Practice Quiz 5 (cells, biomembrane and transporter)
You have 20 minutes to finish the quiz.
Q.1 :
Which statement is true? Natural fatty acids
are strong acids
are completely non polar molecules
are found in phospholipids but not glycolipids
have trans unsaturated double bonds
all statements are false
Q.2 :
Which of the following are located in the center of the lipid bilayer ( not exposed to the surface of the membrane)
polar molecules
small particles such as LDL
cholesterol
none of the above
Q.3 :
Phospholipids in the membrane
are firmly ancored in the bilayer
can diffuse from one side of the bilayer to the other
are major constituents of the biomembrane
all of the above
Q.4 :
Which statement is false. The lipid bilayer
becomes more fluid with increasing content of unsaturated fatty acids
is not an effective barrier for small molecules such as oxgygen and carbon dioxide
consists mainly of phospholipids and triglycerides
is assymetric with respect to the polar head groups of its lipid components
Q.5:
The plasma membrane is assymetric because
some membrane lipid components are optically active (have assymetric C atom)
it contains proteins only on the inside
the fatty acid residues have different chain length
membrane lipids can not diffuse from the inside to the outside of the layer
Q.6:
Diffusion is a process by which a substance moves from an area of
high concentration to an area of higher concentration
low concentration to an area of lower concentration
low concentration to an area of high concentration
high temperature to an area of low temperature
low temperature to an area of high temperature
Q.7 :
Proteins in the plasma membrane
are only on the outer surface
are only on the inner surface
do not associate with the membrane because of their polar nature
can span the membrane
Q.8 :
Glycolipids are
evenly distributed in the plasma membrane
more likely to be found on the inside
more likely to be found on the outside
are storage lipids for sugars
Q.9 :
A diffusion equilibrium is reached when
the molecules stop moving
when a gradient is established
when the solvating water stops crossing the membrane
when there is no net movement of molecules across a permeable membrane
Q.10 :
The section of a transmembrane protein which spans the membrane consists of
mostly polar amino acids e.g. Ser, Glu, Asn, Cys
mostly of amino acids such as Ala, Leu, Gly, Val
fatty acids
glycine
Q.11 :
In an active transport
a molecule moves across the membrane always from the inside to the outside consuming energy
a molecule moves from areas of low concentration to areas of lower concentration
the molecule to be transported has to provide the energy for its transport against its conc. gradient
none of the above
Q.12 :
In a passive mediated process a molecule is transported
by a transporter protein against its own gradient
by a transporter protein from an area of low conc. to an area of lower conc.
by diffusion across the membrane
none of the above
Q.13 :
Identify the mismatched pair
triglyceride - oil
phospholipids - storage lipids
mediated transport - membrane protein
plasma membrane - glycoprotein
Q.14:
The Na/K pump transports
Na and K ions from the cytoplasm to the exterior of the cell
K ions within their own gradient
K ions from the inside to the outside of the cell
Na ions against their own gradient
Q.15 :
Cystic fibrosis is most likely caused by
a faulty Na channel
a faulty Cl channel
too much water crossing the epithelial cell into the air duct
all of the above
Q.16 :
Which is not a major constituents of the plasma membrane in animal cells are
phospholipids
glycolipids
triglycerides
proteins
cholesterol
Q.17 :
Ion gates allow the passage of ions
along a gradient. The released energy moves co-ions against their own gradient
of different chemical nature from high to a low concentration
of the same kind from a high concentration to an area of low concentration
none of the above
Q.18 :
Which is NOT a characteristic of the fluid mosaic membrane
certain protein components can freely move in the bilayer
the fluidity depends on the temperature
the fluidity can vary depending on the lipid composition
all of the above are characteristic of biomembranes
Q.19 :
Which of the substances are most likely to diffuse through the biomembrane without the aid of a transproter protein
K
+
oxygen
glucose
dissolved salt
Q.20 :
A cell is placed into an acqeous solution and gains additional water. Which is the true statement
the fluid content of the cell was isotonic with respect to the solution
the fluid content of the cell was hypotonic with respect to the solution
the fluid content of the cell was hypertonic with respect to the solution
the inside of the cell was less concentrated than the solution