Download WS 9 Notes - Department of Chemistry | Oregon State University

Chemistry 130
Worksheet 9 Notes
1.
Oregon State University
Dr. Richard Nafshun
A student measures the pH of a solution to be 7.0. Is this solution neutral acidic, or
basic?
Neutral.
A student measures the pH of a solution to be 2.7. Is this solution neutral acidic, or
basic?
Less than 7, therefore, acidic.
A student measures the pH of a solution to be 9.3. Is this solution neutral acidic, or
basic?
Greater than 7, therefore, basic.
2.
Identify four acids. What do acids do?
Our definition of an acid: a species that donates a proton. Examples include HCl,
HNO3, and organic acids (carboxylic acids). CH3COOH, benzoic acid, and amino acids
(NH2-CHR-COOH).
3.
Identify four bases. What do bases do?
Our definition of a base: a species that accepts a proton. Examples include NaOH, NH3,
and amines: CH3NH2, and amino acids (NH2-CHR-COOH).
4.
An aqueous solution of CH3COOH is will have a pH of 7, less than 7, greater than 7?
Less than 7 because CH3COOH is a carboxylic acid.
An aqueous solution of CH3NH2 is will have a pH of 7, less than 7, greater than 7?
Less than 7 because CH3NH2 is a base.
5.
What is meant by primary structure? Give an example.
Primary structure is the order that the amino acids are connected. Ala-Gly-Glu-Ala
denotes the order in which the amino acids are connected.
What is meant by secondary structure? Give an example.
Secondary structure is the orientation the primary structure obtains (alpha helix or beta
sheet)
What is meant by tertiary structure? Give an example.
The secondary structure takes on a three-dimensional "globular" structure—this is the
tertiary structure.
What is meant by quaternary structure? Give an example.
Hemoglobin is composed of four tertiary globular structures.
6.
Ala-Gly-Glu can be best described by:
(A)
(B)
(C)
(D)
7.
Alpha helixes and Beta sheets are types of:
(A)
(B)
(C)
(D)
8.
Primary structure.
Secondary structure.
Tertiary structure.
Quaternary structure.
Primary structure.
Secondary structure.
Tertiary structure.
Quaternary structure.
What does hydrogen bonding have to do with secondary structure?
Hydrogen bonding is responsible for the interactions between strands or within a strand.