biomolecules class 9 igcse

1. The Raw Materials of cell
The Building Blocks of Life
The Molecules of Cells
Biomolecules
Rahna.K.Rathnan
Assistant professor
Sahrdaya College of engineering and technology

2. Biomolecules are Organic
Molecules
 Molecules containing Carbon, Hydrogen, Nitrogen, and
Oxygen.
 All are polymers
 All are organic (C) compounds
 They make up living organisms
 Examples: Glucose (C6H12O6)

4. Biological Macromolecules
 Life depends on four types of organic macromolecules:
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic acids
Can you think of an example of each?
Can you think of an example of each?

5.  Carbohydrates
 Energy, support and recognition
 Proteins
 Enzymes, structure, recognition, transport pigments, signals,
mov’t
 Lipids
 Cell membrane structure energy storage, signals cellular
metabolism (VitK..)
 Nucleic Acids
 Hereditary and protein information, energy, signals
Function:

6.  Carbohydrates
 Polysaccharide of simple sugars
 Proteins.
 Polypeptide.of amino acids
 Lipids.
 Insoluble in water..although common polymer glycerol and fatty acid
 Nucleic Acids.
 Polynucleotide..of nucleotides
Structure:

7. Biomolecules made up of
 Subunits ( Monomer)
 The smaller molecules that are the building blocks of macro molecules
 Glucose ---------cellulose
 Amino Acids --------Proteins
 Fatty acids and glycerol -----------lipids

8. Carbohydrate

9. 1. Carbohydrates
 Contain carbon, hydrogen and oxygen in a ratio of 1:2:1
 Account for less that 1% of body weight
 Used as energy source
 Called saccharides

10. Carbohydrate
 Simple sugars:
 Monosaccharide:
 Disaccharides
 Complex sugars
 Polysaccharides

11. Monosaccharides
Disaccharides
Poly saccharides

12. Monosaccharides
 Simple sugars:
 Monosaccharide:
 “One” “Sugar”

glucose

Galactose

Fructose

13. Simple Sugars:Disaccharides
 Disaccharide
 “Two” “Sugars”
 Examples:
 Table sugar = Glucose + Fructose
 Maltose = Glucose + Glucose
 Lactose = galactose + Glucose

14. Disaccharides
Sucrose
Lactose

15. Polysaccharide
 “many sugars” Complex Sugar.: polymer
 any molecule made up of several repeating units.
 Starch is a polymer of glucose.
 Functions: Cells use them for energy and structure.
 They allow organisms to gradually use energy since it is
stored in a large structure. (like the Bank)

16. Polysaccharides
 Starch = energy storage in plants
 Glycogen = energy storage in animals
 Cellulose = plant cell wall
 All are long strings of glucose molecules
 Difference lies in how they are bonded together

17. Starch
 thousands of glucoses (sugars) bonded together
………Thousands

18. Cellulose
 Cellulose:
 Makes up the walls of plant cells.
 made from glucose.

19. Polysaccharides
Starch...bonds between
glucose can be digested
Amylose=plant Glycogen =animal
Cellulose…bonds
between glucose cannot
be digested by mammals

20. Polysaccharides
 Glycogen:
 Animals store carbohydrates
(glucose) in the form of glycogen;
similar in form to starch.
 reserve energy
 Stored in liver and muscles

21. Nucleic acids
Nucleic acids

22. Nucleic Acids
 Molecules of heredity
 Macromolecules
 Made up of nucleotide
 Two types
 DNA ( Nucleus)
 RNA(90% cytoplasm,10% nucleolus)
 mRNA
 tRNA
 rRNA

23. Nucleic Acids
 Information storage
 DNA (deoxyribonucleic acid)
 Protein synthesis
 RNA (ribonucleic acid)
 Energy transfers
 ATP (adenosine tri-phosphate) and NAD
(nicotinamide adenine dinucleotide)

24. Nucleic acids
 Contain C, H, O, N, and P
 Made up of nucleotide
 Nucleotide consists of
 Sugar
 Phosphate group
 Nitrogenous base

25. Nucleotides:
Each nucleotide consists of three
components:
A carbon to carbon ringed
structure with nitrogen
 Called a nitrogenous base
 Either a purine or a pyrimidine
A 5-carbon sugar and
A phosphate group.

26. Nitrogenous bases found in the two nucleic acid types
are different
DNA = A T C G
RNA = A U C G
Two types
Purine :A&G
Pyramidine : T,C,U
 Adenine, cytosine, and guanine
are found in both RNA and DNA
 Thymine -DNA
 uracil - RNA.

27. Nucleic acid types differ in the structure
of the sugar
That OH makes RNA less
stable---easily degraded
RNA is a transient
molecule..
 DNA contains
2-deoxyribose
 RNA contains ribose
 The only difference is
the presence or absence of a a OH
(hydroxyl group) on the second
carbon

28. All nucleotides have a phosphate group
 Phosphate – as found in
phospholipids
 HPO4
 Found between two
adjacent nucleotides in a
polypeptide
 Sugar – phosphate
backbone

29. Nucleotide Polymerization Reaction:
Phosphodiester Bond Formation

30. Structure of DNA

31. DNA Double Helix
DNA Double Helix
Nitrogenous
Nitrogenous
Base (A,T,G or C)
Base (A,T,G or C)
“
“Rungs of ladder”
Rungs of ladder”
“
“Legs of ladder”
Legs of ladder”
Phosphate &
Phosphate &
Sugar Backbone
Sugar Backbone

32. Chapter 10: DNA Structure & Analysis 32
Watson and Crick
Model
 Double stranded
 right-handed helix
 Antiparallel strands
 5’ to 3’polarity
 Sugar phosphate backbone on outside of
helix
 bases pointing inward
 Bases of opposite strands are H-bonded
together
 C-G; 3 bonds
 A-T; 2 bonds

33. • Major and minor groove
• Complementary base pairing
 Bases are 0.34 nm (3.4 angstroms) apart
in a strand
 3.4 nm 0r 34 angstroms per turn of the
helix
 10 nt per turn
 Helix is 2 nm or 20 angstroms in diameter

34. Complementary base pairing Rule
Adenine always base pairs with Thymine (or Uracil if RNA) -----
Double bond
Cytosine always base pairs with Guanine---------- triple bond
Purines Pyramidines
Adenine Thymine
Adenine Uracil
Guanine Cytosine
G C
T A

35. A nucleotide: ATP
 Energy storage for cells
 Many enzymes use ATP
 Provides a way to run
reactions that are
otherwise endergonic
(require energy)

36. three types of RNA
All used in protein synthesis
All encoded in the DNA
RNA includes:
 mRNA (messenger)
 tRNA (transfer)
 rRNA (ribosomal)
 mRNA :
 transcribed genetic information
from (DNA)
 rRNA
 assembly site for protein
synthesis
 in complexes or protein and
RNA known as ribosomes,
 tRNA :
 essential carrier molecule for
amino acids to be used in
protein synthesis.

39. Lipids
 naturally occurring organic compounds
 Insoluble in water
 Soluble in ether, chloroform, acetone & benzene
 Contain carbon, hydrogen, and oxygen
 the ratio of C:H is 1:2 (much less O)
 contain other elements, phosphorous, nitrogen, and sulfur
 Form essential structures in cells
 Are important energy stores

40. 40
Types of Lipids
The types of lipids containing fatty acids are
 Waxes.
 Fats and oils (triacylglycerols).
 Glycerophospholipids.
 Prostaglandins.

41. 41
Structures of Lipids

42. Lipids
 Long-term energy storage
 Generally insoluble in water
 Structural components of cells (phospholipids)
 Cellular messengers (hormones)

43. Lipids: Triglycerides (Fats and
Oils)
 Consist of 3 fatty acids and
glycerol
 Insulation
 Energy
 protection
Q: What ‘s the difference
between saturated and
unsaturated?

44. Lipids: Steroids and
Cholesterol
 All consist of a
complex ring
structure

45. Lipids: Phospholipids
Amphipathic

46. Protein

47. Protein Structure
 most abundant and important organic molecules
 Basic elements:
 carbon (C), hydrogen (H), oxygen (O), and nitrogen (N)
 Basic building blocks:
 20 amino acids

48. AMINO ACIDS are the
basic building blocks
of
PROTEINS

49. Proteins
 Consist of chains of amino
acids
 Linked together by peptide
bonds
 Enzymes are proteins

50. Each ball is
An Amino
Acid.
Bonded by
Peptide
Bonds
There are 20
Amino Acids

51. Each AMINO ACID
has
An amino group,
A carboxyl group,
A hydrogen atom and
a specific side chain (R group)
Bonded to
the α-carbon atom

54. Protein Function………..!! WOW!!
 Structural…. Bones,skin, nails, hooves, hair
 Enzymatic… Digest sugar, makes DNA, makes fatty acids
 Transport… Carries oxygen and fats in blood, Ca2+/Cl-
 Contractile.. Muscles for movement, move chromosomes
 Hormone…. regulate blood sugar, increase heart rate
 Immunity... Antibodies fight foreign substance
 Pigment….. Pigment in skin, eyes
 Recognition. On cell surfaces—Other molecules (receptors)
 Toxins…… Stops nerve transmission, effects movement of
ions, enzymes that destroy red blood cells

55. BIOLOGICAL FUNCTIONS OF PROTEINS
1. Catalytic function:
Nearly all chemical reactions in biological systems are catalyzed
by specific enzymes.
2. Transport and storage:
For example;
 Hemoglobin transports oxygen in erythrocytes
 Myoglobin carries & stores oxygen in muscle.
 Albumin transports free fatty acids in blood.
 Transferrin transports iron in blood.
3. Coordinated motion:Actin and myosin are contractile proteins in
muscle.

56. BIOLOGICAL FUNCTIONS OF PROTEINS (cont.)
4. Structural and Mechanical support:
For Example; collagen, a fibrous protein in skin and bone.
5. Defense function:
For Example Clotting factors prevent loss of blood.
Immunoglobulins protects against infections.
6. Generation and transmission of nerve impulses:
For example, rhodopsin is the photoreceptor protein in retinal
rod cells.
7. Control of growth and differentiation:
For Example
 growth factor proteins.
 hormones such as insulin and thyroid-stimulating
hormone.

57. General structure of protein
 polymers of twenty known amino acids.
 All biologically known amino acids are α L amino acids.

58. Protein Structure – 4 levels
Primary: amino acid sequence
Secondary: Hydrogen bonds form spirals or pleats
Tertiary: Secondary structure folds into a unique shape
Quaternary: several tertiary structures together

59. The shape of
protein is
important to its
function.
Enzyme: Quaternary Structure

60. Protein structure

61. Shape and Function
 Protein function is based on shape
 Shape is based on sequence of amino acids
 Denaturation:
 loss of shape and function (due to heat, pH change or
other factors)