Chapter 12 Gene Experssion

Question 1

The central Dogma

Answer 1

DNA —-> RNA —–> protein

Question 2

Transcription

Answer 2

DNA is transcribed into a pen RNA copy

Question 3

Translation

Answer 3

mRNA is translated into a polypeptide at the ribosome

Question 4

Structural gene

Answer 4

Transcribed to produce an MRNA that specifies the amino acid sequence of a polypeptide

Question 5

tRNA

Answer 5

Translates the language of mRNA into that of amino acids

Question 6

rRNA

Answer 6

Forms part of ribosomes , which provide the site where translation occurs

Question 7

Promoter

Answer 7

Signals the beginning of transcription

Question 8

Transcribed region

Answer 8

Part of this region contains the information that specifies an amino acid sequence

Question 9

Regulatory sequence

Answer 9

Site for the binding of regulatory proteins. The role of regulatory proteins is to influence the rate of transcription

Question 10

Terminator

Answer 10

Signals the end of transcription

Question 11

Transcription occurs in three stages:

Initiation

Answer 11

A recognition step

The pro motor functions as a recognition site for Sigma factor. RNA polymerase is bound to the promoter. Following binding, the DNA is on wound to form an open complex.

Question 12

Three steps for translation

2. Elongation

Answer 12

Synthesizes the RNA transcript

Sigma factor is released, and RNA polymerase slides along the DNA in an open contacts to synthesize RNA. RNA polymerize slides along the template strand to the 3 to 5 direction well it’s the sizes are they in the opposite, 52 to 3, direction

Question 13

Three steps to transcription

3. Termination

Answer 13

When RNA polymerase reaches the terminator, it any RNA transcript dissociate from the RNA

Question 14

Terminator factors

Answer 14

Proteins that influence the ability of RNA polymerase to transcribe genes.

Question 15

RNA always synthesizes

Answer 15

3 to 5 direction

Question 16

Eukaryotic transcription

Answer 16

They have three RNA polymerases

Polymerase II transcribes all mRNA
Polymerase I AND III. Transcribe other RNA’s

Instead of sigma factor RNA polymerase requires five general transcription factors to initiate transcription

Question 17

Eukaryotic RNA processing

Answer 17

Eukaryotic pre mRNA undergoes three types of processing to mature mRNA

5’ capping
3’ splicing to remove introns

Question 18

Capping

Answer 18

Covalent attachment of 7 - methylguanosine to the 5’ end of the mRNA transcript

Occurs while RNA polymerase is still creating the pre mRNA

Question 19

Poly A Tail Addition

Answer 19

Poly adenylation sequence in mRNA attracts enzyme complex that cuts mRNA and adds 100 to 200 adenines to the 3’ end

Increases mRNA stability

Question 20

Splicing

Answer 20

Removes introns and joins extrons together

Question 21

Exons

Answer 21

Are the RNA sequences found in the mature mRNA

Question 22

Introns

Answer 22

Are intervening untranslated sequences

Question 23

Sliceosomes are composed of

Answer 23

snRNP

Question 24

Genetic code

Answer 24

Specifies the relationship between the sequence of amino acids in a polypeptide

Question 25

What code name is CCC

Answer 25

Proline

Question 26

What code is GGC

Answer 26

Glycine

Question 27

Translation | Start codon

Answer 27

A codon that specifies the first amino acid in a polypeptide sequence AUG Met/Start

Question 28

Translation | Coding sequence

Answer 28

A series of codons from the start codon to the stop codon that determine the sequence of amino acids of a polypeptide

Question 29

Translation | Stop codon

Answer 29

End of translation UAA, UAG, UGA

Question 30

Translation | Reading frame

Answer 30

Start codon defines the reading frame of an mRNA

Question 31

Aminoacyl tRNA synthase charging a tRNA

Answer 31

1 a specific amino acid and ATP bind to aminoacyl tRNA synthase 2. The amino acid is activated by the covalent binding of a AMP, and pyrophosphate is released 3. The correct tRNA binds to the synthase. The amino acid is covalently attached to the tRNA. AMP is released 4. The charged tRNA is released

Question 32

Ribosomes

Answer 32

Macromolecular site where translation takes place

Question 33

P site

Answer 33

Peptide site

Question 34

A site

Answer 34

Aminoacyl site

Question 35

E site

Answer 35

Exit site

Question 36

tRNA | Initiation

Answer 36

mRNA and tRNA and ribosomal subunits firm a complex

Question 37

tRNA | Elongation

Answer 37

The ribosome travels in the 5' to 3' direction and synthesizes a polypeptide

Question 38

tRNA | Transcription

Answer 38

The ribosome reaches a stop codon , and all of the components disassemble, releasing a completed polypeptide

Question 39

Which represents the central dogma of gene expression

Answer 39

During transcription, DNA codes for mRNA, which codes polypeptides during translation

Question 40

A mutation prevents a gene from being transcribed into an mRNA. The mutation most likely disrupts

Answer 40

The promoter

Question 41

The functional product of a structural gene is

Answer 41

A polypeptide

Question 42

The part of a mRNA that is complementary to a codon in an mRNA is the

Answer 42

Anticodon

Question 43

During the initiation of translation, the first codon, ______, enters the _______ and associates with the initiator tRNA

Answer 43

AUG, P site

Question 44

During which stage of translation does the synthesis of a polypeptide occur?

Answer 44

Elongation