Question 1

Which of the following best explains why saturated fats are solid at room temperature, while unsaturated fats are liquid?

Accepted Answer

Saturated fats have only single bonds between carbon atoms, allowing them to pack closely together, while unsaturated fats have one or more double bonds that create kinks, preventing tight packing.

Question 2

A triglyceride is formed by the combination of which molecules, and what is released during its formation?

Accepted Answer

One glycerol and three fatty acids; three molecules of water are released.

Question 3

Which of the following best describes the amphipathic nature of phospholipids and its significance in biological membranes?

Accepted Answer

Phospholipids have both hydrophilic heads and hydrophobic tails, allowing them to form bilayers that create a selective barrier in cell membranes.

Question 4

Which of the following is a function of steroids in the body?

Accepted Answer

Regulation of hormones such as sex hormones and adrenal cortical hormones.

Question 5

Which molecule is responsible for information storage in cells, and what is its polymer made of?

Accepted Answer

DNA; a polymer of nucleotide monomers.

Question 6

A nucleotide contains which of the following components?

Accepted Answer

A five-carbon sugar, a nitrogenous base, and a phosphate group.

Question 7

Which of the following best describes the role of proteins as enzymes?

Accepted Answer

They act as organic catalysts, speeding up chemical reactions without being consumed in the process.

Question 8

Which protein is essential for the movement of cilia and flagella in eukaryotic cells?

Accepted Answer

Tubulin

Question 9

What is the primary structure of a protein, and why is it important?

Accepted Answer

The sequence of amino acids in the polypeptide chain; it determines the protein's final shape and function.

Question 10

Which of the following statements about amino acids is TRUE?

Accepted Answer

All living things use the same 20 amino acids to make proteins, which is strong evidence for a common ancestor.

Question 11

Which of the following best describes the secondary structure of proteins?

Accepted Answer

It involves the twisting or folding of the amino acid chain into alpha helices and beta pleated sheets.

Question 12

A patient is diagnosed with a genetic disorder that affects the structure of collagen. Which tissue is LEAST likely to be affected?

Accepted Answer

Liver tissue

Question 13

Which of the following is a correct description of a peptide bond?

Accepted Answer

A strong covalent bond formed between the amino group of one amino acid and the carboxyl group of another.

Question 14

Which of the following best explains why all enzymes are not effective at all temperatures and pH levels?

Accepted Answer

Enzymes have specific three-dimensional structures that can be altered by changes in temperature and pH, affecting their ability to bind substrates.

Question 15

Which of the following is a real-world example of a protein acting as a receptor?

Accepted Answer

A protein in the tongue that binds to taste molecules, allowing the sensation of taste.

Question 16

Which of the following best describes the process of hydrogenation in the context of lipids?

Accepted Answer

It converts double bonds in unsaturated fatty acids into single bonds, making the fat more solid at room temperature.

Question 17

Which of the following is a function of hemoglobin, a transport protein?

Accepted Answer

Transporting oxygen in the blood.

Question 18

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

Their hydrophilic heads interact with water while their hydrophobic tails avoid water, resulting in a bilayer structure.

Question 19

Which of the following is a correct match between a macromolecule and its monomer?

Accepted Answer

Protein – amino acid

Question 20

A scientist is studying a molecule with a five-carbon sugar, a phosphate group, and a nitrogenous base. Which type of macromolecule is she most likely studying, and what is its primary function?

Accepted Answer

Nucleic acid; information storage or transfer

Biological Macromolecules: Lipids, Nucleic Acids, and Proteins

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