gene expression 1.3

Question 1

genotype

Answer 1

the genetic material that an organelle possesses

Question 2

phenotype

Answer 2

the physical appearance of an organism

Question 3

what determines an organelles genotype

Answer 3

sequence of dna bases in its genes

Question 4

what determines an organisms phenotype

Answer 4

the proteins that are produced as a result of expression

Question 5

what determines the structure and function of a protein

Answer 5

the sequence of amino acids

Question 6

messenger rna function

Answer 6

copies code from the dna molecule and carries it out to the ribosome where the proteins are synthesised

Question 7

transfer rna function

Answer 7

attaches to a specific amino acid
transport amino acid to the ribosome
joins together with codon of mrna with anti codon of trna

Question 8

ribosomal rna function

Answer 8

bound to structural proteins so form a ribosome. used in the synthesis of proteins.

Question 9

what is a ribosome made of

Answer 9

rRNA and protein

Question 10

what does rna polymerase do to the gene

Answer 10

unzips and unwinds the dna strands by breaking hydrogen bonds exposing a single template strand of DNA

Question 11

how do free rna nucleotides bind to the dna strand

Answer 11

using base paring rules with weak hydrogen bonds between bases and strong covalent bond between phosphate of one nucleotide and the ribose sugar of the next

Question 12

how is the addition of free rna nucleotides controlled

Answer 12

by rna polymerase

Question 13

what direction ae free rna nucleotides added

Answer 13

only at the 3’ end in a 5’ to 3’ direction

Question 14

when does the mrna stop copying the dna sequence

Answer 14

when a stop codon is reached

Question 15

what happens once the stop codon is reached

Answer 15

the rna polymerase and mRNA strand are released

Question 16

rna splicing

Answer 16

introns (non coding regions) are removed
exons (coding regions) are retained and joined together to form mature transcript of mRNA
(order of exons are unchanged)

Question 17

where does the mature transpript go after splicing

Answer 17

out of a nuclear pore into the cytoplasm to attach to a ribosome

Question 18

different mature mRNA transcripts are produced from the same transcript depending on what exons are retained

Answer 18

alternative RNA splicing

Question 19

the site of protein synthesis

Answer 19

ribosome

Question 20

translation summary

Answer 20

the synthesis of a protein molecule as a polypeptide under the direction of mRNA codons that code for a specific amino acid

Question 21

what are the triplet of bases on tRNA called

Answer 21

anti-codon

Question 22

trna has an attachment site for…..

Answer 22

a specific amino acid

Question 23

where does the trna carry the specific amino acid

Answer 23

to the ribosome to be attached to the growing end of the poly peptide chain

Question 24

each codon on the mRNA codes for

Answer 24

an amino acid

Question 25

the tRNA molecule binds briefly tot he mrna codon and the amino acid is then….

Answer 25

added to the polypeptide chain being synthesised

Question 26

amino acids are joined together by

Answer 26

peptide bonds (type of covalent bond)

Question 27

poly peptide chains are joined together by

Answer 27

covalent bonds

Question 28

proteins are made of

Answer 28

carbon, hydrogen, oxygen, nitrogen

Question 29

primary structure of protein

Answer 29

initial amino acid sequence linked by strong peptide bonds to for a polypeptide chain

Question 30

secondary structure of proteins

Answer 30

coiling and folding of the polypeptide chain due to hydrogen bonds