The internal pH of most cells is near neutral
The internal pH of most cells is near neutral. This allowsA) water to break down into H+ and OH-.B) rapid fluctuations between acidic and basic conditions within the cells.C) the buffers produced within the body to affect these cells.D) enzymes outside of these cells to function.E) enzymes within the cell to act at peak efficiency.PointsEarned:2.0/2.02.With few exceptions, organic compounds are those that containA) carbon.B) nitrogen.C) all of the above.D) ocygen.E) hydrogen.PointsEarned:2.0/2.03.As one form of energy is converted into another, there is always some energy lost asA) heat.B) light.C) chemical energy.D) kinetic energy.E) activation energy.PointsEarned:2.0/2.04.In photosynthesis, the light-dependent reactionsA) can take place day or night.B) produce ATP and energy stored in electron carriers.C) produce ADP and carbon dioxide.D) are uncoupled from the light-independent reactions.E) lead to carbon fixation.PointsEarned:2.0/2.05.What method is often used by cells to move large solid material into the cell?A) simple diffusion.B) phagocytosis.C) facilitated diffusion.D) active transport.E) exocytosis.PointsEarned:2.0/2.06.In a cell,A) energy-absorbing reactions and energy-releasing reactions are unlinked.B) there are many more energy-absorbing reactions than energy-releasing reactions.C) energy-absorbing reactions are coupled to energy-releasing reactions via electron carriers.D) more energy is used up than is produced.E) energy-releasing reactions are coupled to energy-absorbing reactions.PointsEarned:2.0/2.07.The most common energy-carrying molecule in the cell isA) DNA.B) adenine.C) AMP.D) ADP.E) ATP.PointsEarned:2.0/2.08.During the Calvin-Benson cycle (carbon-fixing reactions), in the red Columbine plant, high-energyelectrons are transferred into a newly made 3-carbon compound. Eventually, these electrons willend up as part of glucose molecules. What was the original source of these electrons inphotosynthesis?A) glucoseB) waterC) ATPD) carbon dioxide.E) oxygenPointsEarned:2.0/2.09.The role of oxygen in cellular respiration is toA) act as the final electron acceptor.B) aid in the transport of pyruvate into the mitochondria.C) allow glycolysis to continue.D) combine with carbon atoms to form carbon dioxide.E) supply an energy molecule.PointsEarned:2.0/2.010.Rank the following chemical bonds from weakest to strongest:A) hydrogen, covalent, ionicB) ionic, covalent, hydrogenC) hydrogen, ionic, covalentD) ionic, hydrogen, covalentE) covalent, ionic, hydrogenPointsEarned:2.0/2.011.A hummingbird is “drinking” nectar containing sugar from a red columbine flower. Arrange thefollowing events to occur in the hummingbird in order from the first to last:1. Glucose sugar is converted to pyruvate.2. Energy from high-energy electrons is released from an electron transport chain. Thisenergy is used to make ATP.3. The hummingbird exhales carbon dioxide and energy is stored in electron carriers.4. The hummingbird has the ability to beat its wings 40 – 80 times a second.A) 1, 4, 3, 2B) 1, 2, 3, 4C) 2, 1, 3, 4D) 2, 3, 4, 1E) 1, 3, 2, 4PointsEarned:2.0/2.012.Surface tension of water is due toA) the ability of water to act as a solvent.B) hydrogen bonding.C) ionic bonding.D) ionization of water.E) water molecules repelling each other.PointsEarned:2.0/2.013.Because the shared electrons between hydrogen and oxygen spend more time orbiting theoxygen than the hydrogen, water isA) a neutral molecule.B) a nonpolar molecule.C) a charged molecule.D) a polar molecule.PointsEarned:2.0/2.014.The majority of ATP produced in cellular respiration is produced duringA) fermentation.B) anaerobic processes.C) glycolysis.D) the electron transport chain.E) the Krebs cycle.PointsEarned:2.0/2.015.A stone is pushed from the top of a hill. Halfway to the bottom of the hill, this rolling stoneA) is constantly gaining more energy.B) is using up chemical energy.C) has both potential energy and kinetic energy.D) has kinetic energy only.E) has potential energy only.PointsEarned:2.0/2.016.Most cells are small. When they reach a certain size, cells typically divide. This has to do with theA) amount of genetic material.B) fact that they cannot possess sufficient numbers of organelles for normal cell functioning.C) differences between viral particles and eukaryotic cells.D) surface-to-volume ratio.E) inability to produce more components of the cell membrane.PointsEarned:2.0/2.017.This element is prominent in both living organisms and in the Earth’s surface.A) oxygenB) hydrogenC) aluminumD) siliconE) carbonPointsEarned:2.0/2.018.Because of the atomic structure of carbon, it tends to formA) bonds only with hydrogen.B) ionic bonds.C) sulfide bonds.D) hydrogen bonds.E) covalent bonds.PointsEarned:2.0/2.019.All enzymes act byA) raising the activation energy of specific chemical reactions.B) breaking hydrogen bonds between molecules.C) allowing products to be changed during the chemical reactions.D) breaking and forming ionic bonds between ions.E) lowering the activation energy of specific chemical reactions.PointsEarned:2.0/2.020.The atomic nucleus consists ofA) protons and electronsB) neutrons and electrons.C) neutrons only.D) neutrons and protons.E) protons only.