It's what's inside that counts
A scientist observes a cell with no nucleus and no membrane-bound organelles. What type of cell is it?
Prokaryotic
Why do phospholipid bilayers spontaneously form in water?
Polar heads interact with water; nonpolar tails avoid water
A molecule moves down its concentration gradient through a membrane protein without using ATP. What type of transport is this?
Facilitated diffusion
A cell is placed in a solution with a higher solute concentration than the cell. What will happen to the cell's water content?
Decrease
What does DNA stand for? (spelling counts!)
Deoxyribonucleic acid
A cell specializes in secreting large amounts of protein. Which two organelles would you expect to be especially well developed?
RER & Golgi
A membrane protein contains a long stretch of nonpolar amino acids. Where would this region most likely be located when the protein is embedded in the membrane?
Nonpolar tails
A cell uses ATP to move ions across its membrane. What 2 features of the transport distinguishes it from facilitated diffusion?
Uses energy; agains concentration gradient
A cell has a water potential of −0.8 MPa. The surrounding solution has a water potential of −0.3 MPa. In which direction will water move?
Into the cell
The first vaccine was developed for what disease?
Smallpox
Cell A has a surface area of 840 μm² and a volume of 360 μm³. Cell B has a surface area of 1,120 μm² and a volume of 500 μm³. Cell C has a surface area of 1,350 μm² and a volume of 540 μm³. Which cell would be most efficient at exchanging materials with its environment?
Cell C
A = 2.33
B = 2.24
C = 2.50
Which molecule would cross a phospholipid bilayer most easily without assistance from a membrane protein: Na+, glucose, O2, or H2O?
O2 (small & nonpolar)
A student claims that all transport involving a membrane protein requires ATP. Is the student correct? Explain.
No, facilitated diffusion does not require energy
Draw an animal cell and a plant cell after being placed in a hypertonic environment.
Animal - shrunken / shriveled
Plant - plasmolyzed
Mycology is the scientific study of what?
Fungi
A scientist introduces a substance into a cell that prevents lysosomes from maintaining their acidic internal environment. How would this most directly affect the cell?
No breakdown of cellular components / macromolecules
A drug blocks all proteins embedded in the plasma membrane but does not disrupt the phospholipid bilayer. Which process(es) would be most directly affected?
Facilitated diffusion and active transport
Two solutions have different concentrations of a solute. The solute moves across the membrane until the concentrations become more similar. What provides the driving force for this movement?
Concentration gradient
IV solutions given to patients are normally isotonic. Predict what would happen to cells if an IV of distilled water were given to a patient. Explain.
Water would rush into cells and they would burst (water is hypotonic)
At what temperature are Celsius and Fahrenheit equal?
-40o
A spherical cell increases its diameter from 10 μm to 20 μm while maintaining the same shape. Predict how this change affects the cell's ability to exchange materials with its environment.
Less efficient
A student wants to determine whether a substance can cross a membrane without the help of a transport protein. What characteristics of the substance would be most useful to consider?
Size and polarity
A mutation causes glucose transport proteins in a cell membrane to lose function. How would this affect glucose concentrations inside and outside the cell?
Increase out of cell; decrease inside of cell
Potato cores in solutions of varying concentrations neither gained nor lost mass in a sucrose solution of 0.32M and a temperature of 22oC. Calculate the solute potential of potato cores.
-7.8 bars
How many bones does an adult shark have?
0