3.1.5.1 Structure of DNA and RNA Flashcards
What is a nucleotide?
The monomer of nucleic acid (a polynucleotide)
Which three parts is a nucleotide made up of?
A phosphate group - gives acidic nature
Pentose sugar - ribose(RNA) and deoxyribose(DNA)
Nitrogenous base - 5 different types
What is the name of the bond formed between nucleotides during a condensation reaction?
Phosphodiester bond
How are the phosphodiester bonds bonded between nucleotides?
Between carbon 3 of pentose sugar of one nucleotide and carbon 5 of phosphate group of another nucleotide
How do RNA and DNA differ in pentose sugar?
RNA - ribose (OH)
DNA - deoxyribose (H)
How do RNA and DNA differ in bases?
RNA - AUCG
DNA - ATCG
How do RNA and DNA differ in number of strands?
RNA - usually single
DNA - always double
How do RNA and DNA differ in length?
RNA - shorter (variable length depending on section copied)
DNA - longer
How do RNA and DNA differ in chemical stability?
RNA - less stable
DNA - very stable
What are the three main types of RNA?
m(messenger)RNA, t(transfer)RNA, r(ribosomal)RNA
What is the structure and function of mRNA?
It is a single stranded, uncoiled polynucleotide with unattached bases
It copies the template(un-coding) strand of DNA code which is exported from the nucleus
What is the structure and function of tRNA
It is a single stranded polynucleotide arranged in a clover leaf shape
The top of the tRNA is the amino acid binding site which the anti-codon - found at the bottom of tRNA lines up alongside the appropriate codon on mRNA during protein synthesis
What is it called when a tRNA attaches to an amino acid?
It becomes ‘activated’
What is the structure and function of rRNA?
It is a long length of RNA produced in the nucleolus
It combines with proteins to form ribosomes in the cytoplasm
What bond holds bases together in a double helix?
Hydrogen bonds
A=T, C≡G
