dna, rna + protein synthesis

gene?

section of DNA on a chromosome that codes for the production of a polypeptide/ functional RNA

functional RNA?

RNA other than mRNA

• tRNA

• rRNA

genome?

full set of DNA in an organism

proteome?

full range of proteins a cell is able to produce/DNA is able to code for

genetic code?

rules by which triplets in a DNA base sequence code for the sequence of amino acids in a polypeptide chain

features of genetic code?

degenerate

universal

non-overlapping

degenerate?

more than one triplet of bases can code for a particular amino acid

non-overlapping?

each base in a sequence is read once, and only part of one triplet

universal?

the same triplet of bases codes for the same amino acid in all living things

chromosome structure?

• DNA double helix structure

• is wound around histone proteins

• DNA-protein complex coils to form loops

• loops coil and pack together, to form a chromosome

transcription process?

• H bonds between DNA bases break, separating the strands and exposing the bases

• 1 strand acts as a template

• free RNA nucleotides align w/ complimentary bases

• RNA polymerase joins and forms phosphodiester bonds between them

• forming pre-mRNA

what takes place before translation?

pre-mRNA spliced to remove introns, forming mRNA

leaves nucleus via nuclear pores

translation process?

• mRNA attaches to ribosome that finds start codon

• tRNA anticodon with an amino acid attaches to complimentary one on mRNA via complimentary base pairing

• process repeats with next complimentary codon bringing another amino acid

• ribosome attaches amino acids by peptide bonds via ATP

• catalysed by an enzyme

• ribosome move along mRNA + process repeats until stop codon reached

• polypeptide chain released

what is RNA made up of?

ribose sugar
nitrogenous base
phosphate group

features of RNA?

short
single stranded so no base pairing
AU, GC
no H bonding

features of tRNA?

found in cytoplasm
single stranded, folds to form clover shape held in place by H bonds

function of tRNA?

attach to amino acid + transfer to ribosome for polypeptide chain
contains anticodon that binds to complimentary on on mRNA