Biol 225 Quiz 2

A(n) ________ is a pure substance composed of atoms of only one kind. a) macromolecule b) compound c) ion d) isotope e) element

a) macromolecule

Given the following approximate values, calculate the molecular weight for NaCl. Atomic number for Na: 11, Atomic weight for Na: 23 g/mol, Atomic number for Cl: 17, Atomic weight for Cl: 35 g/mol. a) 11 g/mol b) 58 g/mol c) 40 g/mol d) 34 g/mol e) 28 g/mol

b) 58 g/mol

When electrons are transferred from one atom to another, and the two atoms unite as a result of the opposite charges, a(n) ________ is formed. a) molecule b) ionic bond c) hydrogen bond d) covalent bond e) ion

b) ionic bond

In the process of ________ a phosphate group is transferred to a molecule. a) ionization b) phosphorylation c) dissociation d) amination e) buffering

b) phosphorylation

What is the pH of a solution with a [H+] = 1 X 10-7 mol/L? a)2 b) 7.4 c) 7 d) 6 e) 8.2

c) 7

In the body, inorganic compounds... a) are made from organic compounds. b) are metabolized for cellular energy. c) can serve as buffers. d) can make up proteins. e) are structural components of cells.

c) can serve as buffers.

Which element commonly has only a proton as its nucleus? a) helium b) neon c) hydrogen d) argon e) carbon

c) hydrogen

Which has the greater concentration of hydrogen ions, a substance with a pH of 5 or a substance with a pH of 4? a) pH 9, if you mixed the solutions. b) There is not enough information to determine the answer. c) A pH of 5 is greater. d) A pH of 4 is greater. e) They are both equal; 4 and 5 are relative values.

d) A pH of 4 is greater.

The molecule H2 is known as... a) semi-water b) helium c) hydrohydrogen d) hydrogen e) hydroxide

d) hydrogen

Which of the following functional groups is the carboxyl group? a) PO4 b) OH c) NH2 d) SH e) COOH

e) COOH