Biology 121 - Unit 2 Exam UPDATED
ACTUAL Exam Questions and CORRECT
Answers
Selectively Permeable - CORRECT ANSWER - membrane allows the passage of some
materials but not others
Phospholipid Bilayer - CORRECT ANSWER - made up by the hydrophobic/philic "tails"
and "heads"
Functions of Membrane Proteins - CORRECT ANSWER - transport
enzymes
receptors
recognition
adhesion
attachment to the cytoskeleton
Diffusion - CORRECT ANSWER - the net movement of particles from an area of higher
concentration to an area of lower concentration
What can diffuse past cell membranes? - CORRECT ANSWER - gases
small nonpolar molecules (alcohol)
water
Osmosis - CORRECT ANSWER - the diffusion of water across a selectively permeable
membrane
Isotonic to cells - CORRECT ANSWER - 0.9% NaCl
no net movement of water
, Hypertonic to cells - CORRECT ANSWER - 10% NaCl
water leaves the cell
Crenation - CORRECT ANSWER - shriveling of RBCs in a hypertonic solution
Hemolysis - CORRECT ANSWER - bursting of RBCs in a hypotonic solution
Plasmolysis - CORRECT ANSWER - shriveling of a plant cell in a hypertonic solution;
central vacuole loses water
Turgid - CORRECT ANSWER - when central vacuole is full of water
Carrier (protein-mediated) Transport - CORRECT ANSWER - transport proteins in the
cell membrane move materials across it
Facilitated Diffusion - CORRECT ANSWER - solutes diffuse along a concentration
gradient (higher to lower); no energy required (i.e. ions, small polar molecules like glucose)
Active Transport - CORRECT ANSWER - solutes are pumped against a concentration
gradient (lower to higher); energy (ATP) is required (i.e. sodium-potasium pump)
Endocytosis - CORRECT ANSWER - a small part of the cell membrane sinks inwards and
pinches off as a vesicle in the cytoplasm
Pinocytosis - CORRECT ANSWER - cell engulfs dissolved or suspended molecules
Phagocytosis - CORRECT ANSWER - cell engulfs a large, solid particle (i.e. cells or
organic debris); occurs in amoebas or white blood cells
ACTUAL Exam Questions and CORRECT
Answers
Selectively Permeable - CORRECT ANSWER - membrane allows the passage of some
materials but not others
Phospholipid Bilayer - CORRECT ANSWER - made up by the hydrophobic/philic "tails"
and "heads"
Functions of Membrane Proteins - CORRECT ANSWER - transport
enzymes
receptors
recognition
adhesion
attachment to the cytoskeleton
Diffusion - CORRECT ANSWER - the net movement of particles from an area of higher
concentration to an area of lower concentration
What can diffuse past cell membranes? - CORRECT ANSWER - gases
small nonpolar molecules (alcohol)
water
Osmosis - CORRECT ANSWER - the diffusion of water across a selectively permeable
membrane
Isotonic to cells - CORRECT ANSWER - 0.9% NaCl
no net movement of water
, Hypertonic to cells - CORRECT ANSWER - 10% NaCl
water leaves the cell
Crenation - CORRECT ANSWER - shriveling of RBCs in a hypertonic solution
Hemolysis - CORRECT ANSWER - bursting of RBCs in a hypotonic solution
Plasmolysis - CORRECT ANSWER - shriveling of a plant cell in a hypertonic solution;
central vacuole loses water
Turgid - CORRECT ANSWER - when central vacuole is full of water
Carrier (protein-mediated) Transport - CORRECT ANSWER - transport proteins in the
cell membrane move materials across it
Facilitated Diffusion - CORRECT ANSWER - solutes diffuse along a concentration
gradient (higher to lower); no energy required (i.e. ions, small polar molecules like glucose)
Active Transport - CORRECT ANSWER - solutes are pumped against a concentration
gradient (lower to higher); energy (ATP) is required (i.e. sodium-potasium pump)
Endocytosis - CORRECT ANSWER - a small part of the cell membrane sinks inwards and
pinches off as a vesicle in the cytoplasm
Pinocytosis - CORRECT ANSWER - cell engulfs dissolved or suspended molecules
Phagocytosis - CORRECT ANSWER - cell engulfs a large, solid particle (i.e. cells or
organic debris); occurs in amoebas or white blood cells
