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4.1 DNA, genes & chromosones - Coggle Diagram

- - - - compact structure formed when DNA is wound round histone proteins
    - - pair of chromosomes that are the same size, same shape ad contains the same genes in the same position (locus)
    - - when all the chromosomes in a cell are arranged in their homologous pairs
- - - - a sequence of DNA bases that codes for a sequence of amino acids in a polypeptide or for functional RNA
    - - the position of a gene on a chromosome
    - - a form of a gene
    - - DNA base sequences that don't code for amino acid sequences - can be inbetween genes (intergenic DNA) or within genes (introns) the coding part of genes are called exons
    - - made of base triplets- each sequence of three bases codes for a specific amino acid.
      - the genetic code is degenerate - the same amino acid can be coded for by more than one base triplet
      - the genetic code is universal - all organisms use the same code - the same triplets always code for the same amino acids
      - the genetic code is non-overlapping, each base is only part of one triplet
- - - - long strands (normally thousands of nucleotides) single polynucleotide
      - the base sequence is determined by the sequence of bases in a length of DNA in transcription
      - acts as a template for protein synthesis
      - contains codons
      - contains sugar phosphate backbone and nitrogenous bases (U,A,C,G)
      - associates with ribosome where it passes information in the form of codons, the sequence of codons determines the amino acid sequence of a specific polypeptide
    - - small molecule single stranded/single polynucleotide
      - folded into a clover leaf shape
      - contains an amino acid binding site
      - contains an anticodon (3 bases) complementary to mRNA codon
      - brings specific amino acid to ribosome, each tRNA molecule is specific to one amino acid