dna, rna + protein synthesis

gene?

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

euk dna vs prok dna?

euk: longer, linear, associated w/ histone proteins, contain introns

prok: shorter, circular, no introns

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

non-coding base sequences?

sequence that dont code for amino acid sequence - introns

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 + 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 via condensation

• forming pre-mRNA, which is spliced to form 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

• ribosome moves to next complimentary codon bringing another amino acid + process repeats

• ribosome attaches amino acids by peptide bonds via ATP + condensation

• 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

tRNA v mRNA?

trna: clover shape held by H bonds, shorter, anticodons, amino acids, binding site

mrna: straight, longer codons

function of tRNA?

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

triplet code?

sequence 3 DNA bases code for amino acid

production of mRNA in euk.vs prok?

euk: pre-mRNA produced, introns

prok: mRNA madę directly, no introns due to splicing

role of ATP in translation?

energy so amino acids can join to tRNA and peptide bonds form

role of tRNA in translation?

attaches to specific amino acid

anticodon pairs to complimentary mRNA codon, forming H bonds

bring amino acids together for peptide bond formation

role of ribosomes in translation?

mRNA binds to ribosome w/ space for 2 codons

allows tRNA codon to bind

catalyses peptide bond formation

moves along mRNA to next codon