Question

10. If there were a mutant cell that did not join its Okazaki fragments properly, what enzyme in that cell would be defective? 

11. A protein can have any of 4 types of structure. Match the structure type with at least one of the kinds of bond holding it together

12. There are 20 different tRNA molecules, one for each of the 20 amino acids found in protein. During protein synthesis, the job of a tRNA molecule is to carry its particular amino acid to the growing protein chain and find the correct amino acid position there. It does this by matching a 3-letter anticodon on the RNA to a complementary 3-letter codon on mRNA. Bclow, in a diagram of a tRNA molecule, nucleotides are represented by small circles, some of which contain numbers. Indicate the nucleotide numbers of the amino acid attachment site _______ , and the anticodon site _______ 

13. Proteins require a tertiary structure for their biological activity. Four types of bond can participate in forming and stabilizing the tertiary structure. They are:

Answer 1

10. DNA ligase I

DNA ligase join the okazaki fragments and if it's defective , the okazaki fragments will not be joined properly during replication of lagging strand, leading to unstable DNA . Okazaki fragments will not be joined together to form a one continuous piece of DNA and short pieces of DNA will be formed which might even lead to cell death.

11. Primary - c. Peptide bond

Secondary - d. Hydrogen bond

Tertiary- both a and b

Quarternary- both a and b

Aminoacids are chained together by peptide bonds in primary structure . Peptide bonds are covalent bonds that connect carboxyl group of one aminoacid to amino group of another aminoacid.

Secondary structure is the three dimensional folding of aminoacids.secondary structure is held together by hydrogen bonds.In alpha helix , the carbonyl group of 1st aminoacid is hydrogen bonded to amino group of aminoacid 5.

Tertiary structure of proteins include ionic bonds , hydrophobic interactions( between non polar sections of the protein), disulfide bonds ( covalent linkages between sulfur containing side chains of cysteine )

Quarternary structure share the same chemical bonds of tertiary structure .

Answer 2

Solution

Que 10 answer-

DNA ligase enzyme will defective in that mutatnt cell.becuase okazaki frgamnets can join by enzyme DNA ligase.

Que 11 answer-

1. Primary structure- peptide bond
2. secondary structure- hydrogen bonds
3. Tertiary structure- disulphide bond
4. Quarternary structure -ionic bonds

Que 13 answer-tertairy structure is stabilized by

1. Hydrogen bonding- between hydrophilic amino acids
2. Ionic bonding -between charged amino acids
3. Hydrophobic interaction -contributed by nonpolar amino acids
4. Disulphide bonding- between sulphure containing amino acids

Que 12 answer-

Amino acid attachment site nucleotide number are (74,75,76)

Anticodon site nucleotide number is (34,35,36)