DNA/protein
Chromatin
proteins/nucleic acids
Mitochondria
nucleic acid/proteins
Nucleus
lipid/protein
Cell membranes
Biomolecule components of organelles
Lvl 1: Monomeric Units
Lvl 2: Macromolecules
Lvl 3: Supramolecular Complexes
Lvl 4: The Cell and its organelles
4 Common Procedures used in Homogenization
- Break cells with high freq sound
- Use mild detergent to make holes in the plasma membrane
- Force cells through a small hole using high pressure
- Shear cells between a close-fitting rotating plunger and the thick walls of a glass vessel
What is the first step in purification?
Disrupt tissues and cells
Using gentle mechanical procedures called ____ so that the plasma membranes of the cells can be ruptured and that the cell contents are released.
Homogenization
The resulting thick soup from homogenization is called
Homogenate or an extract
It contains large and small molecules from the cytosol, such as enzymes, ribosomes, and metabolites as well as all of the membrane- enclosed organelles
Homogenate
Repeated centrifugation at progressively higher speeds will fractionate cell homogenate into their components.
Differential Centrifugation
Separates cell components on the basis of size and density.
Centrifugation
In Centrifugation the _____ will form a pellet at the bottom of the tube
Sediments
It is the fluid and the remaining suspension above the test tube
Supernatant
for DNA. Tests for the deoxyribose in DNA
Dische Diphenylamine Test
What are the reagents for Dische Test
diphenylamine,
Sulfuric acid
What is the positive result of Dische Test
light blue to
blue depending on the
amount of DNA
What is the negative result for Dische test?
Clear
What is the Diphenylamine solution
mixture of diphenylamine, glacial
acetic acid and sulfuric acid
General test for carbohydrates
Molisch Test
What is the Reagents of Molisch Test
α-naphthol in
ethanol, Sulfuric Acid
Positive result of Molisch Test
– purple ring
In Dische test, the reaction is a ______ reaction forming a furfural compound
dehydration reaction
In Molisch Test, The
______ forms a complex that gives the positive sample a purple ring
α-naphthol
What is the Positive result of Biuret Test
Violet Solution
What are the Reagents of Biuret Test
KOH, hydrated
CuSO4
, Potassium sodium
tartarate
The reaction in Biuret Test is a formation of complex between copper and
_____ and between copper and _____
oxygen; nitrogen
General Test for Lipids
Sudan Test
is non-polar and is soluble
only to lipids and similar
macromolecules
Sudan IV
What is the reagent of Sudan Test?
Sudan IV (red
brown crystals)
What is the Positive result of Sudan Test?
– red
globules/red layer
is a fat-soluble dye that
stains lipids red.
Sudan IV (Red)
In Sudan Test what are the two expected result?
There must be 2 layers. The top should be red.
