Problem Set- Chapter 2

Which of the following is not true regarding hydrogen bonds?

are stronger than a covalent bond

The total number of protons and neutrons in an atom can best be determined from which of the following?

atomic mass

A mad scientist has ripped apart an atom and collected all the subatomic particles located in the nucleus of the atom. Which of the following has he collected? A) protons and neutrons B) protons C) electrons D) neutrons and electrons E) electrons and protons

A

The most important physical characteristic of lipids is that they: A) are relatively insoluble in water. B) are composed of long chains of amino acids covalently bonded to one another. C) are used by plant cells to provide structural support to the cells. D) contribute to roughage in the human diet. E) all assume the same shape after a dehydration synthesis reaction.

A

The study of matter and the energy involved in processes associated with matter is: A) chemistry. B) biology. C) physics. D) geology. E) statistics.

A

Which of the following is not a function of a protein? A) stores genetic material B) aids in muscle contraction C) acts as a catalyst D) provides structural support E) forms part of the cell membrane

A

Which of the following is not an example of dehydration synthesis? A) Lithium chloride dissolving in water. B) The production of starch from glucose. C) The production of a nucleic acid from nucleotides. D) A cell producing macromolecules which are used to give structure to a cell. E) A cell producing fat from fatty acids and glycerol in order to store excess energy.

A

Atoms are not considered to be "alive" because: A) they are too small. B) their parts don't move. C) they are made up of smaller parts. D) they are not made up of cells. E) they are not made up of molecules.

D

Each amino acid is composed of a central carbon that forms covalent bonds with four other atoms/molecules. These atoms/molecules include all but a(n): A) amino group. B) R group. C) carboxyl group. D) A group. E) hydrogen atom.

D

A student measuring the pH of the water in a fish tank found it to have a pH of 8. Which of the following statements is true regarding that solution? A) The water does not contain hydrogen ions. B) The water is alkaline. C) The water contains equal numbers of hydrogen ions and hydroxyl ions. D) The water is more alkaline than a solution with a pH of 10. E) The water is highly acidic.

B

Hydrogen gas forms when two atoms of hydrogen come bond. A) disulfide B) covalent C) polar D) hydrogen E) ionic

B

Radioisotopes have a number of uses in science and medicine. These include all but which one of the following? A) dating fossils B) curing diabetes C) treating cancer D) locating damaged heart tissue E) providing the power supply in heart pacemakers

B

Sucrose is an oligosaccharide made up of which of the following sugars? A) deoxyribose and ribose B) glucose and fructose C) maltose and glucose D) glucose and glucose E) starch and glycogen

B

Which of the following characteristics applies to both living organisms and nonliving things? A) are made up of cells B) are made up of matter C) have the ability to store energy for later use D) are capable of growth E) are capable of reproduction

B

Which of the following is not true regarding carbohydrates? A) The simplest form of carbohydrate is the monosaccharide. B) Cells convert large carbohydrates to proteins when energy is needed by the cell. C) Carbohydrates are made up of carbon, oxygen and hydrogen. D) Plants produce a carbohydrate that is used for structural support. E) In most living organisms, carbohydrates are used as a source of energy.

B

Which of the following is not true regarding carbon? A) is an ideal structural component of living systems B) is most stable when its outermost shell is filled with seven electrons C) is capable of forming strong covalent bonds with other elements D) can form molecules that branch in many directions E) is found in organic molecules

B

Which of the following is not true regarding denaturation of proteins? A) When a protein becomes denatured, its shape is changed. B) Denaturation can result from exposure of the protein to low temperatures. C) In living organisms, proteins that become denatured lose their biological function. D) Denaturation is an irreversible process. E) Changes in pH can cause denaturation.

B

Which of the following is not true regarding nucleotides? A) RNA nucleotides are assembled into RNA by the process of dehydration synthesis. B) DNA nucleotides contain deoxyribose; RNA nucleotides contain sucrose. C) An RNA nucleotide could be made up of ribose, a phosphate, and cytosine. D) Nucleotides are bonded together by covalent bonds between the sugars and the phosphates. E) There are four different DNA nucleotides.

B

DNA differs from RNA in that DNA: A) contains cytosine. B) is single stranded. C) contains deoxyribose. D) is made up of nucleotides. E) contains phosphates.

C

Given a certain atom is electrically neutral and contains five electrons, how many protons will it have? A) one B) four C) five D) fifteen E) ten

C

Isotopes of an element have the same ________, but different ________. A) atomic mass, atomic numbers B) number of neutrons, numbers of protons C) atomic number, atomic masses D) number of electron shells, numbers of protons E) name, chemical symbols

C

Ninety-nine percent of human body weight is made up of only six different elements. These include all but which one of the following? A) hydrogen B) nitrogen C) magnesium D) phosphorus E) carbon

C

Which of the following is an oligosaccharide? A) ribose B) DNA C) maltose D) starch E) glucose

C

Which of the following is not true regarding macromolecules? A) Cells use certain macromolecules to store energy. B) An example of a macromolecule is a protein. C) Cells produce macromolecules by the process of hydrolysis. D) The subunits needed to make macromolecules important to the human body result from the digestion of food. E) Cells use macromolecules to signal other cells.

C

Which of the following is the correct list of lipid subclasses? A) DNA, RNA, and nucleic acids B) polysaccharides, proteins, and steroids C) triglycerides, phospholipids, and steroids D) steroids, phospholipids, and fat E) steroids, oligosaccharides, and triglycerides

C

Which of the following is true regarding enzymes? A) Enzymes are consumed in a chemical reaction, so an organism must constantly replace these enzymes. B) Enzyme function is not affected by changes in temperature or pH. C) Each enzyme catalyzes one specific reaction or group of reactions. D) Enzymes convert products into reactants. E) Enzymes slow the rate of chemical reactions in living systems.

C

Which of the following is true regarding ions and ionic bonds? A) An ion would have a negative charge if it had more protons than electrons. B) Ionic bonds in watery solutions are stronger than covalent bonds. C) Ions in aqueous solutions are known as electrolytes. D) The movement of ions in and out of cells usually causes the cells to die. E) Ionic bonds form when atoms share electrons.

C

A solution with a pH of 6 has ________ times as many hydrogen ions as a solution with a pH of 7. A) 100,000 B) 1,000 C) 10,000 D) 10 E) 100

D

Pancreatic cells make insulin, which is a type of protein. These cells use ________ in order to synthesize insulin by the process of ________. A) monosaccharides, dehydration synthesis. B) fatty acids and glycerol, hydrolysis. C) nucleotides, condensation. D) amino acids, dehydration synthesis. E) oligosaccharides, hydrolysis.

D

The most important physical characteristic of lipids with regard to living organisms is that they: A) are typically a form of waste product that is difficult to eliminate. B) are very large and therefore difficult to store. C) are more dense than water. D) are hydrophobic. E) dissolve easily in water.

D

Which of the following best explains how an atom with seven electrons in its outermost shell will react with another atom? A) This atom will develop a positive charge once the reaction has proceeded. B) This atom will lose seven electrons in a reaction in order to fill its outermost shell. C) This atom will most likely form a covalent bond with another atom, thereby becoming an ion. D) In order to fill its outermost shell, this atom will gain one electron. E) This atom will most likely gain three neutrons during the reaction.

D

Which of the following is a monosaccharide that is a very important source of energy for cells? A) starch B) cellulose C) ribose D) glucose E) deoxyribose

D

Which of the following is not a molecule? A) H2O B) CO2 C) NaCl D) C E) H2

D

Which of the following is not a reason why the human body uses buffers to maintain a stable pH? A) A change in hydrogen ion concentration can interfere with transport of molecules across the cell membrane. B) A change in pH can interfere with the maintenance of homeostasis. C) A change in pH can result in a change in the shape of molecules important in physiological functions. D) A rapid change in pH causes a dramatic rise in body temperature. E) A rapid fluctuation in pH can interfere with the speed of chemical reactions.

D

Which of the following molecules is stored in adipose tissue and serves as an important source of energy for the human body? A) steroids B) glucose C) glycogen D) triglycerides E) phospholipids

D

Which of the following occurs when a phosphate is removed from an ATP molecule? A) Fat is converted to protein. B) Energy is added to the ATP molecule to form ATP4. C) Chemical reactions stop in a cell due to lack of an energy source. D) Energy is released for cell work. E) Oxygen produced in the reaction causes the molecule to explode.

D

A research student is analyzing the nucleic acid of a virus. He finds that the nucleic acid contains thymine. From this it can be concluded that the nucleic acid: A) is actually a protein. B) is a strand of DNA. C) contains glucose. D) contains ribose. E) is double stranded.

E

Before a cell can reproduce, it must copy its DNA. Which of the following molecules would the cell use to make the DNA? A) polypeptides B) amino acids C) fatty acids D) disaccharides E) nucleotides

E

Chlorine has an atomic number of 17 and an atomic mass of 35. Therefore, chlorine has protons and neutrons. A) 18, 17 B) 17, 17 C) 35, 35 D) 17, 35 E) 17, 18

E

Disulfide bonds are most characteristic of which of the following levels of protein structure? A) primary B) secondary C) none of the above D) quaternary E) tertiary

E

Which of the following is not a property of water? A) is a liquid at room temperature B) is a biological solvent for polar molecules C) holds heat energy D) is composed of polar molecules E) consists of molecules attracted to each other by covalent bonds

E

Which of the following is not true regarding antioxidants? A) Antioxidants prevent the formation of free radicals which oxidize other molecules. B) Vitamin C and beta-carotene are examples of antioxidants. C) Fresh fruits and vegetables contain a high level of antioxidants. D) Observational studies have led to the conclusion that antioxidants may be associated with a lower risk of cardiovascular death. E) Research indicates that antioxidants are most likely the cause of early aging.

E

Which of the following is true regarding electrons, shells, and energy? A) Electrons are attracted to each other because they have the same charge. B) As an electron moves to a shell further from the nucleus, it loses energy. C) In order for an electron to move closer to the nucleus, it must absorb energy. D) The innermost electron shell has the most potential energy. E) Electrons are located in shells around the nucleus.

E

Which of the following is true regarding water? A) Water is a type of ion. B) Electrons are shared equally between the atoms of water. C) The oxygen side of the water molecule is partially positive. D) Water molecules are attracted to each other by ionic bonds. E) Each molecule of water consists of two atoms of hydrogen and one atom of oxygen covalently bonded to each other.

E

As radioisotopes give off energy and emit particles over time, they become less stable.

F

Carbon accounts for more than 25% of the Earth's crust, but is only found in minimal amounts in living organisms.

F

FIGURE

F

It is possible for scientists to use an electron microscope to determine the location of an electron in its shell at any point in time.

F

Kinetic energy is always more powerful than potential energy because kinetic energy stores more energy than does potential energy.

F

Matter is most stable when it contains the maximum amount of potential energy.

F

The diagram below shows water molecules in close proximity to one another. FIGURE 2.1The type of bond indicated by the dotted lines is a covalent bond.

F

The more buffers present in a body fluid, the less stable the pH will be.

F

Which of the following is true regarding the structure of the atom

Most of the mass of an atom is due to its protons and neutrons.

Because carbon requires four additional electrons to fill its outermost shell, it has a natural tendency to form four covalent bonds with other atoms, making it an ideal element for forming structures in living cells.

T

Because water absorbs and holds heat well, it helps prevent rapid changes in body temperature when the body is exposed to changes in environmental temperatures.

T

If the number of protons in an atom equals the number of electrons in the atom, the atom is electrically neutral.

T

One of the most important buffer pairs in blood is carbonic acid and bicarbonate because they regulate the pH of blood by absorbing and releasing hydrogen ions as needed.

T

Recent improvements in technology have resulted in the production of new, specialized microscopes with which scientists can now view several of the largest atoms.

T

The function of a protein depends on its structure and shape.

T

Unsaturated fats are liquid at room temperature because of "kinks" in their fatty acids that result from double covalent bonds between the carbon atoms; these "kinks" prevent the fats from closely associating with each other.

T