RNA

Question 1

What does RNA stand for?

Answer 1

• Ribonucleic acid.

Question 2

True or False

RNA is a monomer that makes up DNA.

Answer 2

• FALSE!!!
• RNA is a polymer of nucletodies.

Question 3

What are the components of the RNA nucleotide?

Answer 3

• Ribose (pentose) sugar.
• Nitrogen- containing organic base.
• Phosphate group.

Question 4

What are the 4 nitrogen- containing organic bases in RNA?

Answer 4

• Guanine.
• Adenine.
• Cytosine
• Uracil (instead of thymine.)

Question 5

What is the difference between RNA and DNA in terms of length and size?

Answer 5

• RNA is a relatively short polynucleotide chain and it’s single- stranded.

Question 6

What are the two MAIN functions of RNA?

Answer 6

1.) Copies and transfers genetic code from DNA in nucleus to the ribosomes.
2.) Some RNA (rRNA) combines with proteins to form ribosomes.

Question 7

What two components are ribosomes formed from?

Answer 7

• RNA
• Proteins.

Question 8

What are the 3 types of RNA?

Answer 8

• mRNA
• tRNA
• rRNA

Question 9

What is mRNA?

Answer 9

• mRNA is a copy of a gene from DNA.

Question 10

Where is mRNA created and where does it go to?

Answer 10

• mRNA created in nucleus.
• Leaves nucleus/ carries the copy of the genetic code of one gene to a ribosome in the crytoplasm.

Question 11

What are the 2 main reasons as to why DNA cannot leave the nucleus and go to the ribosomes to give the code for specific proteins? Why CAN mRNA leave nucleus and go to ribosomes in cytoplasm?

Answer 11

1.) DNA = Too large so cannot pass out of nucleus whereas, mRNA = much shorter so can leave nucleus.
2.) DNA = at risk of being damaged by enzymes in cytoplasm (hydrolysed) - this would destroy the genetic code permanently. So, instead mRNA (copy of gene) is temporarily used to help create a protein before any enzymes break it down.

Question 12

Why is mRNA much shorter than DNA?

Answer 12

• mRNA is much shorter than DNA because it is only the length of one gene (DNA has thousands of genes!)

() extra info for clarification.

Question 13

What is meant by the fact that mRNA is short-lived?

Answer 13

• This means it is broken down/ hydrolysed quickly.
• But, mRNA is only temporarily needed (because its just a copy of the genetic code) to help create a protein (so, by the time the enzyme breaks it down, it would have already carried out its function.)

Question 14

What is the structure of mRNA?

Answer 14

• Single- stranded.
• Every 3 bases in the sequence code for a specific amino acid.

Question 15

What are the three bases in mRNA that code for a specific amino acid called?

Answer 15

• Codons.

Question 16

What does mRNA stand for?

Answer 16

• Messenger RNA.

Question 17

True or False

tRNA is found in cytoplasm and nucleus.

Answer 17

• False
• tRNA is only found in the cytoplasm.

Question 18

What is the structure/ shape of tRNA?

Answer 18

• Single- stranded.
• Folded to create shape that looks like cloverleaf.
• The cloverleap shape is held in place by hydrogen bonds.

Question 19

What is the function of tRNA?

Answer 19

• Carries specific amino acids to ribosome to create polypeptide chain.

Question 20

How is it ensured that tRNA transfers the specific amino acid needed to be part of the polypeptide chain made by mRNA?

Answer 20

• The specific tRNA anticodon binds to specific amino acid.

Question 21

What does tRNA stand for?

Answer 21

• Transfer RNA.

Question 22

What does rRNA stand for?

Answer 22

• Ribosomal RNA.

Question 23

What is function of rRNA?

Answer 23

• Combines with protein to form a ribosome.

Question 24

Give two differences between the RNA/ DNA monomers (ie. their nucleotides.)

Answer 24

• DNA contains base thymine whereas, RNA contains uracil instead.
• DNA contains pentose sugar: deoxyribose whereas, RNA contains pentose sugar: ribose.

Question 25

Give two differences between the DNA/ RNA polymers.

Answer 25

- DNA is much larger (contains many genes) whereas, RNA is much shorter (mRNA is only length of one gene. ) - DNA is double- stranded whereas, RNA is single- stranded.