CHEM 131 EXAM 1 UNL UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

CHEM 131 EXAM 1 UNL UPDATED ACTUAL QUESTIONS
AND CORRECT ANSWERS

Question:
1. T or F. The nucleus is the center of the atom, which contains most of the mass.
Answer:
True

Question:
2. The smallest part of an element that retains the properties of the element.
Answer:
Atom

Question:
3. The number of protons of an element.
Answer:
Atomic Number

Question:
4. The part of an atom with a positive charge.
Answer:
Proton

Question:
5. A pure substance made of two or more elements that are chemically bonded.
Answer:
Compound

Question:
6. How many electrons does 15P (phosphorus) have in the outermost shell (Hint: use periodic table)?
Answer:
5

Question:
7. All organic compounds contain:
Answer:
Carbon

Question:
8. Hydrogen, oxygen, nitrogen and carbon make how many bonds respectively?
Answer:
1,2,3,4

Question:
9. Type of bond that occurs as a result of electron sharing

,Answer:
Covalent

Question:
10. Type of bond that occurs as a result of electron transfer.
Answer:
Ionic

Question:
11. An O-H group is called a(n)
Answer:
Hydroxyl

Question:
12. A mixture that is not uniform.
Answer:
Heterogeneous mixture

Question:
13. T or F. Atoms gain, lose, or share electrons until they are surrounded by eight valence electrons and
this property is known as the octet rule.
Answer:
True

Question:
14. All alcohols contain a(n) _________ group.
Answer:
Hydroxyl

Question:
15. Proteins that function as enzymes are able to:
a. Break bonds
b. From bonds
c. Transform bonds
d. All of the above
Answer:
d. All of the above

Question:
16. T or F. A peptide bond is a chemical bond between the amino group of one amino acid and the
carboxylic acid of a second amino acid.
Answer:
True

Question:
17. A compound that helps oil to be suspended in water is called a(n):

, Answer:
Emulsifier

Question:
18. How many of the 20 amino acids are essential to humans?
Answer:
9

Question:
19. The 3-D shape of a protein is very important to its function. This bending and folding of the protein
chain is called its
Answer:
Tertiary structure

Question:
20. Heat is capable of causing a change in the 3-D shape of a protein. When this occurs, we describe the
change as
Answer:
Denaturation

Question:
21. Three-dimensional folding pattern of a protein.
Answer:
Tertiary structure

Question:
22. Structure associated with folds of the polypeptide chain.
Answer:
Secondary structure

Question:
23. Structure present in proteins when it has more than one amino acid chain.
Answer:
Quaternary structure

Question:
24. Order and number of amino acids in a protein chain.
Answer:
Primary chain

Question:
25. In the three-dimensional organization of a protein chain, the folded configuration usually:
Answer:
Places the hydrophobic amino acids in the interior region of the protein