Lecture 3 - DNA Flashcards
What is Hereditary information important for ?
Passing genetic information from cell to cell
How is DNA stable?
Because it has a lot of Hydrogen bonds
Why is DNA being a large molecule important?
Because it can’t hold a lot of information
Helical/ coiled so ?
Compact
What does base sequence allow?
Information to be stored and for base sequence to code for amino acids
Why are weak Hydrogen bonds important?
So the 2 strands can be unzipped so both strands can act as a template
How is Prokaryotic DNA?
DNA molecules are short, circular, not associated with proteins
How is Eukaryotic DNA?
DNA molecules are long, thin, linear and associated with proteins called histones.
How many chromosomes in humans ?
46 chromosomes and 23 pairs of Homologous chromosomes
Homozygous
A pair of homologous chromosomes carrying the same alleles for a single gene
Heterozygous
A pair of homologous chromosomes carrying two different alleles for a single gene.
Name me 2 nucleic acids
DNA and RNA
Name me the components of DNA
Deoxyribose sugar
Nitrogenous base
phosphate group
Describe Structure of DNA
Polymer of nucleotides
Made from D N P
Phosphodiester Bonds between nucleotides
2 strands held together by H bonds
H bonds between A-T and C-G
Sugar Phosphate back hone
RNA structure
Single sugar-phosphate backbone
Sugar (ribose)
Uracil
Single polynucleotide
Shorter
mRNA, tRNA and rRNA
Name the 2 Purines
Adenine + Guanine
Name the 3 Pyrimidines
Cytosine + Thymine + Uracil
Pyrimidines
one 6 membered ring of carbon and nitrogen atoms) C,T,U
Purines
(larger 6 membered ring fused to a 5 membered ring) A,G
What is the name of the bond in between 2 nucleotides?
Phosphodiester
What is the name of the bond broken during DNA replication?
Hydrogen
If 30% of the bases in a DNA molecule are adenine, what % of the bases are guanine?
20%
If you can see the Nitrogenous base what’s the other 2 components?
Deoxyribose and Phosphate
