RNA and protein synthesis

Question 1

Characteristics of mRNA

Answer 1

• mRNA is made during transcription
• It carries the genetic code from the DNA to the ribosomes where it is used to make protein during translation
• mRNA is a single polynucleotide strand
• In mRNA groups of three adjacent bases are called codons there sometimes called triplets or base triplets

Question 3

Transfer RNA characteristics/ tRNA
functions of tRNA

Answer 3

• Involved in translation
• it carries the amino acids that are used to make proteins to the ribosomes
• tRNA is a single polynucleotide strand that’s folded into a clover shape
• Hydrogen bonds between specific base pairs hold the molecule in this shape
• Every tRNA molecule has a specific sequence of three bases at one end called an anticodon
• They also have an amino acid binding site at the other end

Question 4

What is an anticodon?

Answer 4

A specific sequence of three bases at one end of tRNA

Question 5

Describe the transcription stage of protein synthesis

Answer 5

• In eukaryotes the hydrogen bonds between the two DNA strands in the gene are broken by DNA healer case this causes the DNA molecule uncoil exposing the bases
• One of the strands is used as a template to make an mRNA copy
• RNA polymerase lined up free RNA nucleotides alongside exposed bases on the template strand
• Complementary based pairing occurs except the T base is replaced by U
• RNA polymerase binds the two strands together for me an mRNA molecule
• The hydrogen bonds between the uncoiled strands reform once the RNA polymerase has passed and the strands coil back into a double helix

Question 6

What happens when RNA polymerase reaches a stop codon

Answer 6

It stops making mRNA and attaches from the DNA

Question 7

Where does the mRNA move to after transcription in eukaryotes?

Answer 7

Moves out of the nucleus through the nuclear power and attaches to a ribosome in the cytoplasm and whether the next stage of protein synthesis takes place

Question 8

What happens during splicing?

Answer 8

Entrance are removed and exons are joints together forming mRNA strands

Question 9

Does slicing occur in prokaryotes?

Answer 9

No mRNA is produced directly from the DNA without splicing taking place due to being no introns

Question 10

Describe the process of translation in protein synthesis

Answer 10

1- mRNA attaches itself to a ribosome and tRNA molecules carry amino acids to it
2- ATP provides the energy needed for the bond between the amino acid and the tRNA molecule to form
3- a tRNA molecule carrying an amino acid with an anticodon that’s complimentary to the first code on on the mRNA attaches itself to the mRNA by specific base pairing
- The second tRNA molecule touches itself to the next code on on the mRNA in the same way
- The two amino acids attached to the tRNA molecules are joined by a peptide bond and the first tRNA molecule moves away leaving amino acid behind
- 3rd tRNA molecule line to the next code on on the mRNA and it’s amino acid bones to the first two and the second tRNA moves away
- This process continues producing a chain of linked to amino acids/ polypeptide chain until there is a stop sign signal
- A polypeptide chain moves away from the ribosome and translation is complete