1. Chemistry

2. Session
BIOMOLECULES - 2

3. Session Objectives Enzymes Cofactors Sucrase Mechanism
Carboxypeptidase
Metabolism
DNA and RNA
Lipids
Hormones and Vitamins

4. Enzymes
An enzyme is a protein that acts as a catalyst for a biological reaction.
Most enzymes are specific for substrates while enzymes involved in digestion such as papain attack many substrates

5. Cofactors
In addition to the protein part, many enzymes also have a nonprotein part called a cofactor
The protein part in such an enzyme is called an apoenzyme, and the combination of apoenzyme plus cofactor is called a holoenzyme. Only holoenzymes have biological activity; neither cofactor nor apoenzyme can catalyze reactions by themselves
A cofactor can be either an inorganic ion or an organic molecule, called a coenzyme
Many coenzymes are derived from vitamins, organic molecules that are dietary requirements for metabolism and/or growth

6. Types of Enzymes by Function
Enzymes are usually grouped according to the kind of reaction they catalyze, not by their structures

7. How Do Enzymes Work? Citrate Synthase
Citrate synthase catalyzes a mixed Claisen condensation of acetyl CoA and oxaloacetate to give citrate
Normally Claisen condensation require a strong base in an alcohol solvent but citrate synthetase operates in neutral solution

8. Sucrase Mechanism →

9. Sucrase Mechanism →

10. Active Site of Carboxypeptidase

11. Carboxypeptidase's

12. The Structure of Citrate Synthase
Determined by X-ray crystallography
Enzyme is very large compared to substrates, creating a complete environment for the reaction

13. Aspects of Metabolism Metabolism. The life process. Catabolism.
Substances are broken down.
Anabolism.
Substances are built up.

14. Metabolism Lipid metabolism.
Uptake of fats through walls of intestine.
Glycerol converted to glyceraldehyde-3-phosphate.
Fatty acids are oxidized by –oxidation.
Protein metabolism.
Stomach:
HCl and pepsin hydrolize 10% of peptide bonds.
Intestine:
Trypsin and chymotrypsin cleave peptide fragments further.

15. Components of DNA and RNA
DNA: Deoxyribonucleic acid.
Chromosomes: Double stranded DNA rod-like structures.
Genes: Specific locations on chromasomes that code for specific traits.
RNA: Ribonucleic acid
Contains ribose instead of deoxyribose.
Generally single stranded.

16. DNA Double Helix

17. RNA Single Strand

18. Focus On Protein Synthesis and the Genetic Code
How triplets of the four nucleotides unambiguously specify 20 amino acids, making it possible to translate information from a nucleotide chain to a sequence of amino acids.

19. Transcription
How RNA polymerase, guided by base pairing, synthesizes a single-stranded mRNA copy of a gene’s DNA template

20. Protein Synthesis(Translation)
How base pairing between mRNA and tRNAs directs the assembly of a polypeptide on the ribosome

21. DNA Replication

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23. Lipids

24. Some Common Fatty Acids

25. Saponification

26. Fats and Oils Both are triglycerides.
Differ in the nature of the acid components attached.
Both are colorless, odorless and tasteless
Flavors and aromas come from organic impurites.
Fats.
Predominantly saturated fatty acids.
Normally solid at room temperature
Oils.
Predominantly unsaturated fatty acids.
Liquids at room temperature.

27. Butter

28. “Calorie-Free” Fats

29. Phospholipids

30. Phospholipids

31. Hormones
Hormones are molecules that transfer information from one group of cells to a distant tissue or organ.
They are produced by various endocrine glands.
They are classified on the basis of their structure or site of activity in the cell.

32. Vitamins
They are essential dietary factors required by an organism in minute quantities.
They are essential for life and their absence causes deficiency diseases.
Vitamins catalyze biological reactions in very low concentration
Vitamins are designated A,B,C,D,etc. in order of their discovery. Subgroup vitamins are designated by number subscript e.g. B1,B2,B6,B12
Classification:
Fat soluble
Water soluble

33. Thank you