Deck 2: B: The Chemical Basis of Life

Question 1

When atoms combine,they may gain,lose,or share:

A) electrons.
B) protons.
C) neutrons.
D) nuclei.

Answer 1

A

Question 2

The type of reaction in which substances are combined to form more complex substances is called a(n)_____ reaction

A) reversible
B) exchange
C) synthesis
D) decomposition

Answer 2

C

Question 3

Which of the following elements is least likely to combine with another element?

A) Hydrogen
B) Helium
C) Oxygen
D) Carbon

Answer 3

B

Question 4

The process of the digestion of food is an example of which type of reaction?

A) Synthesis
B) Decomposition
C) Exchange
D) Reversible

Question 5

Acids:

A) are proton donors.
B) taste sour.
C) release hydrogen ions in an aqueous solution.
D) are all of the above.

Question 6

The hydrogen isotope tritium consists of:

A) one proton.
B) one proton and one neutron.
C) two protons and one neutron.
D) one proton and two neutrons.

Question 7

In the presence of a base,red litmus paper will:

A) stay red.
B) turn blue.
C) turn green.
D) turn yellow.

Question 8

A negatively charged subatomic particle that moves around the nucleus is a(n):

A) orbital.
B) proton.
C) neutron.
D) electron.

Question 9

The kind of element is determined by the number of:

A) protons.
B) neutrons.
C) mesotrons.
D) electrons.

Question 10

Carbon has an atomic number of 6.The number of electrons found in the first shell is:

A) 2.
B) 4.
C) 6.
D) 8.

Question 11

Which of the following represents a trace element in the body?

A) Sulfur
B) Chlorine
C) Iron
D) Phosphorus

Question 12

The most abundant and important compound(s)in the body is(are):

A) air.
B) water.
C) proteins.
D) nucleic acids.

Question 13

Atomic weight is determined by the number of:

A) protons and electrons.
B) neutrons and electrons.
C) neutrons, protons, and electrons.
D) protons and neutrons.

Question 14

The atomic number of carbon is 6.How many unpaired electrons are in its outer shell?

A) 2
B) 3
C) 4
D) 5

Question 15

A solution that contains a greater concentration of hydroxide ions (OH-)than hydrogen ions (H⁺)is a(n)_____ solution.

A) acidic
B) alkaline (basic)
C) neutral
D) Not enough information is given to determine the character of the solution.

Question 16

An isotope of an element contains different numbers of ____ than other atoms of the same element.

A) electrons
B) protons
C) neutrons
D) both protons and neutrons

Question 17

An ionic bond is formed by:

A) two or more positive ions combining.
B) two or more negative ions combining.
C) a positive and a negative ion attracting each other.
D) sharing of a pair of electrons.

Question 18

Substances that accept hydrogen ions are called:

A) acids.
B) bases.
C) buffers.
D) salts.

Question 19

An example of an element would be:

A) Ne.
B) CO2.
C) C6H12O6.
D) H2O.

Question 20

Which of the following bonds are the weakest?

A) Ionic
B) Hydrogen
C) Electrovalent
D) Covalent

Question 21

A structural lipid found in the cell membrane is a:

A) triglyceride.
B) phospholipid.
C) steroid.
D) Both B and C are correct.

Question 22

Peptide bonds join together molecules of:

A) glycerol.
B) glucose.
C) amino acids.
D) water.

Question 23

An example of a catabolic process is

A) hydrolysis.
B) dehydration synthesis.
C) formation of a peptide bond.
D) both B and C.

Question 24

Which lipid is part of vitamin D?

A) Glycerol
B) Steroids
C) Prostaglandins
D) Fatty acids

Question 25

The element that is present in all proteins but not in carbohydrates is:

A) carbon.
B) hydrogen.
C) oxygen.
D) nitrogen.

Question 26

Which of the following is not one of the major groups of organic substances in the human body?

A) Proteins
B) Salts
C) Lipids
D) Nucleic acids

Question 27

Which of the following represent(s)properties of water?

A) High specific heat
B) High heat of vaporization
C) Strong polarity
D) All of the above

Question 28

All of the following substances are organic except:

A) lipids.
B) electrolytes.
C) carbohydrates.
D) proteins.

Question 29

The basic building blocks of fats are:

A) monosaccharides.
B) disaccharides.
C) amino acids.
D) fatty acids and glycerol.

Question 30

The study of metabolism includes examination of:

A) catabolism.
B) anabolism.
C) ATP requirements.
D) all of the above.

Question 31

Approximately what percentage of body weight is water?

A) 40%
B) 50%
C) 60%
D) 70%

Question 32

The simple sugars that are the building blocks for other carbohydrates are:

A) disaccharides.
B) monosaccharides.
C) polysaccharides.
D) starches.

Question 33

DNA:

A) is a single strand of nucleotides.
B) contains the sugar ribose.
C) is a double helix strand of nucleotides.
D) transports amino acids during protein synthesis.

Question 34

The amino group in an amino acid is:

A) NH3+.
B) COO-.
C) symbolized by the letter R.
D) SO2.

Question 35

Humans can synthesize 13 of 21 basic amino acids; the remaining 8,which must be included in the diet,are called:

A) enzymes.
B) essential amino acids.
C) structural proteins.
D) peptide bonds.

Question 36

AB + C→ AD + CB is an example of a(n)_____ reaction.

A) synthesis
B) exchange
C) decomposition
D) reversible

Question 37

The type of lipid found in sex hormones is:

A) triglycerides.
B) phosphoglycerides.
C) steroids.
D) prostaglandins.

Question 38

The formation of sucrose involves the removal of a molecule of water.This is called:

A) hydrolysis.
B) oxidation.
C) decomposition.
D) dehydration synthesis.

Question 39

The approximate pH of gastric fluid is:

A) 10.
B) 8.
C) 4.
D) 2.

Question 40

The type of lipoprotein associated with "bad" cholesterol and the production of atherosclerotic changes in blood vessels is:

A) HDL.
B) LDL.
C) VHDL.
D) none of the above.

Question 41

The element oxygen has an atomic number of 8,which means it contains:

A) 4 protons and 4 neutrons.
B) 8 protons.
C) 8 neutrons.
D) 4 protons and 4 electrons.

Question 42

Amino acids frequently become joined by:

A) peptide bonds.
B) catabolic reactions.
C) atrophic reactions.
D) all of the above.

Question 43

A weak acid:

A) dissociates very little in solution.
B) dissociates almost completely in solution.
C) will cause the pH of the solution to rise above 7.
D) do both B and C.

Question 44

The total number of electrons in a neutral atom equals the number of:

A) neutrons orbiting the atom.
B) protons plus the number of neutrons in its nucleus.
C) protons in its nucleus.
D) ions in its nucleus.

Question 45

Chemical bonds formed by the sharing of electrons are called:

A) ionic.
B) covalent.
C) hydrogen.
D) isotopic.

Question 46

Salts:

A) can form as the result of a chemical reaction between acids and bases.
B) are electrolytes.
C) will form crystals if the water is removed.
D) All of the above are correct.

Question 47

A molecule that is polar:

A) can form a hydrogen bond.
B) must be ionic.
C) has an unequal charge.
D) is both A and C.

Question 48

The type of chemical reaction most likely to require energy is _____ reaction.

A) synthesis
B) decomposition
C) exchange
D) All of the above reactions are equally likely to require energy.

Question 49

Which subatomic particles carry a charge?

A) Protons and neutrons
B) Neutrons and electrons
C) Protons and electrons
D) Neutrons only

Question 50

Which of the following is not one of the major elements present in the human body?

A) Oxygen
B) Zinc
C) Carbon
D) Potassium

Question 51

Which of the following is not a subatomic particle?

A) Proton
B) Electron
C) Radon
D) Neutron

Question 52

The elements carbon,hydrogen,oxygen,and nitrogen make up which percentage of the human body?

A) 50%
B) 69%
C) 78%
D) 96%

Question 53

Which of the following is not one of the three major ingredients of a DNA molecule?

A) Sugar
B) Nitrogenous bases
C) Phosphate
D) Lipid

Question 54

Ionic bonds are chemical bonds formed by the:

A) sharing of electrons between molecules.
B) donation of protons from one atom to another.
C) transfer of electrons from one atom to another.
D) acceptance of neutrons from one atom to another.

Question 55

An atom can be described as chemically inert if its outermost electron shell contains _____ electrons.

A) 8
B) 9
C) 2
D) Both A and C are correct.

Question 56

For sodium to transform from a neutral atom to a positive ion,it must:

A) gain an electron.
B) gain a proton.
C) lose an electron.
D) lose a proton.

Question 57

The reaction between hydrogen and oxygen needed to form water is an example of a:

A) hydrogen bond.
B) synthesis reaction.
C) decomposition reaction.
D) None of the above is correct.

Question 58

Proteins are composed of ____ commonly occurring amino acids.

A) 10
B) 18
C) 21
D) 22

Question 59

Electrolytes are:

A) organic compounds.
B) called cations if they have a negative charge.
C) called cations if they have a positive charge.
D) both A and B.

Question 60

Hydrolysis _____ a water molecule.

A) joins compounds by removing
B) breaks down compounds by removing
C) joins compounds by adding
D) breaks down compounds by adding

Question 61

Prostaglandins and steroids share which of the following characteristics?

A) Both are found in the cell membrane.
B) Both have a ring structure in their molecule.
C) Both have a saturated fat in their structure.
D) None of the above are shared characteristics.

Question 62

Which of the following is not true of both triglycerides and phospholipids?

A) They both contain glycerol.
B) They both contain fatty acids.
C) They both contain a hydrophobic and hydrophilic end.
D) All of the above are true of both triglycerides and phospholipids.

Question 63

Which energy-releasing or energy-transferring molecule does not contain a nucleotide?

A) FAD
B) Creatine phosphate
C) NAD
D) ATP

Question 64

A magnesium atom has an atomic number of 12,an atomic mass of 25,and a +2 charge.This atom would contain _____ protons,_____ neutrons,and _____ electrons.

A) 12; 25; 2
B) 12; 13; 14
C) 12; 13; 10
D) Not enough information is given to answer the question.

Question 65

Which of the following is not true of RNA?

A) It contains ribose sugar.
B) It contains adenine.
C) It is composed of smaller molecules called nucleotides.
D) All of the above are true of RNA.

Question 66

Which level of protein structure refers to the number,kind,and sequence of amino acids?

A) Primary
B) Secondary
C) Tertiary
D) Quaternary

Question 67

The type of reaction most likely to release energy is a(n)_____ reaction.

A) synthesis
B) decomposition
C) exchange
D) All of the above reactions are equally likely to release energy.

Question 68

Which of the following is not true of all isotopes of oxygen?

A) They can all react with two hydrogen atoms to form water.
B) They have the same number of protons.
C) They have the same atomic mass.
D) All of the above are true of isotopes of oxygen.

Question 69

A strong acid:

A) holds on strongly to its hydrogen atoms, releasing very few in solution.
B) would cause a drop in the pH of a solution.
C) would cause a rise in the pH of a solution.
D) is both A and C.

Question 70

As the concentration of hydrogen ions (H⁺)increases,the:

A) solution becomes more basic.
B) solution becomes more acidic.
C) pH rises.
D) Both A and C are correct.

Question 71

The alpha helix is an example of which level of protein structure?

A) Primary
B) Secondary
C) Tertiary
D) Quaternary

Question 72

As the concentration of hydroxide ions (OH-)increases,the:

A) solution becomes more basic.
B) solution becomes more acidic.
C) pH rises.
D) Both A and C are correct.

Question 73

Hydrogen can form only when the hydrogen atom is covalently bonded to:

A) an oxygen atom.
B) a nitrogen atom.
C) a fluorine.
D) any of the above.

Question 74

Which level of protein structure is one that contains several polypeptide chains?

A) Primary
B) Secondary
C) Tertiary
D) Quaternary

Question 75

A solution with a pH of 4 has_____ times more _____ ions than a solution with a pH of 6.

A) 10; H+
B) 10; OH-
C) 100; H+
D) 100; OH-

Question 76

Which lipid acts as a "tissue hormone"?

A) Triglyceride
B) Prostaglandin
C) Steroid
D) Phospholipid

Question 77

Which of the following is not a major function of protein?

A) Provides structure for the body
B) Acts as a catalyst for chemical reactions in the form of enzymes
C) Provides energy for the body
D) All of the above are functions of protein.

Question 78

Unsaturated fats:

A) contain all the hydrogen atoms they can hold.
B) contain only single bonds between carbon atoms.
C) are usually solids at room temperature.
D) will kink or bend because of the double bonds between the carbon atoms.

Question 79

Which of the following is not true about oxygen and carbon dioxide?

A) They are both important organic compounds.
B) Molecular oxygen is present as O2 in the body.
C) Oxygen is needed for energy release in cellular respiration.
D) Carbon dioxide is important in maintaining the proper acid-base balance in the body.

Question 80

The octet rule refers to the:

A) stability of the nucleus when the protons are in a multiple of 8.
B) stability of the atom when there are 8 electrons in the outermost energy level.
C) stable configuration of the nucleus when there are 8 more neutrons than protons.
D) principle that one atom can combine with a maximum of 8 other atoms.