Bio Chapter 2 Study Guide

Discuss how buffers help prevent drastic swings in pH.

Buffers readily absorb excess H+ ions and OH- ions.

What property of carbon makes it essential for organic life?

Carbon has the ability to form up to four bonds with different molecules. These bonds can be nonpolar covalent bonds, which allows the formation of long chains of elements that create proteins and carbohydrates.

How many neutrons do carbon-12 and carbon-13 have, respectively?

Carbon-12 has six neutrons and Carbon-13 has seven neutrons

What makes ionic bonds different from covalent bonds?

Ionic bonds involve the complete transfer of valence electrons from one atom to another. Covalent bonds involve the sharing of valence electron pairs between atoms.

Which of the following is not a functional group that can bond with carbon? a. sodium b. hydroxyl c. phosphate d. carbonyl

a. sodium

Which of the following statements is true? a. Acids and bases cannot mix together. b. Acids and bases will neutralize each other. c. Acids, but not bases, can change the pH of a solution. d. Acids donate hydroxide ions (OH-); bases donate hydrogen ions (H+).

b. Acids and bases will neutralize each other.

Which of the following statements is false? a. Molecules with the formulas CH3CH2COOH and C3H6O2 could be structural isomers. b. Molecules must have a double bond to be cis-trans isomers. c. To be enantiomers, a molecule must have at least three different atoms or groups connected to a central carbon. d. To be enantiomers, a molecule must have at least four different atoms or groups connected to a central carbon.

c. To be enantiomers, a molecule must have at least three different atoms or groups connected to a central carbon.

A molecule that binds up excess hydrogen ions in a solution is called a(n) ________. a. acid b. isotope c. base d. donator

c. base

Potassium has an atomic number of 19. What is its electron configuration? a. shells 1 and 2 are full, and shell 3 has nine electrons b. shells 1, 2 and 3 are full and shell 4 has three electrons c. shells 1, 2 and 3 are full and shell 4 has one electron d. shells 1, 2 and 3 are full and no other electrons are present

c. shells 1, 2 and 3 are full and shell 4 has one electron

Which of the following statements is not true? a. Water is polar. b. Water stabilizes temperature. c. Water is essential for life. d. Water is the most abundant molecule in the Earth's atmosphere.

d. Water is the most abundant molecule in the Earth's atmosphere.

Each carbon molecule can bond with as many as________ other atom(s) or molecule(s). a. one b. two c. six d. four

d. four

Atoms that vary in the number of neutrons found in their nuclei are called ________. a. ions b. neutrons c. neutral atoms d. isotopes

d. isotopes

Why are hydrogen bonds and van der Waals interactions necessary for cells?

in cells, hydrogen bonds play a large role in holding DNA strands together so they can later be "unzipped" for transcription. Van der Waals interactions are also present in the formation and three dimensional structure of proteins.

Compare and contrast saturated and unsaturated triglycerides.

Saturated fats are saturated with hydrogens, and are often found as solids at room temperature because they contain single bonds between carbons. Unsaturated fats have less hydrogens, so a double bond forms between carbons, making many of these fats liquid at room temperature.

Why can some insects walk on water?

Water has high surface tension, so when some insects stand on it, the tension does not break.

When acids are added to a solution, the pH should ________. a. decrease b. increase c. stay the same d. cannot tell without testing

a. decrease

Which type of bond represents a weak chemical bond? a. hydrogen bond b. atomic bond c. covalent bond d. nonpolar covalent bond

a. hydrogen bond

If xenon has an atomic number of 54 and a mass number of 108, how many neutrons does it have? a. 54 b. 27 c. 100 d. 108

a. 54