WorksheetsCHM-360 Quiz 1-2
Total questions: 24
Worksheet time: 18mins
If a reaction has a negative ΔG, it is:
a) Nonspontaneous and endergonic
b) Spontaneous and exergonic
c) Nonspontaneous and exothermic
d) Spontaneous and endergonic
Which of the following is NOT a type of work performed in living systems?
a) Osmotic
b) Chemical
c) Mechanical
d) Static
Which of the following best describes coupled reactions?
a) A reaction where energy is used up without any output.
b) A reaction where a non-spontaneous reaction is driven by a spontaneous one.
c) A reaction where two reactions occur independently.
d) A reaction that always results in heat production.
The molecule acting as the reducing agent in the following reaction is:
Glucose+ NAD+→ Pyruvate+ NADH
a) Glucose
b) NAD⁺
c) NADH
d) Pyruvate
In redox reactions, oxidation refers to:
a) Gaining electrons
b) Losing electrons
c) Increasing hydrogen atoms
d) Becoming more negatively charged
The Henderson-Hasselbalch equation is used to calculate:
a) The equilibrium constant of redox reactions
b) The solubility of a solute
c) The pH of a buffer solution
d) The standard free energy change
If a buffer solution has a pKa of 6.4 and the ratio of conjugate base to acid is 10:1, the pH is:
a) 5.4
b) 6.4
c) 7.4
d) 8.4
Which of the following functional groups is acidic and donates protons in solution?
a) Amine (-NH₂)
b) Carboxyl (-COOH)
c) Hydroxyl (-OH)
d) Sulfhydryl (-SH)
Which of the following is NOT a macromolecule?
a) Proteins
b) Nucleic acids
c) Lipids
d) Cholesterol
The cell wall is found in:
a) All eukaryotic cells
b) All prokaryotic cells
c) Plant cells and some prokaryotes
d) Animal cells only
Which of the following is present in both prokaryotic and eukaryotic cells?
a) Mitochondria
b) Endoplasmic reticulum
c) Ribosomes
d) Nucleus
Which of the following statements about hydrogen bonding is FALSE?
a) It is responsible for water’s unique properties.
b) It occurs between a hydrogen atom and an electronegative atom (O, N, F).
c) It is stronger than covalent bonding.
d) It helps stabilize biomolecules like proteins and DNA.
What type of interaction helps proteins fold by bringing nonpolar side chains together?
a) Hydrogen bonds
b) Hydrophobic interactions
c) Hydrophilic interactions
d) Disulfide bonds
Which weak interaction is responsible for stabilizing α-helices and β-sheets in proteins?
a) Ionic interactions
b) Hydrogen bonds
c) Hydrophobic effects
d) Van der Waals forces
What makes water an excellent solvent for biological molecules?
a) It has high density as a solid.
b) It forms hydrogen bonds with polar molecules.
c) It has a low heat capacity.
d) It reacts with most biomolecules.
At room temperature, which fatty acid is solid?
unsaturated fatty acid
saturated fatty acid
Which of the following best describes Van der Waals interactions?
a) A strong, permanent bond between atoms
b) Weak attractions due to transient dipoles
c) An interaction between charged molecules
d) A type of covalent bond
Which solvent would be the best to dissolve this peptide?
Cys-Thr-Ile-Gln-Asn-Cys-Pro-Leu-Gly
a) water
b) hexane
c) cyclohexanol
d) benzene
Ceviche is a dish in which raw fish is marinated with lime juice. Lime juice contains citric acid, which has a pKa of 6.41.
What would be the ratio of citrate:citric acid if the pH of the dish is 5.5?
a) –0.91
b) 0.12
d) 1.57
e) 3.14
A buffer system consists of:
a) A strong acid and a strong base
b) A weak acid and its conjugate base
c) A weak base and a strong acid
d) A strong acid and a strong base
Which of the following statements about pKa and pH is correct?
a) When pH < pKa, the weak acid is predominantly in its protonated form.
b) When pH > pKa, the weak acid is mostly undissociated
c) A high pKa value indicates a strong acid.
d) A low pKa value means the acid is weaker.
A weak acid with a pKa of 5.0 will be predominantly in its conjugate base form at what pH?
a) pH = 3.0
b) pH = 4.5
c) pH = 5.0
d) pH = 6.5
A buffer solution contains 0.2 M of a weak acid (HA) and 0.1 M of its conjugate base (A⁻). What will be the pH if the pKa of the weak acid is 5.0?
a) 4.7
b) 5.0
c) 5.3
d) 6.0
