1.3

Question 1

what is rna

Answer 1

single stranded, made up of a ribose sugar, nucleotides and bases

Question 2

what is used instead of thymine in rna

Answer 2

uracil

Question 3

what does mRNA do

Answer 3

carries a copy of the dna code to the nucleas from the ribosome

Question 4

what is the structure of tRNA

Answer 4

its single stranded and folds due to the complementary base pairing , each carries a specific amino acid

Question 5

what are the stages of transcription

Answer 5

1. RNA polymerase unwinds dna and breaks hydrogen bonds
2. a primary transcript of mRNA is made using RNA nucleotides
3. these form hydrogen bonds with exposed dna strand in a complementary base pair
4. rna splicing forms a mature mRNA transcript

Question 6

what happens during mRNA splicing

Answer 6

introns are removed and the remaining exons are joined together

Question 7

how can different proteins be expressed by the same gene

Answer 7

alternative rna splicing , depending on which exons are retained

Question 8

what are the stages of translation

Answer 8

1. the first codon of mRNA molecule is a start codon, starting translation
2. the anti codons and codons match up to form complementary base paring , making a sequence of amino acids
   3.peptide bonds form between amino acids forming the polypeptide chain

Question 9

where does translation happen

Answer 9

in the cytoplasm

Question 10

where does transcription happen

Answer 10

the nucleas

Question 11

how does a polypeptide chain form a protein

Answer 11

chains fold to form a protein which is held together by hydrogen bonds