Chapter 2

Which of the following statements is incorrect? a. Isotopes have the same atomic number and different mass numbers. b. Atoms have about the same number of electrons as protons. c. All ions are atoms. d. Free radicals are dangerous because they emit energy. e. A carbon atom can share electrons with up to 4 other atoms.

What is the name of an atom that has one proton and no electrons?

The mutual attraction of opposite charges holds atoms together as molecules in a(n) _____ bond.a. ionic b. hydrogen c. polar covalent d. non polar covalent

Rank the following types of bonds by polarity, with 1 being the least polar, and 3 being the most polar: _____1 _____2 _____3 a. ionic b. polar covalent c. nonpolar covalent

\(A(n)\)____ substance repels water. a. acidic b. basic c. hydrophobic d. polar

When dissolved in water, a(n) ______ donates \(\mathrm{H}^{+}\) and \(a(n)\) _____ accepts \(\mathrm{H}^{+}\) a. acid; base b. base; acid c. buffer; solute d. base; buffer

______ is a simple sugar (a monosaccharide). a. Glucose b. Sucrose c. Ribose d. Starch e. a and c f. \(a, b,\) and \(c\)

Unlike saturated fats, the fatty acid tails of unsaturated fats incorporate one or more a. phosphate groups b. glycerols c. double bonds d. single bonds

Which of the following is a class of molecules that encompasses all of the other molecules listed? a. triglycerides b. fatty acids c. waxes d. steroids e. lipids f. phospholipids

___________ are to proteins as ______________ are to nucleic acids. a. Sugars; lipids b. Sugars; proteins c. Amino acids; hydrogen bonds d. Amino acids; nucleotides

A denatured protein has lost its a. hydrogen bonds b. shape c. function d. all of the above

Which of the following are not found in DNA? a. amino acids b. sugars c. nucleotides d. phosphate groups

Match the terms with their most suitable description. _______ hydrophilic _______ atomic number _______ hydrogen bonds _______ positive charge _______ temperature _______ negative charge a. protons \(>\) electrons b. number of protons in nucleus c. polar; dissolves easily in water d. collectively strong e. protons \(<\) electrons f. measure of molecular motion

Match each molecule with its most suitable description. _______wax _______ starch _______triglyceride _______ DNA _______polypeptide _______ ATP a. protein primary structure b. an energy carrier c. water-repellent secretions d. carries heritable information e. sugar storage in plants f. richest energy source in animals

Match each molecule with its component(s). _______protein _______phospholipid _______fat _______nucleic acid _______cellulose _______nucleotide _______wax _______sucrose a. glycerol, fatty acids, phosphate b. glycerol, fatty acids c. nucleotide monomers d. glucose monomers e. sugar, phosphate, base f. amino acid monomers g. glucose, fructose h. fatty acids, carbon rings