Nucleic Acids

Mind Map by hloujefferies, updated more than 1 year ago
Created by hloujefferies about 5 years ago


Biology Mind Map on Nucleic Acids, created by hloujefferies on 16/04/2015.

Resource summary

Nucleic Acids
1 DNA (deoxyribonucleic acid)
1.1 DNA = a polynucleotide made up of lots of nucleotides joined together. the nucleotides join up by a condensation reaction between the phosphate group of one nucleotide and the sugar of another.
1.1.1 each nucleotide is made from a deoxyribose sugar, a phosphate group and a nitrogen containing base
1.1.2 each nucleotide has the same sugar and phosphate. the bases can vary. there are four possible bases Adenine Thymine Guanine Cytosine
1.1.3 two DNA polynucleotide chains join together by hydrogen bonding between the bases. each base can only join with one particular partner. (complementary base pairing) Adenine always pairs with Thymine Guanine always pairs with Cytosine A purine always pairs with a pyrimidine two hydrogen bonds form between A and T and three hydrogen bonds form between G and C. two antiparallel polynucleotide strands, twist to form the DNA double-helix
1.1.4 nucleotides are the monomers of nucleic acids
1.2 DNA replication
1.2.1 DNA replicates semi-conservatively 1) the hydrogen bonds between the two polynucleotide DNA strands break. the helix unzips to form two single strands. 2) each original single strand acts as a template for a new strand. free floating DNA nucleotides join to the exposed bases on each original template strand by complementary base pairing. 3) the nucleotides on the new strand are joined together by the enzyme polymerase. hydrogen bonds form between the bases on the new and original strand. 4) each new DNA molecule contains one strand from the original DNA molecule and one new strand.
2 RNA (ribonucleic acid)
2.1 the structure of RNA differs from DNA in 3 main ways
2.1.1 the sugar is a ribose sugar
2.1.2 the nucleotides form a single polynucleotide strand
2.1.3 Uracil (a pyrimidine) replaces Thmyine as a base. Uracil always pairs with Adenine
2.2 there are 3 forms of RNA
2.2.1 messenger RNA (mRNA) made as a strand complementary to one strand of DNA (template strand). it is a copy of the coding strand of DNA.
2.2.2 ribosomal RNA (rRNA) is found in ribosomes
2.2.3 transfer RNA (tRNA) carries amino acids to the ribosomes where they are bonded together to form polypeptides.
2.3 protein synthesis
2.3.1 the sequences of bases on DNA makes up the codes for a particular protein. these bases can be exposed by splitting the hydrogen bonds that hold the double helix together in that region. RNA nucleotides form a complementary strand (mRNA) which peels away and leaves the nucleus through a nuclear pore. the mRNA attaches to a ribosome. the tRNA molecules bring bring amino acids to the ribosome in the correct order. the amino acids are joined together by peptide bonds to give a protein with a specific primary structure.
3 Genes
3.1 a gene is a sequence of DNA nucleotides that codes for a protein. (a polypeptide)
3.2 its the order of nuleotide bases in a gene that determines the order of amino acids in a particular protein
3.2.1 each amino acid is coded for by a sequence of three bases in a gene
4 too much nucleic acid causes gout
4.1 uric acid is produced when excess purines are broken down in the liver. it is secreted in the urine however some people have too much uric acid in their blood. the uric acid is insoluble at lower temperatures and forms crystals that are deposited in joints at the extremeties, such as the toes.
Show full summary Hide full summary


Biology B1.1 - Genes
F211: Transport in animals keywords and info
Gurdev Manchanda
Exchange surfaces and breathing
Jessica Phillips
Unit 1 Cells, exchange and transport (F211) - cells
DNA Basics
Sarah Juliette B
DNA questions not from the lectures
Biology- Genes, Chromosomes and DNA
Laura Perry
Function and Structure of DNA
Elena Cade
Biological Definitions
Cell Structure