Chapter 17: From Gene to Protein

Question 1

Gene expression

Answer 1

The process by which DNA directs protein synthesis including two stages; transcription and translation

Question 2

Garrod

Answer 2

First suggested that genes dictate phenotypes through enzymes that catalyze specific chemical reactions

Question 3

Beadle and Tatum

Answer 3

Breaded bread mold to create the “one gene - one enzyme hypothesis”

Question 4

One gene - one polypeptide hypothesis

Answer 4

The function of a gene is to dictate production of a specific polypeptide

Question 5

Transcription

Answer 5

Synthesis of RNA using information in DNA

Question 6

Messenger RNA (mRNA)

Answer 6

Carries the instructions for protein synthesis from the nucleus to the ribosome

Question 7

Translation

Answer 7

Synthesis of a polypeptide, using information in the mRNA

Question 8

Triple code

Answer 8

Series of nonoverlapping, three-nucleotides “words”

Question 9

Template strand

Answer 9

One of two strands that provides a template for ordering the sequence of complementary nucleotides in an RNA transcript

Question 10

Codon

Answer 10

mRNA base triplet

Question 11

Reading frame

Answer 11

Correct grouping that codons must be read in in order for the specified polypeptide to be produced

Question 12

RNA polymerase

Answer 12

Pries the DNA strands apart and joins together the RNA nucleotides

Question 13

Promoter

Answer 13

The DNA sequence where RNA polymerase attaches to

Question 14

Terminator

Answer 14

The sequence signaling the end of transcription

Question 15

Transcription unit

Answer 15

The stretch of DNA that is transcribed

Question 16

Transcription factors

Answer 16

Help guide the binding of RNA polymerase and the initiation of transcription

Question 17

Transcription initiation complex

Answer 17

The completed assembly of transcription factors and RNA polymerase II bound to a promoter

Question 18

TATA box

Answer 18

A promoter crucial in forming the initiation complex

Question 19

RNA processing

Answer 19

Enzymes in the eukaryotic nucleus modify pre-mRNA before the genetic messages are passed into the cytoplasm

Question 20

5’ cap

Answer 20

Modified nucleotide added to the 5’ end

Question 21

poly-A tail

Answer 21

Modification added to the 3’ end

Question 22

RNA splicing

Answer 22

The removal of non coding stretches of nucleotides between coding regions

Question 23

Introns

Answer 23

Noncoding segments in genes, also called intervening sequences

Question 24

Exons

Answer 24

The regions not considered introns that eventually get expressed, usually translated into amino acid sequences

Question 25

stop codons

Answer 25

UAA, UAG, UGA

Question 26

Start codon

Answer 26

AUG, codes for Methionine

Question 27

Alternative RNA splicing

Answer 27

Genes that can encode more than one kind of polypeptide, depending on which segments are treated as exons during splicing

Question 28

Translation

Answer 28

Using mRNA to build a polypeptide

Question 29

Anticodon

Answer 29

End of an RNA strand that base pairs with a complementary codon on mRNA

Question 30

Wobble

Answer 30

Flexible pairing at the third base of a codon that allows some tRNAs to bind to more than one codon

Question 31

P site

Answer 31

Holds the tRNA that carries the growing polypeptide chain

Question 32

A site

Answer 32

Arrival site, holds the tRNA that carries the next amino acid to be added to the chain

Question 33

E site

Answer 33

Exit site, where discharged tRNAs leave the ribosome

Question 34

Three stages of translation

Answer 34

Initiation, elongation, termination

Question 35

Polyribosome

Answer 35

Enables a cell to make copies of a polypeptide very quickly

Question 36

Mutations

Answer 36

Changes in the genetic information of a cell, change in the nucleotide sequence of an organisms DNA

Question 37

Point mutation

Answer 37

Change in a single nucleotide pair of a gene

Question 38

Nucleotide pair substitution

Answer 38

Replaces one nucleotide and its partner with another pair of nucleotides. Silent - no effect, missense- code for incorrect amino acid, nonsense - change codon into stop codon

Question 39

Insertions and deletions

Answer 39

Additions or losses or nucleotide pairs in a gene

Question 40

Frameshift mutations

Answer 40

Whenever the number of nucleotides inserted or deleted is not a multiple of three

Question 41

Spontaneous mutations

Answer 41

Errors during DNA replication or recombination

Question 42

Mutagens

Answer 42

Physical and chemical agents that interact with DNA in ways that cause mutations

Question 43

Gene

Answer 43

A region of DNA that can be expressed to produce a final functional product that is either a polypeptide or an RNA molecule