Central Dogma (LEC)

Question 1

central dogma of molecular biology consists of three processes namely

Answer 1

replication
transcription
translation

Question 2

DNA replicates in __ ___ mode that is, a newly synthesized molecule contains an old strand from the parent DNA and a newly synthesized DNA strand

Answer 2

semi conservative

Question 3

the accuracy of replication is guaranteed by

Answer 3

specific base pairing

Question 4

RNA is being synthesized from the DNA template.

Answer 4

transcription

Question 5

three general steps of transcription

Answer 5

initiation
elongation
termination

Question 6

Three types of RNA

Answer 6

messenger RNA
transfer RNA
ribosomal RNA

Question 7

In Translation process, __are synthesized.

Answer 7

protein

Question 8

A ___chain from the activation of amino acids, initiation and termination of translation to undergo further processing becomes a functional protein.

Answer 8

poylpeptide chain

Question 9

A polypeptide chain from the activation of amino acids, initiation and termination of translation to undergo further processing becomes a ___protein.

Answer 9

functional

Question 10

one dauther DNA molecule is all new and other is all old DNA

Answer 10

conservative replication

Question 11

each daughter DNA moelcule contains a mixture of old and new DNA

Answer 11

dispersive replication

Question 12

each daughter DNA molecule contains one new strand and one old strand

Answer 12

semiconservative replication

Question 13

The process begins with the ___of the double strand (ds) DNA into single strands (ss) that would serve as the template

Answer 13

separation

Question 14

which uses ATP to unwind the dsDNA by breaking the hydrogen bonds in between nucleotide pairs.

Answer 14

helix unwinding protein (helicase)

Question 15

The enzyme needed is the helix unwinding protein (HUP) which uses ___to unwind the dsDNA by breaking the hydrogen bonds in between nucleotide pairs

Answer 15

ATP

Question 16

To keep the single strands from reannealing, several helix destabilizing proteins (HDP), also known as ___ bind to the strands of the DNA.

Answer 16

single strand binding protein (SSBP)

Question 17

relaxes twisting tension (supercoils) created during unwinding.

Answer 17

helix relaxing protein (HRP) or DNA gyrase

Question 18

Once the templates are open, short segments of RNA nucleotides are synthesized by RNA polymerase to serve as ___for the elongation of the complementary strand

Answer 18

primers

Question 19

provide the 3’OH needed by the DNA III to catalyze the phosphodiester bond when nucleotides are added during elongation.

Answer 19

RNA primers

Question 20

RNA primers provide the 3’OH needed by the ___ to catalyze the phosphodiester bond when nucleotides are added during elongation.

Answer 20

DNA polymerase III

Question 21

The leading strand needs only __primer because it opens its complementary strand in a 5’ to 3’ direction.

Answer 21

one

Question 22

The other strand is designated as the lagging strand opens its complementary strand in a 3’ to 5’ direction. ___primers are needed when the complementary strand elongates in lagging strand.

Answer 22

several

Question 23

is capable of adding nucleotides by covalently bonding it from the primer.

Answer 23

DYNA polymerase III

Question 24

Nucleotides are added as nucleotide triphosphates such as __, __, __, __that also serve as energy source during bonding

Answer 24

ATP, GTP, TTP, CTP

Question 25

he complementary strand in both templates elongates from what direction

Answer 25

5' to 3' direction

Question 26

The leading strand elongates ____

Answer 26

continuously

Question 27

Its direction is towards the unwinding of DNA.

Answer 27

5' to 3'

Question 28

The ___strand on the other hand, elongates in a discontinuous manner.

Answer 28

lagging

Question 29

he lagging strand is oriented away from the unwinding region strand eventually contains short DNA segments (~1000-2000 nucleotides), known as

Answer 29

okazaki fragments

Question 30

proofreads the DNA and removes the primers by digestion (exonuclease activity) in 3’ to 5’ direction.

Answer 30

DNA polymerase I

Question 31

DNA polymerase I proofreads the DNA and removes the primers by digestion (___activity) in 3’ to 5’ direction.

Answer 31

exonuclease

Question 32

The gaps or breaks within the newly synthesized strands are sealed or joined by an enzyme called

Answer 32

ligase

Question 33

Transcription and translation between prokaryotes and eukaryotes differ mainly due to their ___structures.

Answer 33

cellular

Question 34

In __, transcription occurs within the nucleus and the RNA products are then transported to the cytoplasm for protein synthesis.

Answer 34

eukaryotes

Question 35

___, in absence of nucleus, synthesize their RNA and proteins in the cytoplasm.

Answer 35

prokaryotes

Question 36

The RNA polymerase attaches to a specific sequence in the DNA called the ___sequence or the initiation point with the help of the polypeptide called the sigma factor (ð).

Answer 36

promoter

Question 37

The RNA polymerase attaches to a specific sequence in the DNA called the promoter sequence or the initiation point with the help of the polypeptide called the __ factor (ð).

Answer 37

sigma

Question 38

recognizes the promoter sequence so that the RNA polymerase can selectively bind to it.

Answer 38

sigma factor

Question 39

The RNA polymerase moves along one of the strands of the DNA called the

Answer 39

anticoding/antisense strand

Question 40

it complements the DNA nucleotides with RNA nucleotides

Answer 40

anticoding strand or antisense strand

Question 41

When the segment of DNA is completely transcribed, the DNA strands ___because the DNA-DNA interaction is stronger than DNA-RNA interaction.

Answer 41

reanneal

Question 42

This continues until the enzyme reaches the ___ signal.

Answer 42

termination

Question 43

binds and dissociates from the DNA template to prevent further transcription.

Answer 43

rho factor

Question 44

Another type of termination is by ___formation on the GC rich sequence of the synthesized RNA strand which pulls it away from the DNA template.

Answer 44

loop

Question 45

There are three different types of RNAs namely

Answer 45

messenger RNA transfer RNA ribosomal RNA

Question 46

There are three different types of RNAs namely: messenger RNA (mRNA), transfer RNA (tRNA) and ribosomal RNA (rRNA) which are essential to the next process called

Answer 46

translation

Question 47

The amino acids are attached to their respective tRNAs. This requires energy from ___and it is mediated by amino-acyl synthetase enzyme.

Answer 47

ATP

Question 48

The amino acids are attached to their respective tRNAs. This requires energy from ATP and it is mediated by

Answer 48

amino-acyl synthetase enzyme.

Question 49

The initiation codon _--is always oriented on the 5’ end of the mRNA.

Answer 49

AUG

Question 50

The initiation codon AUG is always oriented on the _’ end of the mRNA.

Answer 50

5'

Question 51

initial steps involve the attachment of the first aa-tRNA complex with a ___ ___ to the 30s subunit through the action of initiation factor 1 (IF1).

Answer 51

formylated methionine (fMET)

Question 52

initial steps involve the attachment of the first aa-tRNA complex with a formylated methionine (fMET) to the ___ subunit through the action of initiation factor 1 (IF1).

Answer 52

30s

Question 53

initial steps involve the attachment of the first aa-tRNA complex with a formylated methionine (fMET) to the 30s subunit through the action of what initiation factor

Answer 53

IF1

Question 54

At the same time, a protein ___, binds the mRNA to 30s subunit and orients the fMET to the AUG codon.

Answer 54

IF3

Question 55

At the same time, a protein IF3, binds the mRNA to 30s subunit and orients the fMET to the __codon.

Answer 55

AUG

Question 56

initiation factor that then completes the 70s ribosome by binding the 50s to the 30s subunit

Answer 56

IF2

Question 57

serves as the energy source during these reactions in translation

Answer 57

GTP

Question 58

prevents the elongation of the polypeptide at the amino-end (N-terminal).

Answer 58

formyl group in fMET

Question 59

The fMET-tRNA complements the AUG codon at the __’end of the mRNA.

Answer 59

5'

Question 60

This site in the ribosome is termed as the

Answer 60

P-site

Question 61

P-site is also known as

Answer 61

peptidyl binding site

Question 62

The other site which is responsible for the entry of other aa-tRNA is the

Answer 62

A site (amino-acyl site)

Question 63

Once the fMET is set at the ___-site, a new aa-Trna complex enters the __-site complementary to the succeeding codon.

Answer 63

P A

Question 64

present in the 50s subunit catalyzes a peptide bond between the fMET and the amino acid carried by the tRNA in the A-site.

Answer 64

peptidyl transferase

Question 65

The tRNA in the __-site is then released to the cytoplasm for reactivation.

Answer 65

P site

Question 66

Termination of translations occurs when the ribosome encounters one of the ___ codons (UAG, UGA, UAA).

Answer 66

termination/stop

Question 67

These codons do not code for any amino acid, but instead code for release factor proteins

Answer 67

termination codon (RF1 or RF2)

Question 68

termination codon code for release factor proteins

Answer 68

RF1 or RF2

Question 69

consists of the sequence of nitrogen bases—A, C, G, U—in an mRNA chain

Answer 69

genetic code

Question 70

The letters are combined in groups of three to form code “words,” called

Answer 70

codons

Question 71

Each codon stands for (encodes) one amino acid, unless it codes for a start or stop signal. There are ___common amino acids in proteins. T

Answer 71

20

Question 72

there are __ possible codons, more than enough to code for the 20 amino acids.

Answer 72

64

Question 73

here are 64 possible codons, more than enough to code for the ___amino acids.

Answer 73

20

Question 74

he genetic code has a number of important characteristics (3)

Answer 74

universal unambiguous redundant

Question 75

All known living organisms use the same genetic code. This shows that all organisms share a common evolutionary history. what characteristic of genetic code?

Answer 75

genetic code is universal

Question 76

Each codon codes for just one amino acid (or start or stop). What might happen if codons encoded more than one amino acid what characteristic of genetic code

Answer 76

unambiguous

Question 77

Most amino acids are encoded by more than one codon. what characteristic of genetic code?

Answer 77

redundant