BIOL 100: Chapter 5

Which of the following is an example of potential rather than kinetic energy?

A molecule of glucose

The sum total of all the chemical reactions that occur in organisms is called ________.

Metabolism

The sodium-potassium pump _______.

Moves sodium ions out of a cell and potassium ions into a cell using energy from ATP

Diffusion is an example of ______.

Passive transport

How is oxygen transported from air into the bloodstream?

Passive transport

Which of these molecules spontaneously form membranes when mixed in water?

Phospholipids

When a plant cell is submerged in a hypertonic solution, what is likely to occur?

Plasmolysis will cause the plasma membrane to detach from the cell wall

A boulder at the top of a hill contains ______ energy.

Potential

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.

Transport proteins; down

T/F: A chemical reaction catalyzed by an enzyme proceeds more rapidly than the same reaction in the absence of the enzyme.

True

T/F: All biological membranes are selectively permeable.

True

T/F: All types of passive transport require a concentration gradient

True

T/F: Osmosis requires a semi-permeable membrane that doe NOT permit passage of solute.

True

T/F: Facilitated diffusion is NOT a type of passive transport

False

T/F: Osmosis requires ATP.

False

Biomedical scientists have recently developed an anticancer drug delivery system that sneaks the anticancer drug into cancer cells before releasing it. They were able to do this by using two sets of liposomes. An anticancer drug (Doxorubicin (Dox)) bound to DNA molecules was added into one set of liposomes, and a high concentration of ATP molecules were added to the other set of liposomes. The drug is inactive when bound to DNA molecules. Researchers inject both types of liposomes into cancer cells, and upon doing so their contents are released. The ATP molecules from one set of liposomes bind to the DNA molecules from the other set of liposomes) and activate the drug, thus inducing cell death and decreasing tumor size.Mice with breast cancer tumors were treated with this liposome system to test the effectiveness of the drug. The scientists performed three trials-one with both types of liposomes (Dox + ATP), one with just the drug (Dox only), and one with a salt solution (control). Examine the figure below and answer the following questions. What is the best explanation for the intermediate tumor size that results from treatment with just the drug (Dox only) compared to the control and treatment with both liposomes (Dox + ATP)?

1) When ATP is lacking, not as much Dox can enter the cell via facilitated diffusion (wrong) 2) Without ATP, Dox becomes an energy source for cancer cells

Which statement about enzyme is TRUE?

1)An enzyme's function depends on its three-dimensional shape 2) They catalyze specific reactions

Cellular respiration converts the energy of fuel molecules to a form of energy that a cell can use to perform work. In an average day, most adult humans need to consume about 2,000 Calories to maintain their health. However, the exact amount of dietary Calories a person needs depends upon many factors, including the person's age, physical activity, size, and health. Foods that we consume vary greatly in their nutritional content and quality. A large hard-boiled egg, for example, has about 75 dietary Calories and contains about 70% of our recommended daily intake of cholesterol. The amount of dietary Calories in one hard-boiled egg could raise the temperature of ________.

1,000 grams of water by 75 degrees Celsius

Ten kilocalories are equivalent to ______ calories.

10,000

You have a 2-kg bottle of liquid water at 0°C. About how many Calories are needed to heat up the water to 100°C?

200 calories

Cellular respiration converts the energy of fuel molecules to a form of energy that a cell can use to perform work. In an average day, most adult humans need to consume about 2,000 Calories to maintain their health. However, the exact amount of dietary Calories a person needs depends upon many factors, including the person's age, physical activity, size, and health. Foods that we consume vary greatly in their nutritional content and quality. A large hard-boiled egg, for example, has about 75 dietary Calories and contains about 70% of our recommended daily intake of cholesterol. Running burns approximately 600 Calories per hour. If you ate four hard-boiled eggs, how long would you have to run to burn them off?

30 minutes

Humans convert approximately ________ of the energy stored in food to useful work.

34%

The force driving simple diffusion is ________, while the energy source for active transport is ________.

A concentration gradient; ATP breakdown

What cell transport is modeled by the diagram belowe?

A liver cell uses endocytosis to take up cholesterol from the blood

What compound directly provides energy for cellular work?

ATP

The region of an enzyme to which a substrate binds is called the ______ site.

Active

Which process could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than in the surroundings?

Active transport

Biomedical scientists have recently developed an anticancer drug delivery system that sneaks the anticancer drug into cancer cells before releasing it. They were able to do this by using two sets of liposomes. An anticancer drug (Doxorubicin (Dox)) bound to DNA molecules was added into one set of liposomes, and a high concentration of ATP molecules were added to the other set of liposomes. The drug is inactive when bound to DNA molecules. Researchers inject both types of liposomes into cancer cells, and upon doing so their contents are released. The ATP molecules from one set of liposomes bind to the DNA molecules from the other set of liposomes) and activate the drug, thus inducing cell death and decreasing tumor size.Mice with breast cancer tumors were treated with this liposome system to test the effectiveness of the drug. The scientists performed three trials-one with both types of liposomes (Dox + ATP), one with just the drug (Dox only), and one with a salt solution (control). Examine the figure below and answer the following questions. A student in your class examines the graph and hypothesizes that ATP is what kills cancer cells, and not Dox. What follow-up experiment would allow you to test this student's hypothesis?

Add a fourth trial, in which mice with breast cancer tumors are treated with liposomes containing just ATP (ATP only).

Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells? The animal cell is in ________.

An isotonic solution, and the plant cell is an hypotonic solution

How are membrane transport proteins like enzymes?

Both are made from RNA molecules (wrong)

Active transport _______.

Can involve the transport of ions

The photos below show a plant before watering (left) and after it was watered (right). What causes the change in plant appearance?

Cells that were in an isotonic environment are restored to a hypotonic environment

Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing ________.

Chemical energy into kinetic energy

Simple diffusion requires _______.

Concentration gradient

The principle that energy cannot be created or destroyed is known as ________.

Conservation of energy

The energy stored in an ATP molecule is located in the ________.

Covalent bond between the second and third phosphate groups

T/F: All types of passive transport require a membrane transport protein.

False

Enzymes increase the rate of a reaction by ________.

Decreasing activation energy

Which os the following pairs of processes are functionally opposite?

Endocytosis and exocytosis

Which of the following is a measure of randomness in a system?

Entropy

What molecules are scientists currently trying to use to generate power for nanotechnology devices, such as microscopic robots?

Enzymes

Which statement best describes enzyme function?

Enzymes speed chemical reactions by lowering the activation energy.

Specialized cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. Which process would be responsible for its secretion?

Exocytosis

Examine the cells below. Cells with a higher concentration of ions than the surrounding medium tend to ______.

Expand

Cellular respiration converts the energy of fuel molecules to a form of energy that a cell can use to perform work. In an average day, most adult humans need to consume about 2,000 Calories to maintain their health. However, the exact amount of dietary Calories a person needs depends upon many factors, including the person's age, physical activity, size, and health. Foods that we consume vary greatly in their nutritional content and quality. A large hard-boiled egg, for example, has about 75 dietary Calories and contains about 70% of our recommended daily intake of cholesterol. A person eats one hard-boiled egg and digests the egg fully. During cellular respiration MOST of the Calories in the egg is converted to ________.

Heat

Cellular swelling is likely to occur when blood cells are immersed in:

Hypotonic solutions

Substances that plug up enzyme's active site are enzyme______.

Inhibitors

Biomedical scientists have recently developed an anticancer drug delivery system that sneaks the anticancer drug into cancer cells before releasing it. They were able to do this by using two sets of liposomes. An anticancer drug (Doxorubicin (Dox)) bound to DNA molecules was added into one set of liposomes, and a high concentration of ATP molecules were added to the other set of liposomes. The drug is inactive when bound to DNA molecules. Researchers inject both types of liposomes into cancer cells, and upon doing so their contents are released. The ATP molecules from one set of liposomes bind to the DNA molecules from the other set of liposomes) and activate the drug, thus inducing cell death and decreasing tumor size.Mice with breast cancer tumors were treated with this liposome system to test the effectiveness of the drug. The scientists performed three trials-one with both types of liposomes (Dox + ATP), one with just the drug (Dox only), and one with a salt solution (control). Examine the figure below and answer the following questions. What would be the best experiment to test the effectiveness of this anticancer drug system?

Inject both sets of liposomes into multiple mice that have tumors and measure what happens to the size of the tumors.

______ occurs when a substance produced by a cell inhibits an enzyme required for synthesizing the substance.

Irreversible inhibition (wrong)

Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment ________.

Is hypotonic to the protozoan

A cell that neither gains nor loses a net amount of water at equilibrium when it is immersed in a solution is ________.

Isotonic to its environment

In the figure below, how does molecule A affect enzyme function?

It is an inhibitor that changes the enzyme's active site

When ATP releases some energy, it also releases inorganic phosphate. What happens to the inorganic phosphate in the cell?

It may be transferred onto other molecules in the cell to activate them

You are riding on your bike and stop pedaling, coasting along the road. Eventually, your bike slows down and stops. What happened to the energy of your motion when your bike stopped?

It was released as heat

An object at rest has no ________ energy, but it may have ________ energy resulting from its location or structure.

Kinetic; potential

Cellular respiration converts the energy of fuel molecules to a form of energy that a cell can use to perform work. In an average day, most adult humans need to consume about 2,000 Calories to maintain their health. However, the exact amount of dietary Calories a person needs depends upon many factors, including the person's age, physical activity, size, and health. Foods that we consume vary greatly in their nutritional content and quality. A large hard-boiled egg, for example, has about 75 dietary Calories and contains about 70% of our recommended daily intake of cholesterol. Molecules that come from the food we eat provide energy for the amazing work that goes on inside of our cells. This energy, stored inside of our food, is a form of ________.

Potential energy called chemical energy

Diffusion______.

Proceeds until a dynamic equilibrium is reached

Usually, enzymes are ______.

Proteins

High levels of cholesterol in the blood are a major risk factor for heart attacks. Which type of membrane transport is used by liver cells to take up cholesterol from the blood?

Receptor-mediated endocytosis

Active transport processes:

Requires cells to expend energy (ATP)

Anything that prevents ATP formation will most likely ______.

Result in cell death

An enzyme's function is most dependent on its ________.

Shape

What kind of molecules pass through a cell membrane most easily?

Small and hydrophobic

The combination of sucrose, sucrase, and water produces sucrase, glucose, and fructose. Which component of the reaction is the enzyme?

Sucrase

The combination of sucrose, sucrase, and water produces sucrase, glucose, and fructose. Which component of the reaction is the substrate?

Sucrose

Energy can be defined as _______.

The capacity to cause change

Which statement is TRUE about the concentrations of sodium and potassium inside animal nerve cells?

The concentration of potassium inside the cell is lower than that outside the cell, while the concentration gradient of sodium is reversed (wrong)

Osmosis can be defined as ______.

The diffusion of water across a selectively permeable membrane

A patient was involved a serious accident and lost a large quantity of blood. In an attempt to replenish body fluids, distilled water—equal to the volume of blood lost—is added to the blood directly via one of his veins. What will be the most probable result of this transfusion?

The patient's red blood cells will swell and possibly burst because the blood has become hypotonic compared to the cells.

A balloon that is permeable to water but not to glucose contains a 10% glucose solution. A beaker contains a 5% glucose solution. Which statement correctly classifies the solutions?

The solution in the beaker is hypertonic relative to the solution in the balloon (wrong)

A balloon contains a 10% glucose solution. The balloon is permeable to water but not to glucose. A beaker contains a 5% glucose solution. What will happen when the balloon is submerged in the beaker?

The volume of water in the beaker will decrease

Biomedical scientists have recently developed an anticancer drug delivery system that sneaks the anticancer drug into cancer cells before releasing it. They were able to do this by using two sets of liposomes. An anticancer drug (Doxorubicin (Dox)) bound to DNA molecules was added into one set of liposomes, and a high concentration of ATP molecules were added to the other set of liposomes. The drug is inactive when bound to DNA molecules. Researchers inject both types of liposomes into cancer cells, and upon doing so their contents are released. The ATP molecules from one set of liposomes bind to the DNA molecules from the other set of liposomes) and activate the drug, thus inducing cell death and decreasing tumor size.Mice with breast cancer tumors were treated with this liposome system to test the effectiveness of the drug. The scientists performed three trials-one with both types of liposomes (Dox + ATP), one with just the drug (Dox only), and one with a salt solution (control). Examine the figure below and answer the following questions. Which statement regarding these data is TRUE?

Tumor weight decreases when you add Dox only to cancer cells