AQA AS Biology DNA

Sarah H-V
Mind Map by Sarah H-V, updated more than 1 year ago
Sarah H-V
Created by Sarah H-V almost 6 years ago


A Levels Biology Mind Map on AQA AS Biology DNA, created by Sarah H-V on 03/05/2014.

Resource summary

AQA AS Biology DNA
1 Nucleotides
1.1 Nitrogen containing base - adenine, cytosine, guanine and cytosine
1.2 Deoxyribose/Pentose Sugar
1.3 Phosphate group
2 Bases
2.1 Adenine and guanine - pyramidine bases/double ring structure
2.2 Cytosine and thymine - purine bases/single ring structure
2.3 Adenine is complementary to thymine - 2 hydrogen bonds
2.4 Cytosine is complementary to guanine - 3 hydrogen bonds
3.1 Uracil replaces thymine
3.2 There is a ribose sugar instead of a deoxyribose sugar
3.3 It is single stranded whilst DNA is double stranded
4 Protein Synthesis
4.1 Process by which proteins are made in cells
4.2 Transcription


  • 1. Hydrogen bonds break between base pairs - DNA strands unzip 2. Free RNA nucleotides form complementary base pairs using one DNA strand as a template (produces mRNA strand)3. Newly formed mRNA strand leaves nucleus through nuclear pores.
4.3 Translation


  • 1. mRNA strand binds to a ribosome 2. Amino acids in cytoplasm become attached to tRNA molecules (they are specific) 3. Anticodon on the tRNA binds to codon on mRNA molecule according to complementary base pairing. 4. Next codon from mRNA allows tRNA anticodon to bind. A peptide bond joins the amino acids. 5. Ribosome moves along the mRNA molecule until all amino acids are linked. 6. Polypeptide chain then dissociates from the ribosome.
5 Triplet Code
5.1 Code is degenerate as most amino acids have 1+ triplet code
5.2 Non - overlapping - each base is only read once
5.3 Three triplet codes don't code for any amino acid (stop codes). They mark the end of a polypeptide chain
5.4 Universal - the same in all organisms
6 DNA - triplet code mRNA - codons tRNA - anticodons

Media attachments

Show full summary Hide full summary


GCSE AQA Biology - Unit 2
James Jolliffe
GCSE AQA Biology 1 Quiz
Lilac Potato
Biology AQA 3.2.5 Mitosis
Biology AQA 3.1.3 Cells
GCSE Biology AQA
AQA Biology 8.1 structure of DNA
Charlotte Hewson
B3 Quiz
Tess Brockway
Enzymes and Respiration
I Turner
Cells - Biology AQA B2.1.1
Biology Unit 1a - GCSE - AQA
B1.1.1 Diet and Exercise Flash Cards