week 10 part 1 Flashcards
microbiology
genetic information flows identically in all current living organisms on earth (central dogma of molecular biology)
role of DNA
information storage
role of RNA
information storage, catalyst
role of proteins
Catalysis (the acceleration of a chemical reaction by a catalyst
nucleotides
the building blocks of dna
strand
a linear polymer strand of DNA
double helix
the two strands of DNA (180DEG TURN IS 3.4 NM!!)
chromosomes
DNA associated with an array of different proteins into a complex structure particularly in eukaryotes`
genome
the complete complement of genetic material in an organism
4 nucleotides that make up DNA
adenine, guanine, thymine, cytosine
nucleotides composed of three components
phosphate group
pentose sugar
nitrogenous base
nitrogenous base types
purines (adenine and guanine)
pyrimidines (cytosine and thymine
nitrogenous base types
purines (adenine and guanine)
pyrimidines (cytosine and thymine
nucleotide numbering system
Sugar carbons are 1’ to 5’
· Base attached to 1’ carbon on sugar
· Phosphate attached to 5’ carbon on sugar
· “What part of the carbon is the base attached?”: 1’
· 2’ tells you if its DNA or RNA
o DNA and RNA Difference on 2’
§ RNA has OH on 2’ (reason why it can destroy itself)
§ DNA has H on 2’
· “5’ Phosphate, 3’ hydroxate”
· 4’ does not do very much
· Number without prime = BASE
· Number with prime = SUGAR (Referred to carbon is base)
DNA strand
Nucleotides are covalently bonded
· Phosphodiester bond
o Phosphate group links two (nucleotides) sugars
§ Between 3’-5’
· Backbone – formed from phosphates and sugars
· Base projects away from backbone
· Directly written 5’ to 3’
· Example: 5’ – TACG – 3’
features of DNA proposed by Watson crick
Double stranded
· Antiparallel strands
· Right-handed helix (B DNA)
· Sugar-phosphate backbone
· Bases on the inside (HYDROPHOBIC)
· Stabilized by H-bonding
· Specific base-paring
· Approximately 10 bp per helical turn
DNA structure
Chargaff’s Rule
· A pair with T (2 hydrogen bonds)
· G pair with C (3 hydrogen bonds)
· Keeps within consistent
· Complementary DNA strands
o 5’ – GCGGATTT – 3’
o 3’ – CGCCTAAA – 5’
· Antiparallel strands
o One strand 5’ to 3’
o Other strand 3’ to 5’
