Mastering biology chapter 5

What compound directly provides energy for cellular work?

ATP

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.

Which of these is exhibiting kinetic energy? -a rock on a mountain ledge -a space station orbiting Earth -a person sitting on a couch while watching TV -the high-energy phosphate bonds of a molecule of ATP -an archer with a flexed bow

a space station orbiting Earth

The concentration of calcium in a cell is 0.3%. The concentration of calcium in the surrounding fluid is 0.1%. How could the cell obtain more calcium?

active transport

The use of energy to move molecules across a membrane defines __________.

active transport

In a hypotonic solution, a plant cell will ________.

become turgid

In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?

cellular respiration

The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of

endocytosis.

"Conservation of energy" refers to the fact that _____.

energy cannot be created or destroyed but can be converted from one form to another

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

entropy

Substances that plug up an enzyme's active site are ________.

enzyme inhibitors

A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of

facilitated diffusion.

How do some inhibitors slow down metabolic pathways when the products of the pathways are not needed but still allow a pathway to proceed when the products are needed?

feedback regulation

Endocytosis moves materials _____ a cell via _____

into ... membranous vesicles

An enzyme _____.

is an organic catalyst

As a result of its involvement in a reaction, an enzyme _____.

is unchanged

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 active transport,

molecules move across the plasma membrane against their concentration gradient.

What name is given to the process by which water crosses a selectively permeable membrane?

osmosis

Diffusion is an example of ________.

passive transport

Facilitated diffusion is a type of _____.

passive transport

A white blood cell engulfing a bacterium is an example of _____.

phagocytosis

The act of a white blood cell engulfing a bacterium is ________.

phagocytosis

A rock on the top of a mountain contains ________ energy.

potential

Chemical energy is a form of _____ energy.

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

Enzymes work by _____.

reducing activation energy

What name is given to the reactants in an enzymatically catalyzed reaction?

substrate

Which component of the following reaction is the enzyme? sucrose + sucrase + water → sucrase + glucose + fructose

sucrase

Osmosis can be defined as ________.

the diffusion of water across a selectively permeable membrane

Water crosses the plasma membrane

through facilitated diffusion or diffusion.

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

transport proteins... down

Usually, enzymes are ________.

proteins

Most enzymes are _____.

proteins

Enzymes increase the rate of a reaction by ________.

decreasing activation energy

Which of these are by-products of cellular respiration? -ATP -glucose and water -heat and water -ATP and water -water

heat and water

What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?

hydrolysis

What is energy?

the capacity to cause change

On a lab bench, there are four balloons filled with identical volumes of different salt solutions: 0% (balloon A), 5% (balloon B), 10% (balloon C), and 15% (balloon D). There are also four beakers each filled with identical volumes of a 10% salt solution. The balloons are semi-permeable; that is, only water can enter and exit the balloon. All four balloons are placed in separate beakers at the same time and are allowed to come to equilibrium. Which is the correct order of balloon volumes at equilibrium, from largest to smallest?

A < B < C < D

Which of these statements is TRUE with regard to this animation? -Sodium ions are transported down their concentration gradient. -The cell does not expend ATP. -Sodium and potassium ions are transported against their concentration gradients. -Potassium ions are transported down their concentration gradient. -The cell is not expending energy.

Sodium and potassium ions are transported against their concentration gradients.

Which of the following processes 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

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 two solutions that differ in solute concentration are placed on either side of a selectively permeable membrane, and osmosis is allowed to take place, the water will ________.

exhibit a net movement to the side with lower water concentration

In osmosis, water always moves toward the __________ solution, that is, toward the solution with the __________ solute concentration.

hypertonic ... greater