Quiz Questions

Matter is made of elements, which are composed of atoms

Which statement best describes the relationship between matter, atoms, and elements?
a.) Matter is made of elements, which are composed of atoms

b.) Atoms are made of elements, which are composed of matter
c.) Elements are made of matter, which are composed of atoms

d.) Matter is made of atoms, and atoms are composed of multiple elements

Ionic bond; water’s polarity separates the ions

What type of bond holds Na⁺ and Cl⁻ together in table salt, and how does water disrupt it?
a.) Covalent bond; water competes for shared electrons
b.) Ionic bond; water’s polarity separates the ions
c.) Hydrogen bond; water breaks hydrogen interactions

d.) Nonpolar bond; water dissolves all nonpolar molecules

Saturated fatty acids contain the maximum number of hydrogens, while unsaturated contain fewer due to double bonds.

Which of the following best describes the difference between a saturated and an unsaturated fatty acid?
a.) Saturated fatty acids contain only double bonds, while unsaturated contain none
b.) Saturated fatty acids are bent, while unsaturated are straight
c.) Saturated fatty acids contain the maximum number of hydrogens, while unsaturated contain fewer due to double bonds.
d.) Saturated fatty acids are amphipathic, while unsaturated are not

A water molecule is removed to form a covalent bond

Dehydration synthesis is used in forming both disaccharides and peptide bonds. What is common about the chemistry in both cases?
a.) A water molecule is added to link monomers
b.) A water molecule is removed to form a covalent bond
c.) Hydrogen bonds hold the monomers together
d.) Ionic interactions stabilize the new bond

They stabilize α-helices and β-sheets in proteins and base-pairing in DNA

How do hydrogen bonds contribute to the structure of both proteins and DNA?
a.) They hold amino acids together in primary protein structure and link nucleotides in RNA

b.) They stabilize α-helices and β-sheets in proteins and base-pairing in DNA
c.) They form peptide bonds in proteins and phosphodiester bonds in DNA
d.) They make proteins hydrophobic and DNA hydrophilic

Disulfide bonds

Which of the following is an example of a covalent bond between different amino acids of a protein?
a.) Hydrogen bonds
b.) Van der Waals
c.) Electrostatic
d.) Disulfide bonds

R group

Which of the following groups varies among different amino acids?
a.) hydrogen atom
b.) carboxyl group
c.) R group
d.) amino group

Peptide bonds

Which of the following bonds are not involved in tertiary structure?
a.) Peptide bonds

b.) Ionic bonds
c.) Hydrophobic interactions
d.) Hydrogen bonds.

Prions are misfolded proteins rich in β-pleated sheets that induce normal cellular PrP to refold into the diseased form

Which of the following best describes the mechanism by which prions cause disease?

a.) Prions contain nucleic acids that integrate into the host genome, altering protein expression
b.) Prions are misfolded proteins rich in β-pleated sheets that induce normal cellular PrP to refold into the diseased form
c.) Prions are bacterial pathogens that secrete toxins causing neuronal death
d.) Prions are viral particles that replicate within neurons using host enzymes

They exist as flexible chains in their functional state and often gain structure upon binding to partners

Which statement correctly describes Intrinsically Disordered Proteins (IDPs)?

a.) They have a stable, well-defined 3D structure in their functional state

b.) They exist as flexible chains in their functional state and often gain structure upon binding to partners

c.) They are always non-functional due to lack of stable structure

d.) They are misfolded proteins that cause disease, like prions

Protect chromosome ends

What is the primary role of telomeres?

a.) Protect chromosome ends

b.) Attach spindle fibers

c.) Bind histones

d.) Initiate transcription

It prevents excess product accumulation

How does feedback inhibition benefit a metabolic pathway?

a.) It increases ATP consumption

b.) It prevents excess product accumulation

c.) It permanently inactivates enzymes

d.) It increases enzyme diversity

A regulatory molecule induces a shape change away from the active site

Which scenario best explains allosteric regulation?

a.) A regulatory molecule induces a shape change away from the active site

b.) A substrate forms a covalent bond

c.) An enzyme is degraded

d.) A ligand binds the active site directly

DNA is more accessible

Why does euchromatin tend to be transcriptionally active?

a.) It contains mutations

b.) It lacks histones

c.) DNA is more accessible

d.) It is highly condensed

Acetylation opens chromatin; methylation often compacts it

How do histone acetylation and methylation differ in gene regulation?

a.) Both alter DNA sequence

b.) Both block transcription

c.) Both compact chromatin

d.) Acetylation opens chromatin; methylation often compacts it

They allow strong but reversible interactions

Why are non-covalent interactions ideal for protein–ligand binding?

a.) They allow strong but reversible interactions

b.) They form peptide bonds

c.) They require ATP hydrolysis

d.) They permanently lock ligands in place

They carry positive charges that bind DNA

Why are histones rich in lysine and arginine? 

a.) They form hydrogen bonds with RNA

b.) They degrade DNA

c.) They carry positive charges that bind DNA

d.) They repel DNA

Their hypervariable loops differ in amino acid sequence

Why can antibodies recognize billions of different antigens

a.) Their hypervariable loops differ in amino acid sequence

b.) They bind antigens covalently

c.) They contain multiple cofactors

d.) They are encoded by multiple genes

Reduced ligand-binding specificity

A mutation alters several amino acid side chains within a protein’s binding site. Which outcome is most likely?

a.) Complete loss of protein synthesis

b.) Reduced ligand-binding specificity

c.) Increased protein stability

d.) Increased transcription of the protein

Nucleosome

What is the basic unit of chromatin structure?

a.) Nucleosome

b.) Chromatid

c.) Centromere

d.) Histone tail