Chapter 13

Question 1

Ribosomal RNA

Answer 1

RNA molecule that is a structural component of the ribosome

Question 2

messenger RNA

Answer 2

carries the coding instructions for polypeptide chains from DNA to a ribosome; after attaching to the robosome, mRNA specifies the sequence of amino acids in a polypeptide chain and provides a template for joining amino acids

Question 3

pre-messenger RNA

Answer 3

the immediate products of transcription in eukaryotic cells

Question 4

transfer RNA

Answer 4

serves as the link between the coding sequence of nucleotides in the mRNA and the amino acid sequence of a polypeptide chain

Question 5

template strand

Answer 5

the nucleotide strand used for transcription

Question 6

nontemplate strand

Answer 6

the other strand of RNA that is not transcribed

Question 7

transcription unit

Answer 7

a stretch of DNA that encodes an RNA molecule and the sequences necessary for transcription

Question 8

promoter

Answer 8

a DNA sequence that the transcription apparatus recognizes and binds to; indicates which strand is leading and indicates the direction; determines the transcription start site

Question 9

RNA coding region

Answer 9

a sequence of DNA nucleotides that is copied into an RNA molecule

Question 10

terminator

Answer 10

a sequence of nucleotides that signals where transcription is to end, usually part of the RNA coding sequence

Question 11

ribonucleoside triphosphates

Answer 11

rNTPs a substrate of RNA synthesis; consists of ribose, a nitrogenous base, and three phosphates linked to the 5’ carbon atom of the ribose; during transcription, 2 of the phosphates are cleaved, producing an RNA nucleotide

Question 12

RNA polymerase

Answer 12

carries out all the required steps of transcription

Question 13

RNA polymerase I

Answer 13

transcribes RNA

Question 14

RNA polymerase II

Answer 14

transcribes pre-mRNA and other types of RNA

Question 15

consensus sequences

Answer 15

the sequences that possess considerable similarity; usually implies that the nucleotide sequence is associated with an important function

Question 16

general transcription factors

Answer 16

a protein that binds to eukaryotic promoters near the start site and is a part of the basal transcription apparatus

Question 17

basal transcription apparatus

Answer 17

a complex of transcription factors, RNA polymerase, and other proteins that assemble on the promoter and are capable of initiating minimal levels of transcription

Question 18

mediator complex

Answer 18

a complex of proteins that is one of the components of the basal transcription apparatus

Question 19

chromatin-remodeling proteins

Answer 19

binds to a DNA sequence and disrupts chromatin structure, causing DNA to become more accessible to RNA polymerase and other proteins

Question 20

TATA box

Answer 20

a common consensus sequence: TATAAA commonly found in eukaryotic RNA polymerase II promoters; usually located from 25-30 bp upstream of the transcription start site; determines the startpoint of transcription

Question 21

TATA-binding protein (TBP)

Answer 21

a polypeptide chain found in several different transcription factors that recognizes and binds to sequences in eukaryotic promoters