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TLS Online TPP Program

#Question id: 1219

Many G protein-coupled receptors contain seven transmembrane α-helical domains. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior surface or on the cytosolic surface of the membrane. The loop on the cytosolic side between helices 5 and 6 is usually substantially longer than the others. Where would you expect to find the carboxyl end of the protein?

#Unit 4. Cell Communication and Cell Signaling

  1. at the exterior surface

  2. at the cytosolic surface

  3. connected with the loop at H5 and H6

  4. embedded in the phospholipid bilayer of the membrane

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TLS Online TPP Program

#Question id: 2252

#Unit 2. Cellular Organization

The generation and maintenance of a membrane electric potential requires which of the following:

a. active pumping of ions       

b. ion-specific membrane channel proteins

c. ATP                                    

d. a generally permeable membrane
TLS Online TPP Program

#Question id: 2253

#Unit 2. Cellular Organization

Match the following lipid linked proteins (column I) with their function (Column II).

Column I

Column II

A. prenylated proteins

i. These proteins are located in a number of subcellular compartments, including the cytosol, the endoplasmic reticulum, the inner face of the plasma membrane, and the nucleus.

B. fatty acylated proteins

ii. The core structure of these proteins consists of phosphatidylinositol glycosidically linked to a linear tetrasaccharide composed of three mannose residues and one glucosaminyl residue.

C. glycosylphosphatidylinositol-linked proteins

iii. The proteins that have covalently attached lipids that are built from isoprene units

TLS Online TPP Program

#Question id: 2253

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the following lipid linked proteins (column I) with their function (Column II).

Column I

Column II

A. prenylated proteins

i. These proteins are located in a number of subcellular compartments, including the cytosol, the endoplasmic reticulum, the inner face of the plasma membrane, and the nucleus.

B. fatty acylated proteins

ii. The core structure of these proteins consists of phosphatidylinositol glycosidically linked to a linear tetrasaccharide composed of three mannose residues and one glucosaminyl residue.

C. glycosylphosphatidylinositol-linked proteins

iii. The proteins that have covalently attached lipids that are built from isoprene units

TLS Online TPP Program

#Question id: 2254

#Unit 2. Cellular Organization

If the intracellular [Ca2+] is 10−7 mol/L and the extracellular [Ca2+] is 2 × 10−3 mol/L, at what potential difference across the cell membrane will Ca2+ be at electrochemical equilibrium?
TLS Online TPP Program

#Question id: 2255

#Unit 2. Cellular Organization

Following statements are regarding to the Na+/K+ ATPase maintains the intracellular Na+ and K+ concentrations in animal cells. Which of the following statement is incorrect?
TLS Online TPP Program

#Question id: 2256

#Unit 2. Cellular Organization

Match the following inhibitors (Column I) with their effect (Column II).

Column I

Column II

A. A23187

I. endoplasmic reticulum Ca2+ ATPase inhibitor

B. valinomycin

II. Na+/K+ ATPase inhibitor

C. thapsigargin

III. K+ ionophore

D. ouabain

IV. Ca2+ ionophore