Plant Biochemistry & Molecular Biology -

Semester-III

Title of the Course: Plant Biochemistry & Molecular Biology
Nature of course : Core/Major-IV
Course code :
Total Credits : 04
Distribution of Marks: 60+40=100

Lectures: 60

Unit 1: Biomolecules: (10 lectures)

Types and significance of chemical bonds; Structure and properties of water; pH and buffers. Carbohydrates: Nomenclature and classification; Monosaccharides; Disaccharides; Oligosaccharides and polysaccharides.
Lipids: Definition and major classes of storage and structural lipids; Fatty acids structure and functions; Essential fatty acids; Triacyl glycerols structure, functions and properties; Phosphoglycerides.
Proteins: Structure of amino acids; Levels of protein structure-primary, secondary, tertiary and quarternary; Protein denaturation and biological roles of proteins.
Nucleic acids: Structure of nitrogenous bases; Structure and function of nucleotides; Types of nucleic acids; Structure of A, B, Z types of DNA; Types of RNA; Structure of tRNA.

Unit 2: Bioenergetics (5 lectures)

Laws of thermodynamics, concept of free energy, endergonic and exergonic reactions, coupled reactions, redox reactions. ATP: structure, its role as a energy currency molecule.

Unit 3: Enzymes (5 lectures)

Structure of enzyme: holoenzyme, apoenzyme, cofactors, coenzymes and prosthetic group; Classification of enzymes; Features of active site (Click here to view details notes), substrate specificity, mechanism of action (activation energy, lock and key hypothesis, induced – fit theroy), Michaelis – Menten equation, enzyme inhibition and factors affecting enzyme activity.

Unit 4: Genetic material and its organization ( 07 lectures)

DNA as the carrier of genetic information (Griffith’s, Hershey & Chase, Avery, McLeod & Mc Carty experiment); denaturation and renaturation of DNA,; Organization of DNA- Prokaryotes, Viruses, Eukaryotes. RNA Structure; Organelle DNA-mitochondria and chloroplast DNA.

Unit 5: Replication and Transcription of DNA (10 lectures)

General principles – bidirectional, semi-conservative and semi discontinuous replication, RNA priming; Various models of DNA replication, replication of linear ds-DNA Click here to view. Transcription in prokaryotes and eukaryotes; Post-Transcriptional modification of RNA Operon concept: Lac
operon and its regulation.

Unit 6: Genetic codes & Translation (08 lectures)

Genetic codes: salient features; Ribosome structure and assembly, mRNA; Charging of tRNA, aminoacyl tRNA synthetases; Various steps in protein synthesis, factors involve in initiation, elongation and termination of polypeptides; Post-translational modifications of proteins.

Laboratory activities (Practical)

1. Qualitative tests for carbohydrates, reducing sugars, non-reducing sugars, lipids and proteins.
2. Cytochemical staining of : DNA- Feulgen and cell wall in the epidermal peel of onion using Periodic Schiff’s (PAS) staining technique.
3. Estimation of plant proteins by Biuret/Lowry method.
4. Estimation of reducing and non-reducing sugars in plant samples.
5. Isolation of genomic DNA
6. DNA estimation by diphenylamine reagent/UV Spectrophotometry.
7. Study of DNA replication mechanisms through photographs (Rolling circle, Theta replication and semi-discontinuous replication).
8. Study of structures of prokaryotic RNA polymerase and eukaryotic RNA polymerase II through photographs.
9. Photographs establishing nucleic acid as genetic material (Messelson and Stahl’s, Avery et al, Griffith’s, Hershey & Chase’s and Fraenkel & Conrat’s experiments)