CH 5

These are some common problems associated with gel electrophoresis. Put which one is the most likely cause to each problem. Problem: 1 - A single blob is in one lane 2 - The bands are very close together, spread only halfway down the gel 3 - There are no bands in a lane 4 - The DNA appears smeared, rather than in clean bands Cause: A - There was no DNA loaded into the well B - The run time was very short C - The DNA was not properly loaded D - The DNA was not digested by restriction enzymes

1 = D 2 = B 3 = A 4 = C

Calculate the SA/V ratio for a cube that is 3cm on each side. Hint: SA = Length x Width x Number of sides V = Length x Width x Height SA / V

2 (54/27)

Fill in the blanks: (some may be used more than once) Beaker is filled with distilled water. Beet Core: - Wp = 0.2 - Ws = -0.4 Words/numbers: 0 0.2 -0.2 0.6 into out of Sentences: A: The water potential in the beaker is ____ bars B: The water potential in the beet core is ____ bars C: Water will flow ____ the beet core cells

A = 0 B = -0.2 C = into

WHich of the following would tend ot increase membrane fluidity?

A greater proportion of phospholipids with unsaturated hydrocarbon tails

Which of the following factors would tend to increase membrane fluidity?

A greater proportion of unsaturated phospholipids

Which of the following would be least likely to pass through a plasma membrane without the help of a transport protein?

A large polar molecule

Which beaker(s) contain(s) a solution that is hypertonic to the bag? A: Beaker = 0.2 M ; Bag = 1.0 M B: Beaker = 1.0 M ; Bag = 0.2 M C: Beaker = 0.4 M ; Bag = 0.2 M D: Beaker = 0.2 M ; Bag = 0.2 M E: Beaker = 0.6 M ; Bag = 0.2 M

B, C, E

If the mass of each dialysis bag is measured before each is immersed in its respective solution, and the mass is measured again 45 minutes later, which bag would you predict will show the greatest increase in mass? A: Beaker = 0.4 M ; Bag = 0.2 M B: Beaker = 0.6 M ; Bag = 0.2 M C: Beaker = 0.2 M ; Bag = 1.0 M D: Beaker = 0.6 M ; Bag = 0.2 M E: Beaker = 0.2 M ; Bag = 1.0 M F: Beaker = 1.0 M ; Bag = 0.2 M G: Beaker = 0.2 M ; Bag = 0.2 M

C

Beaker A: - Distilled water - Plant Cell A: Wp 0 bars + Ws -2 bars = W -2 bars Beaker B: - Distilled water - Plant Cell B: Wp 2 bars + Ws -2 bars = W 0 bars Which statements are true/false? C - Plant cell B is isotonic to the fluid in the beaker D - Plant cell B's water potential increased due to an increase in solutes inside the cell E - Plant cell A is at equilibrium with the fluid in the beaker F - Plant cell B is at equilibrium with the fluid in the beaker G - Plant cell A has higher water potential than cell B H - Plant cell A has lower water potential than cell B

C = F D = F E = F F = T G = F H = T

Which of the following molecules is most likely to passively diffuse across the plasma membrane?

Carbon dioxide

In what way do the membranes of a eukaryotic cell vary?

Certain proteins are unique to each kind of membrane

A red blood cell is placed into each of the following solutions. Indicate whether crenation, hemolysis, of neither will occur. Solution A: 3.21% (m/v) NaCl Solution B: 1.65% (m/v) glucose Solution C: distilled H2O Solution D: 6.97% (m/v) glucose Solution E: 5.0% (m/v) glucose and 0.9% NaCl

Crenation: - A - D - E Hemolysis: - B - C Neither:

Which of these experimental treatments would increase the rate of sucrose transport into a plant cell?

Decreasing extracellular pH

Using the values provided, arrange the beakers in the order of the mass inside the dialysis bags after the experiment has run for 45 minutes, beginning with the bag that loses the most mass first (has the smallest mass after 45 minutes) A: Beaker = 0.2 M ; Bag = 0.2 M B: Beaker = 0.2 M ; Bag = 1.0 M C: Beaker = 0.6 M ; Bag = 0.2 M D: Beaker = 0.4 M ; Bag = 0.2 M E: Beaker = 1.0 M ; Bag = 0.2 M

E, C, D, A, B

Which of the following processes and organelle(s) account for the replacement of lipids and proteins lost from the plasma membrane?

Exocytosis and smooth and rough ER

Which of these statements describes some aspect of facilitated diffusion?

Facilitated diffusion of solutes may occur through transport proteins in the membrane

If you were given a cube of modeling clay, how could you shape it to have the greatest surface area-to-volume ratio?

Flatten the cube into a pancake with numerous projections

What is the function of cholesterol?

Helps to stabilize the structure of the plasma membrane

Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the plasma membrane would cholesterol most likely be found?

In the interior of the membrane

Lipid-soluble signaling molecules, such as aldosterone, cross the membranes of all cells but affect only target cells because

Intracellular receptors are present only in target cells

An open container where solute ahs been added to the water, brings its solute potential to -3.4 bars. What effect does adding solute to distilled water have on its solute potential? On its water potential? Wp = 0 bars Ws = -3.4 bars

It lowers the solute potential and lowers the water potential

Which of the following statements best describes the behavior of DNA during electrophoresis?

Migration distance is inversely proportional to the fragment size

Steroid hormones enter a cell bu simple diffusion. In doing so, these steroids ____

None of the listed responses are correct - Move down a concentration gradient and are polar - Move up a concentration gradient and are nonpolar - Move through a channel and down a gradient and are nonpolar - Move up a concentration and are polar

Which of the following processes includes all the others?

Passive transport Others: - Osmosis - Diffusion of a solute across a membrane - Transport of an ion down its electrochemical gradient

The general name for an enzyme that transfers phosphate groups from ATP to a protein is ____

Protein kinase

The molecule cAMP directly activates ____

Protein kinase A

Which of the following enables a cell to concentrate and take in a specific kind of molecule?

Receptor-mediated endocytosis

What event would activate a G protein?

Replacement of GDP and GTP

A semipermeable membrane is placed between the following solutions: Solution A: 1.4% (m/v) starch Solution B: 7.62% (m/v) starch Which solution will decrease in volume?

Solution A

A semipermeable membrane is placed between the following solutions: Solution C: 9% (m/v) NaCl Solution D: 12.4% (m/v) NaCl Which solution will increase in volume?

Solution D

Beaker A: - Distilled water - Beet Core: Wp = 0.4 ; Ws = -0.4 Beaker B: - Distilled water - Beet core: Wp = 0.2 ; Ws = -0.4 Which of the following statements is true?

The beet core in beaker A is at equilibrium with the surrounding water

Beaker: - Distilled Water - Plant cell: Wp = 0 bars ; Ws = -3 bars What will occur when this system is at dynamic equilibrium?

The cell will gain water until its pressure potential equals 3 bars

The plasma membrane is referred to as a "fluid mosaic" structure. Which of the following statements about that model is true?

The fluid aspect of the membrane is due to the lateral and rotational movement of phospholipids, and embedded proteins account for the mosaic aspect

How can you recognize the phospholipid bilayer of membrane?

The presence of a head and two tails

Which of these two plants' cells have the highest water potential? One is wilted and sagging, the other is upright and full

The upright and full plant

Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because

They amplify the original signal manyfold

Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because ____

They amplify the original signal manyfold

Which of the following correctly describes a general property of all electrogenic pumps?

They create a voltage difference across a membrane

Osmosis is a specialized type of diffusion. Which of the following is specific only to osmosis?

Water molecules pass through a semipermeable membrane

Describe the net movement of water when a dialysis bag containing a 0.2 M sucrose solution is placed into distilled water, which contains no solutes

Water will move into the bag. Distilled water has no solute and is hypotonic to the solution in the bag