nucleic acids Flashcards
What type of molecule is DNA
A nucleic acid
what does DNA stand for
deoxyribonucleic acid
what does RNA stand for
ribonucleic acid
Functions of DNA
Codes for the specific sequence of amino acids in a protein
Replication in dividing cells
function of RNA
used in protein synthesis
what is the monomer that nucleic acids are made from
nucleotides
Components of nucleotides
Phosphate, pentose sugar, nitrigenous base
what sugar does DNA contain
deoxyribose
what sugar does RNA have
ribose
Names of nitrogenous bases
Adenine, Thymine
Guanine, Cytosine
What are the two categories of nitrogenous bases
purines and pyramidines
Which bases are pyramidines
Thymine, Cytosine, Urasil (T and C have a ‘y’ like pyramidines)
Which bases are purines
Adenine, Guanine
which is the only type of nucleic acid that urasil is found in
RNA
Which bases pair up (complementary base pairs)?
Adenine and thymine
Guanine and cytosine
Tigers Are Great Cats
How many H bonds between A and T
2
how many H bonds between C and G
3
What is the main characteristic of purines
they have 2 rings, pyramidines have 1
structure of molecule of DNA
double stranded helix of anti parallel stands attached by H bonds between bases
By what reaction is a nucleic acid formed
condensation reaction
What structure do pentose sugar with phosphate form
sugar phosphate backbone
What structure do pentose sugar with phosphate form
sugar phosphate backbone
anti parallel strands meaning
two strands with one running in the opposite direction to the other
what makes DNA molecule so stable
anti parallel strands joined by H bonds between bases
How can the direction of strands in DNA be described
One strand runs 5’-3’ based on the number of the carbon atom exposed at the top and bottom of the strand. The other is 3’-5’
how is 3’ said
3 prime
size of DNA
Large: macromolecule, made of a long chain of nucleotides
what type of bonds are between sugar and phosphate group
covalent bonds- very strong
Describe the process of replication of DNA
The 2 DNA strands unwind from the helix shape and seperate
Each parental strand serves as a template
Free DNA nucleotides bind to the template strands
Results in 2 double stranded DNA molecules in the nucleus so when the cell divides each new nucleus contains DNA identical to the original
During which phase of the cell cycle does replication occur
inter phase (just before cell division)
Enzyme that breaks down H bonds between complementary base pairs in DNA replication? ‘unzipping enzyme’
DNA helicase
Enzyme that adds appropriate nucleotides to make each strand a new partner? ‘glueing enzyme’
DNA polymerase
Another name for DNA replication
Semi conservative replication
Explain semi conservative replication
Each daughter DNA molecule consists of one parental strand and one new strand, the parental strands having acted as template strands
how is DNA suited to its function
Base pairs are in the inside of the double helix, so genetic info is protected
Very large so can carry alot of generic info
Two strands can separate bc of H bonds
Very stable molecule
Template?
A molecule of which the chemical structure determines the chemical structure of another molecule
