Pre Practical

Question 1

Aim

Answer 1

Analyse the enzyme kinetics of Alcohol Dehydrogenase (ADH)
Measure how substrate concentration affects the rate of reaction

CH3CH2OH + NAD+ —> <—CH3CHO + NADH + H+

Answer 2

Ethanol is converted to acetaldehyde in the cytosol of the cells

Acetaldehyde is then transported to the mitochondria of the cells and converted into acetic acid

Ethanol —> alcohol dehydrogenase (adh)—> acetaldehyde
—> (aldehyde dehydrogenase ) ALDH —> acetic acid —> CoA —> acetyl CoA

340 wavelength is visible light

One ethanol = 1 NAD+ = 1 NADH

Question 3

Materials

Answer 3

Enzyme reaction mix
Ethanol dilutions
Spectrophotometer

Blanking spectrometers = water is the blank
Curvettes = the see through side is the one for the light to go through.

Answer 4

Starting concentration C1
FINAL CONCENTRATION C2

V1
V2 = final volume

C1 X V1 = C2 X V2

4.8 x 1 / 6

Answer 5

We’ve said the spectrophotometer will be measuring the change in absorbance per minute (ΔA/min)
• ThemoreNADHweareproducing, the more light at 340nm we are absorbing.
• RemembertheBeer-Lambertlaw A = εcl
• This means that:
• This means if we know the absorbance of a sample,
We can find its concentration