All living things are primarily composed of large biomolecules called biomolecules, which are made up of many atoms bonded together. Biomolecules contain carbon and are classified into four main types: carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates include sugars and starches, lipids are fats and oils, proteins are made of amino acids, and nucleic acids include DNA and RNA. These macromolecules are essential for life and perform important functions in cells and organisms.

2. All LIVING things are mostly
made of 4 types of molecules
called BIOMOLECULES.
BIOMOLECULES are very
large molecules of many
ATOMS covalently bonded
together
All BIOMOLECULES contain
CARBON (C)

3. Organic Compounds
Organic Compounds
Compounds
Compounds that contain CARBON
CARBON
are called organic
organic.
Macromolecules
Macromolecules are large organic
organic
molecules
molecules.
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4. Carbon
Just like water carbon is very important to
life
Most molecules of the cell are carbon-based
Molecules in the cell are called
biomolecules
These consist of a backbone of carbon
atoms
Atoms of other elements may branch off this
backbone
This is the basic structure of most of the

5. Carbon (C)
Carbon (C)
Carbon
Carbon has 4 electrons
4 electrons in outer
shell.
Carbon
Carbon can form covalent bonds
covalent bonds
with as many as 4
4 other atoms
(elements).
Usually with C, H, O or N
C, H, O or N.
Example:
Example: CH
CH4
4(methane)
(methane)
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6. Why are carbon atoms so common in
living things?
Because carbon is a very versatile element
Lets look at the element carbon
It has 4 electrons on it’s outer shell/energy level
This means it can form up to four bonds with other atoms
Carbon-based molecules are called organic molecules
Non- carbon based molecules are called……
Inorganic molecules
e.g. water, oxygen, ammonia

7. Monomers & Polymers
Some biomolecules consist of hundreds or even millions of atoms
Large molecules are made from smaller units called monomers
Monomers are linked to form polymers
Every cell has thousands of different polymers
All these are built from fewer than 50 monomers
Life’s large molecules are classified into 4 main categories:
carbohydrates, lipids, proteins and nucleic acids
The 4 types of biomolecules often consist of large
carbon chains

8. 4 categories of
BIOMOLECULES
proteins
carbohydrates
lipids
nucleic acids

9. Macromolecules
Macromolecules
 Large organic molecules.
Large organic molecules.
Also called POLYMERS
POLYMERS.
Made up of smaller “building blocks” called
MONOMERS
MONOMERS.
 Examples:
Examples:
1. Carbohydrates
1. Carbohydrates
2. Lipids
2. Lipids
3. Proteins
3. Proteins
4. Nucleic acids (DNA and RNA
4. Nucleic acids (DNA and RNA)
)
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10. Carbohydrates
Carbohydrate means “hydrated” carbon
Composing elements C, H, O
Hydrogen and Oxygen are in a ratio of 2:1
Can be simple monomers like glucose
Can be complex polymers like cellulose
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11. Carbohydrates
Carbohydrates
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12. Carbohydrates
Carbohydrates
 Organic compounds made up of Sugar molecules.
 Contain C, H, O in the ratio 1:2:1
Small sugar molecules
Small sugar molecules to large sugar molecules
large sugar molecules.
Examples:
Examples:
A.
A. monosaccharide
monosaccharide
B.
B. disaccharide
disaccharide
C.
C. polysaccharide
polysaccharide
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13. Carbohydrates
Carbohydrates
Monosaccharide: one sugar unit
Monosaccharide: one sugar unit
Examples:
Examples: glucose (
glucose (C6H12O6)
deoxyribose
deoxyribose
ribose
ribose
Fructose
Fructose
Galactose
Galactose
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glucose
glucose

14. Carbohydrates
Organic compounds made up of sugar molecules
Contain C, H, O in the ratio 1:2:1
Monosaccharides
Consist of just one sugar unit
E.g. glucose, fructose and galactose
Honey contains glucose and fructose
Main fuel for cellular work
Cells break down glucose molecules and
extract their stored energy

15. Carbohydrates
Carbohydrates
Disaccharide:
Disaccharide: Made by joining 2 monosaccharides by process of
dehydration Examples:Sucrose,lactose, maltose
Examples:Sucrose,lactose, maltose
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•These sugars give energy that lasts a little longer than monosaccharides because
the glycosidic bond (a covalent bond between two monosaccharides) must be
broken before the sugar can be used for energy

16. Using a dehydration reaction cells can make disaccharides
from two monosaccharides
Sucrose is made from glucose and fructose
Found in plant sap
Table sugar is sucrose which comes from sugar cane

17. Polysaccharide: many sugar units
Polysaccharide: many sugar units
Examples:
Examples:starch (bread, potatoes), glycogen(beef muscle) cellulose
starch (bread, potatoes), glycogen(beef muscle) cellulose
(lettuce, corn)
(lettuce, corn)
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glucose
glucose
glucose
glucose
glucose
glucose
glucose
glucose
glucose
glucose
glucose
glucose
glucose
glucose
glucose
glucose
cellulose
cellulose

18. Polysaccharides
 Also called complex carbs
 Starch made of glucose monomers
 Starch is found mostly in plants
 Glycogen is found in animal cells
 Stored in liver and muscle
 Cellulose is a polysacc that acts as a building material
 Commonly known as fiber
 We do not have a digestive enzyme to break it down

19. Functions of carbohydrates.
 HOW DO THEY HELP THE CELL?
HOW DO THEY HELP THE CELL?
 Carbohydrate functions as an energy source of the body and acts as Bio fuel.
 1. PROVIDE ENERGY.
1. PROVIDE ENERGY.
 Polysaccharide starch acts as storage food for plants.
 Glycogen stored in liver and muscles acts as storage food for animals.
 2. STRUCTURAL SUPPORT.
2. STRUCTURAL SUPPORT.
 Cellulose forms cell wall of plant cell
 3. CELL-CELL COMMUNICATION.
3. CELL-CELL COMMUNICATION.
 Therefore the building block of Carbohydrates are sugars
Therefore the building block of Carbohydrates are sugars

20. Lipids
Lipids
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21. Lipids
Have you ever looked into a bottle of salad dressing….
What did you notice?
Lipids are hydrophobic – afraid of water
This is very important to their function
Cell membranes surround the cell
Lipids also make signalling molecules
Form energy storage

22. Lipids
Lipids
 General term for compounds which are not soluble in water
not soluble in water.
 Lipids are soluble in hydrophobic solvents
are soluble in hydrophobic solvents.
 Remember:
Remember: “stores the most energy”
“stores the most energy”
 Examples:
Examples: 1. Fats
1. Fats
2. Phospholipids
2. Phospholipids
3. Oils
3. Oils
4. Waxes
4. Waxes
5. Steroid hormones
5. Steroid hormones
6. Triglycerides
6. Triglycerides
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23. Lipids
Lipids
Six functions of lipids:
Six functions of lipids:
1.
1. Long term
Long term energy storage
energy storage
2.
2. Protection against heat loss (insulation)
Protection against heat loss (insulation)
3.
3. Protection against physical shock
Protection against physical shock
4.
4. Protection against water loss
Protection against water loss
5.
5. Chemical messengers (hormones)
Chemical messengers (hormones)
6.
6. Major component of membranes
Major component of membranes
(phospholipids)
(phospholipids)
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24. Lipids- structure
Lipids- structure
C
Composed of 3 carbon backbone called glycerol and 3
3
fatty acids
fatty acids.
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H
H-C----O
H-C----O
H-C----O
H
glycerol
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
=
fatty acids
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
=
O
C-CH2-CH2-CH2-CH =CH-CH
2 -CH
2 -CH
2 -CH
2 -CH
3
=

25. Fatty Acids
Fatty Acids
There are two kinds of fatty acids
fatty acids you may see these on food labels:
1.
1. Saturated fatty acids:
Saturated fatty acids: no double bonds (bad)
no double bonds (bad) Lard and butter (solid at RT)
2.
2. Unsaturated fatty acids:
Unsaturated fatty acids: double bonds (good)
double bonds (good) Fats found in fruit, vegetable, fish,
corn oil, vegetable oil
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O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
=
saturated
saturated
O
C-CH2-CH2-CH2-CH=CH-CH
2 -CH
2 -CH
2 -CH
2 -CH
3
=
unsaturated

26. Saturated fats…..take care
Diets rich in saturated fats are unhealthy….
Cause the build up of plaque-like substance in your
arteries

27. Protein

28. Amino acids
 Each amino acid consists of a central carbon with 4 partners
In all amino acids 3 of the partners are the same with
 Hydrogen
 Amino group – NH2
 Carboxyl group – COOH
R-group is the functional group which is different in all amino acids
This is responsible for the properties of each AA

29. Building a protein….
Cells make proteins by linking 20 amino acids by peptide bonds.
Amino acids are joined together when a dehydration reaction removes a
hydroxyl group from the carboxyl end of one amino acid and a hydrogen
from the amino group of another.
This chain of AA’s is called a polypeptide (also known as a protein)
Proteins are made from one or more polypeptide chains.
Human body makes lots of proteins using different arrangements of
amino acids
Each protein has a unique sequence of AA’s

30. Protein shape
 An chain of AA’s on it’s own cannot function.
 A functional or working protein consists of polypeptide chains twisted,
folded and coiled in a special way.
 There are 4 levels of proteins
Four levels of protein structure are:
Four levels of protein structure are:
A.
A.Primary Structure
Primary Structure
B.
B. Secondary Structure
Secondary Structure
C.
C. Tertiary Structure
Tertiary Structure
D.
D.Quaternary Structure
Quaternary Structure
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32. Primary Structure
Amino acids bonded together by
peptide bonds (straight chains)
peptide bonds (straight chains)
Amino acid sequence of the protein
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aa1 aa2 aa3 aa4 aa5 aa6
Peptide Bonds
Amino Acids (aa)

33. Secondary Structure -
Secondary Structure - H bonds in the peptide chain
backbone
3-dimensional folding arrangement of a
primary structure
primary structure into coils
coils and pleats
pleats held
together by hydrogen bonds
hydrogen bonds.
Two examples:
Two examples:
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Alpha Helix
Alpha Helix
Beta Pleated Sheet
Beta Pleated Sheet
Hydrogen Bonds
Hydrogen Bonds

34. Tertiary Structure
Tertiary Structure
Secondary structures
Secondary structures bent
bent and folded
folded
into a more complex 3-D arrangement
more complex 3-D arrangement
of linked polypeptides
Bonds: H-bonds, ionic, disulfide
Bonds: H-bonds, ionic, disulfide
bridges (S-S)
bridges (S-S)
Call a “subunit”.
“subunit”.
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Alpha Helix
Alpha Helix
Beta Pleated Sheet
Beta Pleated Sheet

35. Quaternary Structure
Quaternary Structure
Composed of 2 or more “subunits”
Globular in shape
Form in Aqueous environments
Example: enzymes (hemoglobin)
enzymes (hemoglobin)
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subunits
subunits

36. Proteins (Polypeptides)
Proteins (Polypeptides)
Amino acids (20 different kinds of aa) bonded together by
peptide bonds
peptide bonds (polypeptides
polypeptides).
Building blocks of Proteins are Amino Acids.
 Six functions of proteins :
Six functions of proteins :
1.
1. Storage:
Storage: albumin (egg white)
albumin (egg white)
2.
2. Transport:
Transport: hemoglobin
hemoglobin
3.
3. Regulatory:
Regulatory: hormones
hormones
4.
4. Movement:
Movement: muscles
muscles
5.
5. Structural:
Structural: membranes, hair, nails
membranes, hair, nails
6.
6. Enzymes:
Enzymes: cellular reactions
cellular reactions
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37. Functions of proteins.
Structural proteins -they form structures like hair. Horns, feather &
fur.
As storage- Make up muscles and provide long term nutrient
storage. (Albumin in the egg. And seeds of plants)
As Hormones – Insulin, a hormone secreted by the pancreas causes
other tissues to take up glucose and regulates blood sugar
concentration.
As Defense mechanism- They circulate in blood and defend from
harmful microbes.(Antibodies inactivate and help destroy viruses and
bacteria).
Transport – Hemoglobin a protein in blood helps carrying oxygen.
Some act as signals, conveying messages from cell to cell.
As enzymes -A group of proteins controls the chemical reactions in
a cell.(enzymes)
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38. Nucleic Acids
Nucleic Acids
• There are two types of nucleic acids
– Deoxyribonucleic acid (DNA)
– Ribonucleic acid (RNA)
• Each nucleic acid is made of monomers called nucleotides
• Each nucleotide consists of
phosphate group
phosphate group
pentose sugar (5-carbon)
pentose sugar (5-carbon)
nitrogenous bases:
nitrogenous bases:
adenine (A)
adenine (A)
thymine (T) DNA only
thymine (T) DNA only
uracil (U) RNA only
uracil (U) RNA only
cytosine (C)
cytosine (C)
guanine (G
guanine (G
38

39. DNA - double helix
DNA - double helix
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P
P
P
O
O
O
1
2
3
4
5
5
3
3
5
P
P
P
O
O
O
1
2 3
4
5
5
3
5
3
G C
T A

40. How do enzymes work?
In the human body catalysts are called enzymes
Each enzyme catalyzes (or speeds up) only one type of reaction – an
enzyme is specific
The molecules that an enzyme reacts with are called substrate
The substrate fits exactly into a part of the enzyme called the active
site.
Sucrase is an enzyme that breaks down Sucrose into glucose and
fructose
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Substrate
Enzyme Active
site

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42. Macromolecules
Macromolecules
Formed and
Formed and
broken?
broken?
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Dehydration Synthesis
&
Hydrolysis

43. Dehydration Synthesis
Dehydration Synthesis
Also called “condensation reaction”
“condensation reaction”
Forms polymers
polymers by combining
monomers
monomers by “removing water”
“removing water”.
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HO H
HO HO H
H
H2O

44.  Most macromolecules are made from single subunits, or building blocks,
called monomers.
 The monomers combine with each other using covalent bonds to form
larger molecules known as polymers.
 In doing so, monomers release water molecules as byproducts.
 This type of reaction is known as dehydration synthesis, which means “to
put together while losing water.”
Question:
Question:
How are Macromolecules separated or digested?
How are Macromolecules separated or digested?
Hydrolysis - Polymers are broken down into monomers in a process
known as hydrolysis, which means “to split water,” a reaction in which a
water molecule is used during the breakdown
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45. Answer:
Answer: Hydrolysis
Hydrolysis
Separates monomers
monomers by “adding
“adding
water”
water”
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HO HO H
H
HO H
H2O

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