Bios 251 - Week 3 & 4 / Exam 2 Review Questions
and Answers
What is the purpose of the Cytoskeleton? - -It provides structural support for the cell, aides
in cell motility (Movement) and moves organelles.
-What are cells composed of? - -They are composed of a plasma (Cell Membrane),
cytoplasm, cytosol, nucleus, and cytoskeleton.
-Cytosol - -Clear gel within the cell sometimes referred to as Intracellular Fluid (ICF).
-Cytoplasm - -ALL FLUID and COMPONENTS between the nucleus and cell membrane
(Includes the cytosol and cytoskeleton).
-What molecules are embedded in the phospholipid bilayer? - -Transmembrane proteins,
peripheral proteins, cholesterol, and sugars (glycolipids and glycoproteins).
-Plasma membrane proteins? - -Membrane channel proteins, Glycoproteins, Enzymes,
CAMs, Receptor proteins, and Second-messenger system.
-What is the function of a receptor? - -Binds to chemical messengers such as hormones
sent by other cells.
-What is the function of an enzyme? - -Breaks down a chemical messenger and terminates
its effects.
-What is the function of a channel? - -Allows solutes to pass into and out of the cell. Always
open.
-What is the function of a gated channel? - -Opens and closes to allow solutes only at a
certain time
-What is the function of a Cell identity marker (Glycoprotein)? - -Distinguishes the body's
own cells from foreign cells.
-What is the function of a Cell Adhesion Molecule (CAMs)? - -Binds one cell to another
-What is passive transport? - -The movement of materials across the cell membrane
without using energy (ATP). Occurs from high to low concentration.
-What is simple diffusion? - -Molecules move from high to low concentration, with or
without a membrane, and with or without channel proteins.
, -What is facilitated diffusion? - -Polar molecules move through a channel protein, from a
high to low concentration.
-What is osmosis? - -WATER MOLECULES move directly through a membrane or through
special proteins called Aquaporins. High to low concentration.
-What is hypertonicity? - -Solutions have high ECF osmolarity. Water moves out of the cell,
causing the cell to shrink.
-What is Isotonicity? - -Solutions have the same osmolarity, no movement into or out of
the cell.
-What is Hypotonicity? - -Solutions have low ECF osmolarity. Water moves into the cell,
causing swelling and potential bursting.
-What is active transport? - -Utilizes energy to move substance against the concentration
gradient, lower to higher concentration.
Depends on a few factors: ATP, membrane proteins, concentration of molecules, and
membrane potentials.
-What is bulk transport? - -The movement of large molecules by way of vesicles.
-What is endocytosis? - -Transports materials into the cell
-What is phagocytosis & pinocytosis? - -phagocytosis brings in solids (cell eating) and
pinocytosis brings in liquids (cell drinking).
-What is exocytosis? - -The transportation of materials out of the cell.
-What is intracellular and extracellular fluid? - -Intra - Known as cytosol, more gel like
than ECF
Extra - Sometimes called "tissue fluid", includes plasma.
-What is voltage? - -Any difference in electrical charge (+) or (-).
The uneven distribution of ions across the membrane is controlled by protein pumps and
leak channels. Resulting in more (+) ions outside, and more (-) ions inside the cell.
-What is the resting membrane potential value? - -RMP = -70mV
-sodium-potassium pump - -Moves 3 sodium ions out & 2 potassium ions into the cell.
Creates a (-) charge in the cell.
Muscle and nervous system rely on it.
-Explain Depolarization and Repolarization - -Depolar - Na+ channels open and Na+ enters
cell making it more positive.
and Answers
What is the purpose of the Cytoskeleton? - -It provides structural support for the cell, aides
in cell motility (Movement) and moves organelles.
-What are cells composed of? - -They are composed of a plasma (Cell Membrane),
cytoplasm, cytosol, nucleus, and cytoskeleton.
-Cytosol - -Clear gel within the cell sometimes referred to as Intracellular Fluid (ICF).
-Cytoplasm - -ALL FLUID and COMPONENTS between the nucleus and cell membrane
(Includes the cytosol and cytoskeleton).
-What molecules are embedded in the phospholipid bilayer? - -Transmembrane proteins,
peripheral proteins, cholesterol, and sugars (glycolipids and glycoproteins).
-Plasma membrane proteins? - -Membrane channel proteins, Glycoproteins, Enzymes,
CAMs, Receptor proteins, and Second-messenger system.
-What is the function of a receptor? - -Binds to chemical messengers such as hormones
sent by other cells.
-What is the function of an enzyme? - -Breaks down a chemical messenger and terminates
its effects.
-What is the function of a channel? - -Allows solutes to pass into and out of the cell. Always
open.
-What is the function of a gated channel? - -Opens and closes to allow solutes only at a
certain time
-What is the function of a Cell identity marker (Glycoprotein)? - -Distinguishes the body's
own cells from foreign cells.
-What is the function of a Cell Adhesion Molecule (CAMs)? - -Binds one cell to another
-What is passive transport? - -The movement of materials across the cell membrane
without using energy (ATP). Occurs from high to low concentration.
-What is simple diffusion? - -Molecules move from high to low concentration, with or
without a membrane, and with or without channel proteins.
, -What is facilitated diffusion? - -Polar molecules move through a channel protein, from a
high to low concentration.
-What is osmosis? - -WATER MOLECULES move directly through a membrane or through
special proteins called Aquaporins. High to low concentration.
-What is hypertonicity? - -Solutions have high ECF osmolarity. Water moves out of the cell,
causing the cell to shrink.
-What is Isotonicity? - -Solutions have the same osmolarity, no movement into or out of
the cell.
-What is Hypotonicity? - -Solutions have low ECF osmolarity. Water moves into the cell,
causing swelling and potential bursting.
-What is active transport? - -Utilizes energy to move substance against the concentration
gradient, lower to higher concentration.
Depends on a few factors: ATP, membrane proteins, concentration of molecules, and
membrane potentials.
-What is bulk transport? - -The movement of large molecules by way of vesicles.
-What is endocytosis? - -Transports materials into the cell
-What is phagocytosis & pinocytosis? - -phagocytosis brings in solids (cell eating) and
pinocytosis brings in liquids (cell drinking).
-What is exocytosis? - -The transportation of materials out of the cell.
-What is intracellular and extracellular fluid? - -Intra - Known as cytosol, more gel like
than ECF
Extra - Sometimes called "tissue fluid", includes plasma.
-What is voltage? - -Any difference in electrical charge (+) or (-).
The uneven distribution of ions across the membrane is controlled by protein pumps and
leak channels. Resulting in more (+) ions outside, and more (-) ions inside the cell.
-What is the resting membrane potential value? - -RMP = -70mV
-sodium-potassium pump - -Moves 3 sodium ions out & 2 potassium ions into the cell.
Creates a (-) charge in the cell.
Muscle and nervous system rely on it.
-Explain Depolarization and Repolarization - -Depolar - Na+ channels open and Na+ enters
cell making it more positive.
