PRINCIPLES OF BIOCHEMISTRY 7TH
EDITION EXAM STUDY GUIDE 2026
COMPREHENSIVE QUESTIONS AND
SOLUTIONS
◉ RNA world hypothesis
Answer: Suggesting that RNA molecules participate in biologically
significant reactions, serve as an information-carrying molecule, and
catalyze peptide bond formation.
◉ Oxygen-producing bacteria
Answer: Led to the eventual predominance of aerobic organisms on
earth, welcoming oxygen as a preferable choice for metabolic
reactions.
◉ Endosymbiotic association
Answer: Explaining the evolution of eukaryotic cells capable of
carrying out photosynthesis and/or aerobic metabolism through the
engulfing of an aerobic bacterium by a eukaryotic cell.
◉ Cell dimensions
, Answer: Limited on the lower end by the minimum number of
biomolecules necessary for function and on the upper end by the
rate of diffusion of solutes such as oxygen.
◉ Three domains of life
Answer: Archaea, Bacteria, and Eukarya, each with distinct
characteristics.
◉ Membrane lipids in archaea
Answer: Contain ether-linked alkyl acids, while eukaryotic
membrane lipids consist of glycerol ester-linked to three fatty acids.
◉ Fatty acids
Answer: Longer chains have higher melting points and lower
solubility in water, and those with more double bonds have higher
melting points.
◉ Trans fats
Answer: Associated with increased inflammatory response in the
body, raising of LDL cholesterol, and increased risk of heart disease.
◉ Waxes
Answer: Used for energy storage, lubrication, structure, insulation,
and waterproofing.
EDITION EXAM STUDY GUIDE 2026
COMPREHENSIVE QUESTIONS AND
SOLUTIONS
◉ RNA world hypothesis
Answer: Suggesting that RNA molecules participate in biologically
significant reactions, serve as an information-carrying molecule, and
catalyze peptide bond formation.
◉ Oxygen-producing bacteria
Answer: Led to the eventual predominance of aerobic organisms on
earth, welcoming oxygen as a preferable choice for metabolic
reactions.
◉ Endosymbiotic association
Answer: Explaining the evolution of eukaryotic cells capable of
carrying out photosynthesis and/or aerobic metabolism through the
engulfing of an aerobic bacterium by a eukaryotic cell.
◉ Cell dimensions
, Answer: Limited on the lower end by the minimum number of
biomolecules necessary for function and on the upper end by the
rate of diffusion of solutes such as oxygen.
◉ Three domains of life
Answer: Archaea, Bacteria, and Eukarya, each with distinct
characteristics.
◉ Membrane lipids in archaea
Answer: Contain ether-linked alkyl acids, while eukaryotic
membrane lipids consist of glycerol ester-linked to three fatty acids.
◉ Fatty acids
Answer: Longer chains have higher melting points and lower
solubility in water, and those with more double bonds have higher
melting points.
◉ Trans fats
Answer: Associated with increased inflammatory response in the
body, raising of LDL cholesterol, and increased risk of heart disease.
◉ Waxes
Answer: Used for energy storage, lubrication, structure, insulation,
and waterproofing.
