L6: DNA as genetic material Flashcards
(31 cards)
What was DNA discovered as in 1869?
Nuclein
What are the 4 bases in DNA?
Adenine
Thymine
Guanine
Cytosine
Define nucleotide
A molecule made up of a nitrogenous base, sugar, and 1 or more phosphate groups
e.g adenosine monophosphate (AMP), deoxyadenosine triphosphate (dATP)
Define nucleoside
A molecule made up of a nitrogenous base & sugar
e.g (deoxy) adenosine, (deoxy) guanosine, (deoxy) cytidine
Define polynucleotide
Combination of nucleotide monomers which are connected through covalent bonds
Which bases are purines?
Adenine & Guanine
Which bases are pyrimidines?
Thymine & Cytosine
Structure of DNA
Right-handed double helix composed of 2 antiparallel sugar-phosphate ‘backbone’
How many hydrogens bond between A-T?
2
Where are the nitrogenous bases pair on the helix?
Inside
How many hydrogen bonds between C-G?
3
What is the direction of DNA backbone?
5’ to 3’
How can hydrogen bonds be disrupted?
Heat or chemicals
When does the major groove in DNA occur?
When backbones are far apart
When does the minor groove in DNA occur?
When they are close together
What is the major groove like in an RNA molecule?
Narrow & deep
What is the minor groove like in an RNA molecule?
Wide & shallow
What makes up a nucleoside?
Base + Sugar
What makes up a nucleoside triphosphate?
Base + Sugar + Triphosphate
What makes up a nucleotide?
Base + Sugar + Phosphate
What is a nucleotide sequence that pairs with another given sequence ?
The reverse complement of the original sequence
What is genomic DNA?
DNA that represents the entire genome
How is DNA in eukaryotic cells?
Homologous pairs of linear chromosomes in the nucleus
How is DNA in prokaryotic cells?
Single circular chromosome in the cytoplasm
