1. All enzymes act by
A) allowing products to be changed during the chemical reactions.
B) raising the activation energy of specific chemical reactions.
C) lowering the activation energy of specific chemical reactions.
D) breaking and forming ionic bonds between ions.
E) breaking hydrogen bonds between molecules.
2. During the Calvin-Benson cycle (carbon-fixing reactions), in the red Columbine plant, high-energy electrons are transferred into a newly made 3-carbon compound. Eventually, these electrons will end up as part of glucose molecules. What was the original source of these electrons in photosynthesis?
A) water
B) carbon dioxide.
C) oxygen
D) ATP
E) glucose
3. Because the shared electrons between hydrogen and oxygen spend more time orbiting the oxygen than the hydrogen, water is
A) a polar molecule.
B) a charged molecule.
C) a neutral molecule.
D) a nonpolar molecule.
4. With few exceptions, organic compounds are those that contain
A) all of the above.
B) nitrogen.
C) hydrogen.
D) ocygen.
E) carbon.
5. The most common energy-carrying molecule in the cell is
A) DNA.
B) adenine.
C) ATP.
D) AMP.
E) ADP.
6. The internal pH of most cells is near neutral. This allows
A) the buffers produced within the body to affect these cells.
B) water to break down into H+ and OH-.
C) enzymes outside of these cells to function.
D) enzymes within the cell to act at peak efficiency.
E) rapid fluctuations between acidic and basic conditions within the cells.
7. What method is often used by cells to move large solid material into the cell?
A) exocytosis.
B) phagocytosis.
C) active transport.
D) facilitated diffusion.
E) simple diffusion.
8. The role of oxygen in cellular respiration is to
A) combine with carbon atoms to form carbon dioxide.
B) act as the final electron acceptor.
C) supply an energy molecule.
D) allow glycolysis to continue.
E) aid in the transport of pyruvate into the mitochondria.
9. A stone is pushed from the top of a hill. Halfway to the bottom of the hill, this rolling stone
A) has both potential energy and kinetic energy.
B) has potential energy only.
C) is using up chemical energy.
D) is constantly gaining more energy.
E) has kinetic energy only.
10. Surface tension of water is due to
A) the ability of water to act as a solvent.
B) ionic bonding.
C) water molecules repelling each other.
D) ionization of water.
E) hydrogen bonding.
11. Rank the following chemical bonds from weakest to strongest:
A) covalent, ionic, hydrogen
B) ionic, covalent, hydrogen
C) ionic, hydrogen, covalent
D) hydrogen, covalent, ionic
E) hydrogen, ionic, covalent
12. Most cells are small. When they reach a certain size, cells typically divide. This has to do with the
A) differences between viral particles and eukaryotic cells.
B) amount of genetic material.
C) inability to produce more components of the cell membrane.
D) fact that they cannot possess sufficient numbers of organelles for normal cell functioning.
E) surface-to-volume ratio.
13. The atomic nucleus consists of
A) neutrons and protons.
B) protons only.
C) neutrons only.
D) protons and electrons
E) neutrons and electrons.
14. This element is prominent in both living organisms and in the Earth’s surface.
A) carbon
B) aluminum
C) hydrogen
D) silicon
E) oxygen
15. In a cell,
A) energy-releasing reactions are coupled to energy-absorbing reactions.
B) more energy is used up than is produced.
C) energy-absorbing reactions and energy-releasing reactions are unlinked.
D) there are many more energy-absorbing reactions than energy-releasing reactions.
E) energy-absorbing reactions are coupled to energy-releasing reactions via electron carriers.
16. In photosynthesis, the light-dependent reactions
A) produce ADP and carbon dioxide.
B) lead to carbon fixation.
C) produce ATP and energy stored in electron carriers.
D) can take place day or night.
E) are uncoupled from the light-independent reactions.
17. The majority of ATP produced in cellular respiration is produced during
A) the Krebs cycle.
B) the electron transport chain.
C) glycolysis.
D) anaerobic processes.
E) fermentation.
18. Because of the atomic structure of carbon, it tends to form
A) ionic bonds.
B) hydrogen bonds.
C) sulfide bonds.
D) bonds only with hydrogen.
E) covalent bonds.
19. A hummingbird is “drinking” nectar containing sugar from a red columbine flower. Arrange the following events to occur in the hummingbird in order from the first to last:
Glucose sugar is converted to pyruvate.
Energy from high-energy electrons is released from an electron transport chain. This energy is used to make ATP.
The hummingbird exhales carbon dioxide and energy is stored in electron carriers.
The hummingbird has the ability to beat its wings 40 – 80 times a second.
A) 2, 1, 3, 4
B) 1, 4, 3, 2
C) 1, 3, 2, 4
D) 1, 2, 3, 4
E) 2, 3, 4, 1
20. As one form of energy is converted into another, there is always some energy lost as
A) heat.
B) activation energy.
C) chemical energy.
D) kinetic energy.
E) light.