ANSC 221 Test 2 Questions with Verified Correct
Answer
Which of the following organisms is likely to contain biomembranes?
All living organisms contain biomembranes
Which of the following is the major lipid found in membranes?
phospholipids
Which of the following is not true of the plasma membrane
the extracellular and intracellular layers or leaflets are highly symmetrical
Scientists unearth a Wooly Mammoth from the Siberian Ice Sheath and discover that a
eukaryotic "amoeba"- like cell is still alive. Which component of the cell membrane might
contribute to maintaining the fluidity of plasma membranes under freezing conditions?
high levels of unsaturated fatty acyl tails within lipid bilayer
HIV is a viral disease. The cells are tricked into taking in viruses when the viruses activated
a cell surface protein. How would you describe the manner in which the viruses get into his
cells?
Receptor mediated endocytosis
During exposure to elevated glucose, a yeast cell's membrane glucose transporters will
rapidly increase so the cell can import glucose. Which would represent the signal for the
yeast cell?
glucose
, The sodium potassium ATpase pump moves sodium out of the cell and potassium into the
cell against their concentration gradients. This process requires energy in the form of ATP.
The best description for this type of transport is
active transport through an antiport
If a blood cell (0.9% NaCl) is placed in a 4% NaCl solution what will occur?
Crenation (shrinking of the cell)
Based on the following information, which has the highest concentration gradients. This
process requires energy in the form ATP. The best description for this type of transport is
Calcium
Which of the following events in a biological membrane can never be energetically
favorable and therefore will not occur spontaneously?
the flip-flop of phospholipids to the opposite leaflet
__% of all genes may encode membrane proteins
20-30%
What are the two types of phospholipids?
Hydrophilic and Hydrophobic
the phospholipid bilayer contains?
proteins and carbohydrates
Why is the membrane considered a Fluid-mosaic model?
Answer
Which of the following organisms is likely to contain biomembranes?
All living organisms contain biomembranes
Which of the following is the major lipid found in membranes?
phospholipids
Which of the following is not true of the plasma membrane
the extracellular and intracellular layers or leaflets are highly symmetrical
Scientists unearth a Wooly Mammoth from the Siberian Ice Sheath and discover that a
eukaryotic "amoeba"- like cell is still alive. Which component of the cell membrane might
contribute to maintaining the fluidity of plasma membranes under freezing conditions?
high levels of unsaturated fatty acyl tails within lipid bilayer
HIV is a viral disease. The cells are tricked into taking in viruses when the viruses activated
a cell surface protein. How would you describe the manner in which the viruses get into his
cells?
Receptor mediated endocytosis
During exposure to elevated glucose, a yeast cell's membrane glucose transporters will
rapidly increase so the cell can import glucose. Which would represent the signal for the
yeast cell?
glucose
, The sodium potassium ATpase pump moves sodium out of the cell and potassium into the
cell against their concentration gradients. This process requires energy in the form of ATP.
The best description for this type of transport is
active transport through an antiport
If a blood cell (0.9% NaCl) is placed in a 4% NaCl solution what will occur?
Crenation (shrinking of the cell)
Based on the following information, which has the highest concentration gradients. This
process requires energy in the form ATP. The best description for this type of transport is
Calcium
Which of the following events in a biological membrane can never be energetically
favorable and therefore will not occur spontaneously?
the flip-flop of phospholipids to the opposite leaflet
__% of all genes may encode membrane proteins
20-30%
What are the two types of phospholipids?
Hydrophilic and Hydrophobic
the phospholipid bilayer contains?
proteins and carbohydrates
Why is the membrane considered a Fluid-mosaic model?
