5 Written questions
5 Matching questions
- Which best describes the first law of thermodynamics?
A. Energy is changed from one form to another with a loss of usable energy.
B. Energy is not created nor destroyed, but it can change from one energy form to another.
C. Energy can be created from matter or used to produce matter.
D. Some useful energy is lost as heat whenever an energy transfer occurs.
E. Energy transfers are always 100% efficient in changing energy from one useful form to another.
- Energy coupling of endergonic and exergonic reactions within cells
A. permits biological reactions to proceed at temperatures consistent with life.
B. uses heat released by one reaction to fuel the other reaction.
C. utilizes ATP to carry energy between the exergonic and endergonic reactions.
D. All of the choices are correct.
- Lactose is milk sugar, and humans produce substantial lactase enzyme to digest it when we are infants. However, we soon lose some or even all of our lactase after childhood. In such cases, undigested lactose passes to the lower intestine where bacteria break it down into lactic acid and CO2, causing painful gas bloating. This problem could be avoided by
A. avoiding all dairy products containing lactose.
B. taking lactase enzyme tablets when consuming lactose products.
C. taking any enzyme tablets when consuming dairy products.
D. consuming lactose in tablet form.
E. Both taking lactase enzyme and avoiding all dairy products would be correct.
- Which of the following is consistent with the laws of physics governing energy?
A. When a liter of gasoline is burned in a car engine, 100% of its energy goes into moving the car along the road.
B. You eat a "quarter-pounder" hamburger and assemble exactly a quarter-pound of additional body weight on your body.
C. Eventually sunlight that is absorbed on the earth returns to space as dispersed heat.
D. A calorie of sunlight becomes a calorie of plant tissue that, eaten by you, becomes a calorie of heat lost in muscle "power."
E. 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?
A. All chemicals immediately lose their high-energy bonds.
B. All molecules immediately degrade into basic elements.
C. All energy immediately leaves, and that is one manifestation that the organism is dead.
D. The chemical compounds in cells lose their organization over time because there is no longer an input of energy to maintain the organized state.
E. The chemical compounds remain exactly intact and ready to start up again unless digested by a consumer or decay organism.
- a D. All of the choices are correct.
- b C. Eventually sunlight that is absorbed on the earth returns to space as dispersed heat.
- c D. The chemical compounds in cells lose their organization over time because there is no longer an input of energy to maintain the organized state.
- d E. Both taking lactase enzyme and avoiding all dairy products would be correct.
- e B. Energy is not created nor destroyed, but it can change from one energy form to another.
5 Multiple choice questions
- B. Second Law of Thermodynamics.
- D. An enzyme's activity is generally reduced by an increase in substrate concentration.
- D. addition of distilled water
5 True/False questions
The activity of an enzyme might be increased by all of the following except ________?
A. increase in substrate concentration.
B. a vitamin.
C. 2-4 degree increase in temperature.
D. lead. → D. lead.
Which statement is NOT true about enzyme inhibition?
A. In competitive inhibition, the inhibitor binds to the active site of the enzyme.
B. In noncompetitive inhibition, the inhibitor binds to the allosteric site of the substrate.
C. In irreversible inhibition, a poison binds to the enzyme so that it can never work again.
D. Most inhibitors act in a reversible fashion.
E. All of the statements are true. → E. All of the statements are true.
In this reaction, the reactant (s) are _____________ and the coenzyme NAD is ____________.
A. reduced; oxidized
B. oxidized; oxidized
C. reduced; reduced
D. oxidized; reduced → D. oxidized; reduced
The energy for ATP synthesis in chemiosmotic phosphorylation comes from the movement of hydrogen ions across a membrane down a concentration gradient.
True False → D. All of the choices are correct.
If the reaction graphed at right is coupled with D→E, then D →E is:
D. none of the above → A. five