Which of the following organisms is likely to contain biomembranes?
Which of the following is NOT true of the plasma membrane?
Which of the following statements about plasma membranes is INCORRECT?
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?
Which of the following statements is CORRECT about biomembranes?
A scientist produces an artificial membrane from phospholipids and notices that oxygen, but not glucose readily moves through the membrane. What might account for the inability of glucose to move through the artificial membrane?
Which of the following statements is TRUE of membrane phospholipids?
Cell surface molecules are labeled with a fluorescent tag and then a portion of them are bleached with a laser beam. What would one observe after the cell is incubated for a few minutes?
The following affect membrane fluidity EXCEPT
Which of the following is TRUE of phospholipids that flip-flop across the lipid bilayer?
How might a plant cell compensate for the excessive membrane fluidity that occurs during prolonged exposures to elevated temperature?
Glycosylated proteins and lipids within the plasma membrane are important for
Which of the following is important for allowing large, charged molecules to pass through the membrane?
Placing celery sticks in fresh water will make them more turgid and harder. This is because
Which of the following molecules would you predict moves through a lipid bilayer most rapidly?
Animal cells are permeable to water and urea but NOT to sucrose. The inside of a cell contains 1 M sucrose and 1 M urea and the outside 1 M sucrose and 2 M urea. The solution inside with respect to outside the cell is
Animal cells are permeable to water and urea but NOT to sucrose. Initially, the inside of a cell contains 1 M sucrose and 1 M urea and the outside 1 M sucrose and 2 M urea. After the system reaches equilibrium, what changes are observed?
Which of the following statements is CORRECT about active transport?
Which of the following is NOT true of passive diffusion?
Following a meal glucose must move from the gut lumen where there is a high glucose concentration into the intestinal cell where there is a relatively low level of glucose. This movement is called
The pressure required to stop water from moving across the membrane by osmosis is called
Water diffuses through certain organs such as the kidneys and bladder much faster than would occur by passive diffusion through a lipid bilayer alone. What accounts for this more rapid rate of water transport in these organs?
The movement of sucrose and H+ into the cell by a common membrane protein reflects transport through a
The statements about transport of Ca2+ from the cytosol (low Ca2+ concentration) into the endoplasmic reticulum (high Ca2+ concentration) are true EXCEPT which of the following?
Acetylcholine binds this membrane protein, which subsequently opens to allow sodium to enter the cell. Acetylcholine exerts its effect on what type of transport protein?
Sodium concentrations are higher outside and glucose concentrations are higher inside the cell. Using the same membrane protein for Na+ and glucose transport, what is it called when a Na+ electrochemical gradient is used to drive glucose transport into the cell against its concentration gradient?
________ bind two or more ions or molecules and transport them in opposite directions across a membrane.
Which of the following statement about the plasma membrane Na+/K+-ATPase pump is INCORRECT?