Question

Answer the following questions in at least two paragraph (Be as descriptive as possible)

Compare the structure of DNA and RNA. Explain how the structure of tRNA correlates to its function? Discuss any versatility or redundancy that is present?

Answer 1

Ans:- DNA (Deoxyribose Nucleic Acid):-

1. Sugar moeity is deoxyribose.

2. Uracil is absent.

3. Double stranded molecules.

4. sum of purine bases is equal to sum of pyrimidine base (A+G) = (C+T)

5. Resistant to hydrolysis by alkali because of absence of hydroxyl group on 2 carbon atom of deoxyribose.

RNA (Ribose Nucleic Acid):-

1.sugar moiety is ribose.

2. Thymione is absent.

3. single stranded molecules.

4. sum of purine bases is not equal to sum of pyrimidine base.i.e, (A+G) is not equal to (C+T).

5. Because of the presence of hydroxyl group on 2 carbon atom of ribose, RNA is easily hydrolyzed by alkali.

tRNA Structure and its functions;-

1. tRNA is also named as S-RNA (soluble or supernatant RNA) and adaptor RNA.

2. it is a family of nearly 60 small sized ribonucleic acids.

3. 10-15 % of cellular RNA is tRNA.

4. tRNA are small molecules with about 74-95 ribonucleotides.

5. sedimentation contant is 3.8S

6. Molecular weight is nearly 25000 to 30000 Dalton.

7. tRNAs are made up of a single stranded polynucleotide chain.

tRNA functional parts:- tRNA has two functional parts.

A. Acceptor stem (Amino acid attachment site) :-3' terminus of tRNA has always the sequence 5' .....CCA-OH 3'

B. Anticodon:- these base nucleotide sequence, that recognize a specific codon on the mRNA and they are complementary and antiparallel, the codon specifies the amino acid that will be inserted into the growing polpeptide.