bchem

Question 1

Gene

Answer 1

basic physical and functional unit of heredity located on chromosomes consisting of specific DNA sequences.

Question 2

Allele

Answer 2

different form of a gene.can be dominant or recessive

Question 3

chromosomes

Answer 3

descrete physical entities that carry genes.Each gene has a locus on a chromosome

Question 4

3 domains of life

Answer 4

eukaryotes ,bacteria and archaea-(thermophiles,halophiles and methanogens

Question 5

Central dogma of Molecular biology

Answer 5

-DNA molecules serve as templates for complementary DNA strands during replication or complementary RNA during transcription. RNA molecules serve as templates for ordering amino acids by ribosomes during translation.

Question 6

Functional genomics

Answer 6

study of expression of large number of genes

Question 7

Transcriptomics

Answer 7

study of transcriptomes

Question 8

Proteomics

Answer 8

study of proteomes

Question 9

bacteriophages

Answer 9

viruses that infect bacteria

Question 10

DNA replication system

Answer 10

Template:DS DNA Substrate:dNTP Primer:short RNA fragment with free 3’-OH end Enzyme:DNa dependent dna polymerase

Question 11

characteristics of repliction

Answer 11

semi-continous Semi-conservative Bidirectional High fidelity

Question 12

direction of replication

Answer 12

5’-3’

Question 13

leading strand

Answer 13

daughter strand synthesized from the 5’-3’ direction.

Question 14

okazaki fragment

Answer 14

daughter strands synthesized from the 3’ end to 5’ end .Called lagging strand.

Question 15

all DNa polymerases possess

Answer 15

5’-3’ polymerizing exonuclease

Question 16

DNA pol 1

Answer 16

proofreading and filling the gaps and repairing DNA damage

Question 17

structure of DNA pol 3

Answer 17

it is the true enzyme for elongation. alpha-has 5’-3’ polymerizing activity epsilon-has 3’-5’ exonuclease activity-ensures replication fidelity. theta-maintains heterodimer structure.

Question 18

5’-3’ exonuclease activity

Answer 18

cut primer or excise mutated segment.

Question 19

3’-5” exonuclease activity

Answer 19

excise mismatched nucleotides.

Question 20

Transcription

Answer 20

Initiation elongation termination

Question 21

eukaryotic replication

Answer 21

requires replication factors. for termination a telomere is needed which is rich in T and G

Question 22

point mutation

Answer 22

single nucleotide alteration. -transition-alteration btwn purine and purine -transversion-base mutation between pyrimidine and purine

Question 23

DNA repairing

Answer 23

light repairing using UV Excision repairing

Question 24

Excision repairing

Answer 24

uses number of enzymes ; UvrA and UvrB- Recognize and bind the damaged region of DNA. UvrC-excises the damaged segmwnt DNA -pol 1 -synthesize DNA to fill the gap ligase -seals the nick