This document defines and describes the main types of biomolecules found in living organisms. It begins by explaining that chemical analysis of tissues reveals elements like carbon, hydrogen and oxygen that are present in higher concentrations than in non-living materials. The document then defines biomolecules as the carbon compounds present in living cells, dividing them into macromolecules and micromolecules. It provides examples of different classes of biomolecules including proteins, carbohydrates, lipids, nucleic acids and their monomers. The document explains how to analyze the chemical composition of tissues and describes some of the key properties and examples of amino acids, lipids, carbohydrates and nitrogen bases that make up nucleic acids. It concludes by distinguishing between primary metabolites

1. BIOMOLECULES
Dr. Harinatha Reddy
Assistant Professor
Department of Microbiology

2. • Chemical analysis on a plant tissue, animal tissue or a
microbial paste..
• we obtain a list of elements like
• carbon,
• hydrogen,
• oxygen
• and several others ..

3. • If the same analysis is performed on a earth’s crust as
an example of non-living matter:
• we obtain a similar list.
• However, carbon and hydrogen elements is higher in
any living organism than in earth’s crust..

4. The element present in highest concentration in body is : Oxygen
Lowest is : Si

5. What are biomolecules?
• All the carbon compounds present in living cell called
‘biomolecules
Biomolecules
Bio Macromolecules Bio Micromolecules
Proteins
Polysaccharides
Nucleic acids
Amino acids
Monosaccharide's
(Glucose, Fructose)
Nucleotides
Lipids
Vitamins Molecular weight:
18 to 800 daltons (Da)

6. How to analyse chemical composition?
(Cl3 CCOOH)
Living tissue

7. How to analyse chemical composition?
• We can take any living tissue (a vegetable or a piece of
liver, etc.)..
• and grind it in trichloroacetic acid (Cl3 CCOOH) using a
mortar and a pestle.
• We obtain a thick slurry.

8. • If we were to strain this through a cheesecloth or
cotton we would obtain two fractions.
• One is called the filtrate or, the acid-soluble pool,..
• The second, the retentate or the acid-insoluble fraction.
• Scientists have found thousands of organic compounds
in the acid-soluble pool.

9. • Analytical techniques, applied to the compound give us
an idea of the molecular formula and the probable
structure of the compound.

10.  However, living organisms have inorganic elements and
compounds in them.
 How do we know this?

11. • One weighs a small amount of a living tissue (say a leaf
or liver) and dry it.
• All the water, evaporates.
• The remaining material gives dry weight.

12. • Now if the tissue is fully burnt,..
• All the carbon compounds are oxidised to gaseous form
CO2 and water vapour are removed.
• What is remaining is called ‘ash.

13. • This ash contains inorganic elements:
• like calcium, magnesium etc.
• Inorganic compounds:
• like sulphate, phosphate, etc.
• Inorganic element and compounds are also seen in the
acid-soluble fraction.

14. Amino acids

15. Amino acids are organic compounds..
• Amino acids contain an amino group and Carboxylic
acid groups attached α-carbon.
• Hence, they are called α-amino acids.

16. • There are four substituent groups occupying the four
valency positions.
• These are hydrogen, carboxyl group, amino group and a
variable group designated as R group.

17. • Based on the nature of R group there are 20 amino
acids.
• Amino acids occur in proteins..

19. • The R group in amino acids could be a hydrogen (the
amino acid is called glycine),
• a methyl group (alanine),
• hydroxy methyl (serine), etc.

20. • The chemical and physical properties of amino acids are
essentially of the amino, carboxyl and the R functional
groups.
• Based on number of amino and carboxyl groups:
• Acidic: glutamic acid and Aspertic acid.
• Basic: lysine and Arginine.
• Neutral: valine, glycine, serine, alanine
• Aromatic : tyrosine, phenylalanine, tryptophan.

22. • A particular property of amino acids is the ionizable
nature of –NH2 and –COOH groups.
• Hence in solutions of different pHs, the structure of
amino acids changes.
• B is called zwitterionic form

23. Lipids

24. • Lipids are generally water insoluble.
• They could be simple fatty acids.
• A fatty acid has a carboxyl group attached to an R group.
• COOH----R
• The R group could be a methyl (–CH3 ), or ethyl (–C2H5 )
or higher number of –CH2 groups (1 carbon to 19
carbons).

25. • Palmitic acid has 16 carbons including carboxyl carbon.
• It is Saturated lipid.
• COOH—(CH2)14—CH3
• Arachidonic acid has 20 carbon atoms including the
carboxyl carbon.
• It is Unsaturated.
• COOH—(CH2)18=CH3

26. • Fatty acids could be saturated (without double bond)..
• Unsaturated (with one or more C=C double bonds).

27. • Another simple lipid is glycerol which is trihydroxy
propane.
• Many lipids have both glycerol and fatty acids.

28. • Here the fatty acids are found esterified with glycerol.
• They can be then monoglycerides, diglycerides and
triglycerides..

29. • Lipids are also called fats and oils based on melting
point.
• Oils have lower melting point (e.g., gingely oil) and
hence remain as oil in winters..

30. Some lipids have phosphorous
• These are phospholipids.
• They are found in cell membrane.
• Lecithin is one example.

31. • Some tissues especially the neural tissues have lipids
with more complex structures…

32. Carbohydrates
1. Monosaccharide's:
2. Disaccharides
3. Polysaccharides

33. Nitrogen bases

34. Nitrogen bases
• Two types of nitrogen bases
• Purines: (Adenine and Guanine)
• Pyrimidines: (Cytosine, Thymine and Uracil)

35. Nitrogen bases are heterocyclic rings
• When Nitrogen bases attached to a sugar, they are
called nucleosides.
• If a phosphate group is also found esterified to the
sugar they are called nucleotides.

36. • Nitrogen bases are: adenine, guanine, cytosine, uracil,
and thymine.
• Nucleosides: Adenosine, guanosine, thymidine, uridine
and cytidine.
• Nucleotides: Adenylic acid, thymidylic acid, guanylic
acid, uridylic acid and cytidylic acid.

37. Nucleic acids are DNA and RNA.
• DNA and RNA Polymer of nucleotides.
• DNA and RNA function as genetic material..

39. Primary and secondary metabolites

40. Primary metabolites:
• Biomolecules, have thousands of organic compounds
including amino acids, sugars, proteins, nucleic acids
etc.
• biomolecules also known as primary metabolites..
• Primary metabolites play known roles in normal
physiologial processes

41. Secondary metabolites
• Plant, fungal and microbial cells, have thousands of
compounds other than these called primary metabolites..
• alkaloids,
• flavonoids,
• rubber,
• essential oils,
• antibiotics,
• coloured pigments,
• scents,
• gums,
• spices.
• These are called secondary metabolites

42. • we do not at the moment, understand the role or
functions of all the ‘secondary metabolites’ in host
organisms.
• However, many of them are useful to ‘human welfare’
(e.g., rubber, drugs, spices, scents and pigments).
• Some secondary metabolites have ecological
importance.

44. THANK YOU::::::::