Question

1. When activated, a G-protein has a structure that

a) Forms a transmembrane domain

b) Is bound to GTP

c) Forms a complete complex with three subunits

d) Is able to bind to extracellular signals

2. Which of the following ions have cytosolic concentrations so that a flood of this ion into the cell can be used as a signal for cell processes like fertilization?

a) Ca2+

b) K+

c) H+

d) phosphate

3. What is responsible for moving glucose from the gut lumen into intestinal epithelial cells?

a) Glucose sodium antiport

b) Uniport glucose transporter

c) Passive diffusion

d) Glucose sodium symport

4. The citric acid cycle produces which activated carriers that transfer high energy electrons to the electron transport chain?

a) NADP and FAD

b) NADPH and NADH

c) NADH and FADH2

d) NAD+ and FAD

Answer 1

Q.1. G protein in inactive condition is made up of three subunit alpha, beta and gama. In this condition it is bounded with GDP. When a ligand bind to GPCR it activate G protein and this activation replace GDP to GTP. So answer is option 'b'.

Q.2. Calcium ion is the universal signal for egg activation at fertilization in all sexually reproducing species. So option 'a' is the answer.

Q.3. In the epithelial cell Sodium glucose symporter absorb glucose and sodium from intestinal lumen, this glucose is transported into blood from epithelial cell via GLUT-2. So option 'd' is the right answer.

Q.4. In citric acid cycle three NADH and one FADH2 is produce to transfer high energy electron to ETS. So answer is option 'c'.