RNA structure and function

Question 1

what is RNA ?

Answer 1

RNA is a polymer of a nucleotide formed of a ribose , a nitrogenous base and a phosphate group

Question 2

what are the nitrogenous bases in RNA ?

Answer 2

• adenine
• guanine
• cytosine
• uracil

Question 3

what is uracil the base instead of ?

Answer 3

thymine

Question 4

what is the length of the RNA molecule in comparison to DNA ?

Answer 4

RNA molecule is a relatively short polynucleotide chain

Question 5

how many strands does RNA have ?

Answer 5

its a single stranded molecule

Question 6

what is the function of RNA ?

Answer 6

to copy and transfer the genetic code from DNA in the nucleus to the ribosomes

Question 7

what is some RNA combined to do ?

Answer 7

some RNA is combined with proteins to create ribosomes

Question 8

what are the 3 types of RNA ?

Answer 8

• mRNA
• tRNA
• rRNA

Question 9

what is MRNA ?

Answer 9

messenger RNA is a copy of a gene from DNA

Question 10

where is mRNA created ?

Answer 10

in the nucleus

Question 11

what happens to mRNA when it is created in the nucleus ?

Answer 11

the mRNA leaves the nucleus to carry a copy of the genetic code of one gene to a ribosome in the cytoplasm

Question 12

why is mRNA made ?

Answer 12

because DNA is too large to leave the nucleus and would be at risk of being damaged by enzymes therefore destroying the genetic code permanently

Question 13

what is the advantage of mRNA over DNA ?

Answer 13

mRNA is much shorter because it is only the length of one gene and can therefor leave the nucleus

Question 14

what is mRNA described as in terms of its life span ? and why ?

Answer 14

mRNA is short lived
because it is only needed to temporarily create a protein therefore by the time an enzyme could break it down, it has already carried out its function

Question 15

how many mRNA bases code for a specific amino acid ?

Answer 15

every 3 base in the sequence codes for a specific amino acid

Question 16

what are the mRNA’s bases called ?

Answer 16

codons

Question 17

where is tRNA found in ?

Answer 17

tRNa is only found in the cytoplasm

Question 18

what is the structure of tRNA ?

Answer 18

it is single stranded but folded to create a shape that looks like a cloverleaf shape held in place by hydrogen bonds

Question 19

what is the function of tRNA ?

Answer 19

the function of tRNA :
is to attach to one of the 20 amino acids and transfer this amino acid to the ribosome to create the polypeptide chain.

Question 20

wha do specific amino acids do ?

Answer 20

specific amino acids attach to specific tRNA molecules

Question 21

how is the specific amino acids only attaching to specific tRNA determined ?

Answer 21

it is determined by 3 bases found on the tRNA which are complimentary to the 3 bases on mRNA

Question 22

what are the complimentary bases found on tRNA called ?

Answer 22

anticodons

Question 23

what does the attachment for amino acids on tRNA require ?

Answer 23

attachments for amino acid requires ATP and an enzyme to do thsi

Question 24

where is the amino acid attachment site on the tRNA found ?

Answer 24

attachment site is at the top of the tRNA

Question 25

what is ribosomal RNA ?

Answer 25

rRNA is the type of RNA that makes up the bulk of ribosomes

Question 26

what is the function of rRNA ?

Answer 26

it combines with a protein to make a ribosome

Question 27

DNA vs RNA - monomers

Answer 27

• DNA contains thymine whereas RNA contains uracil instead
• DNA contains the pentose sugar deoxyribose where as RNA contains the pentose sugar ribose

Question 28

DNA vs RNA - polymers

Answer 28

• DNA is much larger because it contains the entire genome ( approx 23,000 genes ) whereas RNA is much shorter because it is only one length of a gene
• DNA is double stranded whereas RNA is single stranded