Labs

Question 1

Effect of heat on quarternary proteins

Answer 1

Disrupts hydrophobic interactions and dipole-dipole interactions

Question 2

Thiol reducing agent on proteins

Answer 2

Disrupts disuphide bonds

Question 3

SDS on proteins

Answer 3

Is an anionic detergent.

It solubilises, denatures + coats proteins w/ -ve charge

Question 4

What property allows SDS to dissolve hypdrophobic molecules?

Answer 4

Lipophillic tail

Question 5

Conjugate

Answer 5

Combine with another molecule or join together

Question 6

Pattern of absorbance measure

Answer 6

the particular wavelengths of light absorbed by conjugated bonds in a molecule

Question 7

Deuterium lamps in spectrophotometry

Answer 7

Emit UV light so are suitable for measuring the absorbance of DNA, RNA and proteins.

Question 8

Absorbance of UV light in proteins

Answer 8

Peptide bonds and aromatic rings in amino acids absorb UV light

Question 9

Scanning spectroscopy

Answer 9

Uses a range of wavelengths when measuring absorbance.

Question 10

When using a micropipette

Answer 10

1) Have appropriate tip on when touching liquid
2) Hold pipette up straight with liquid in
3) Take liquid in slowly so it doesnt ‘jump’ in the mechanism

Question 11

Wavelength absorbed by DNA

Answer 11

~260nm

Question 12

WAvelength absorbed by protein

Answer 12

~280nm

Question 13

Absorbance measure at 280nm generally has absorbance equivalent to :

Answer 13

1mg of protein per imL of solution

Question 14

Measuring protein quantification

Answer 14

A280 of 1 ~ 1g/L = 1mg/mL of protein

Question 15

What causes bands to be fainter in electrophoresis?

Answer 15

Sample more diluted

Question 16

Cell volume equals

Answer 16

(Pi x 6) x width^(2) x length

Question 17

What causes lipid accumulation to increase with cell biovolume in algae?

Answer 17

As the cells generate and accumulate oil bodies within the cytosol in response to nitrogen starvation this causes and increase in cell volume, hence an increase in cell biovolume positively correlates with increased lipid content.

Question 18

Why is oil immersion used in microscopy?

Answer 18

to increase the resolution of the image of the small cell.

Question 19

When making a blood film, which cell type is most abundant?

Answer 19

Erythrocytes

Question 20

Microcytic means someones red cells are…

Answer 20

Low mean corpuscular (cell) volume (MCV)

Question 21

When identifying ABO blood groups, an individual showing agglutination w/ anti-B antisera only will have the following blood group

Answer 21

B

Question 22

1fl equals

Answer 22

10^(-15) L

Question 23

1pg equals

Answer 23

10^(-12) g

Question 24

Blood pressure equals

Answer 24

BP = CO x TPR

Question 25

An old man was found to have a BP of 160/100 on four occasions. What is this condition? What happens to BP w/ age? Why?

Answer 25

Patient is Hypertensive. Systolic BP increases because blood vessels become hardened (arteriosclerosis) and lose elasticity

Question 26

What does resolved mean?

Answer 26

Separated

Bands on a gel that are well resolved are well separated from each other, and each band is distinct

Question 27

What gel concentration is better for larger DNA fragments? AND why

Answer 27

Lower concentrations

Larger pore size, so DNA fragments can better resolve, and their bands more defined.

Question 28

Why is a control used when studying enzyme substrate reactions?

Answer 28

To prove changes in enzyme activity are due to substrate. Without control, you couldn’t conclude substrate addition had any effect.

Question 29

If you repeated the ‘Switching on Genes’ experiment, but grew the E. coli cells in glucose-containing growth medium, rather than glycerol medium, how would you expect the result to differ and why?

Answer 29

Inducible lac operon will show a basal level of B-gal production even in absence of inducer; operon is repressed by presence of glucose. Thus if the medium was glucose-based, there would be no increase in basal level of B-gal production

Question 30

In the experiment ‘Switching on Genes’, you adjust you readings for any base level of β-galactosidase present at time T=0. Why is this important?

Answer 30

Aim of experiment is to see what happens to β-galactosidase activity upon addition of inducer. Even without inducer there is low level transcription of lac operon, giving low but detectable β-galactosidase activity. By subtracting this uninduced β-galactosidase activity from each sample the graph will show the induced level of β-galactosidase activity at each time point