Chapter 13 : Bacterial Genome Replication and Expression

Question 1

Genome

Answer 1

all DNA present in a cell or virus

Include DNA of chromosomes and plasmids

Question 2

Genotype

Answer 2

specific set of genes coded for in DNA sequences (ATGC)

Question 3

Phenotype

Answer 3

collection of physical characteristics determined by the genotype

Question 4

The nucleotides, DNA and RNA, are polymers of ________

Answer 4

Nucleotides

Linked together by phosphodiester bonds

Question 5

DNA and RNA differ in:

Answer 5

Base Adenine (A), Guanine (G),Cytosine (C), and Thymine (T)

Phosphate group and a pentose sugar

Question 6

G (______) and C (_________) pair by 3 hydrogen bonds

Question 7

STOPPED

Answer 7

D

Question 8

BEGIN WITH HER PDF 59

Answer 8

D

Question 9

Termination occurs when core RNA polymerase
_______ from template DNA

Answer 9

dissociates

Question 10

There are two types of terminators:

Question 11

DNA sequences mark the end of gene in the ____ and
the ________

Answer 11

trailer ; terminator

Question 12

Factor-independent termination

Answer 12

is an inverted repeat followed by an A-rich nucleotide sequence

Question 13

Factor-dependent termination

Answer 13

Does not have a string of adenine

requires a protein called → rho factor (ρ)

Question 14

Rho binds to the mRNA at a specific site
called →

Answer 14

rut

Question 15

Rho uses _____ energy to move along mRNA and catch up to RNA __________, causing it to _________ from DNA

Answer 15

ATP ; polymerase ; dissociate

Question 16

Final step in expression of protein encoding genes is →

Answer 16

Translation

Question 17

mRNA is translated into an ___________ of a
polypeptide chain during translation

Answer 17

amino acid sequence

Question 18

Codon

Answer 18

genetic code word found on
the mRNA, 3 base pairs long
* Specifies an → amino acid

Question 19

Anticodon

Answer 19

found on the tRNA is complementary to the codon of the
mRNA

Question 20

Start codon

Answer 20

start site for translation
* Always → AUG

Question 21

Sense codons

Answer 21

the 61 codons that specify amino acids

Question 22

Stop (nonsense) codons

Answer 22

the three codons used as
translation termination signals (UAA, UGA, UAG)
* Do not encode amino acids

Question 23

Code degeneracy

Answer 23

up to six different codons can code for a single amino acid

Question 24

Wobble

Answer 24

loose base pairing

Question 25

___ position of codon less important than 1st or 2nd

Answer 25

3rd Eliminates need for unique tRNA for each codon

Question 26

? Several exceptions to the code exist. Some protists use a single stop codon; the other two _________

Answer 26

code for amino acids instead

Question 27

? Some microbes incorporate two rare amino acids into polypeptides

Answer 27

* Selenocysteine inserted at certain UGA codons * Pyrrolysine inserted at certain UAG codons

Question 28

Translation

Answer 28

mRNA is decoded and amino acids are covalently linked to form a polypeptide at the ribosome

Question 29

Polyribosome

Answer 29

complex of mRNA with several ribosomes

Question 30

tRNA has a 3D structure due to ____________ _____ _____ within the tRNA molecule

Answer 30

complimentary base pairing

Question 31

Amino acid activation

Answer 31

attachment of amino acid to tRNA

Question 32

Amino acid activation, attachment of amino acid to tRNA, is catalyzed by

Answer 32

aminoacyl-tRNA synthetases

Question 33

There are at least __ aminoacyl-tRNA synthetases (one for each amino acid)

Answer 33

20

Question 34

Order for tRNA is

Answer 34

APE

Question 35

Order for ribosomes is

Answer 35

EPA

Question 36

Ribosomes are the sites of →

Answer 36

protein synthesis

Question 37

Bacterial ribosome 70S ribosomes =

Answer 37

30S + 50S subunits

Question 38

Translational domain on both subunits is responsible for _______

Answer 38

translation

Question 39

The translational domain contains three sites for tRNA binding:

Answer 39

* A (amino or acceptor) site – receives tRNAs carrying an → amino acid * P (peptide or donor) site – holds a tRNA attached to the growing → polypeptide * E (exit) site – where empty tRNAs leave the ribosome

Question 40

A (amino or acceptor) site

Answer 40

receives tRNAs carrying an → amino acid

Question 41

P (peptide or donor) site

Answer 41

holds a tRNA attached to the growing → polypeptide

Question 42

E (exit) site

Answer 42

where empty tRNAs leave the ribosome

Question 43

rRNA molecules contribute to _______ of ribosome

Answer 43

structure

Question 44

16S rRNA ribosomal binding site (RBS)

Answer 44

binds to ShineDalgarno site on mRNA for protein synthesis → initiation * Binds protein needed for initiation of translation and → amino acyl-tRNA

Question 45

23S rRNA is a ribozyme that catalyzes

Answer 45

peptide bond formation