WorksheetsUnit 1 Mastery
Total questions: 82
Worksheet time: 41mins
Name
Class
Date
1.
Which is the smallest unit of an element that retains the properties of the element?
a)
atom
b)
compound
c)
ion
d)
molecule
e)
mixture
2.
Which is NOT an element?
a)
water (H20)
b)
oxygen (O)
c)
carbon (C)
d)
chlorine (Cl)
e)
hydrogen (H)
3.
The atomic number refers to the
a)
mass of an atom
b)
number of protons in an atom
c)
number of both protons and neutrons in an atom
d)
number of neutrons in an atom
e)
number of electrons in an atom
4.
Isotopes of atoms
a)
are electrically unbalanced
b)
behave the same chemically and physically but differ biologically from other isotopes
c)
are the same physically and biologically but differ from other isotopes chemically
d)
have the same number of protons but a different number of neutrons
e)
are produced when atoms lose electrons
5.
The subatomic particle(s) with a negative charge is(are)
a)
the neutron
b)
the proton
c)
the electron
d)
both the neutron and proton
e)
both the proton and electron
6.
The nucleus of an atom contains
a)
neutrons and protons
b)
neutrons and electrons
c)
protons and electrons
d)
protons only
e)
neutrons only
7.
The atomic mass (mass number) of an atom is determined by the combined masses of its
a)
neutrons and protons
b)
neutrons and electrons
c)
protons and electrons
d)
protons, neutrons, and electrons
e)
neutrons, nucleus, and electrons
8.
Which of the following statements is NOT true?
a)
All isotopes of an element have the same number of electrons
b)
All isotopes of an element have the same number of protons
c)
All isotopes of an element have the same number of neutrons
d)
We refer to isotopes by mass number
e)
12C and 13C are isotopes
9.
In a chemical equation, the chemicals to the left of the arrow are
a)
products
b)
in greater abundance
c)
at higher energy levels
d)
reactants
e)
all of these
10.
In a chemical equation, the chemicals to the right of the arrow are
a)
products
b)
in greater abundance
c)
at higher energy levels
d)
reactants
e)
all of these
11.
Radioactive isotopes have
a)
excess electrons
b)
excess protons
c)
excess neutrons
d)
insufficient neutrons
e)
insufficient protons
12.
Tracers are elements that
a)
are used in minute amounts in plants
b)
can be monitored through biochemical imaging
c)
must be inert
d)
have an unbalanced electrical charge
e)
must have a stable nucleus
13.
Argon has 18 protons. How many electrons does it usually have?
a)
12
b)
14
c)
16
d)
18
e)
10
14.
Which of the following is NOT accurate concerning ionization?
a)
When an atom loses an electron, it becomes a positively charged cation
b)
When an atom loses an electron, it becomes a negatively charged anion
c)
Ionic bonds form between ionized atoms
d)
In the compound NaCl, Na loses an electron to become positive
e)
In an ion, the number of protons and electrons is unequal
15.
Carbon dioxide is an example of a(n)
a)
atom
b)
ion
c)
compound
d)
mixture
e)
element
16.
Which statement is false?
a)
A molecule is made of at least two atoms
b)
Compounds are made of elements
c)
Two atoms of oxygen make a molecule of oxygen
d)
All of these are true
e)
Elements are found in compounds and molecules
17.
A molecule is
a)
a combination of two or more atoms
b)
a mixture of atoms
c)
electrically charged
d)
a carrier of one or more extra neutrons
e)
none of these
18.
The bond in table salt (NaCl) is
a)
polar
b)
ionic
c)
covalent
d)
double
e)
nonpolar
19.
In ____ bonds, both atoms exert the same pull on shared electrons
a)
nonpolar covalent
b)
polar covalent
c)
ionic
d)
hyrogen
e)
-
20.
Which of these statements is false concerning covalent bonds?
a)
Atoms share electrons
b)
Molecules may possess many covalent bonds
c)
Water contains polar covalent bonds
d)
Covalent bonds may be "double bonds"
e)
Electrons are always shared equally
21.
A hydrogen bond is a(n)
a)
sharing of a pair of electrons between a hydrogen and an oxygen nucleus
b)
sharing of a pair of electrons between a hydrogen nucleus and either an oxygen or a nitrogen nucleus
c)
attractive force between a hydrogen atom and either an oxygen or a nitrogen atom that are in other molecules or within the same molecule
d)
covalent bond between two hydrogen atoms
e)
covalent bond between a hydrogen atom and either an oxygen atom or a nitrogen atom
22.
Water is important to the interactions of biological molecules because it
a)
promotes hydrophobic and hydrophilic interactions
b)
stabilizes temperature
c)
is an excellent solvent for polar and ionic substances
d)
has strong cohesive properties
e)
does all of these
23.
The most likely reason that glucose dissolves in water is that it is
a)
an ionic compound
b)
a polysaccharide
c)
polar and forms many hydrogen bonds with the water molecules
d)
a very unstable molecule
e)
highly nonpolar
24.
The very unique properties of water are due to its
a)
ionic bonds
b)
hydrogen bonds
c)
ability to promote hydrophobic interactions
d)
nonpolar nature
e)
-
25.
The column of water extending in tubes from plant roots to leaves is maintained by
a)
cohesion among water molecules and adhesion to the plant walls
b)
ionic bonds
c)
covalent bonds
d)
hydrophobic interactions
e)
hydrophilic interactions
26.
Sodium chloride (NaCl) in water can be described by any EXCEPT which of the following?
a)
Na+ and Cl− form
b)
a solute
c)
ionized
d)
forms hydrophobic interactions
e)
dissolved
27.
A salt will dissolve in water to form
a)
acids
b)
ions other than H+ and OH−
c)
bases
d)
buffers
e)
-
28.
"Acidic" is an appropriate description for all EXCEPT which one of the following?
a)
excess hydrogen ions
b)
the contents of the stomach
c)
ammonia (pH 10.8)
d)
vinegar (pH 2.8)
e)
lemon juice (pH 2.3)
29.
As the concentration of hydrogen ions (H+) in a solution increases, the solution becomes
a)
more acidic
b)
more basic
c)
more hydrophobic
d)
neutral
e)
-
30.
Which of the following would be the most alkaline?
a)
gastric juice at pH 2.1
b)
urine at pH 6.0
c)
seawater at pH 8.2
d)
oven cleaner at pH 13.2
e)
saliva at pH 7.0
31.
What is the approximate pH of household bleach?
a)
1
b)
3
c)
7
d)
11
e)
14
32.
What does a pH of 5 represent?
a)
a neutral solution
b)
a slightly basic solution
c)
a slightly acidic solution
d)
a strongly acidic solution
e)
-
33.
Energy is commonly defined as "the capacity to do work." This definition is
a)
a. incorrect
b)
b. adequate in the physical sciences
c)
c. adequate in the biological sciences
d)
d. a clue to the actual properties of the concept
e)
e. not accepted by most scientists
34.
According to the first law of thermodynamics
a)
a. the energy of a system may increase if there is a corresponding decrease in energy elsewhere in the universe
b)
b. the amount of energy in the universe is constant
c)
c. chemical reactions do not create or destroy energy
d)
d. energy can change from one form to another
e)
e. all of these are true
35.
Which of the following statements is false?
a)
a. The universe has a specific amount of energy
b)
b. One form of energy can be converted to other forms of energy
c)
c. Whenever energy conversions occur, some energy is converted to less concentrated forms
d)
d. Once energy is utilized, it disappears
e)
e. There are differences in the quality of energy
36.
Which of the following is an application of the first law of thermodynamics?
a)
a. The level of entropy increases as time passes
b)
b. Living organisms represent an exception to the laws of energy
c)
c. The quantity of energy does not increase or decrease in the universe
d)
d. Fungi and plants do not make their own energy but derive it from somewhere else
e)
e. The amount of energy found in the compounds on one side of an equation is equal to that on the other side
37.
The activation energy of a reaction refers to the minimum amount of energy
a)
a. released by the reaction
b)
b. in the reactants
c)
c. in the products
d)
d. necessary to cause a reaction to proceed on its own
e)
e. difference between the energy of the reactants and the energy of the products
38.
CO2 and H2O will not form glucose on their own because
a)
a. CO2 does not contain sufficient energy
b)
b. H2O does not contain sufficient energy
c)
c. neither CO2 nor H2O contain sufficient energy
d)
d. the concentration of CO2 is too low in the atmosphere
e)
e. the bonds of CO2 and H2O are too stable to be broken without an input of energy
39.
Endergonic reactions
a)
a. result in products with less energy than the reactants
b)
b. require a net input of energy
c)
c. occur in the breakdown of glucose
d)
d. are used by cells to provide energy for biological reactions
e)
e. break down large molecules into smaller molecules
40.
Which of the following statements about exergonic reactions is false?
a)
a. They release energy
b)
b. Glucose metabolism is an example
c)
c. Their products have more energy than the reactants
d)
d. Some energy is converted to less biologically useful forms
e)
e. Bonds are broken
41.
Which of the following is NOT true of enzyme behavior?
a)
a. Enzyme shape may change during catalysis
b)
b. The active site of an enzyme orients its substrate molecules, thereby promoting interaction of their reactive parts
c)
c. All enzymes have an active site where substrates are temporarily bound
d)
d. Each enzyme can catalyze only a specific reaction
e)
e. Enzyme activity is not affected by pH and temperature
42.
Enzymes do not
a)
a. control the speed of a reaction
b)
b. change shapes to facilitate certain reactions
c)
c. may place physical stress on the bonds of the substrate
d)
d. always work on their own
e)
e. do all of these
43.
Which of the following statements is false?
a)
a. Enzymes catalyze reversible reactions in either direction
b)
b. Enzymes are highly specific
c)
c. Most enzymes are carbohydrate molecules
d)
d. Enzymes allow some reactions to occur that would never occur without them
e)
e. Enzymes may be temporarily modified during their involvement with the substrate
44.
The active site of an enzyme
a)
a. is where the coenzyme is located
b)
b. is a specific bulge or protuberance on an enzyme
c)
c. is a groove or crevice in the structure of the enzyme complementary to the substrate
d)
d. will react with only one substrate no matter how many molecules may resemble the shape of the substrate
e)
e. rigidly resists any alteration of its shape
45.
All of the following are factors in enzyme-catalyzed reactions that work alone or in combination to lower the activation energy EXCEPT
a)
a. helping substrates get together
b)
b. orienting substrates in positions favoring reaction
c)
c. breaking the laws of thermodynamics
d)
d. shutting out water molecules
e)
e. inducing a fit between enzyme and substrate
46.
An enzyme is thought to optimize the fit between substrates by restraining and stretching or squeezing them into certain shapes and moving them to the transition state as described by the ____ model of enzyme activity.
a)
a. lock and key
b)
b. induced-fit
c)
c. template
d)
d. activation
e)
e. conformational
47.
Which of the following statements is false?
a)
a. Enzymes are highly specific and act on chemicals called substrates
b)
b. Enzymes act as catalysts and speed up chemical reactions within cells
c)
c. Most enzymes work best under very low pH conditions
d)
d. Most enzymes are proteins
e)
e. Enzymes can become deactivated by high fevers
48.
Allosteric inhibition generally results from
a)
a. excess substrates
b)
b. binding of regulatory molecules at sites other than the active sites
c)
c. a change in the temperature of the system
d)
d. a lack of coenzymes
e)
e. changes in pH
49.
Allosteric enzymes
a)
a. have regions that bind with inhibitor or activator molecules
b)
b. are associated with important energy-carrying nucleotides
c)
c. are not affected by temperature or pH
d)
d. have two active sites
e)
e. have all of these
50.
Which of the following statements is true of metabolic pathways?
a)
a. They are enzyme-mediated sequences of reactions
b)
b. They may be biosynthetic or degradative
c)
c. Photosynthesis is a biosynthetic pathway
d)
d. Catabolism is a degradative pathway
e)
e. All of these statements are true
51.
A "high-energy bond" in ATP
a)
a. absorbs a large amount of free energy when the phosphate group is attached during phosphorylation
b)
b. is formed when ADP is phosphorylated to ATP
c)
c. is similar to the bonds in GTP
d)
d. contributes to the “energy in” part of some reactions
e)
e. is/does all of these
52.
2. Fats are major constituents of
a)
a. proteins
b)
b. genes
c)
c. photosynthesis
d)
d. cell membranes
e)
e. all of these
53.
3. Typical fat molecules have ____ chain(s).
a)
a. 1
b)
b. 2
c)
c. 3
d)
d. 4
e)
e. 5
54.
4. A single atom of carbon may form up to ____ covalent bonds
a)
a. 2
b)
b. 3
c)
c. 4
d)
d. 5
e)
e. 6
55.
6. A hydrolysis reaction results in
a)
a. formation of a macromolecule
b)
b. bond breakage
c)
c. lipid molecule
d)
d. nucleic acids
e)
e. proteins
56.
7. An −OH group is a(n) ____ group.
a)
a. carboxyl
b)
b. hydroxyl
c)
c. amino
d)
d. methyl
e)
e. carbonyl
57.
8. An −NH2 group is a(n) ____ group.
a)
a. carboxyl
b)
b. hydroxyl
c)
c. amine
d)
d. methyl
e)
e. carbonyl
58.
9. What kind of reaction produces large molecules by linking small molecules
a)
a. oxidation
b)
b. reduction
c)
c. dehydration
d)
d. hydrolysis
e)
e. decarboxylation
59.
10. Monosaccharides may be characterized by all EXCEPT...
a)
a. a 1:2:1 ratio
b)
b. carbon, hydrogen and oxygen
c)
c. a backbone of five to six carbon atoms
d)
d. a ring shape
e)
e. the presence of glycerol
60.
11. Fructose and glucose are
a)
a. isotopes
b)
b. monosaccharides
c)
c. disaccharides
d)
d. six-carbon sugars
e)
e. BOTH monosaccharides and six-carbon sugars
61.
13. Glucose and fructose
a)
a. form rings with the same number of sides
b)
b. both have two oxygen atoms as part of their ring structure
c)
c. both have identical functional groups
d)
d. contain the same number of carbon atoms
e)
e. are disaccharides
62.
14. Glucose and sugars in DNA and RNA
a)
a. have the same number of oxygen atoms
b)
b. have the same structural formulas
c)
c. are the two components of sucrose
d)
d. are monosaccharides
e)
e. are both components of RNA
63.
15. Sucrose is composed of
a)
a. two molecules of fructose
b)
b. two molecules glucose
c)
c. a molecule of fructose and a molecules of glucose
d)
d. a molecule of fructose and a molecules of galactose
e)
e. a monosaccharide
64.
16. Glycogen is a polysaccharide used for energy storage in ______
a)
a. animals
b)
b. plants
c)
c. protistans
d)
d. bacteria
e)
e. archaea
65.
17. Cellulose is
a)
a. a polysaccharide
b)
b. a component of cell membranes
c)
c. an oligosaccharide
d)
d. formed by hydrolysis
e)
e. a component of invertebrate exoskeletons
66.
18. Which of the following does NOT describe some aspect of polysaccharides?
a)
a. energy storage
b)
b. straight or branched
c)
c. glucose subunits
d)
d. contain only carbon, hydrogen, and nitrogen
e)
e. produced by dehydration reactions
67.
19. Which of the following is NOT true of polysaccharides?
a)
a. composed of many linked monosaccharides
b)
b. may be straight and unbranched or highly branched
c)
c. most likely made of glucose molecules
d)
d. may be insoluble due to their large structure
e)
e. are formed by cleavage reactions
68.
20. Which of the following does not belong?
a)
a. phospholipids
b)
b. polysaccharides
c)
c. unsaturated fats
d)
d. steroids
e)
e. saturated fats
69.
21. Triglycerides are
a)
a. carbohydrates
b)
b. nucleotides
c)
c. proteins
d)
d. neutral fats
e)
e. amino acids
70.
22. Steroids
a)
a. have no fatty-acid
b)
b. consist of four rings
c)
c. may have different functional groups
d)
d. are a specialized type of lipid
e)
e. are described by all of these
71.
23. Cholesterol
a)
a. has a rigid backbone of four carbon rings
b)
b. is the most common steroid in animal tissue
c)
c. is a lipid without a fatty acid
d)
d. is needed to produce sexual development hormones
e)
e. is all of these
72.
24. ____ are long-chain fatty acids attached to alcohols
a)
a. triglycerides
b)
b. phospholipids
c)
c. sterols
d)
d. waxes
e)
e. most neutral fats
73.
25. Which is True of Polyunsaturated fats
a)
a. have fewer hydrogen atoms than do saturated fats
b)
b. are more characteristic of animal fats than plant fats
c)
c. have no double bonds
d)
d. are solid at room temperature
e)
e. are none of these
74.
26. Lipids
a)
a. yield less energy per gram than do carbohydrates.
b)
b. include cartilage and chitin
c)
c. include fats consisting of one fatty-acid molecules and three glycerol molecules.
d)
d. are composed of monosachharides
e)
e. are none of these
75.
27. All steroids have
a)
a. the same number of double bonds.
b)
b. one or more fatty acids.
c)
c. four rings of carbon to which other atoms are attached.
d)
d. the same functional groups.
e)
e. the same number and positions of double bonds.
76.
28. The sequence of amino acids is the ____ structure?
a)
a. primary
b)
b. secondary
c)
c. tertiary
d)
d. quaternary
e)
e. stereo
77.
29. Amino acids are linked by what kind of bonds?
a)
a. disulfide
b)
b. hydrogen
c)
c. ionic
d)
d. peptide
e)
e. none of these
78.
30. The interaction of several polypeptide chains in a hemoglobin molecules is it's ______________ structure
a)
a. primary
b)
b. secondary
c)
c. tertiary
d)
d. quaternary
e)
e. combined
79.
31. Denaturation of proteins may result in all of the following EXCEPT
a)
a. breakage of hydrogen bonds
b)
b. loss of three-dimensional structure
c)
c. removal of R groups from amino acids
d)
d. alteration of enzyme fucntion
e)
e. endangerment of a cell's life
80.
32. Which of the following is NOT found in every nucleotide?
a)
a. ribose
b)
b. a phosphate
c)
c. a nitrogenous base
d)
d. a sugar group
e)
e. nitrogen
81.
33. Nucleotides contain what kind of sugars?
a)
a. three-carbon
b)
b. four-carbon
c)
c. five-carbon
d)
d. six-carbon
e)
e. seven-carbon
82.
34. Which molecule is incorrectly matched with its monomer
a)
a. fat; fatty acid
b)
b. starch; ribose
c)
c. protein; amino acid
d)
d. glycogen; glucose
e)
e. nucleic acids; Nucleotide
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