BIO 1201 GREGG EXAM 2 2026 MOLECULAR BIOLOGY DRILL PACK ANSWER SHEET

BIO 1201 GREGG EXAM 2 2026
INTRODUCTORY BIOLOGY ASSESSMENT
QUESTIONS SOLUTIONS GRADED A+

◉ fluid mosaic model.
Answer: The membrane is a mosaic of protein molecules bobbing in
a fluid bilayer of phospholipids


◉ fatty acid tails.
Answer: nonpolar, hydrophobic


◉ fatty acid heads.
Answer: hydrophilic, polar


◉ periphial proteins.
Answer: bound to the surface of the membrane


◉ integral proteins.
Answer: penetrate the hydrophobic core (ones that span the
membrane are transmembrane protiens


◉ How do cells recognize each other?.

,Answer: by binding to molecules, often containing carbohydrates, on
the extracellular surface of the plasma membrane


◉ Glycolipids.
Answer: Membrane carbohydrates that are covalently bonded to
lipids.


◉ Hypdrophobic.
Answer: molecules such as hydrocarbons that can dissolve in the
lipid bilayer and pass through the membrane rapidly


◉ Hydrophilic.
Answer: molecules that don't cross the membrane easily (ions and
polar molecules)


◉ transport proteins.
Answer: allow passage of hydrophilic substances across the
membrane


◉ carrier proteins.
Answer: bind to molecules and change shape to shuttle them across
the membrane

, ◉ passive transport.
Answer: the diffusion of a substance across a membrane with no
energy investment


◉ Diffusuion.
Answer: Spreading out of particles away from each other, from an
area of high concentration to an area of low concentration. (move to
where space is available)


◉ concentation gradient.
Answer: substances diffuse from high concentration----> low
concentration


◉ Osmosis.
Answer: Diffusion of water through a selectively permeable
membrane


◉ Isotonic.
Answer: when the concentration of two solutions is the same (no net
movement)


◉ Hypertonic.
Answer: cell losses water and shrivils