How is it possible for two samples of hydrogen to contain the same number of atoms, yet one sample weighs more than the other?

1
How is it possible for two samples of hydrogen to
contain the same number of atoms, yet one sample
weighs more than the other?

1. One sample has more bonds.
2. One sample contains fewer electrons, decreasing
   weight.
3. One sample contains more of hydrogens heavier
   isotope(s).
4. One sample includes more protons, increasing
   weight.

2
What is a mole and why is it useful to describe
elements in terms of moles?

1. 6.023 x 1023/easier to keep track of relative
   numbers of atoms in chemical samples
2. Is a quantity with a weight in grams equal to
   that elements atomic weight/because one mole of
   a given element always contains the same number
   of atoms as one mole of any other element
3. The total number of neutrons and protons in the
   nucleus/nuclei sometimes emit subatomic particles
   or radiation in measurable amounts
4. A and B are correct

3
Which kind of bond holds atoms in a water
molecule together? What attracts water
molecules to one another?

1. Polar covalent bonds hydrogen bonds
2. Ionic bonds charge interactions
3. Hydrogen bonds charge interactions
4. Covalent bonds hydrogen bonds

4
Both oxygen and neon are gases at room
temperature. Oxygen combines readily with other
elements, but neon does not. Why?

1. Neon has 8 electrons in its valence shell, oxygen
   has only 6.
2. Neon cannot undergo bonding due to its polarity.
3. Neon is exergonic.
4. Neons molecular weight is too low to allow
   bonding.

5
The chemical shorthand used to describe chemical
compounds and reactions effectively is known as__.

1. Molecular formula
2. Chemical notation
3. Molecular weight
4. Mass number

6
Which of these notations describes dehydration
synthesis and why?

1. A-B-C-H HO-DE ? A-B-C-D-E H2O formation of a
   complex molecule by removal of a water molecule
2. A-B-C-D-E H2O ? A-B-C-H HO-D-E a chemical
   bond was broken through the addition of a water
   molecule
3. AB ? A B a molecule is broken into smaller
   fragments
4. AB CD ? AD CB molecules are shuffled around
   to produce a new product

7
In cells, glucose, a six-carbon molecule, is
converted into two three-carbon molecules by a
reaction that releases energy. How would you
classify this reaction?

1. Endergonic
2. Exergonic
3. Decomposition
4. B and C are correct

8
Why are enzymes needed in our cells?

1. To promote chemical reactions
2. For chemical reactions to proceed under
   conditions compatible with life
3. To lower activation energy requirements
4. All of the above

9
Which property of water accounts for the cooling
effect of perspiration?

1. Solubility solutes easily break up in water
2. Reactivity hydrolysis causes salt crystals to
   form on the skin
3. High heat capacity water carries away heat when
   it changes from a liquid to a gas
4. Lubrication there is little friction between
   molecules

10
Wine has a pH of 3. This means that compared to
tomatoes that have a pH of 4.

1. Wine is closer to neutral pH than tomatoes.
2. The concentration of hydrogen ions is 10 times as
   great in the wine as in a tomato and both are
   acidic.
3. The concentration of hydroxide ions is ten times
   as great in the tomato as in the wine and both
   are basic.
4. The concentration of hydrogen ions is 100 times
   as great in the wine as the tomato and both are
   acidic.

11
How does an antacid help decrease stomach
discomfort?

1. By reducing buffering capacity of the stomach
2. By decreasing pH of stomach contents
3. By reacting a weak acid with a stronger one
4. By neutralizing acid using a weak base

12
Why does a solution of table salt conduct
electricity, but a sugar solution does not?

1. Electrical conductivity requires ions.
2. Sugar forms a colloid, salt forms a suspension.
3. Electricity is absorbed by glucose molecules.
4. Table salt is hydrophobic, sugar is hydrophilic.

13
A food contains organic molecules with the
elements C, H, and O in a ratio of 121. What
class of compounds do these molecules belong to,
and what are their major functions in the body?

1. Lipids energy source
2. Proteins support and movement
3. Nucleic acids determining inherited
   characteristics
4. Carbohydrates energy source

14
Which lipids would you find in human cell
membranes?

1. Cholesterol
2. Glycolipids
3. Phospholipids
4. All of the above

15
Why is cholesterol important in the human body?

1. It transforms into prostaglandins, which are
   released by damaged tissues causing pain.
2. Cells need it to maintain their membranes and for
   growth and division.
3. It is an essential component of eicosanoids
4. It is the only site of storage for lipid soluble
   vitamins.

16
What are structural and functional similarities
of phospholipids and glycolipids?

1. Their hydrocarbon tails are hydrophobic.
2. They help form and maintain intracellular
   structures.
3. They are primarily composed of phosphate and
   glycogen, respectively.
4. A and B are correct

17
When two monosaccharides undergo a dehydration
synthesis reaction, which type of molecule is
formed?

1. Polypeptide
2. Disaccharide
3. Eicosanoid
4. Polysaccharide

18
Proteins are chains of which small organic
molecules?

1. Saccharides
2. Fatty acids
3. Amino acids
4. Nucleic acids

19
Which level of protein structure would be
affected by an agent that breaks hydrogen bonds?

1. The primary level of protein structure
2. The secondary level of protein structure
3. The tertiary level of protein structure
4. The protein structure would NOT be affected by
   this agent

20
How does boiling a protein affect its structural
and functional properties?

1. Heat denatures the protein, causing unfolding.
2. Heat causes the formation of additional
   quaternary structure.
3. Heating rearranges the primary structure of the
   protein.
4. Heat alters the radical groups on the amino acids.

21
Why is it significant that keratin and collagen
are fibrous proteins and myoglobin and hemoglobin
are globular proteins?

1. Fibrous proteins are tough and insoluble in
   water they play structural roles
2. Fibrous proteins are only functional when they
   are in solution
3. Globular proteins readily enter aqueous solutions
   and function only when they are in solution
4. A and C are correct

22
How might a change in an enzymes active site
affect its functions?

1. Increased activity due to a better fit with the
   substrate
2. Decreased activity due to a poor substrate fit
3. Inhibited activity due to no substrate fit
4. All of the above

23
A large organic molecule composed of the sugar
ribose, nitrogenous bases, and phosphate groups
is which kind of nucleic acid?

1. DNA
2. ATP
3. tRNA
4. RNA

24
All of the following except __ are functions of
DNA.

1. Encoding information needed to build proteins.
2. Controlling physical characteristics of our
   bodies.
3. Manufacturing specific proteins.
4. Regulating all aspects of cellular metabolism.

25
What molecule is produced by the phosphorylation
of ADP?

1. ATPase
2. ATP
3. Adenosine Diphosphate
4. Uridine Triphosphate

26
Metabolic turnover refers to ____. The rate at
which this happens to glycogen in the liver is
about ___.

• The conversion of diglycerides to
  triglycerides/once in a lifetime
• The method by which a disaccharide becomes a
  polysaccharide/every few minutes
• Continuous removal and replacement of organic
  molecules/every 12 days
• The rate at which ATP is synthesized/every
• 12 weeks