BIO 156 CORRECT EXAM QUESTIONS AND
ANSWERS SET A+
✔✔Distinguish between microfilaments and microtubules. - ✔✔microfilament: fibers that
consist primarily of subunits of a protein called actin
microtubule: long, hollow cylinders that consist of subunits of the protein tubulin.
✔✔Describe the structure and function of cell walls. - ✔✔Protects, structurally supports
cell
✔✔Describe the structure and function of cell junctions. - ✔✔structures that connect a
cell directly to other cells or to its environment. Cells send and receive substances and
signals through some junctions.
✔✔Describe the essential structure and function of the cell membrane. - ✔✔All cell
membranes, including the plasma membrane and organelle membranes, consist mainly
of phospholipids organized as a lipid bilayer.
organized as a lipid bilayer with many proteins embedded in it and attached to its
surfaces.
✔✔Describe the function of the cell membrane. - ✔✔proteins embedded in or attached
to a lipid bilayer add specific functions to each cell membrane.
✔✔Define the term diffusion. Explain what causes diffusion and why it is a spontaneous
event. - ✔✔Diffusion is the spontaneous spreading of molecules or ions, and it is an
essential way in which substances move into, through, and out of cells.
✔✔Distinguish between passive transport and active transport. - ✔✔passive transport:
Membrane-crossing mechanism that requires no energy input.
active transport: Energy-requiring mechanism in which a transport protein pumps a
solute across a cell membrane against the solute's concentration gradient.
, ✔✔Explain what is meant by a concentration gradient, and why molecules passively
move down concentration gradients. - ✔✔A difference in solute concentration between
adjacent regions of solution is called a concentration gradient. Solutes tend to diffuse
"down" their concentration gradient, from a region of higher concentration to one of
lower concentration
✔✔Define the term osmosis and be able to predict the direction of water movement
based upon differences in solute concentration. - ✔✔The movement of water across
membranes
water will move across the membrane from the hypotonic fluid into the hyper- tonic one
✔✔Define the terms: isotonic, hypotonic and hypertonic. - ✔✔isotonic: the same overall
solute concentration. I
hypotonic: the fluid with the lower concentration of solutes
hypertonic: with the higher solute concentration
✔✔Sketch and describe the concept of facilitated diffusion. - ✔✔Passive transport
mechanism in which a solute follows its concentration gradient across a membrane by
moving through a transport protein.
✔✔Distinguish between exocytosis and endocytosis. - ✔✔endocytosis: Process by
which a cell takes in a small amount of extracellular fluid (and its contents) by the
ballooning inward of the plasma membrane.
exocytosis: Process by which a cell expels a vesicle's contents to extracellular fluid.
✔✔Describe an amoeba feeding by phagocytosis. - ✔✔a type of receptor-mediated
endocytosis in which motile cells engulf microorganisms, cellular debris, or other large
particles.
✔✔Describe the basic events of glycolysis. - ✔✔a series of reactions beginning with the
breakdown of a glucose molecule to pyruvate. A small amount (two molecules) of ATP
is produced directly at this time. Electrons are carried to the electron transport chain by
NADH, a special coenzyme electron carrier. Glycolysis takes place in the cytoplasm of
the cell.
✔✔Describe the basic events of Krebs Cycle - ✔✔The Krebs cycle, or Citric Acid Cycle,
is the name given to the set of reactions in which pyruvate is broken down by enzymes
to carbon dioxide. Again, a small amount of ATP (two molecules) is made directly during
these events. Once again, electrons are carried to the electron transport chain by
NAD+. Another electron carrier, FAD, is also active here. The Krebs cycle takes place in
the matrix of the mitochondria - the area outside of the cristae.
✔✔aerobic - ✔✔Involving or occurring in the presence of oxygen.
✔✔anaerobic - ✔✔Occurring in the absence of oxygen.
ANSWERS SET A+
✔✔Distinguish between microfilaments and microtubules. - ✔✔microfilament: fibers that
consist primarily of subunits of a protein called actin
microtubule: long, hollow cylinders that consist of subunits of the protein tubulin.
✔✔Describe the structure and function of cell walls. - ✔✔Protects, structurally supports
cell
✔✔Describe the structure and function of cell junctions. - ✔✔structures that connect a
cell directly to other cells or to its environment. Cells send and receive substances and
signals through some junctions.
✔✔Describe the essential structure and function of the cell membrane. - ✔✔All cell
membranes, including the plasma membrane and organelle membranes, consist mainly
of phospholipids organized as a lipid bilayer.
organized as a lipid bilayer with many proteins embedded in it and attached to its
surfaces.
✔✔Describe the function of the cell membrane. - ✔✔proteins embedded in or attached
to a lipid bilayer add specific functions to each cell membrane.
✔✔Define the term diffusion. Explain what causes diffusion and why it is a spontaneous
event. - ✔✔Diffusion is the spontaneous spreading of molecules or ions, and it is an
essential way in which substances move into, through, and out of cells.
✔✔Distinguish between passive transport and active transport. - ✔✔passive transport:
Membrane-crossing mechanism that requires no energy input.
active transport: Energy-requiring mechanism in which a transport protein pumps a
solute across a cell membrane against the solute's concentration gradient.
, ✔✔Explain what is meant by a concentration gradient, and why molecules passively
move down concentration gradients. - ✔✔A difference in solute concentration between
adjacent regions of solution is called a concentration gradient. Solutes tend to diffuse
"down" their concentration gradient, from a region of higher concentration to one of
lower concentration
✔✔Define the term osmosis and be able to predict the direction of water movement
based upon differences in solute concentration. - ✔✔The movement of water across
membranes
water will move across the membrane from the hypotonic fluid into the hyper- tonic one
✔✔Define the terms: isotonic, hypotonic and hypertonic. - ✔✔isotonic: the same overall
solute concentration. I
hypotonic: the fluid with the lower concentration of solutes
hypertonic: with the higher solute concentration
✔✔Sketch and describe the concept of facilitated diffusion. - ✔✔Passive transport
mechanism in which a solute follows its concentration gradient across a membrane by
moving through a transport protein.
✔✔Distinguish between exocytosis and endocytosis. - ✔✔endocytosis: Process by
which a cell takes in a small amount of extracellular fluid (and its contents) by the
ballooning inward of the plasma membrane.
exocytosis: Process by which a cell expels a vesicle's contents to extracellular fluid.
✔✔Describe an amoeba feeding by phagocytosis. - ✔✔a type of receptor-mediated
endocytosis in which motile cells engulf microorganisms, cellular debris, or other large
particles.
✔✔Describe the basic events of glycolysis. - ✔✔a series of reactions beginning with the
breakdown of a glucose molecule to pyruvate. A small amount (two molecules) of ATP
is produced directly at this time. Electrons are carried to the electron transport chain by
NADH, a special coenzyme electron carrier. Glycolysis takes place in the cytoplasm of
the cell.
✔✔Describe the basic events of Krebs Cycle - ✔✔The Krebs cycle, or Citric Acid Cycle,
is the name given to the set of reactions in which pyruvate is broken down by enzymes
to carbon dioxide. Again, a small amount of ATP (two molecules) is made directly during
these events. Once again, electrons are carried to the electron transport chain by
NAD+. Another electron carrier, FAD, is also active here. The Krebs cycle takes place in
the matrix of the mitochondria - the area outside of the cristae.
✔✔aerobic - ✔✔Involving or occurring in the presence of oxygen.
✔✔anaerobic - ✔✔Occurring in the absence of oxygen.
