1. C4 : Nutrients Building block of life
Iron absorb Oxygen Haemoglobin
Protein folding
How does AA turn to Proteins
20 AA

2. 5094 Pure Syllabus (a) state the roles of water in living organisms.
(b) list the chemical elements which make up:
• carbohydrates
• fats
• proteins
(c) describe and carry out tests for:
• starch (iodine in potassium iodide solution)
• reducing sugars (Benedict’s solution)
• protein (biuret test)
• fats (ethanol emulsion)
(d) state that large molecules are synthesised from smaller basic units:
• glycogen from glucose
• polypeptides and proteins from amino acids
• lipids such as fats from glycerol and fatty acids
Form ppt
Turns colour

3. Intro Why do we need food? Energy for daily activities (respiration)
Repair or Replace damaged or worn-out tissues/cells
Keep us healthy (prevent diseases)
To Grow

4. Constituents of Food So what can we find in food?
Dietary Fibre (vegetables like cellulose are not digested)
Water
Nutrients
Carbohydrates
Proteins
Fats (lipids)
Vitamins
Mineral Salts

5. Roles of Water 70% of the Body is made up of WATER Lost of water by
Breathing
Urination
Excretion of faeces
Perspiration
Extreme loss of water may affect the homeostasis of the body causing many vital processes unable to function and may lead to death.

6. Roles of Water Water is used as a solvent Regulating body temperature
Dissolves a range of substances that are useful or waste products.
Eg: glucose, amino acids, mineral salts, urea.
Regulating body temperature
Water enables the loss of heat from the body in the form of perspiration (Heat Capacity of water = 4.2 kJ/Kg°C)
Prevent overheating of the body (fever)
Supporting structure
Shape of eye maintained by aqueous and vitreous humour which is largely made up of water.
Amniotic fluid in the placenta protects the foetus from mechanical stress.

7. Water plays a role as lubricant
Mucus in digestive and respiratory tract
Synovial fluid in joints
Carries sperms in seminal fluid
Water as a site of many reactions
Water is needed for transport of substances (diffusion & osmosis)
Movement of water and mineral salts in the xylem
Diffusion of carbon dioxide in the mesophyll layers in the leaf
Water as a reactant in photosynthesis
Water used for dispersal of fruits (coconut)

8. Carbohydrates

9. Nutrients Carbohydrates
Made of elements Carbon (C), Hydrogen (H) and Oxygen (O)
Good source of energy
Eg : Rice, noodles, potato, starch, sugar
Consist of 3 Groups
Simple sugars (monosaccharides)
Complex sugars (disaccharides)
Polysaccharides

11. Simple Sugars (Monosaccharide)
Mono – single or one
Eg : glucose, fructose, galactose

12. Complex Sugar ( Disaccharide)
Di – two
Made up of 2 simple sugars joined together
Eg :

13. Formation of Disaccharides by Condensation (removal of water)
Breakdown of Disaccharides by Hydrolysis (addition of water)

14. Polysaccharide
Poly – many
Made up of multiple simple sugars
Eg : starch, glycogen

15. Different Forms of Polysaccharides
Starch (Cell Sap) & Glycogen
Many units of glucose
Used as energy reserves in plants(starch) and animals(glycogen).
Starch – long chains with few side branches
Glycogen – many side branches
Cellulose (Cell Wall)
Multiple units of glucose
Arranged differently thus more difficult to break
Used as a structural support in leaves and plants
Referred to as fibre

16. Starch vs Cellulose vs Glycogen

17. Function of Carbohydrates
Simplest unit of Carbohydrate (Monosaccharides) provides energy for the human body
It releases energy during aerobic respiration in the cell’s mitochondria.
Glucose is the most common form of monosaccharide.

18. # JC Level

19. #Uni Level – Molecular BioChemistry

20. Test for Carbohydrates : Iodine Test
Iodine test used to detect the presence of starch.
Procedure
Add a few drops of iodine solution onto the sample that is placed on a white glass tile.
+ve – iodine turns blue black
-ve – iodine remains brown

21. Test for Reducing Sugar : Benedict’s Test
Some sugars act as a reducing agent and reduces Copper(II) Sulfate. These sugars are known as reducing sugar.
Procedure
Add 2cm3 of Benedict’s solution to 2cm3 of sample
Shake & immerse test tube into beaker of boiling water for 2 mins
+ve result
Brick red precipitate
Orange precipitate
Green solution
-ve result
Remain blue solution

22. Sugar : Reducing & Non-reducing
Reducing sugars
Sugar that reduces Copper(II) Sulfate [Benedict’s Solution]
Usually has an aldehyde group
Eg: glucose, galactose, lactose
Non-Reducing sugars
Sugars that do not reduce Benedict’s Solution
Eg: Sucrose

23. # Classification of Carbohydrates

24. 5094 Pure Syllabus (a) state the roles of water in living organisms.
(b) list the chemical elements which make up:
• carbohydrates
• fats
• proteins
(c) describe and carry out tests for:
• starch (iodine in potassium iodide solution)
• reducing sugars (Benedict’s solution)
• protein (biuret test)
• fats (ethanol emulsion)
(d) state that large molecules are synthesised from smaller basic units:
• glycogen from glucose
• polypeptides and proteins from amino acids
• lipids such as fats from glycerol and fatty acids

25. Proteins

26. Proteins
Proteins are made up of carbon (C), nitrogen (N), oxygen (O) and hydrogen (H)
Proteins are made up of simple units of amino acids
Amino Acids  amino and carboxyl group
22 amino acids (9 essential amino acids)
Structure : AA  polypeptides  Proteins
AA are held by hydrogen bonds & sulfide bridges.
Affected by heat and ph.

29. Functions of Proteins
Synthesis of new protoplasm for growth, repair and replacement.
Synthesis of muscle, enzymes, hormones and antibodies.
Deficiency of proteins may lead to Kwashiorkor

30. Test for Proteins : Biuret’s Test
Test for presence of proteins
Procedure
Add 1cm3 of sodium hydroxide to 1cm3 of sample
Shake thoroughly. Then add 1% copper(II) sulfate drop by drop. Observe colour change.
+ve result
Turns from blue to pink to violet. Intensity of colour depicts concentration of protein

31. 5094 Pure Syllabus (a) state the roles of water in living organisms.
(b) list the chemical elements which make up:
• carbohydrates
• fats
• proteins
(c) describe and carry out tests for:
• starch (iodine in potassium iodide solution)
• reducing sugars (Benedict’s solution)
• protein (biuret test)
• fats (ethanol emulsion)
(d) state that large molecules are synthesised from smaller basic units:
• glycogen from glucose
• polypeptides and proteins from amino acids
• lipids such as fats from glycerol and fatty acids

32. FATS

33. Fats & Oils
Fats are made up of carbon (C), oxygen (O) and hydrogen (H).
Fats produce twice amount of energy of carbohydrates.
Fats broken down by hydrolysis to a Glycerol head and 3 Fatty acid tails.

34. Test for Fats Emulsion Test
Add 2cm3 of ethanol to the substance in a test tube
Shake the test tube.
Add 2cm3 of water.
+ve result
White emulsion

35. Functions of Fat Provide a source & storage of energy
Provides insulation to prevent excessive loss of heat.
Solvent for fat-soluble substances (vitamins, minerals)
Part of the cell membrane
Reduce water loss from skin
Prevent organs from physical injuries.

36. 5094 Pure Syllabus (a) state the roles of water in living organisms.
(b) list the chemical elements which make up:
• carbohydrates
• fats
• proteins
(c) describe and carry out tests for:
• starch (iodine in potassium iodide solution)
• reducing sugars (Benedict’s solution)
• protein (biuret test)
• fats (ethanol emulsion)
(d) state that large molecules are synthesised from smaller basic units:
• glycogen from glucose
• polypeptides and proteins from amino acids
• lipids such as fats from glycerol and fatty acids