Part B: Lecture 8

Question 1

Why do scientist use model organisms?

Answer 1

They ate used to understand biological processes

Question 2

Examples of unicellular model organisms

Answer 2

E-coli bacteria
S. cerevisiae yeast
Neurospora crassa - orange bread mold

Question 3

unicellular model organisms can be grown in ____ and _____

Answer 3

-agar plate (colonies)
-liquid media (cells)

Question 4

You can grow unicellular organisms in two types of media

Answer 4

-minimal media (MM)
-complete media (CM)

Question 5

Minimal media (MM) contain three things:

Answer 5

-carbon source (ex. glucose)
-energy source (ex. glucose)
-salts (ex. Na+)

Question 6

Complete media (CM) contain four things:

Answer 6

-amino acids
-sugars
-lipids
-nucleotides

Question 7

Source of prototroph?

Answer 7

wild

Question 8

Source of auxotroph?

Answer 8

lab

Question 9

Genotype of prototroph?

Answer 9

genes are all functional (+)

Question 10

Genotype of auxotroph?

Answer 10

one gene is non-functional

Question 11

Phenotype of prototroph?

Answer 11

can grow on CM and MM

Question 12

Phenotype of auxotroph?

Answer 12

can grow on CM

Question 13

Significance of Srb and Horowitz experiment

Answer 13

experimental proof of the one-gene-one-enzyme + invention of biochemical pathway analysis

Question 14

Srb and Horowitz experiment summary

Answer 14

1.WT cells exposed to UV light (1 mutation/cell)
2. Collected cells with random DNA damage
3. Collected mutant strains that can’t make arginine
4.Grew mutant cells on CM, MM, MM + Arg etc.
5. WT cells can make Arg in specific pathway using 3 enzymes made by 3 genes

Question 15

Mutant strains (def.)

Answer 15

cells with random DNA damage

Question 16

Mutagen (def.)

Answer 16

something capable of inducing changes in DNA

Question 17

By studying mutant types, you can learn _____

Answer 17

how wildtype works

Question 18

Purpose of biochemical pathway analysis

Answer 18

To determine how a cell/organism synthesizes an organic molecule

Question 19

Mutation in ___ gene prevents production of ___ enzyme and blocks the pathway at ____ place

Answer 19

-one
-one
-one

Question 20

Biochemical pathway analysis: providing different nutrients- WT appearance

Answer 20

the nutrient has recused the mutant so the nutrient is after the blocked step

Question 21

Biochemical pathway analysis: providing different nutrients- mutant appearance

Answer 21

the nutrient has not recused the mutant so the nutrient is before the blocked step

Question 22

Positive controls (def.)

Answer 22

If the experiment worked these will be positive

Question 23

Negative controls (def.)

Answer 23

If the experiment worked these will be negative

Question 24

Purpose of transformation rescue

Answer 24

to determine if a new mutation is in a known gene

Question 25

Transformation (def.)

Answer 25

the uptake and use of DNA or RNA by a cell/organism

Question 26

Transformation in animals is called ____

Answer 26

transfection

Question 27

Transformation rescue experiment summary

Answer 27

1. Plasmid with functional gene transforms mutant strain
2. WT appearance: transgene rescued mutant so transgene=mutant gene
3. Mutant appearance: transgene doesn’t rescue mutant so transgene ≠ mutant gene