Question 1

In an endergonic reaction,

Accepted Answer

A)  large molecules are broken down into smaller ones. 
B)  small molecules are assembled into larger ones. 
C)  molecules are rearranged to form new molecules. 
D)  molecules move from reactants to products and back. 
E)  energy is consumed during the reaction.

Question 2

The most important metabolic fuel molecule in the body is

Accepted Answer

A)  sucrose. 
B)  starch. 
C)  protein. 
D)  vitamin B12. 
E)  glucose.

Question 3

Functionally, carbohydrates are most important as

Accepted Answer

A)  storage of glucose molecules. 
B)  a part of nucleic acid structure. 
C)  sources of energy. 
D)  receptors of the cell surface. 
E)  insulation under the skin.

Question 4

Which of the following constitutes most of the total body weight in humans?

Accepted Answer

A)  water 
B)  acids 
C)  bases 
D)  salts 
E)  organic molecules

Question 5

Which of these is a molecule but is not considered to be a compound?

Accepted Answer

A)  H2O 
B)  CO2 
C)  C6H12O6 
D)  H2 
E)  CO

Question 6

Which of the following is unique to RNA?

Accepted Answer

A)  glucose 
B)  phosphate group 
C)  ribose 
D)  adenosine triphosphate 
E)  deoxyribose

Question 7

Figure 2-4 An Overview of the Structures of Organic Compounds in the Body
Use Figure 2-4 to answer the following questions:
-What is/are the primary function(s) of the structure labeled #9?

Accepted Answer

A)  determines an individual's inherited characteristics 
B)  structural role when attached to lipids 
C)  energy source; insulation 
D)  manufactures specific proteins 
E)  storage or transfer of energy

Question 8

Which of the following is a characteristic of hydrogen bonds?

Accepted Answer

A)  Hydrogen bonds are strong attractive forces between hydrogen atoms and negatively charged atoms. 
B)  Hydrogen bonds occur only in water. 
C)  Hydrogen bonds can form between adjacent molecules. 
D)  Hydrogen bonds are part of fatty-acid structure. 
E)  Hydrogen bonds are part of carbohydrate structure.

Question 9

Carbon dioxide is produced as a result of

Accepted Answer

A)  metabolic activity. 
B)  carbon monoxide instability. 
C)  oxygen synthesis during aerobic respiration. 
D)  the breakdown of water into oxygen. 
E)  glucose synthesis.

Question 10

Which is the correct description of a molecule?

Accepted Answer

A)  It is an electrically charged atom. 
B)  It cannot be broken down physically. 
C)  It is comprised of two or more elements bonded together. 
D)  It is the smallest unit of matter. 
E)  It is comprised of two or more atoms sharing electrons.

Question 11

A(n) ________ contains atoms with the same atomic number.

Accepted Answer

A)  base 
B)  element 
C)  cation 
D)  anion 
E)  enzyme

Question 12

Which of the following is an example of an anion?

Accepted Answer

A)  magnesium 
B)  potassium 
C)  calcium 
D)  chloride 
E)  sodium

Question 13

Which of the following substances would be nearest the pH of human blood?

Accepted Answer

A)  milk, pH ≈ 6.5 
B)  pure water, pH ≈ 7 
C)  tomato juice, pH ≈ 4 
D)  wine, pH ≈ 3 
E)  stomach secretions, pH ≈ 1

Question 14

Which of the following can be denatured?

Accepted Answer

A)  enzymes 
B)  ions 
C)  atoms 
D)  molecules 
E)  isotopes

Question 15

Lipids are used for which of the following?

Accepted Answer

A)  to form essential structural components of cells 
B)  to provide roughly 10 times as much energy as carbohydrates 
C)  to help reduce body temperature 
D)  to help protect the skeleton 
E)  to carry genetic information

Question 16

Figure 2-2 A Molecule
Use Figure 2-2 to answer the following question:
The molecule shown in the figure is considered to be the most important metabolic "fuel" in the body. Choose the best category of molecules to which it belongs.

Accepted Answer

A)  steroid 
B)  saturated fatty acid 
C)  monoglyceride 
D)  cholesterol 
E)  monosaccharide

Question 17

A bond between a phosphate group and a sugar can be found linking together

Accepted Answer

A)  two simple sugars. 
B)  one amino acid to an amino group of another. 
C)  two nucleotides. 
D)  a fatty acid and a glycerol molecule. 
E)  a cholesterol molecule and a fatty-acid molecule.

Question 18

Atoms that are of the same element but contain different numbers of neutrons are called

Accepted Answer

A)  isomers. 
B)  cations. 
C)  isotopes. 
D)  anions. 
E)  None of these is correct.

Question 19

The hydrolysis of ATP yields the molecule

Accepted Answer

A)  adenine. 
B)  phospholipid. 
C)  ribose. 
D)  thymine. 
E)  adenosine diphosphate.

Question 20

Substrate molecules bind to enzymes at the

Accepted Answer

A)  allosteric sites. 
B)  modification sites. 
C)  reaction sites. 
D)  active sites. 
E)  ionic sites.

Exam 2: The Chemical Level of Organization