3.4 Biological Molecules – Lipids

Question 1

a lipid molecule composed of three fatty acids and glycerol (triglyceride) that typically exists
in a solid form at room temperature

Answer 1

fat

Question 2

a chemical signaling molecule, usually a protein or steroid, secreted by an endocrine
gland or group of endocrine cells; acts to control or regulate specific physiological processes

Answer 2

hormone

Question 3

describes a substance that dissolves in water; water-loving

Answer 3

hydrophilic

Question 4

describes a substance that does not dissolve in water; water-fearing

Answer 4

hydrophobic

Question 5

a class of macromolecules that are nonpolar and insoluble in water

Answer 5

lipids

Question 6

an unsaturated fat that is a liquid at room temperature

Answer 6

oil

Question 7

a major constituent of the membranes of cells; composed of two fatty acids and a
phosphate group attached to the glycerol backbone

Answer 7

phospholipid

Question 8

a long-chain hydrocarbon with single covalent bonds in the carbon chain;
the number of hydrogen atoms attached to the carbon skeleton is maximized

Answer 8

saturated fatty acid

Question 9

a type of lipid composed of four fused hydrocarbon rings

Answer 9

steroid

Question 10

a form of unsaturated fat with the hydrogen atoms neighboring the double bond across
from each other rather than on the same side of the double bond

Answer 10

trans-fat

Question 11

a fat molecule; consists of three fatty acids linked to a glycerol molecule

Answer 11

triglyceride

Question 12

a long-chain hydrocarbon that has one or more than one double bonds
in the hydrocarbon chain

Answer 12

unsaturated fatty acid

Question 13

a type of lipid made up of a hydrocarbon chain with an alcohol (–OH) group and a fatty
acid

Answer 13

waxes