A8 N, base sequence on m-RNA before 4-12 N,
base of initiation codon called
(A)_. in
smaller subunit of ribosome a complementary
sequence of SD sequence called (B) :-
(1) (A)-SD sequence
(B)-ASD sequence
(2) (A)-ASO sequence (B)-SD sequence
(3) (A)-Nonsense codon
(B)-Sense codon
(4) (A)-Sense codon
(B)-Nonsense codon
Answers
Answer:
Explanation:
Proteins are synthesized from mRNA templates by a process that has been highly conserved throughout evolution (reviewed in Chapter 3). All mRNAs are read in the 5´ to 3´ direction, and polypeptide chains are synthesized from the amino to the carboxy terminus. Each amino acid is specified by three bases (a codon) in the mRNA, according to a nearly universal genetic code. The basic mechanics of protein synthesis are also the same in all cells: Translation is carried out on ribosomes, with tRNAs serving as adaptors between the mRNA template and the amino acids being incorporated into protein. Protein synthesis thus involves interactions between three types of RNA molecules (mRNA templates, tRNAs, and rRNAs), as well as various proteins that are required for translation.
(1) A- SD sequence.
B- ASD sequence.
Explanation:
A- The SD (Shine-Dalgarno) sequence is ribosomal sequence site in bacterial cells located about 4-12 bases upstream of the initiation codon AUG. The RNA sequence helps recruit the ribosome to the messenger RNA or m-RNA to initiate protein synthesis.
B- The ASD (Anti-shine-Dalgarno) sequence is located in the 3' end of 16S region of the smaller Ribosomal subunit . Upon encountering the SD sequence the ASD base pairs with it and translation process is initiated.