The document discusses the structure and function of macromolecules, including carbohydrates, lipids, proteins, and nucleic acids, which are essential for living systems. It outlines the types, monomer units, and biological roles of these macromolecules, emphasizing their importance in energy storage, cellular structure, metabolism, and genetic information. Additionally, it covers large macromolecular assemblies, such as protein complexes and nucleoproteins, and their roles in cellular processes.

1. Cellular Macro molecules
&
Large Macromolecular Assemblies
By: Dr.S.Kameshwaran

2. Molecule Two or more atoms joined by
chemical bonds
Macromolecule Large polymer made of
repeating monomer units
Four types of organic macromolecules
are important in living systems.
Macromolecules

3. Macromolecules
“Polymers Made of Repeating Monomers”
Macromolecule Monomer Unit
Carbohydrates Sugars
Lipids Fatty acids
Proteins Amino acids
Nucleic Acids Nucleotides

4. Carbohydrates
Simple Carbohydrates :
Monosaccharides:
Glucose , Galactose, Fructose
Disaccharides :
Sucrose, Lactose, Maltose
Complex Carbohydrates:
Polysaccharides
Starch, Glycogen, Cellulose, Chitin

5. Carbohydrates
Types : Simple & Complex CHs
• Simple CH - Structure
– Monosaccharides= one sugar unit
Glucose = blood sugar
All cells use glucose for energy

6. • Simple Carbohydrates
Disaccharides = two sugar units
• Sucrose (table sugar) = glucose + fructose
Lactose (milk sugar)= glucose + galactose
Maltose (seed sugar) = glucose + glucose

7. • Complex Carbohydrates
– Polysaccharides= many sugar units
• Starch -- storage in plants
• Glycogen -- storage in animals
• Cellulose -- plant cell walls, indigestible
• Chitin -- exoskeletons of insects,
fungal cell walls

8. Carbohydrates: Functions
• Energy source
• Structural component
• Cell-cell communication

9. Macromolecule II : Lipids
Lipids (fats, oils, waxes) formed from Fatty
acids monomer units
Structure
• Triglyceride—predominant form in diet
– One molecule of glycerol
– Three fatty acids
– C:H:O ratio- 1:2:very few

10. Types of Fatty Acids
– Saturated – 2H per internal carbon
– Unsaturated -- <2H per internal carbon
one or more double bonds
• Monounsaturated – one double bond
Polyunsaturated – more than one double bond

11. H H
C
H
C
H
OH
C
H
OH
OH
C O
C
C
C
H
H
H
H
H
H
H
C
C
H
H
H
H
H
H
H
C
C O C O
C
C
C
H
H
H
H
H
H
H
Triglyceride
Triglyceride Formation
C
OH
C
C
C
O
H
H
H
H
H
H
H
Add 3
Fatty
Acids
Glycerol
HOH HOH HOH
3 Waters
C
OH
C
C
C
O
H
H
H
H
H
H
H
C
OH
C
C
C
O
H
H
H
H
H
H
H
O
C
H
C
H
C
H
O O
H H
Remove
These
Waters
C O
C
C
C
H
H
H
H
H
H
H
C
C
H
H
H
H
H
H
H
C
C O C O
C
C
C
H
H
H
H
H
H
H

12. Polar
Head
Glycerol Fatty Acid Tails
Hydrophobic
Hydrophilic
•Phospholipid—component of cell membranes

13. • Steroids
– Linked carbon rings
– Natural body components
• Hormones
• Cholesterol

14. Steroids
Cholesterol Estradiol
Testosterone

15. Lipids: Functions
• Concentrated energy source
• Structural components of cell membranes
– Phospholipids
– Cholesterol
• Communication
– Steroid Hormones
• Protection from water
– Waxes
Cholesterol
Phospholipids

16. Macromolecules: Polymers Made of
Repeating Monomers
Macromolecule Monomer Unit
Protein Amino acids

17. Four Levels of Protein Structure
Primary
(Sequence)
Secondary
(Coiling by
Hydrogen Bonding)
Tertiary
(Folding by
R-group
interactions)
Quaternary
(Two or more chains
associating)

18. Primary Structure
Sequence of amino acids in chain

19. Found in most proteins Found in silk
Secondary Structure
Folded structure due to hydrogen bonds between the amino
and acid groups of amino acids

20. Tertiary Structure:
Three dimensional folded structure due to
attractions and repulsions between R groups
Can involve
covalent bonding
hydrogen bonding
ionic interactions
hydrophilic and hydrophobic interactions

21. Tertiary Structure:
Three dimensional folded structure due to attractions and
repulsions between R groups
Can involve
covalent bonding
hydrogen bonding
ionic interactions
hydrophilic and hydrophobic interactions

22. Hair Curling
|
S
|
S
|
|
S
|
S
|
|
S
|
S
|
|
S
|
S
|
|
S
|
S
|
Straight
Hair
Naturally
Curly
Hair

23. Quaternary Structure:
Association of two or more protein chains
eg. Hemoglobin is composed
of 4 protein chains
2 are called alpha
hemoglobin
2 are called beta
hemoglobin

24. Proteins: Functions
• Structural Component of Cells
• Control of Metabolic Reactions: enzymes
• Growth and Repair
• Communication
– Protein Hormones
– Cell Receptors
• Energy source
• C:H:O ratio –no reliable ratio
• For proteins
Protein
Protein

25. Nucleic Acids
• Nucleic acids store, transmit, and help
express hereditary information
• The amino acid sequence of a polypeptide is
programmed by a unit of inheritance called a
gene
• Genes are made of DNA, a nucleic acid
made of monomers called nucleotides
25

26. Two Types of Nucleic Acids
• There are two types of nucleic
acids
– Deoxyribonucleic acid
(DNA)
– Ribonucleic acid (RNA)
• DNA provides directions for its
own replication
• DNA directs synthesis of
messenger RNA (mRNA) and,
through mRNA, controls protein
synthesis
• Protein synthesis occurs on
ribosomes
26

27. Figure 5.25-1
Synthesis of
mRNA
mRNA
DNA
NUCLEUS
CYTOPLASM
1

28. Figure 5.25-2
Synthesis of
mRNA
mRNA
DNA
NUCLEUS
CYTOPLASM
mRNA
Movement of
mRNA into
cytoplasm
1
2

29. The Components of Nucleic Acids
• Each nucleic acid is made of monomers called
nucleotides
• Each nucleotide consists of a nitrogenous base,
a pentose sugar, and one or more phosphate
groups
• C:H:O ratio: No reliable ratio for nucleic acids
29

30. Figure 5.26c
Nitrogenous bases
Cytosine
(C)
Thymine
(T, in DNA)
Uracil
(U, in RNA)
Adenine (A) Guanine (G)
Sugars
Deoxyribose
(in DNA)
Ribose
(in RNA)
(c) Nucleoside components
Pyrimidines
Purines

31. The Devil is in the Details
• There are two families of nitrogenous bases
– Pyrimidines (cytosine, thymine, and uracil)
have a single six-membered ring
– Purines (adenine and guanine) have a six-
membered ring fused to a five-membered ring
• In DNA, the sugar is deoxyribose; in RNA, the
sugar is ribose
31

32. The Devil is in the Details
• The nitrogenous bases in DNA pair up and form
hydrogen bonds: adenine (A) always with
thymine (T), and guanine (G) always with
cytosine (C)
• Called complementary base pairing
• Complementary pairing can also occur between
two RNA molecules or between parts of the
same molecule
• In RNA, thymine is replaced by uracil (U) so A
and U pair
32

33. Sugar-phosphate
backbones
Hydrogen bonds
Base pair joined
by hydrogen bonding
Base pair joined
by hydrogen
bonding
(b) Transfer RNA
(a) DNA
5 3
5
3

35. Large macromolecular assemblies
Protein Complexes & Nucleoproteins
• Protein Complexes

36. Nucleoprotein,
• It is a conjugated protein - Protein linked to a nucleic acid --
DNA or RNA.
• The protein combined with DNA is commonly either histone or
protamine; those nucleoproteins are found in chromosomes.
• Typical nucleoproteins include
ribosomes,
nucleosomes
viral nucleocapsid proteins.
Deoxyribonucleoproteins
- a complex of DNA and protein
- Participate in regulating DNA replication and transcription
Ribonucleoproteins
- a complex of ribonucleic acid and RNA-binding protein
- Involves in transcription, translation and regulating gene expression
& regulating metabolism of RNA