Molbio Handout

Question 1

The substrates for RNA synthesis are?

Answer 1

RIBONUCLEOSIDE TRIPHOSPHATES

Question 2

The ____ controls the binding of the core enzyme to the promoter

Answer 2

Sigma factor

Question 3

3 stages jn the transcription process:

Answer 3

Initiation, elongation, and termination

Question 4

Transcription begins at the start site, which is determined by___

Answer 4

Consensus sequences

Question 5

2 types of terminators in bacterial cells

Answer 5

Rho- independent terminators and rho dependent terminators

Question 6

True or false
RNA polymerases are capable of proofreading

Answer 6

True

Question 7

It is often defined as a sequence of DNA nucleotides that is transcribed into a single RNA molecule

Answer 7

GENE

Question 8

Noncoding sequences that interrupt the coding sequences (exons) of gene, which are common in eukaryotic cells but are rare in bacterial cells

Answer 8

INTRONS

Question 9

An mRNA molecule has three primary parts:

Answer 9

5’ untranslated region
Protein coding seauence
3 untranslated region

Question 10

The pre mRNA of a eukaryotic protein encoding gene is extensive processed:

Answer 10

A modified nucleotide and methyl groups
Collectively termed the cap are

Question 11

Introns that are removed within a structure is called?

Answer 11

Spliceosome

Question 12

Messenger RNAs may be altered by the addition, deletion, or modification of nucleotides in the coding sequence, a process called ?

Answer 12

RNA EDITING

Question 13

The amino acids in a protein are linked together by?

Answer 13

Peptide bonds

Question 14

It is a triplet code

Answer 14

Genetic code

Question 15

Protein synthesis comprises four steps

Answer 15

The binding of amino acids to the appropriate tRNAs
Initiation
Elongatin
Termination

Question 16

The binding of an amino acid to a tRNA requires the presence of a specific:

Answer 16

AMINOACYL- tRNA SYNTHASE AND ATP

Question 17

Each mRNA may be simultaneously translated by several ribosomes, producing a structure called

Answer 17

Polyribosome

Question 18

The simplest type of substitution is a :

Answer 18

Bass substitution

Question 19

Are base substitutions in which purines are replaced by purines or pyrimidines are replaced by pyrimidines

Answer 19

Transitions

Question 20

Are base substitutions in which a purine replaces a pyrimidine or a pyrimidine replaces a purine

Answer 20

Transversions

Question 21

Are the addition of nucleotides

Answer 21

Insertions

Question 22

Are the removal of nucleotides

Answer 22

Deletions

Question 23

This type of mutation alters the coding sequence so that one amino acid substitutes for another

Answer 23

Missense mutation

Question 24

This type of mutation changes a codon that specifies an amino acid into a termination codon

Answer 24

Nonsense mutation

Question 25

This type of mutation produces a synonymous codon that specifies the same amino acid as the original sequence

Answer 25

Silent mutation

Question 26

This type of mutation alters the amino acid sequence but does not change the functioning of the protein

Answer 26

Neutral mutation

Question 27

This type of mutation reverses the effect of a previous mutation at a different site and may be intragenic or intergenic

Answer 27

Supressor mutation

Question 28

DNA repair mechanisms

Answer 28

Mismatch repair
Direct repair
Base- excision repair
Nucleotide- excision repair and other repair pathways

Question 29

Double strand breaks are repaired by:

Answer 29

Homologous recombination and nonnomologous end joining

Question 30

The strand that gets transcribed is the:

Answer 30

Template strand

Question 31

Transcribing the template strand requires getting its complementary RNA sequence to produce the transceipt so that the template strand is also known as the

Answer 31

ANTISENSE STRAND

Question 32

Nontemplate strand is also known as the

Answer 32

Sense strand

Question 33

The 5’ intronic signal is ?

Answer 33

GU

Question 34

3’ intonic signal is

Answer 34

AG

Question 35

Stop codons are

Answer 35

UAA
UAG
UGA

Question 36

Refers to the multistep process that ultimately results in the production of a functional gene product: either RNA or protein

Answer 36

Gene expression

Question 37

The first step in gene expression is the:

Answer 37

Use of DNA for the synthesis of RNAs

Question 38

True or false: Not all genes are regulated

Answer 38

True

Question 39

The initial step in all gene expression, is controlled by regulatory sequences of DNA, usually embedded in the non coding regions of the genome

Answer 39

Regulation of transcription

Question 40

These DNA sequences flanking a gene are called

Answer 40

Cis acting

Question 41

It is the regulatory molecule itself, which can diffuse through the cell from its site of synthesis to its DNA binding site

Answer 41

Trans acting factor

Question 42

The binding of proteins to DNA is through structural motifs such as:

Answer 42

Zinc finger
Leucine zipper
Helix turn helix

Question 43

Genes can be either

Answer 43

Constitutive or regulated

Question 44

It seals the nicks that remain in the sugar phosphate backbones when the tRNA primers are replaced by DNA nucleotides

Answer 44

DNA LIGASE

Question 45

Is non reciprocal genetic exchange and produces abnormal ratios of gametes

Answer 45

Gene conversion gene conversion

Question 46

The sample is suspended in an alkaline solution containing NaOH and SDS detergent, causing the denaturation of chromosomal DNA.

Answer 46

Alkaline extraction