BIOL1P91 MIDTERM LATEST
EXAM
Which of the following events in a biological membrane can never be
energetically favourable and therefor will not occur spontaneously?
A) The rotation of phospholipids
B) The lateral movement of phospholipids
C) The flip-flop of phospholipids to the opposite leaflet
D) The rotation of membrane proteins
E) The lateral movement of membrane proteins - ANSWERS-C) The
flip-flop of phospholipids to the opposite leaflet
Let's suppose an insect, which doesn't maintain a constant body
temperature, was exposed to a shift in temperature from 60 F to 80 F.
Which of the following types of membrane changes would be the most
beneficial to help this animal cope with the temperature shift?
A) Increase the number of double bones in the lipids tails of
phospholipids
B) Increase the length of the lipid tails of phospholipids
C) Decrease the amount of cholesterol in the membrane
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PAGE
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, BIOL1P91 MIDTERM LATEST
EXAM
D) Decrease the amount of carbohydrate attached to membrane proteins
E) Decrease the amount of carbohydrate attached to phospholipids -
ANSWERS-B) Increase the length of the lipid tails of phospholipids
Carbohydrates of the plasma membrane
A) Are bonded to a protein or lipid
B) Are located on the outer surface or the plasma membrane
C) Can function as cell markers for recognition by other cells
D) All of the above
E) a and c only - ANSWERS-D) All of the above
A transmembrane protein in the plasma membrane is glycosylated at two
sites in the polypeptide sequence. Where in this protein would you
expect these two sites to be found
A) In transmembrane segments
B) In hydrophilic regions that project into the extracellular environment
C) In hydrophilic regions that project into the cytosol
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, BIOL1P91 MIDTERM LATEST
EXAM
D) Could be anywhere
E) b and c only - ANSWERS-B) In hydrophilic regions that project into
the extracellular environment
The tendency for Na+ to move into the cell be due to
A) The higher numbers of Na+ outside the cell, resulting in a chemical
concentration gradient
B) The net negative charge inside the cell attracting the positively
charged Na+
C) The attractive force of K+ inside the cell pulling Na+ into the cell
D) All of the above
E) a and b only - ANSWERS-E) a and b only
Let's suppose the solute concentration inside the cells of a plant is 0.3M
and outside is 0.2M. If we assume that the solutes do not readily cross
the membrane, which of the following statements best describes what
will happen?
A) The plant cells will lose water, and the plant will wilt
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PAGE
3
EXAM
Which of the following events in a biological membrane can never be
energetically favourable and therefor will not occur spontaneously?
A) The rotation of phospholipids
B) The lateral movement of phospholipids
C) The flip-flop of phospholipids to the opposite leaflet
D) The rotation of membrane proteins
E) The lateral movement of membrane proteins - ANSWERS-C) The
flip-flop of phospholipids to the opposite leaflet
Let's suppose an insect, which doesn't maintain a constant body
temperature, was exposed to a shift in temperature from 60 F to 80 F.
Which of the following types of membrane changes would be the most
beneficial to help this animal cope with the temperature shift?
A) Increase the number of double bones in the lipids tails of
phospholipids
B) Increase the length of the lipid tails of phospholipids
C) Decrease the amount of cholesterol in the membrane
END OF
PAGE
1
, BIOL1P91 MIDTERM LATEST
EXAM
D) Decrease the amount of carbohydrate attached to membrane proteins
E) Decrease the amount of carbohydrate attached to phospholipids -
ANSWERS-B) Increase the length of the lipid tails of phospholipids
Carbohydrates of the plasma membrane
A) Are bonded to a protein or lipid
B) Are located on the outer surface or the plasma membrane
C) Can function as cell markers for recognition by other cells
D) All of the above
E) a and c only - ANSWERS-D) All of the above
A transmembrane protein in the plasma membrane is glycosylated at two
sites in the polypeptide sequence. Where in this protein would you
expect these two sites to be found
A) In transmembrane segments
B) In hydrophilic regions that project into the extracellular environment
C) In hydrophilic regions that project into the cytosol
END OF
PAGE
2
, BIOL1P91 MIDTERM LATEST
EXAM
D) Could be anywhere
E) b and c only - ANSWERS-B) In hydrophilic regions that project into
the extracellular environment
The tendency for Na+ to move into the cell be due to
A) The higher numbers of Na+ outside the cell, resulting in a chemical
concentration gradient
B) The net negative charge inside the cell attracting the positively
charged Na+
C) The attractive force of K+ inside the cell pulling Na+ into the cell
D) All of the above
E) a and b only - ANSWERS-E) a and b only
Let's suppose the solute concentration inside the cells of a plant is 0.3M
and outside is 0.2M. If we assume that the solutes do not readily cross
the membrane, which of the following statements best describes what
will happen?
A) The plant cells will lose water, and the plant will wilt
END OF
PAGE
3
