Question 1

Which of the following is an advantage of storing glucose in a branched formation, such as in glycogen, compared to an unbranched formation like amylose?

Accepted Answer

Branched formation enables more rapid mobilization of glucose because enzymes can act on multiple ends simultaneously.

Question 2

In starch, glycogen, and cellulose, the glucose monomers are linked by different types of glycosidic bonds. Which type of bond is found in cellulose, and how does it affect its function?

Accepted Answer

Cellulose contains $$\beta-1$$,4 glycosidic bonds, resulting in a rigid structure that provides support in plant cell walls.

Question 3

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

Accepted Answer

Saturated fatty acids have only single bonds in their hydrocarbon tails, making them solid at room temperature.

Question 4

A triacylglycerol molecule is formed by a dehydration reaction between which functional groups?

Accepted Answer

Hydroxyl group of glycerol and carboxyl group of fatty acid

Question 5

Why are animal fats typically solid at room temperature, while plant and fish fats are liquid?

Accepted Answer

Animal fats are composed of saturated fatty acids, which allow molecules to pack closely, forming solids.

Question 6

Which of the following best explains why 1g of fat stores approximately twice the energy of 1g of polysaccharide?

Accepted Answer

Fats are more reduced, containing more C-H bonds, which release more energy upon oxidation.

Question 7

Phospholipids are essential components of cell membranes. Which structural feature allows them to form bilayers in aqueous environments?

Accepted Answer

Phospholipids have a hydrophilic phosphate head and two hydrophobic fatty acid tails.

Question 8

Which of the following is NOT a function of proteins in living organisms?

Accepted Answer

Encoding genetic information

Question 9

A mutation in the hemoglobin gene causes sickle-cell disease by substituting valine for glutamic acid. Which level(s) of protein structure are most directly affected by this change?

Accepted Answer

Primary, secondary, tertiary, and quaternary structures

Question 10

Which type of chemical bond is primarily responsible for the secondary structure of proteins, such as $$\alpha-$$helices and $$\beta-$$sheets?

Accepted Answer

Hydrogen bonds between backbone atoms

Question 11

Which of the following amino acids is most likely to be found on the interior of a folded protein, away from water?

Accepted Answer

Valine

Question 12

Given a protein with a primary structure of 100 amino acids, how many possible unique sequences can be formed using the 20 common amino acids?

Accepted Answer

$$20^{100}$$

Question 13

Which of the following statements about nucleic acids is correct?

Accepted Answer

DNA contains thymine and deoxyribose.

Question 14

What type of reaction forms the phosphodiester bonds that link nucleotides together in nucleic acids?

Accepted Answer

Dehydration synthesis

Question 15

In a DNA double helix, the two strands run in opposite directions. What is this arrangement called?

Accepted Answer

Antiparallel

Question 16

Which nitrogenous base is found only in RNA and not in DNA?

Accepted Answer

Uracil

Question 17

A DNA strand has the sequence 5'-ATCG-3'. What is the sequence of the complementary strand?

Accepted Answer

3'-TAGC-5'

Question 18

Which of the following best describes the backbone of a nucleic acid strand?

Accepted Answer

Alternating phosphate and sugar groups

Question 19

Which macromolecule is NOT classified as a polymer made of repeating monomer units?

Accepted Answer

Lipids

General Biology: Macromolecules – Carbohydrates, Lipids, Proteins, and Nucleic Acids

Guida di studio - Domande di pratica

Study guide - Flashcard