16.1 + 16.2

Question 1

Controlling gene expression is often accomplished by controlling ______ _______

Answer 1

transcription initiation

Question 2

Regulatory proteins bind to _____, modulate binding of ____ _____ to promoter

Answer 2

DNA; RNA polymerase

Question 3

Prokaryotic organisms regulate gene expression in response to their ______

Answer 3

environment

Question 4

Eukaryotic cells regulate gene expression to

Answer 4

maintain a constant internal environment (homeostasis) in the organism

Question 5

gene expression is often controlled by ____ _____ binding to specific DNA sequences

Answer 5

regulatory proteins

Question 6

Where do regulatory proteins gain access to the bases of DNA?

Answer 6

The Major groove

Question 7

Regulatory proteins block transcription by

Answer 7

preventing RNA polymerase to bind

Question 8

Regulatory proteins stimulate transcription by

Answer 8

facilitating RNA polymerase binding to promoter

Question 9

Within the major groove, nucleotides’ ____ _____ donors and acceptors are accessible

Unique pattern of accessibility for each base pair combination enables proteins to….

Answer 9

Hydrogen bonds; read the sequence without unwinding DNA

Question 10

DNA binding motifs

Answer 10

regions of regulatory proteins which bind to DNA

Question 11

helix turn helix motif

Answer 11

two alpha-helical segments linked by a nonhelical segment

Question 12

homeodomain

Answer 12

a special class of helix turn helix and is critical in eukaryotic devlopment

Question 13

zinc finger motif

Answer 13

several forms, use zinc atoms to coordinate DNA binding

Question 14

Leucine zipper motif

Answer 14

dimerization motif in which region in one subunit interacts with a similar region on another subunit forming a zipper-like connection