2(c) Biological Molecules

Question 1

Identify the chemical elements present in carbohydrates, protein and lipids (fats and oils).

Answer 1

Carbohydrates
* Carbon, Hydrogen and Oxygen

Protein
* Carbon, Hydrogen, Oxygen, Nitrogen and sometimes Sulfur

Lipids
* Carbon, Hydrogen and Oxygen

Question 2

Describe the structure of carbohydrates, proteins and lipids

Answer 2

Large molecules made up from smaller basic units: Starch and glycogen from simple sugars, protein from amino acids and lipids from fatty acids and glycerol.

Question 3

Investigate food samples for the presence of glucose, starch, protein and fat

Practical

Question 4

Understand the role of enzymes

Answer 4

A biological catalyst that speeds up metabolic reactions but remained unchanged. Are made up of protein.

Question 5

Understand how temperature changes can affect enzyme function, including changes to the shape of active site.

Answer 5

If the temperature is to high the rate of enzyme activity decreases and the active site of the enzyme will be denatured so that the substrate wont be able to fit in.

Question 6

Investigate how enzyme activity can be affected by changes in temperature

Practical

Answer 6

40℃
* At the optimum temp the enzymes can work at their quickest rate so all or almost all the iodine has turned orange after adding amylase.

60℃
* At a to high temperature the enzymes active sites are denatured and rate of activity decreases, so all the starch is present due to the little to no enzyme activity.

Question 7

Understand how enzyme function can be affected by changes in pH altering the active site

Answer 7

Deviation from the optimum pH can decrease enzyme activity.
Acidic pH values can denatured enzymes.

Question 8

Lipase or Amylaze

Investigte how enzyme activity can be affected by changes in pH

Practical