A1.2 (Nucleic Acids) Flashcards
Nucleic Acid
Polymers of nucleotides such as DNA and RNA
DNA
Deoxyribonucleic acid: Molecule that carries genetic information for development and functioning of an organism
RNA
Ribonucleic acid: A type of nucleic acid that has riobose sugar in its structure and is used by viruses to replicate
How was DNA discovered
Friedrich Miescher performed experiments with white bloodcells which led to DNA extraction as the membrane had to be disintegrated first. this was based on the solubility of DNA in certain substances
Components of as nucleotide
pentose sugar, nitrogenous base, phosphate group
How does sugar phosphate bonding work
nucleotides link together through a covalent bond to form the single strands of DNA/RNA
1. Bond betwen phosphate group and hydroxylgroup attached to 3C
2. releases one molecule of water
3. continuous chain
4. forms strong sugar phosphate backbone
5. forms 2 ends: 3C hydroxyl group and 5C phosphate group
Pure As Gold
Purines: Adenine, Guanine
Nitrogenous bases with two rings
Cut The Pie
Pyrimidines: Cytosine, Thymine, Uracil
Nitrogenous bases with only one ring
features of RNA
- single stranded
*has uracil instead of thymine - has AGUC as nitrogenous bases
- 2C has an OH
Features of DNA
- double stranded
- strands are connected by hydrogen bonds
- has AGTC as nitrogenous bases
- 2C has an H
structure of DNA explained
two polynucleotide chains aree coiled around the same axis in which the bases inside are supported by the sugar phosphate backbone
role of complementary base pairing
- cell division
- gene expression
how does complemetary base pairing affect cell division
dna replicates: CBP maintains base sequnece during copying as it uses 1 strand as template to create a new one (semi conservative)
how does complementary base pairing affect gene expression
Complemetary base pairing ensures that the same protein is produced as the same bases = same code = same protein
Genetic Code
Instructions in a gene in the form of a base sequence that become translated into a functional protein
replication
Copying of DNA to make a new DNA molecule