BT-202 Netaji Subhas Institute of Technology, Dwarka, New Delhi. Dr. Amita Pandey Sept 14, 2011
Deoxyribonucleotide: -dAMP -dGMP -dTMP -dCMP Ribonucleotide: -AMP -GMP -UMP -CMP Nucleoside: -Deoxyadenosine -Deoxyguanosine -Deoxythymidine -Deoxycytidine Nucleoside: -Adenosine -Guanosine -Uridine -Cytidine
Hydrolysis of RNA molecules Mixture of 2’- and 3’- monophoaphate derivatives
DNA structure by Watson and Crick 1953 -hydrophobic interactions -van der Waals interactions -dipole-dipole interactions -hydrogen bonds
- -stable structure taken up by nucleotides
- Frederich Miescher (1868 ): isolated and characterized DNA from leukocytes and called it “ nuclein ” . He found that it was rich in phosphorus and nitrogen.
- O. T. Avery, C. MacLeod, and M. McCarty (1940s) : first time said DNA was the genetic material.
- A.D. Hershey and M. Chase (1952) : confirmed that DNA not protein is the genetic material.
- E. Chargaff (1940s) : “Chargaff’s rules” he said that A = T and G = C.
- R. Franklin and M. Wilkins (1950s) : DNA molecules are helical with two periodicities along their long axis.
- Watson and Crick (1953) :
- -hydrophillic phosphate and deoxyribose on outside
- -hydrophobic bases on inside
- -hydrogen bonding between base pair
- Complementarity laid the foundation for DNA replication
B-form is the most stable A form B-form Z-form -A-form arises dehydration -Z-form is detectable in both bacteria and eukaryotes
- F. Jacob and J. Monod (1961) : proposed the name messenger RNA.
- Transcription: process of forming mRNA on DNA template.
- Monocistronic: mRNA encoding a single polypeptide.
- Polycistronic: mRNA encoding for more than one polypeptide.
mRNA G pairs with C and A pairs with U
- A-form of RNA is predominant form
- Hairpins are most common secondary structures
- rRNA: provides peptidyl transferase activity during translation
- Large subunit (LSU): 18S rRNA
- Small subunit (SSU): 5S, 5.8S, and 28S rRNAs
Reversible denaturation and annealing of DNA -viscosity of DNA -pH -temperature -absorption of UV light -hypochromic effect -hyperchromic effect
Partially denatured DNA
- -higher GC content higher melting temp
- -evolutionary relationship
- Alteration in DNA structure that produce permanent changes in the genetic information
- deamination spontaneously
- Adenine deaminates to Hypoxanthine
- Guanine deaminates to Xanthine
- -apurinic or apyrimidinic
- - cyclobutane pyrimidine dimers
- -deaminating agents eg. Nitrous acid
- -hydrogen peroxide, hydroxyl radicals, and superoxide radicals
- Phosphatidylethanolamine has a net charge of
- Lipids molecules are the only essential components of biological membranes.
- Lipids in bilayer have high ratio of diffusion.
- Glycerophospholipids Cholesterol
- Sphingolipids Phosphatidylcholine
- Lipids containing hydrocarbon chain serve as energy stores.
- Ergosterol is a glucorticoid.
- Polyunsaturated Fas contain multiple bonds.
- Phospholipases are enzymes that catalyz e of glycophospholipids.
- Which of the following is not a complex lipid
- Sphingolipids are significant components of biological membranes.
- Which FA would have a melting temperaturehigher than palmitic acid (16:0)?
Assignment # 4
- Question 2, 5, 6, 8, and 9.