Mastering Biology - Ch5
Which of the following is a difference between active transport and facilitated diffusion?
Active transport requires the expenditure of cellular energy, and facilitated diffusion does not.
Macrophages are white blood cells that roam the body searching for invading microbes. These invaders are destroyed inside macrophage vacuoles. How do the macrophages bring the microbes inside?
Microbes are engulfed into the macrophage via phagocytosis.
The reaction ADP + P --> ATP is a(n) _____ reaction.
endergonic
Which of these reactions requires a net input of energy from its surroundings?
endergonic
"Conservation of energy" refers to the fact that ____
energy cannot be created or destroyed but can be converted from one form to another
The energy for an endergonic reaction comes from a(n) _____ reaction.
exergonic
The reaction A --> B + C + heat is released in a(n) _____ reaction.
exergonic
The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of
exocytosis.
A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of
facilitated diffusion
What condition might result from an excess of aquaporins?
fluid retention
Diffusion moves these waste molecules_______ the blood _____the dialysate.
from....to
The shell-less egg in the deionized water will
gain weight
Which of these are by-products of cellular respiration?
heat and water
In the process of osmosis, water displays a net movement from an area of __________ water concentration to an area of __________ water concentration.
higher.....lower
Small waste molecules such as potassium, creatinine, and urea occur at a _______ concentration in the blood and at a______concentration in the dialysate.
higher.....lower
What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?
hydrolysis
A plant cell placed in a _____________ solution will lose water and plasmolyze.
hypertonic
This cell is in a(n) _____ solution.
hypertonic
You know that this cell is in a(n) _____ solution because it _____.
hypertonic solution ... lost water
There is a net diffusion of water out of an animal cell when it is placed in a(n) _________solution.
hypertonnic
active transport
molecules move across the plasma membrane against their concentration gradient.
You're on the pilot episode of a new game show called "The Transport Factor." The host hands you three different amino acids, four different sugars, and two different ions. Then the host shouts, "How many different proteins does the cell need to move these molecules across the plasma membrane using facilitated transport?" Quickly, you correctly respond: _____.
nine
You can recognize the process of pinocytosis when _____.
the cell is engulfing extracellular fluid
The transport of molecules of a particular solute from inside an animal cell across the cell membrane to the extracellular fluid always requires energy when _____.
the concentration of the solute is lower inside the cell than outside it
Osmosis is often viewed incorrectly as a process driven directly by differences in solute concentration across a selectively permeable membrane. What really drives osmosis?
the difference in water concentration across a selectively permeable membrane
What controls the net direction of the movement of oxygen molecules in passive transport?
the direction of the oxygen concentration gradient
Which of the following would be a factor that determines whether the molecule selectively enters the target cells?
the similarity of the drug molecule to other molecules that are transported into the target cells
What is energy coupling?
the use of energy released from an exergonic reaction to drive an endergonic reaction
Water crosses the plasma membrane
through facilitated diffusion or diffusion.
Structure B is a _____.
transport protein
Aquaporins are proteins that facilitate the transport of __________ across the membrane.
water
In the figure below, working from the inside of the "water-filled bubble" out, what would be the order of components observed?
water, hydrophilic head, hydrophobic tail, hydrophobic tail, hydrophilic head, water
When considering the formation of membranes, they __________.
water, hydrophilic head, hydrophobic tail, hydrophobic tail, hydrophilic head, water
Recall from Chapter 4 that phospholipids have two parts: a nonpolar head and two nonpolar tails. In an oil-based, nonpolar environment, phospholipids would arrange themselves so that they __________.
would stay together but in a reverse orientation, with their tails projecting outward
In a catalyzed reaction, a reactant is often called a
substrate
Identify Structure A.
-glycoprotein Structure A is composed of both a carbohydrate and a protein.
n cells, what is usually the immediate source of energy for an endergonic reaction?
ATP
Most cellular work is accomplished by the consumption of __________, which energizes molecules by __________ them.
ATP ... phosphorylating
Which of the following is an accurate comparison of active transport and facilitated diffusion?
Active transport moves solutes against their concentration gradient; facilitated diffusion moves substances down their concentration gradient.
What is the function of Structure E?
stabilization of the phospholipids
Cells A and B are the same size and shape, but cell A is metabolically quiet and cell B is actively consuming oxygen. Oxygen will diffuse more quickly into cell _____ because _____.
B ... the diffusion gradient there is steeper
Green olives may be preserved in brine, which is a 20-30% salt solution. How does this method prevent contamination by microorganisms?
Bacteria can't survive because they would lose water in a hypertonic solution.
In plant cells, carbon dioxide and water are joined to form carbohydrates. Plant cells can also break down carbohydrates such as glucose, releasing carbon dioxide, water, and energy. No one has ever observed such reactions between water and carbon dioxide outside of living cells. What allows living cells to assemble and disassemble complex molecules, which is not possible in nonbiological environments?
Cells couple energy-releasing reactions to energy-requiring reactions.
4Which of these reactions requires a net input of energy from its surroundings?
Endergonic reactions
first law of thermodynamics
Energy cannot be created or destroyed
How are the results of the hemodialysis experiment involving diffusion (Experiment 1) similar to the results of the egg osmosis experiment (Experiment 2)?
Excess water from the blood moved to the hypotonic dialysate fluid, similar to how water from the egg moved to the hypotonic corn syrup.
Which of these statements describes what occurs in facilitated diffusion?
Facilitated diffusion of solutes occurs through protein pores in the membrane.
a red blood cell will shrink in this solution?
Hypertonic
a solution that has a higher concentration of solute than the cell
Hypertonic
a red blood cell will swell in this solution
Hypotonic
a solution that has a lower concentration of solute than the cell
Hypotonic
In a hypothetical world where all things are possible, how could you increase the amount of energy that could be stored in a molecule of ATP?
Increase the negative charge of each phosphate group.
a red blood cell will remain the same shape in this solution
Isotonic
a solution that has the same concentration of solute as the cell
Isotonoic
In Experiment 1, two chemical compounds are introduced. Sodium hydroxide, or NaOH, is a basic compound, with a molecular weight of about 40 g/mol. Phenolphthalein is a colored indicator that turns pink in the presence of a base. Its molar mass is almost eight times the mass of sodium hydroxide, at about 318 g/mol. Based on what you know about diffusion, which hypothesis best describes which molecule is more likely to move across the semipermeable membrane in this process?
Only sodium hydroxide (NaOH) will diffuse across the dialysis tubing.
What name is given to the process by which water crosses a selectively permeable membrane?
Osmosis
What is the role of osmosis in the dialysis process?
Osmosis moves excess fluids from the blood to the dialysate for removal.
Review the figure below of passive transport, then choose one of the following statements as being descriptive of this process.
Passive transport can transport molecules without the assistance of proteins from an area of high concentration to an area of lower concentration.
Which of the following statements is true about passive transport?
Passive transport requires no expenditure of cellular energy.
Frequently, transplanted organs are rejected by the recipient's body. How is this reaction related to plasma membranes?
Proteins
Which of these statements is TRUE with regard to this animation?
Sodium and potassium ions are transported against their concentration gradients.
Which of the following is an example of the second law of thermodynamics?
The aerobic respiration of glucose generates heat, which is dissipated from cells
What happens to the portion of chemical energy that is extracted from molecules by cellular activities but that is not used for cellular work?
The energy contributes to the entropy of the system.
A(n) _____ reaction occurs spontaneously.
The energy for an endergonic reaction comes from a(n) _____ reaction.
The energy for an endergonic reaction comes from a(n) _____ reaction.
The energy for an endergonic reaction comes from a(n) _____ reaction.
In this diagram of the plasma membranes of two adjoining cells, identify the protein indicated by the white arrow, including its function.
a receptor protein that binds with a signaling molecule and relays the message into the cell by activating other molecules inside the cell
Which of these is exhibiting kinetic energy?
a space station orbiting Earth
The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of
active transport
When in solution, a molecule that moves very slowly across an artificial membrane moves rapidly across a plasma membrane. This molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. Using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane?
active transport
Utah's Great Salt Lake has an average salinity seven times higher than that of the oceans. Very few multicellular organisms live in this harsh environment. An example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. These brine shrimp must _____.
actively pump water back into their cells to counter its loss due to osmosis
An enzyme is considered a _______because it speeds up a chemical reaction without being used up.
catalyst
In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?
cellular respiration
Cells store energy that they can access when needed by converting it to ATP. This energy is stored in the form of the _____.
chemical energy within molecules
Fluidity of an animal cell plasma membrane is enhanced by?
cholesterol molecules
The movement of atoms, ions, or molecules from a region of higher concentration to regions of lower concentration is called _____.
diffusion
The ideal osmotic environment for a plant cell is a _________environment.
hypotonic
xAn animal cell placed in a(n) _______Blank solution will gain water, swell, and possibly burst.
hypotonic
You know that this cell is in a(n) _____ solution because the cell _____.
hypotonic ... swelled
New drugs are being developed to lower levels of circulating cholesterol. A successful drug would be one that _____.
increases the rate of LDL receptor-mediated endocytosis
Endocytosis moves materials _____ a cell via _____.
into ... membranous vesicles
A plant cell surrounded by a _______________will be flaccid (limp).
isotonic
The ideal osmotic environment for an animal cell is a(n) Blank environment.
isotonic
In Experiment 2, three shell-less eggs are submerged in three different solutions—an isotonic solution, deionized water, and corn syrup. If you were testing the hypothesis that the eggs will lose water in two of the solutions, which solution is being used for comparison and therefore is the control group?
isotonic solution
Light is _____ energy, which is converted by plants into molecules that possess _____ energy.
kinetic chemical
The shell-less egg in the corn syrup wil
loss weight
The diffusion of water across a selectively permeable membrane is called __________.
osmosis
The plasma membrane is selectively permeable. Which of the following can pass freely through the membrane with no assistance?
oxygen and carbon dioxide
Facilitated diffusion is a type of _____.
passive transport
A white blood cell engulfing a bacterium is an example of ____
phagocytosis
Identify Structure D.
phospholipid bilayer of membrane
Chemical energy is a form of _____ energy.
potential
When placed in a hypotonic environment, where the solute concentration is below that of the cell, a houseplant will _____.
remain standing upright
The shell-less egg in the isotonic solution wil
remain the same
The lipids in a cell membrane are arranged?
so that the nonpolar parts of two lipids point toward each other
A substance that is dissolved in a solvent is called a
solute
Structure A is a _____.
solute
A mixture of a fully combined solute and solvent is called a?
solution
The dissolving agent is called a
solvent
