AP Biology : AP Biology

Study concepts, example questions & explanations for AP Biology

varsity tutors app store varsity tutors android store

Example Questions

Example Question #26 : Identify Structure And Purpose Of Carbohydrates, Lipids, Proteins, And Nucleic Acids

Chitin is what class of molecule?

Possible Answers:

Nucleic acid

Lipid

Wax

Carbohydrate

Correct answer:

Carbohydrate

Explanation:

Chitin is a carbohydrate. Specifically, it is a polysaccharide used by arthopods to build exoskeletons, and is found in the cell walls of fungi. Waxes are types of lipids, and nucleic acids are DNA and RNA.   

Example Question #27 : Identify Structure And Purpose Of Carbohydrates, Lipids, Proteins, And Nucleic Acids

Starch belongs to which class of macromolecules?

Possible Answers:

Nucleic acids

Carbohydrates

Lipids

Polypeptides

Correct answer:

Carbohydrates

Explanation:

Starch is a carbohydrate. Specifically, it is a polysaccharide carbohydrate used in plants. The enzyme amylase breaks down starch in the mouth and small intestine, where it can is absorbed as monosaccharides and disaccharides.

Example Question #31 : Identify Structure And Purpose Of Carbohydrates, Lipids, Proteins, And Nucleic Acids

Which of the following is an example of a lipid?

Possible Answers:

Disaccharide

Cellulose

Amino acid

Cholesterol

Correct answer:

Cholesterol

Explanation:

Cholesterol is a type of steroid, which is a lipid. Amino acids are part of proteins. Cellulose and disaccharides are examples of carbohydrates.

Example Question #63 : Macromolecules

Which of the following includes all the other answer choices?

Possible Answers:

Fats

Waxes

Phospholipids

Lipids

Correct answer:

Lipids

Explanation:

Lipids are a large class of hydrocarbon-based molecules that includes waxes, steroids, phospholipids and fats. Lipids are hydrophobic and have functions in energy storage, providing support to the cell/organism, cell signaling, and make up the majority of the cell membrane. 

Example Question #91 : Biochemical Concepts

A lipid that consists of a long chain of hydrocarbons with the maximum number of hydrogens possible is referred to as __________.

Possible Answers:

a steroid

a saturated fatty acid

a vitamin

a triglyceride

Correct answer:

a saturated fatty acid

Explanation:

Saturated fatty acids contain the maximum number of hydrogens on their hydrocarbon tails. These molecules form long, straight chains that can be very densely packed. By contrast, unsaturated fatty acids, do not contain the maximum number of hydrogens on their hydrocarbon tails, and thus have "kinks" in their tails. This does not allow for dense packing and storage of unsaturated fatty acids, and thus make them easier to burn.

Example Question #92 : Biochemical Concepts

Hemoglobin is an example of a __________.

Possible Answers:

phospholipid

steroid

protein

nucleic acid

Correct answer:

protein

Explanation:

Hemoglobin is the protein in red blood cells that binds and transports oxygen to the body tissues. It contains an iron core, and each hemoglobin molecule can bind up to four oxygen molecules.

Example Question #101 : Biochemical Concepts

If a phospholipid's phosphate group is replaced with another fatty acid chain, the result is a __________.

Possible Answers:

wax

saturated fatty acid

steroid

fat (triglyceride)

Correct answer:

fat (triglyceride)

Explanation:

A phospholipid has two fatty acid chains and a phosphate group attached to glycerol. By replacing the phosphate group of a phospholipid with another fatty acid, the result is a glycerol with three fatty acid chains which makes it a fat (triglyceride). Saturated fatty acids are single chains of fatty acids, the resulting molecule has three fatty acids, which each could be saturated or unsaturated. Steroids have structures that consist of four fused carbon rings. 

Example Question #2483 : Ap Biology

Fat is composed of which of the following smaller molecules?

Possible Answers:

None of these

Fatty acids

Glycerol

Glycerol and fatty acids

Correct answer:

Glycerol and fatty acids

Explanation:

Fat is made up of glycerol and fatty acids. Specifically, a fat is composed of three fatty acids chains—composed of 16 or 18 carbon atoms in length—connected to a glycerol by way of an ester linkage.

Example Question #102 : Biochemical Concepts

Which of the following best describes the composition of glycerol molecules?

Possible Answers:

An alcohol with three carbons without any hydroxyl group

An alcohol with three carbons each bearing a hydroxyl group

An alcohol with one carbon bearing a hydroxyl group

An alcohol with two carbons each bearing a hydroxyl group

Correct answer:

An alcohol with three carbons each bearing a hydroxyl group

Explanation:

Glycerol is composed of an alcohol attached to three carbons each bearing a hydroxyl group.

Example Question #103 : Biochemical Concepts

Fatty acids vary in length and in the number and locations of double bonds between the carbon atoms. If there are no double bonds between the carbon atoms in the tail then the fatty acid is said to be __________.

Possible Answers:

monounsaturated

unsaturated

saturated

low density

Correct answer:

saturated

Explanation:

A saturated fatty acid has no double bonds between the carbon atoms making up the tail of the fatty acid. This lack of double bonding allows for as many hydrogen atoms as possible to be bonded to the carbon skeleton, thus the fatty acid is said to be saturated with hydrogen atoms.

Learning Tools by Varsity Tutors