Chapter 16

Question 1

In multi cellular organisms genes maybe ____

Answer 1

Turned on or off

Question 2

Where are the hydrogen bond donors and and acceptors located on DNA which allows proteins to read the base base pairs

Answer 2

Major grooves

Question 3

This is 3D substructure found on many proteins usually interacting with specific sequences of based by way of the major groove

Answer 3

DNA binding motifs

Question 4

What do repressors bind to

Answer 4

Operators

Question 5

These are proteins that prevent or decrease the initiation of transcription by binding to the operators

Answer 5

Repressors

Question 6

This molecule can alter confirmation of the repressors to either enhance or abolish its binding to DNA it works along side with the repressors

Answer 6

Effector molecule

Question 7

The repressors proteins are ______ with an active site, that binds DNA, and a ________ that binds the effectors

Answer 7

Allotristic

Regalatory

Question 8

These stimulate or enhance the transcription of DNA to make more proteins enhance the binding of the RNA polymerase to bind the promoter

Answer 8

Activators

Question 9

Proteins that are necessary for the utilization of lactose are encoded by the

Answer 9

Lac operon

Question 10

Proteins necessary for the synthesis of tryptophan are encoded by the

Answer 10

trp operon

Question 11

On the lac operon where is the promoter that rna polymerase binds to

Answer 11

P-lac

Question 12

What parts on the lac operon breakdown the lactose

Answer 12

lacZ

lacA

Question 13

If lactose is present in environment the lac operon is turned ____ and if the lactose is not present the lac operon is turned _____

Answer 13

On

Off repressed

Question 14

When their is no presence of lactose in the environment the repressors bound to _____

Answer 14

Operator

Question 15

In the absence of tryptophan the repressors _________ to the operator allowing production of enzymes to make tryptophan

Answer 15

Does not bind

Question 16

How many enzymes are needed to make tryptophan

Answer 16

5

Question 17

If the tryptophan is absent the repressors _______ bind and allows transcription of the genes

Answer 17

Does not

Question 18

When trp is present the trp binds to the allotristic site of the repressors which changes shape of active site and _____ bind

Answer 18

Can

Question 19

Gene expressions differ in prokaryotes by

Answer 19

Prokaryotes control the initiation of transcription

Eukaryotes have post transcriptional control

Question 20

Give two examples of alternative splicing

Answer 20

Thyroid gland and hypothalamus

Question 21

This small RNA repress genes different from the mRNA

Answer 21

miRNA

Question 22

This small RNA tend to repress genes by the mRNA

Answer 22

siRNA

Question 23

The small RNAs miRNA and siRNA both bind to a protein complex called

Answer 23

RISC

Question 24

This small RNA is composed of short RNA (20- 60 bases ) which act as translation repressors

Answer 24

miRNA

Question 25

A single primary transcript can be spliced one way by one cell to make 1 mature RNA to male one protein and the same transcript can be sliced a 2 way to result in the a 2 nd mature RNA and protein

Answer 25

Alternative splicing