translation

Question 1

what is translation?

Answer 1

the transmission of the genetic information from mRNA to protein.

Question 2

explain the process of translation?

Answer 2

Newly processed mRNA is transported from the nucleus to the cytoplasm, where it becomes associated with the ribosomes, which are the site of protein synthesis

Question 3

Genetic code describe?

Answer 3

-Degenerate or Redundant Code:
-each codon corresponds to only one amino acid or stop signal

-Some flexibility in the genetic code, allowing for certain changes in DNA sequence without altering the protein sequence.

Question 4

how does mrna molecules get exported from nucelus to cytoplasm

Answer 4

Here they are bound by ribosomes

Question 5

proteins are??

Answer 5

made up amino acids linked by peptide bonds

Question 6

describe eukarytic ribosomes?

Answer 6

Ribosomes provide a structure in which translation can take place

They also catalyse the reaction that links amino acids to make a new protein

Question 7

describe the structure of a ribosome

Answer 7

made up of two basic pieces: a large and a small subunit. During translation, the two subunits come together around a mRNA molecule, forming a complete ribosome

Question 8

Both subunits contains many ribosomal proteins arranged on a scaffold composed of ribosomal RNA (rRNA)

True or false

Answer 8

true

Question 9

In order for translation to start, need:

Answer 9

A ribosome
An mRNA with instructions for the protein to be built
An ‘initiator’ tRNA carrying the amino acid in the protein Met (AUG)

Question 10

Translation - initiation (1)

Answer 10

mRNA contains coding parts (exons) and noncoding parts (5’UTR and 3’UTR). Ribosomes recognize mRNA by binding to the 5’ cap, then scan until they find the start codon AUG

Question 11

Translation - initiation (2)

Answer 11

A transfer RNA (tRNA) carrying the amino acid methionine attaches to the small ribosomal subunit. This subunit binds to the 5’ end of mRNA, recognizing the 5’ cap, and then moves along the mRNA in the 3’ direction until it reaches the start codon, which codes for methionine (AUG). This start codon marks the beginning of an open reading frame, where codons specify successive amino acids in the protein chain. Finally, the large ribosomal subunit joins the small subunit to form the initiation complex, initiating protein synthesis.

Question 12

each tRNA has a what>

Answer 12

anti codon

Question 13

what is an anticodon

Answer 13

a set of 3 nucleotides that binds to a matching mRNA CODON through base pairing

Question 14

Translation - elongation

Answer 14

(tRNAs) bring amino acids to ribosomes, linking them together to form a protein chain. Different tRNAs, each carrying a specific amino acid, ensure the correct sequence. Ribosomes have three slots (A, P, and E) where tRNAs dock and move as they deliver amino acids and then exit.

Question 15

Translation – elongation (peptide bonds)

Answer 15

During protein synthesis, peptide bonds are formed between adjacent amino acids, connecting them into a growing polypeptide chain. The ribosome moves along the mRNA, pulling it forward by one codon after each peptide bond formation, exposing a new codon for the next amino acid-tRNA pairing. As each tRNA exits via the E site, a new tRNA enters the A site to continue the process until a STOP codon signals the end of protein synthesis.

Question 16

Translation - termination

Answer 16

-Translation ends in a process called Termination
-Termination happens when a stop codon in mRNA (UAA, UAG, or UGA) enters the A site
-Stop codons are recognised by proteins called release factors which fit into the P site

Question 17

summarise tRNA

Answer 17

tRNAs(transfer RNAs) carry amino acids to the ribosome. Act as ‘bridges’ matching a codon in an mRNA with the amino acid it codes for

Question 18

Deamination

Answer 18

(chemical reaction in which anamide functional group is removed from an organic compound)

Question 19

Methylation

Answer 19

installation of a methyl group on a substrate)

Question 20

summarise translation. 1/3

Answer 20

First, a molecule called aminoacyl-tRNA brings the right amino acid to the protein-making machine (the ribosome) and attaches to a specific spot (the A site) on it.

Question 21

summarise translation. 2/3

Answer 21

Then, the amino acid from the aminoacyl-tRNA forms a bond with the amino acid at the end of the growing protein chain (which is already attached to the ribosome).

Question 22

summarise translation. 3/3

Answer 22

After that, the mRNA moves along the ribosome, kind of like a conveyor belt, making space for the next set of instructions. This also kicks out the old aminoacyl-tRNA, getting the ribosome ready for the next amino acid.

Question 23

Aminoacyl-tRNA synthetases catalyze a two-step reaction

Answer 23

1. Adenylation of amino acid is the process of attaching an AMP molecule to a protein side chain by covalent bonding)
2. Aminoacylation of tRNA

Question 24

Attachment of AA to tRNA

Answer 24

An enzyme called aminoacyl-tRNA synthetase connects a specific amino acid to its matching tRNA molecule.

Question 25

where does the AA get attached to the t rna

Answer 25

connection happens at the 3’ end of the tRNA through a high-energy ester linkage with the terminal adenosine.

The anticodon on the aminoacyl-tRNA then pairs up with the corresponding codon on the mRNA,