Chapter 3 Carbon & the Molecular Diversity of Life

The different macromolecules used by living things are:

• Carbohydrates, lipids, proteins, and nucleic acids

• Vitamins, minerals, water, and oxygen

• Sugars, salts, acids, and bases

• Enzymes, hormones, antibodies, and pigments

All of life is built on _______.

• carbon

• hydrogen

• oxygen

• nitrogen

Cells are composed of approximately what percentage of H2O?

• ~72%

• ~40%

• ~85%

• ~55%

Cells are composed of approximately what percentage of carbon compounds?

• ~25%

• ~2%

• ~50%

• ~75%

C atoms are versatile building blocks.

• True

• False

How many valence electrons does a carbon atom have?

• 4

• 2

• 6

• 8

The great diversity of organisms on the planet is due to the _______ of carbon.

• versatility

• rarity

• toxicity

• instability

Carbon chains form the skeletons of most _______ molecules.

• organic

• inorganic

• metallic

• radioactive

Hydrocarbons are organic molecules consisting of only _______ and _______.

• carbon and hydrogen

• carbon and oxygen

• hydrogen and nitrogen

• carbon and sulfur

What are isomers?

• Compounds with the same molecular formula and same structures

• Compounds with the same molecular formula but different structures and properties

• Compounds with different molecular formulas

• Compounds with the same properties but different formulas