Nucleic acids Flashcards
2 main types of nucleic acids
- Deoxyribonucleic acid (DNA)
2. Ribonucleic acid (RNA)
What is nucleic acids?
consist of either one or two long chains of repeating units (nucleotides)
Nucleotides consist of a ___ attached to a sugar phosphate backbone.
a nitrogen base (a purine or pyrimidine)
If the sugar is ribose, the polymer is ___
RNA
If the sugar is deoxyribose, the polymer is ___
DNA
Building blocks of DNA/RNA consist of
- pentose sugar (5 carbon sugar)
- a nitrogenous base
- a phosphate group (acidic)
All 3 components (pentose sugar, nitrogenous base & phosphate group) are linked through ____ reactions.
condensation
What is polynucleotide synthesis?
phosphate of one nucleotide is joined to the pentose of the next nucleotide by phosphodiester bond
What is polynucleotide chain?
the 5’ position of one pentose sugar is connected to the 3’ position of the next pentose sugar by a phosphate group
Who propose structure of DNA?
Watson & Crick (1953)
DNA consists of
two polynucleotide chains coiled together in a double helix
The two chains of DNA are in ____orientation
anti-parallel
opposite directions
What are the components that form backbones outside of helix for DNA?
- sugar (deoxyribose)
- phosphate
Nitrogenous bases are ___ inside the helix & held by___.
- paired
- H bonds
What are the specific pairing of nitrogenous base?
- A&T
2. G&C
DNA structure is stablised by
- H bonds between paired bases
- Hydrophobic forces between stacked bases
Diameter of DNA helix
2 nm
Distance between base pairs
0.34 nm
A complete turn of DNA helix consists of ___ base pairs with a distance of ___.
- 10
- 3.4 nm
What is the function of DNA?
to store & transmit genetic information
The sequence of bases acts as information storage in the form of___to build protein.
codes
Base pairing allows ___ of complementary strand.
replication
copying of genetic information to pass on to next generation
The structure of RNA
short, single stranded polymer consists of RNA nucleotides
Function of ribosomal RNA (rRNA)
rRNA combined with proteins to form ribosomes
Function of messenger RNA (mRNA)
contains genetic information copied from DNA
Function of transfer RNA (tRNA)
transfer amino acids from cytoplasm to ribosome
