dna genes and chromsomes and protein synthesis 4.1/2

Question 1

similarities in dna in euk and prok

Answer 1

the nucleotide structure identical deoxyribose attached to phosphate and base
adjacent nucleotides joined by phosphodiester bonds
comp bases joined by hydrogen bonds
dna in mitochondria have similar strucutre to prok as its short and circular and not associated with protiens

Question 2

how is euk and prok dna different

Answer 2

euk dna long and linear but prok is short and circular
euk dna associated with histones
euk dna introns

Question 3

chromsome

Answer 3

long linear dna associated with histones in the nucleus of euk cells

Question 4

gene

Answer 4

sequence of dna bases that code for a AA seq of polypeptide
or functional RNA

Question 5

locus

Answer 5

fixed position a gene occupies on a particular dna molecule

Question 6

universal

Answer 6

the same base triplets code for the same amino acid in all living organisms

Question 7

non coding base sequence

Answer 7

dna that doesnt code for an amino acid sequence
between genes
or within are introns

Question 8

tRNA vs mrna

Answer 8

both are single polynucleotide strands
tRNA - clover leaf shape but mrna is straight and linear
tRNA has hydrogen bonds between paired bases mrna doesnt
tRNA is a short fixed length whereas mrna is a long variable length
tRNA has anticodons mrna has codons
tRNA has an amino acid binding site

Question 9

transcription

Answer 9

h bonds between dna base break
only one strand acts as a template
free rna nucleotides align next to comp base pairs on template strand
rna u replaces t
rna polymerase joins adjacent nucleotides
forming phosphodiester bonds via condensation
pre mrna formed and spliced to remove introns

Question 10

translation

Answer 10

mrna attaches to ribosome
ribosome moves to start codon
tRNA brings a specific AA
tRNA anticodon binds to comp mrna codon
ribosome moves to next codon and another tRNA binds so 2 AA joined by condensation forming peptide bond using energy from hydrolysis of atp
tRNA released after AA joined polypeptide
ribosome moves along mrna to form the polypeptide till stop codon reached

Question 11

atp role in translation

Answer 11

hydrolysis of atp to adp and pi releases energy
so amino acids join tRNA and peptide bonds form between amino acids

Question 12

tRNA

Answer 12

attaches to and transports specifc amino acids in relation to its anticodon
tRNA anticodon - comp base pair to mrna codon forming hydrogen bonds
2 trnas bring amino acids together so peptide bonds can form

Question 13

ribosomes

Answer 13

mrna bind to ribosome with space for two codons
allows trna with anticodon to bind
catalysis formation of peptide bonds between amino acids
moves along mrna to the next codon