1. 1.3.4 Biomolecular Sources and the Components of Food

2. Carbohydrates Carbohydrates contain the elements Hydrogen Oxygen
Carbon
Hydrogen
Oxygen
Usually in the ratio of 1C:2H:1O
They have twice as many hydrogen molecules as oxygen molecules

3. 3 Types of Carbohydrate
Monosaccharides
Disaccharides
Polysaccharides

4. Monosaccharides These are single sugar molecules simple sugars
soluble in water
sweet to taste
smallest carbohydrate unit
Examples: glucose, fructose
Found in: fruit

5. Carbon Hydrogen Oxygen
Learning check
What are the elements that make up all carbohydrates?
Carbon Hydrogen Oxygen
Can you remember the general formula for a carbohydrate?
Cx(H2O)y

6. Disaccharides These are
two monosaccharide sugar units joined together – known as double sugar molecules
soluble in water
sweet to taste
Examples: sucrose, lactose, maltose
Found in: table sugar, milk

7. Polysaccharides These are
Many monosaccharide sugar molecules joined together
Not soluble in water
Do not taste sweet
Example: starch, cellulose
Found in: bread, pasta, cereals

8. Learning check Name the three types of carbohydrate Monosaccharides
Disaccharides
Polysaccharides

9. Lipids Lipids are a diverse group of substances which include
fats (solid at room temp.)
oils (liquid at room temp.)
steroids which include cholesterol and some of the sex hormones
waxes which cover insect bodies and plant leaves.

10. Structure of Lipids They are made up of the elements carbon hydrogen
oxygen
But not have the same ratios as carbohydrates.
They are made up of two main types of molecules
Fatty acids and
Glycerol

11. Learning check Give examples and sources of: Examples Sources
Monosaccharides
Disaccharides
Polysaccharides
Glucose
Fructose
fruit
Sucrose
Lactose
Table sugar
Milk
Starch
Cellulose
Bread, Pasta,
Cereals

12. Types of Lipid Two of the main types of lipids are Triglycerides
Phospholipids

13. Triglyceride This is the smallest lipid It is made up of
3 fatty acid molecules
and
1 glycerol molecule

14. Phospholipids
If one fatty acid of a lipid molecule is replaced by a phosphate group then a phospholipid is formed

15. Sources of Lipids
Fat – in and on meat
Butter (80% fat)
Cooking oils

16. Learning check
The two main types of molecules that make up lipids are:
Fatty acids and
Glycerol
The two main types of lipids are:
Triglycerides
Phospholipids

17. Proteins Proteins contain the elements Carbon Hydrogen Oxygen Nitrogen
Some may also contain sulphur, phosphorous or iron
Proteins are found in lean meat, fish, pulses, soya and eggs

18. Structure of Proteins Proteins are made up of long chains of
amino acids
There are 20 common and several rare amino acids found in proteins
More amino acids are found in cells and tissues but are not in proteins
Amino acids are joined together by
peptide bonds
This results in the formation of polypeptide chains

19. Amino Acids
All amino acids contain four distinct chemical groups connected to a central carbon atom:
a single hydrogen atom
an amino group
a carboxyl group
a side chain

20. sulphur, phosphorous or iron
Learning check
Proteins contain the elements
Carbon Hydrogen
Oxygen Nitrogen
Sometimes they contain
sulphur, phosphorous or iron
Proteins are made up of long chains of
amino acids

21. Vitamins Vitamins are essential organic catalysts of metabolism
Needed in small amounts, cannot be produced in the body
Must be supplied continuously and in sufficient quantities
Differ from each other chemically

22. Vitamins
We need Vitamins A, B, C, D, E and K in our diets to keep us healthy
Vitamins can be water soluble or fat soluble
Vitamins B and C are water soluble
Vitamins A, D, E and K are fat soluble

23. Sources of Vitamins Green leafy vegetables, Eggs, Cheese, Carrots
Lean Meat, Cereals, Nuts C
Citrus Fruits, Green vegetables, Turnips D
Milk and Milk products, Sunlight E
Vegetable oils, fish, nuts K
Green leafy vegetables

24. Learning check What is a vitamin?
A vitamin is an essential organic catalyst of metabolism
What vitamins dissolve in water?
B & C
What vitamins are fat-soluble?
A, D, E and K

25. Need to know
State that simple bio molecular units are composed of a combination of elements in different ratios e.g. carbohydrates Cx(H2O)y
Name the element components, bio molecular components and sources of: carbohydrates, lipids and proteins.
State that carbohydrates are composed of indivisible units and give examples of these e.g.
Monosaccharides – glucose;
Disaccharides – maltose; &
Polysaccharides – starch/cellulose.

26. Need to know What is a vitamin? Name one water soluble vitamin.
Name one water in-soluble vitamin (fat-soluble)
List the sources of these vitamins

27. END