BIOL 1201 EXAM 2 QUESTIONS AND
ANSWERS 2026 VERIFIED.
What is the hydrophilic head of a phospholipid? - ANS Polar, interacts with water
What are the hydrophobic tails of a phospholipid? - ANS Nonpolar, avoid water
What do phospholipids form in water? - ANS Bilayer with heads outward, tails inward
What do integral proteins do? - ANS Span the membrane
What are peripheral proteins? - ANS Attached to the membrane surface
What are the functions of membrane proteins? - ANS Transport, enzymatic activity, signal
transduction, cell-cell recognition, intercellular joining, attachment
What role do membrane carbohydrates play? - ANS Involved in cell-cell recognition
What is the fluid mosaic model? - ANS Membrane is flexible with proteins embedded
How do hydrophobic molecules cross the membrane? - ANS Easily
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, What do hydrophilic molecules/ions need to cross the membrane? - ANS Transport proteins
Why can't ions/polar molecules cross the membrane efficiently? - ANS Due to charge
What is the order of crossing rates for molecules? - ANS Small nonpolar > small polar > large
polar > ions
What do channel proteins provide? - ANS Hydrophilic tunnel
What do carrier proteins do? - ANS Change shape to move molecules
What is diffusion? - ANS Movement from high to low concentration
What is osmosis? - ANS Diffusion of water
What is facilitated diffusion? - ANS Passive transport using proteins
What is a concentration gradient? - ANS Difference in concentration (stores potential energy)
What happens in a hypertonic solution? - ANS Cell loses water
What happens in a hypotonic solution? - ANS Cell gains water
What is an isotonic solution? - ANS No net movement
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ANSWERS 2026 VERIFIED.
What is the hydrophilic head of a phospholipid? - ANS Polar, interacts with water
What are the hydrophobic tails of a phospholipid? - ANS Nonpolar, avoid water
What do phospholipids form in water? - ANS Bilayer with heads outward, tails inward
What do integral proteins do? - ANS Span the membrane
What are peripheral proteins? - ANS Attached to the membrane surface
What are the functions of membrane proteins? - ANS Transport, enzymatic activity, signal
transduction, cell-cell recognition, intercellular joining, attachment
What role do membrane carbohydrates play? - ANS Involved in cell-cell recognition
What is the fluid mosaic model? - ANS Membrane is flexible with proteins embedded
How do hydrophobic molecules cross the membrane? - ANS Easily
@COPYRIGHT ALL RIGHTS RESERVED PAGE 1 OF 12
, What do hydrophilic molecules/ions need to cross the membrane? - ANS Transport proteins
Why can't ions/polar molecules cross the membrane efficiently? - ANS Due to charge
What is the order of crossing rates for molecules? - ANS Small nonpolar > small polar > large
polar > ions
What do channel proteins provide? - ANS Hydrophilic tunnel
What do carrier proteins do? - ANS Change shape to move molecules
What is diffusion? - ANS Movement from high to low concentration
What is osmosis? - ANS Diffusion of water
What is facilitated diffusion? - ANS Passive transport using proteins
What is a concentration gradient? - ANS Difference in concentration (stores potential energy)
What happens in a hypertonic solution? - ANS Cell loses water
What happens in a hypotonic solution? - ANS Cell gains water
What is an isotonic solution? - ANS No net movement
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 12
