SEMESTER – II
DSC – 1B
APMB 121 MOLECULAR BIOLOGY (3 credits)
Unit - I
History of molecular biology, DNA and RNA as genetic materials, experiments of Griffith, Avery, Macleod and McCarty. Hershey and Chase, Leaderberg and Tatum, Chargaff’s principles, primary and secondary structure of DNA and RNA. Alternative forms of DNA double helices – types of RNA.
Unit - II
DNA replication in prokaryotes: Replicons – models of DNA replication – origin and termination of replication – rolling circle replication – proof for semi conservative replication (Meselson and Stahl Experiment) – enzymes and proteins involved in DNA replication (nucleases, polymerases, ligases,helicases, gyrases, single strand binding protein, replisome and primosome) – mechanism of semi discontinuous replication.
Unit - III
Steps involved in transcription of prokaryotes, promoters, transcription factors, RNA polymerases I, II and III – ribosomal RNA transcription and processing – genetic code, deciphering the genetic code, characteristics of genetic code, Wobble hypothesis, central dogma of life and reversal of central dogma.
Unit - IV
Steps involved in translation of prokaryotes – role of proteasomes in protein degradation – mechanism of action of antibiotics on protein synthesis (puromycin, chloramphenicol and streptomycin). Regulation of gene expression in prokaryotes – polycistronic mRNA and operons (lac operon and trp operon and attenuation mechanism).
Unit - V
Mutation: spontaneous and induced mutations – UV and X - rays – mechanism of action of base analogues, alkylating agents, intercalating agents and teratogens – reversion suppressor mutations and mutation rate – repair of damaged DNA - excision repair, SOS, photoreactivation – CRISPR and their role in genome stability.
Text Books
1. Verma P.S. and Agarwal V.K. (2016) Cell Biology (Cytology, Biomolecules, Molecular Biology), Paperback, S. Chand and Company Ltd.
2. McLennan A., Bates A., Turner P. and White M. (2012) Bios Instant Notes Molecular Biology, 4th Edn. Taylor & Francis.
Reference Books
1. Watson J.D., Baker T.A., Bell S.P., Gann A., Levine M., Losick R. and Harrison S.H. (2014) Molecular Biology of Gene, 7th Edn. Pearson Benjamin - Cummings.
2. Cox M.M., Doudna J.A. and O’ Donnell M. (2012) Molecular biology: Principles and Practice, WH Freeman and Company.
3. Lodish H., Berk A., Kaiser C.A., Krieger M., Bretscher A., Ploegh H., Amon A. and Martin K.C. (2016) Molecular Cell Biology, 8th Edn. WH
Freeman and Company.