AP Bio Chapter 6 Test

If enzymes could not be used during a reaction, which of the following could be added to a system to make

the reaction occur?

• Substrate

• Energy, possibly in the form of heat

• Product

• Water

Which form of energy is correctly associated with an example?

• Kinetic energy: fat molecules

• Kinetic energy: movement of muscles

• Chemical energy: sunlight

• Potential energy: water rushing down a narrow gorge

Which best describes the first law of thermodynamics?

• Energy is not created nor destroyed, but it can change into matter.

• Energy is not created nor destroyed, but it can change from one energy form to another.

• Some useful energy is lost as heat whenever an energy transfer occurs.

• Energy transfers are always 100% efficient in changing energy from one useful form to

  another.

Which of the following is consistent with the laws of physics governing energy?

• When a liter of gasoline is burned in a car engine, 100% of its energy goes into moving the car along the road.

• Eventually sunlight that is absorbed on the earth returns to space as dispersed heat.

• A calorie of sunlight becomes a calorie of plant tissue that, eaten by you, becomes a calorie of heat lost in muscle "power."

• Chemical bonds are a case of converting energy to matter; breaking the bonds converts matter to energy.

A living organism represents stored energy in the form of chemical compounds. When an organism dies, what happens to this stored energy?

• All molecules immediately degrade into basic elements.

• All energy immediately leaves.

• The chemical compounds in cells lose their organization over time because there is no longer an input of energy to maintain the organized state.

• The chemical compounds remain exactly intact and ready to start up again unless digested by a consumer or decay organism.

All of the biochemical pathways used in a cell constitute

• coupling reactions

• endergonic reactions only

• exergonic reactions only

• metabolism

Coupling occurs when the energy released by an exergonic reaction is

• used to drive another exergonic reaction

• used to drive an endergonic reaction

• lost as non-usable heat to the environment

• used to prevent an endergonic reaction

ATP is considered to be

• an enzyme used widely in all kinds of cells

• a coenzyme used to inhibit or activate different enzymes

• a molecule that carries a great deal of chemical energy in a chemical bond

• the precursor of a high-energy membrane-bounded protein

While eating a container of yogurt, you have to leave, so you store the yogurt in the refrigerator. A day later you return and find the surface of the yogurt is no longer smooth but has broken into several liquefied products. You correctly guess that enzymes from your saliva, via the spoon, have continued digesting the yogurt in your absence. What will happen over time?

• The reaction will soon stop because the amount of saliva is small, and you would have to add more saliva to continue the degradation.

• The reaction will continue indefinitely since the enzyme is not consumed by the reaction.

• The reaction will continue until half is digested and then stop because the reaction between substrate and product will be balanced.

• The reaction will stop because the enzyme will be denatured in the refrigerator.

There are twelve different intermediate products produced during the production of a molecule in a cell. One can expect that there

• is one enzyme that carries this process through to the end product

• is one enzyme for degradation and another enzyme for synthesis

• must be twelve different raw materials combined in the cell by one enzyme

• are about twelve enzymes, at least one responsible for each step in the metabolic pathway