1 DNA Synthesis occurs in the 3 to 5 direction 5 to 2 direct

1. DNA Synthesis occurs in the

3\' to 5\' direction.

5\' to 2\' direction.

5\' to 3\' direction.

3\' to 2\' direction.

2. Which of the following statements is FALSE?

The Lagging strand is synthesized as Okazaki fragments

DNA polymerases need a primer to start DNA synthesis

The Lagging strand is synthesized in the same direction as the Leading strand.

A primer is made from RNA

3. Which of the following statements is FALSE?

Mature mRNA strands are generally shorter than the gene from which they are transcribed.

Some RNA, like rRNA, have catalytic activity.

Genes are always immutably fixed on a chromosome.

Several slightly different mRNAs can be made form the same gene.

4. What does EF-Tu do?

It binds to f-Met-tRNA and a molecule of GTP and together they form the ternary complex.

It carries a GTP into the ribosome and enables the ribosome to slide doen the mRNA molecule.

It ensures that the proper tRNA enters the A site.

It terminates translation.

4. Very few proteins are degraded via the 26S proteosome.

True

False

6. Select the correct terms to complete the following sentence: Sickle cell anemia is the result of a single base mutation in the DNA sequence for beta-globin. This, in turn, results in a change in in one amino acid from the category of  Polar (hydrophilic)HydrophobicBasicAcidic to the category of  Polar (hydrophilic)HydrophobicBasicAcidic.

7. Peptide bond formation requires the addition of a water molecule to the amino acids involved.

True

False

8. Proteins are modified while they are being synthesized.

True

False

9. There is redundancy in the genetic code. This means that....... (Choose ALL that apply)

Changes in the DNA sequence for some Codons may not affect the protein sequence

For most amino acids there is more than one Codon.

The third nucleotide in the sequence is unimportant.

There must be a tRNA for each Codon.

10. mRNA and tRNA are both synthesized by the same RNA polymerase.

True

False

	A.	3\' to 5\' direction.
	B.	5\' to 2\' direction.
	C.	5\' to 3\' direction.
	D.	3\' to 2\' direction.

Solution

Q.1 ans- [c] DNA Synthesis occurs in the 5\' to 3\' direction, generally Dna replication start from 5\' to 3\' direction

Q.2 ans- [c] The Lagging strand is synthesized in the same direction as the Leading strand

basically wrong statement, because both are moving in opposite direction

Q.3 ans-[B] Some RNA, like rRNA, have catalytic activity.

not some RNA only r-RNA {ribonucleic acid enzymes} have catalytic activity and play important role in protein synthesis, peptidyl transferase is an integral part of large subunit part of ribosome

Q.4 ans- [c] It ensures that the proper tRNA enters the A site. EF-Tu role in elongation during protein synthesis, EF-TU -directs the next tRNA to its correct position it the ribosome A site

Q.5 ans- true, 26s proteasome is protease that is present in cytosol,and nucleus of eukaryotic cell, this protease can degrades only ubiquitinated protein, not all the protein, there are two main proteolytic system withing eukaryotic cell , Lysosomes or proteasomes.

Q.6 ans-  replacement of Glutamate residue Polar (hydrophilic) at position 6 in the beta-chain by Valine residue (non-polar hydrophobic) is only chemical differeance between sickle-cell anemia or hemoglobin, these change produce sticky hydrophobic spot on surface that result in abnormal quaternary association of hemoglobin.

Q.7 ans- false,

peptide bond are amide linkage formation between alpha-amino group of one amino acide or alpha carboxyl group of another amino acide. this reaction is dehydration reaction, that is water molecule is remove not addition, and linked amino acide

Q.8 ans-false, normally protein are modified after the translation process, called-post-translational modification, simple chemical modification like hydroxylation and phosphorylation, acetylation,methylation,carboxylation,o & n-linked glycosylation,ADP ribosylation,etc

Q.9 ans- [C] The third nucleotide in the sequence is unimportant, according to wobble hypothesis

Q.10 ans-false m-RNA is product of RNA polymerase-2

and t-Rna is product of RNA polymarease-3