Protein Synthesis

Question 1

Explain why cells need to make polypeptides of defined length and sequence.

Question 2

Describe importance of base-pairing for accuracy of protein synthesis.

Question 3

Describe the machinery, raw mats, and instruction tape for protein synthesis.
(ribosome, aminoacyl-tRNAs, mRNA, translation. Respectively)

Question 4

Explain the main characteristics of genetic code that defines the association of anticodons and codons.

Question 5

Explain how a cell can function properly by using their proteins.

Question 6

Basic concept of translation?

Answer 6

Cell interprets a genetic message which is the instruction for building a specific polypeptide.
Message in codons of mRNA is deciphered by interpreter (codons in tRNA). mRNA is moved through ribosome, being translated into amino acids. tRNA adds amino acid cargo to growing polypeptide chain when anticodon recognises codon.

Question 7

tRNA structure and function?

Answer 7

STRUCTURE:
Amino acid attachment site
Anticodon
Hydrogen bonds holding together a cross shape
20 specific tRNA types to match 20 different amino acids

FUNCTION:
tRNA molecule used repeatedly to pick up amino acid cargo and deposit it in ribosome, then leave to repeat the process.

Question 8

2 Important recognition step in tRNA?

Answer 8

For accurate transcription:
-between tRNA and AA
-between tRNA anticodon and mRNA codon

Question 9

What is aminoacyl-tRNA synthetase and what does it do?

Answer 9

The enzyme that assists with loading the tRNA with the correct amino acid. Joining requires ATP. Each enzyme has an active site specific to one of the 20 amino acids. Specificity is key to accurate translation.

Question 10

What does rRNA do in ribosome?

Answer 10

Catalyses synthesis of peptide bonds. (like a ribozyme)