AP Biology Unit 1 Lipids

Which of the following element(s) are found in lipids?

• Carbon / Hydrogen

• Oxygen

• Phosphorus

• Sulfur

• Nitrogen

Which of the following is NOT a lipid?

• Steroid

• Fat

• Lipase

• Phospholipid

Answer explanation

Anything that ends in -ase is an enzyme!

Which of the following describes the difference between a phospholipid and a fat?

• Phospholipids are polar and fats are nonpolar

• Phospholipids are nonpolar and fats are polar

• Phospholipids have one more fatty acid than fats

• Phospholipids have one less fatty acid than fats

Phospholipids are amphipathic. Which of the following describes how that term applies to phospholipids?

• The phosphate group is nonpolar and the fatty acids are polar

• The phosphate group is polar and the fatty acids are nonpolar

• The phosphate group can amplify signal transduction by phosphorylating signaling molecules

• Fatty acids can amplify signal transduction by phosphorylating signaling molecules

Steroids are a type of hormone. Polar materials require a transport protein while nonpolar materials can easily pass through the plasma membrane. Which of the following describes how steroid hormones enter the cell.

• Steroids are polar so they pass easily through the plasma membrane

• Steroids are nonpolar so they pass easily through the plasma membrane

• Steroids are polar so they require a transport protein to pass through the plasma membrane

• Steroids are nonpolar so they require a transport protein to pass through the plasma membrane

Which of the following describes the difference between saturated and unsaturated fatty acids?

• Saturated fatty acids are more polar than unsaturated fatty acids

• Unsaturated fatty acids are more polar than saturated fatty acids

• Saturated fatty acids have more double bonds than unsaturated fatty acids

• Unsaturated fatty acids have more double bonds than saturated fatty acids

Lipids are polymers.

• True

• False

Which of the following describes the function of cholesterol (a steroid) in the plasma membrane?

• Cholesterol is a polar compound that that aids in transport of polar substances across the membrane

• Cholesterol acts as a receptor molecule to bind to signaling molecules in the signal transduction pathway

• Cholesterol provides energy for active transport across the plasma membrane

• Cholesterol binds to the fatty acid tails to maintain fluidity of the membrane

Which of the following describes the process to add a fatty acid to the glycerol in a triglyceride?

• This is a dehydration reaction leading to water loss

• This is a hydrolysis reaction leading to water loss

• This is a dehydration reaction leading to water used

• This is a hydrolysis reaction leading to water used

Which of the following describes why lipids are hydrophobic?

• Lipids are composed mostly of hydrocarbons which are nonpolar

• Lipids have hydrogen bonds that repel the hydrogen bonds in water

• Lipids have more neutrons in their atoms, making the compound neutral

• Lipids are gaseous materials that do not dissolve in water