DNA And RNA Flashcards
Nucleic acids
DNA and RNA are both nucleic acids because they are weak acids found in nuclei of cells.
They are polymers made of monomers called nucleotides.
Nucleotides
Contain CHONP
They contain:
Phosphate group
Penrose sugar
Nitrogenous base
Bases in DNA
Adenine, Guanine, Thymine, Cytosine
A-T
C-G
How is a dinucleotide made
Two nucleotides joined together by condensation reaction between deoxyribose sugar of one nucleotide and phosphate group of another
Bond in DNA
Phosphodiester bond
Strong covalent bonds
Structure of DNA related to its function
Sugar phosphate backbone provide strength and protect bases
large so can store lots of info
helix so compact
base sequence codes for amino acids
double-stranded so strands can act as templates
Complementary base pairing so identical copies can be made
Weak H bonds for strand separation
Many H bonds so stable/strong
How many H bonds between bases
3 H bonds between G-C
2 H bonds between A-T
Replication of DNA
DNA helicase beaks H bonds to separate the strands and these act as templates
These nucleotides complementary base pair to the old strands
DNA polymerase joins the new nucleotides to each other by phosphodiester bonds
This is semi conservative replication
RNA bases
Adenine
Guanine
Uracil
Cytosine
Purine and pyrimidine
Purine - double ring
Pyrimidine - single ring
RNA contains
Phosphate group
Nitrogen containing base
Ribose sugar
Messenger RNA
A copy of genetic info found in a cell’s nucleus
Travels from nucleus to ribosomes
Linear and has 3 codons
Transfer RNA
Found in cells cytoplasm
tRNA transfers amino acids to the mRNA in a ribosome
Folded and has anticodon
Ribosomal RNA
forms part of the structure of ribosomes
Ribosomes made of protein and rRNA
How many polynucleotide strands in RNA
1
