Question 1

Which of the biomolecules is incorrectly matched with its building block?

Accepted Answer

Carbohydrates are not built from polysaccharides; they are built from monosaccharides. Polysaccharides are actually complex forms of carbohydrates.

Question 2

What type of reaction does the figure show?

Accepted Answer

The answer of What type of reaction does the figure...

Question 3

A micelle is formed of

Accepted Answer

Micelles are formed by amphipathic molecules, which have both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts. In a micelle, the hydrophobic portions face toward the center, away from water, while the hydrophilic portions face outward, interacting with the water. This arrangement minimizes the free energy of the system, allowing the hydrophobic parts to avoid contact with water.

Question 4

Van der Waals interactions

Accepted Answer

Van der Waals interactions occur due to temporary dipoles in molecules, not specifically involving hydrogen bonds to O, N, or F atoms. These interactions are weaker than hydrogen and ionic bonds and do not specifically relate to the repulsion between hydrophilic and hydrophobic compounds, nor are they another name for hydrogen bonds.

Question 5

Which statement does not describe a catalyst?

Accepted Answer

A catalyst increases the rate of a reaction by lowering the activation energy required for the reaction to proceed, but it does not decrease the rate of a reaction.

Question 6

The type of bond which links the amino group of one amino acid to the carboxyl group of another amino acid is called a(n)

Accepted Answer

A peptide bond is the type of covalent bond that forms between the carboxyl group of one amino acid and the amino group of another, through a dehydration synthesis reaction, which is fundamental in the formation of proteins.

Question 7

Deoxyribonucleotides and ribonucleotides differ in all of the following except

Accepted Answer

Phosphodiester bonds can form between both deoxyribonucleotides and ribonucleotides, which is essential for the structure of both DNA and RNA.

Question 8

Which term is incorrectly matched to its description?

Accepted Answer

The answer of Which term is incorrectly matched to its...

Question 9

In a dehydration synthesis reaction, macromolecules are built when is removed to form a covalent bond.

Accepted Answer

In a dehydration synthesis reaction, water (H2O) is removed to form a covalent bond between monomers, leading to the creation of polymers. This process is common in the formation of carbohydrates, proteins, and nucleic acids.

Question 10

Consider the reaction AB - A + B. What is the product of this reaction?

Accepted Answer

The reaction AB -> A + B indicates that AB breaks down into A and B, making them the products.

Question 11

Which of the following does not describe equilibrium?

Accepted Answer

The answer of Which of the following does not describe...

Question 12

The figure shown is an exergonic reaction because

Accepted Answer

The answer of The figure shown is an exergonic reaction...

Question 13

Plasma membranes, the key boundary layer of cells, are composed of amphipathic molecules called phospholipids. Why would neither purely hydrophilic nor purely hydrophobic molecules be a suitable molecule for plasma membranes?

Accepted Answer

Hydrophilic molecules would indeed dissolve or be too soluble in the aqueous environment, potentially disrupting the cell's integrity by not forming a stable barrier. Hydrophobic molecules, on the other hand, would not be able to interact with the aqueous environment, preventing the formation of a functional barrier that can interact with both the cell's interior and the external environment. Amphipathic molecules, like phospholipids, have both hydrophilic and hydrophobic parts, allowing them to form stable bilayers that are crucial for the structural integrity and function of plasma membranes.

Question 14

Activation energy

Accepted Answer

The answer of Activation energy
...

Question 15

Which of the following is not one of the four main groups of biomolecules?

Accepted Answer

Electrolytes are not considered one of the four main groups of biomolecules. The four main groups are nucleic acids, carbohydrates, proteins, and lipids. Electrolytes are ions in solution that conduct electricity, not complex organic molecules.

Question 16

Which reaction has X and Y as reactants?

Accepted Answer

In option D, X and Y are the reactants that combine to form the product XY, which directly answers the question.

Question 17

Which statement is true about carbohydrates?

Accepted Answer

Carbohydrates are a component of the cell wall in plants (cellulose) and fungi (chitin).

Question 18

Which reaction is incorrectly matched with its name?

Accepted Answer

Hydrolysis involves the chemical breakdown of a compound due to reaction with water, not the simple combination of elements or compounds as described.

Question 19

Hydrogen bonds

Accepted Answer

Hydrogen bonds are crucial for the unique properties of water, such as its high boiling point relative to its molecular weight, and its ability to dissolve many substances. They also play a key role in stabilizing the three-dimensional structures of proteins and nucleic acids, such as DNA and RNA, which is essential for their biological functions.

Question 20

Which type of lipid is incorrectly matched to its description?

Accepted Answer

Waxes are not defined by their state at room temperature but rather by their structure, which typically involves long-chain fatty acids esterified to long-chain alcohols, making them highly hydrophobic. They are used by plants and animals for protection and water-proofing, among other functions, not merely classified by their physical state.

Quiz 2: Biochemistry Basics