2. • ELEMENT IN THE CELL
1. There are about 92 element occurring naturally in
nature.
2. From these 92 element, only about 25 element are
needed to build living organisms.
3. Not all these element found in all living cell.
4. Main element (CHON) are the most frequently found
elements in cells, forming about 96% of the human
body mass.
5. Trace-elements are the elements are found in small
quantity in cells, but are important in biological
processes.
3. CHEMICAL COMPOUND IN THE CELL
1. Chemical compounds in the cell can be divided into two
major group:
• Organic
• Inorganic
2. Organic compounds are:
• Chemical compounds contain carbon (exception are
carbon monoxide, carbon dioxide, carbides and
carbonates which are typically considered as inorganic)
• Are usually found in and originate from living organism.
• Usually consist of macromolecules (large molecules).
3. Inorganic compounds are:
• Chemical compounds that do not contain carbon
• Usually a smaller and simpler than organic compounds
• Founds in cells water, acids, alkalis and mineral salts
4. • There are 4 main group of organic compounds in cells:
I. Carbohydrates
II. Lipids
III. Proteins
IV. Nucleic acids
• Carbohydrates
I. The carbohydrates are made up of carbon, hydrogen and oxygen.
The ratio of hydrogen to oxygen atoms in a molecule usually 2:1.
II. Many carbohydrates have the general formula CX(H2O)Y,where x is
approximately equal to y.
III. Three basic types of carbohydrates are monosaccharide,
disaccharides and polysaccharides
5. • Monosaccharide
i. Monosaccharide also called simple
sugar
ii. The common monosaccharide are
six-carbon sugar with a molecular
formula of C 6 H 12 O 6
iii.Example of monosaccharide are
glucose, fructose (fruit sugar) and
galactose
iv. Glucose is the most common
monosaccharide and respiratory
substrate
v. Monosaccharide are sweet-tasting
crystalline substances which are
6. • Disaccharides
i. Disaccharides are formed from two
monosaccharide molecules combining together
with the elements of a molecule of water. The
chemical reaction of the formation is known as
condensation.
ii. The general formula of a disaccharides is C12H22O11
iii. Disaccharides also called double sugar.
iv. Disaccharides can be broken down to their
constituent monosaccharide by a chemical
reaction involving the addition of water. The
reaction is know as hydrolysis.
7. v. Like monosaccharide, they are sweet-tasting
crystalline substances that are soluble in
water.
Condensation
+ + H2 O
Hydrolysis
C12H22O11 water
C6H12O6 C6H12O6
sucrose
glucose fructose
vi. The most common disaccharides are maltose,
lactose and sucrose.
8. Condensation
+ + H2 O
Hydrolysis
C12H22O11 water
C6H12O6 C6H12O6
maltose
glucose glucose
Condensation
+ + H2 O
Hydrolysis
C12H22O11 water
C6H12O6 C6H12O6
sucrose
glucose fructose
Condensation
+ + H2 O
Hydrolysis
C12H22O11 water
C6H12O6 C6H12O6
lactose
glucose galactose
9. • Polysaccharides
i. Many monosaccharide molecules join together in a
condensation reaction (with the removal of water
molecules) to form a large polysaccharides
molecules.
ii. Polymerisation is the process of condensing many
individual monosaccharide molecules to form a
large polysaccharides molecules.
iii. In polymerisation, the individual monosaccharide
molecule are called monomers.
iv. Polymerisation of monosaccharide forms:
• Glycogen – in humans and animals
• Starch and cellulose – in plants
10. glucose
Starch structure
Sub unit: Glucose
Consists of two components.
a) Unbranched, helical chains of glucose units
b) Branched chains of glucose units
Major storage of carbohydrate in plants
11. glucose
glycogen
•Sub unit: Glucose
•Molecules with many side branches
•Major storage of carbohydrates in animals and fungi, for
examples, in muscle cells and liver cells
12. glucose
cellulose
Straight unbranched chain of glucose units
Plant cell wall
13. • Reducing and non-reducing sugar
a) Some sugars act as mild reducing agents
b) Two common test reagent to test for reducing
sugar are:
i. Benedict’s reagent (alkaline solution of
CuSO4)
ii. Fehling’s reagent (alkaline solution of CuSO 4)
c) Reducing sugars reduce Cu²+ (blue solution) to
Cu+ (brick red precipitate) in both reagents.
14. • Proteins
1. Proteins are compounds of these element: carbon,
hydrogen, oxygen, nitrogen sulphur and phosphorus.
2. Amino acids are the subunits of all proteins.
3. Each amino acids carries two functional group:
a) A carboxyl group (- COOH) which is acidic and
b) An amino group (-NH2) which is basic.
COOH carboxyl group
C
NH2 amino group
15. • Two amino acids can combine together to form
a dipeptide by a condensation reaction
between the carboxyl group of one and the
amino group of the other. The resulting a bond
liking the two amino acids that is called a
peptide bond.
H2O
O Peptide bond h
cooh Hn c n
condensation
C C c c
NH2 hooc
h nh2 hooc
16. • Long chains of amino acids are called polypeptides.
• A polypeptide is formed by the condensation reaction
of many amino acids, with the removel of water.
• A polypeptide chain can also be hydrolysed, with the
addition of water molecules to form individual amino
acids.
PROTEIN STRUCTURE
• Primary-linear sequence of amino acids
• Secondary structure- forming ahelixor pleated sheet.
• Tertiary structure- compact structure
• Quaternary structure- 2 or more tertiary structure
17. LIPIDS
• Lipids a diverse group of substance that
contain carbon, hydrogen and oxygen. The
proportion of oxygen is lower than that in
carbohydrates. For example, the general
formula of stearic acid is C 18 H 36 O 2.
• All lipids are insoluble in water
• Lipids dissolve readily in other lipids and in
organic solvent such as ether and ethanol.
• The main types of lipids are:
a) Fats
b) Oils
c) Waxes
d) Phospholipids
18. Fats and oils
• Fats are solid at room temperature (20°C), whereas oil
are liquid
• Each molecule of fats or oils is made up of one glycerol
combine with three fatty acids which may be the same or
may be different. Three molecule of water are remove in
this condensation reaction.
Condensation (- H2O)
+
Hydrolysis (+ H2O)
glycerol 3 fatty acids Triglyceride +
molecules 3 water molecules
19. • These molecules of fats and oils are known as
triglycerides.
• Fats often contain only saturated fatty acids.
• Oils usually contain unsaturated fatty acids.
• In a saturated fatty acids , the carbon atoms are
bonded to the maximum number of other atoms.
Saturated fatty acid has only single bond and the
hydrocarbon chain is relatively straight.
• Unsaturated fatty acids has double bond in the form of
–CH=CH- in the hydrocarbon chain. Fatty acids; those
with two or more double bond are called
polyunsaturated fatty acids.
20. Type of Example Structural formula
fatty
acids
Saturated Stearic acid CH3(CH2)16COOH
Unsaturated Oleic acid CH3(CH2)7CH=CH(CH2)7COOH
• Fats and oils function efficiently as energy storage
material. Fats and oils provide 38kJ per gram, while
carbohydrates can provide only 17 kJ per gram.
21. Waxes
• Waxes are similar to triglycerides, but the fatty
acids are bonded to long-chain alcohols rather than
glycerol
• Waxes are usually hard solids at room temperature
• Waxes are used to waterproof the external surface
of plants and animal. The cuticle of a leaf and the
protective covering on an insect’s body are made of
waxes.
• Wax is also a constituent of the honeycomb of bees
22. Phospholipids
• Phospholipids have a similar structure to
triglycerides but one of the fatty acids is replaced
by a phosphate group
• The end of the phospholipids molecule containing
the phosphate group is hydrophilic. The other end
containing the hydrocarbon chain of the fatty acids
is hydrophobic.
• The hydrophilic end is soluble in water while
hydrophobic is insoluble in water.
• Phospholipids bilayer from the basis of all cell
membrane.
23. Steroids
• A steroid molecule has a complex ring structure
• Steroid occur in plants and animals
• Examples of steroids are cholesterol, testosterone,
estrogen and progesterone.
Steroid Function
cholesterol Strengthens the cell membrane at high
body temperature
testosterone Male reproductive hormone
estrogen and female reproductive hormone
progesterone.
24. • Saturated and and saturated fats
• Animal fats such as lard, butter and cream are
example of saturated fats
• Vegetable oil such as olive oil and sunflower oil are
example of unsaturated fats.
25. Saturated fats Unsaturated fats
Similarities
1. Both are triglycerides
2. They yield 38 kJ per gram
3. Their molecules congregate into globule because of their
hydrophobic properties
Differences
Saturated fats Unsaturated fats
Higher melting point Lower melting point
Most are solid at room Most are liquid at room
temperature temperature
More likely to cause disease of the Less likely to cause disease of the
heart and arteries heart and arteries
More stable at room temperature Unstable at room temperature
and less readily become rancid and less readily become rancid
26. ENZYMES
• Enzymes are protein molecules act as biological
catalysts. They speed up the rate of metabolic
reactions and do not chemically changed at the
end of the reaction
• The substance whose reactivity is increased by
an enzymes is knowing as a substrate
27. THE GENERAL CHARACTERISTICS
OF ENZYMES
• Enzymes speed up the rates of biochemical reactions
in cells.
• Only a small amount of enzymes is needed to catalyse
a lot of substrate.
• Enzymes are very specific – each class of enzymes
will catalyse only one particular reaction.
• Enzymes are not used up or destroyed in the reactions
that they catalyse, but can be reused again.
• Enzymes catalyse reversible reactions
• Many enzymes are only able to work with in presence
of a coenzymes (or cofactor).
• Enzymes are effected by changes in temperature and
pH
28. NAMING OF ENZYMES
• An emzyme is named by taking its substrate name
and adding the suffix ‘-ase’
• Example, protease catalyses the hydrolysis of protein.
• The ‘-ase’ rule does not apply to enzymes discover
before the ‘-ase’ idea was introduced. For example,
pepsin, rennin, ptyalin and tripsin.
• The modern classification of enzymes was decided by
the International Union of Biochemistry (IUB) in
1961
29. INTRACELLULAR AND
EXTRACELLULAR ENZYMES
• Intracellular emzyme that catalyses reaction
within a cell and formed by the free ribosome in
the cytoplasm.
• Extracellular emzyme that leaves the cell and
catalyses reaction outside the cell and
synthesised by ribosome attached to the rough
endoplasmic recticulum.
30. MECHANISM OF ENZYMES
ACTION
• Each enzyme molecule has a region with very precise
shape called active site.
• The substrate molecule fit into the active site of the
enzymes like a key into a lock, forming an enzyme-
substrate complex, a temporary structure.
• Reaction take place at active site to form a product.
• The product have a different shape from the substrate
and therefore repelled from a active site.
31. • THERE ARE 4 FACTORS AFFECT THE ACTIVITY OF
ENZYMES
1. pH
2. Temperature
3. Concentration of enzyme
4. Concentration of substrate
The effect of pH on enzyme activity
• Each enzyme has a optimum pH at which its rate of
reaction is the fastest. i.e. pepsin at pH 2,(acidic)
amylase pH 7 (neutral) and trypsin at pH 8-9
(alkaline)
32. The effect of temperature on enzyme activity
• The rate of reaction will increase up to
maximum, known as optimum temperature.
• After the optimum temperature around 37ºC-
40ºC, the rate of reaction falls quickly because
of the bonds maintaining the structure of the
enzyme start to break and the active site loses
its shape.
• At 60ºC, enzyme activity will stop altogether
because the enzyme is denatured
33. The effecT of subsTraTe
concenTraTion on enzyme
acTiviTy
1. Increase the substrate
concentration will increase the
chance of enzyme-substrate
collision, and the rate of reaction
will increase.
2. Addition of substrate will not
increase the rate of reaction
anymore because the constant
enzyme concentration becomes
the limiting factor.
34. The effecT of enzym
concenTraTion on enzyme
acTiviTy
1. When the concentration of enzyme increase,
there are more chance enzyme-substrate
collision. The rate of reaction increase linearly
as long as no other factors are limiting.
The uses of enzymes
1. Enzyme can extracted from any living
organism, and used either at home or
in industry
2. Enzymes that are commonly used in
daily life are:
a. Papain-found in papaya used to
tenderise meat
b. Protease-used to tenderise meat and
remove hair from the skin etc.
35. Health problems
Leads to What
Deficiency Definition
CHEMICAL
COMPOSITION Water
OF THE CELL How
Compound Mechanism
Element Consists of
Enzymes
Can be classified
Forms
Includes
Carbohydrate Lipid Protein
Why
Importance
Affected by
Break down into Form
Simpler Factors
molecules
