Question 22
What intrinsic enzymatic activity do G proteins have?
They are ATPases
They are glycosidases
They are GTP synthases
They are GTPases
Question 23
How are G proteins activated?
The GTP dissociates from the G protein and GDP associates with the G protein
The GDP dissociates from the G protein and GTP associates with the G protein
The G protein synthesizes GTP from GDP
The G protein synthesizes GTP from ATP
Question 24
How are G proteins inactivated?
Hydrolyze ATP
Bind GTP
Bind ATP
Hydrolyze GTP
Question 25
What is a GTPase activating protein (GAP)?
It hydrolyzes GTP
It promotes release of GDP and binding of GTP of a G protein
It speeds up the rate of GTPase activty of a G protein
Question 26
What is a guanine nucleotide exchange factor (GEF)?
It speeds up the rate of GTPase activty of a G protein
It hydrolyzes GTP
It promotes release of GDP and binding of GTP to a G protein
Question 27
Which of the following types of enzyme activate G proteins?
GAP
GEF
Question 28
Which of the following types of enzyme inactivate G-proteins?
GAP
GEF
Question 29
What is receptor internalization and recycling?
It is when the receptor is co-translationally imported into the ER before being degraded by the unfolded protein response
It is when the receptor is endocytosed and then the vesicle fuses with the endosome, releases ligand and the receptor is returned to the plasma membrane
It is when the receptor is digested with proteases into amino acids and those amino acids are used to synthesize a new receptor
It is when the receptor cycles in and out of the nucleus
Question 30
How do large proteins get into the nucleus?
Simple diffusion
Facilitated diffusion through the nuclear pore
Active transport through the nuclear pore
Question 31
How easy is it for the following reaction to occur?
ADP + Pi â ATP
This is very exergonic and highly favorable
This is very endergonic and highly unfavorable
This is slightly exergonic and somewhat favorable
Question 32
The hydrolysis of ATP is highly...
Exergonic
Endergonic