Last min revision - topic 1

Question 1

How might you test for amylase in a sample?

Answer 1

• Add starch, (leave for a time), test for
  reducing sugar/absence of starch;

Question 2

How are triglycerides good energy stores

Answer 2

• large ratio of energy storing C-H (compared to number of carbon atoms)

Question 3

properties of triglycerides.

Answer 3

• large ratio of energy storing C-H (compared to number of carbon atoms)
• High ratio of H:O atoms, act as metabolic water source when oxidised
• no effect on water potential (hydrophobic, insoluble)
• low mass, store lots without affecting mass

Question 4

draw an amino acid

Answer 4

go online g

Question 5

How do enzymes lower activation energy? (induced fit)

Answer 5

Shape of tertiary structure slightly changed to fit substrate, tension on bonds of substrate, easier to brake.

Question 6

non-competitive inhibitors bind to the….

Answer 6

allosteric site, away from active site

Question 7

Test for starch

Answer 7

add iodine
positive = from orange to blue/black

Question 8

Testing for reducing sugars vs non reducing sugar

Answer 8

reducing sugars
- add benedict’s reagent and heat
- positive blue to brick red

non-reducing sugars
- negative benedict’s test
- add acid and BOIL
- cool and neutralize with alkali
- add benedict’s reagent and heat

intensity indicates conc of sugars

Question 9

Test for proteins

Answer 9

• add biuret
• positive = solution from blue to purple

Question 10

Test for lipids

Answer 10

• dissolve sample in ethanol
• add distilled water
• white EMULSION = positive

Question 11

Waters high heat capacity ______ changes in temperature.

Answer 11

BUFFERS

Question 12

Hydrogen bonds form between _____ and _____ atoms between water molecules

Answer 12

oxygen and hydrogen