ANATOMY & PHYSIOLOGY BIO 168
CHAPTER 3 QUESTIONS &
ANSWERS(RATED A+)
Cytology - ANSWERscientific study of cells
Cell theory - ANSWER1) All living things made of cells
Human cell size - ANSWER10-15um in diamete
Plasma Cell - ANSWERSurrounds cell, defines boundaries
Made of proteins and lipids
Cytoplasm - ANSWERConsists of organelles, cytoskeleton, and cytosol
Extracellular fluid (ECF - ANSWERThe fluid outside the body's cells
includes tissue
Limit on cell size - ANSWERan overly large cell cannot support itself, may rupture
For a given increase in diameter, volume increases more than surface area
Light microscope (LM) - ANSWERrevealed plasma membrane, nucleus, and
cytoplasm (fluid between nucleus and surface)
Transmission electron microscope (TEM) - ANSWERimproved resolution (ability to
reveal detail)
Scanning electron microscope (SEM) - ANSWERimproved resolution further, but
only for surface features
Basic components of a cell - ANSWERPlasma, Cytoplasm, Extracellular fluid
Plasma membrane - ANSWERBoundary of cell. Holds things together and controls
entry and exit of substances.
98% of membrane molecules are - ANSWERlipids
Phospholipids - ANSWERA molecule that is a constituent of the inner bilayer of
biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic
tail.
Cholesterol - ANSWER20% of the membrane lipids
Holds phospholipids still and can stiffen membrane
, Enzymes - ANSWERcatalyze reactions including digestion of molecules, production
of second messengers
Channel proteins - ANSWERallow hydrophilic solutes and water to pass through
membrane
some are always open, some are gated
Ligand-gated channels - ANSWERrespond to chemical messengers
Voltage-gated channels - ANSWERrespond to charge changes
Glycolipids - ANSWERAre complexes of carbohydrates and lipids
5% of the membrane lipids
Membrane proteins - ANSWER2% of the molecules but 50% of the weight of
membrane
Integral proteins - ANSWERpenetrate the hydrophobic core of the lipid bilayer, often
completely spanning the membrane (as transmembrane proteins).
Peripheral proteins - ANSWERAre proteins that are attached to the surface of the
membrane.
does not penetrate
tethered to the cytoskeleton
Functions of membrane proteins include: - ANSWERReceptors, second-messenger
systems, enzymes, channels, carriers, cell-identity markers, cell-adhesion molecules
Receptors - ANSWERbind chemical signals
Second messenger systems - ANSWERcommunicate within cell receiving chemical
message
Mechanically-gated channels - ANSWERrespond to physical stress on cell
Carriers - ANSWERbind solutes and transfer them across membrane
Cell-identity markers - ANSWERglycoproteins acting as identification tags
Cell-adhesion molecules - ANSWERmechanically link cell to extracellular material
Chemical first messenger - ANSWER(epinephrine) binds to a surface recepto
G protein - ANSWERrelays signal to adenylate cyclase which converts ATP to cAMP
(second messenger)
cAMP activates cytoplasmic kinases
Kinases - ANSWERAdd a phosphate group to a molecule
CHAPTER 3 QUESTIONS &
ANSWERS(RATED A+)
Cytology - ANSWERscientific study of cells
Cell theory - ANSWER1) All living things made of cells
Human cell size - ANSWER10-15um in diamete
Plasma Cell - ANSWERSurrounds cell, defines boundaries
Made of proteins and lipids
Cytoplasm - ANSWERConsists of organelles, cytoskeleton, and cytosol
Extracellular fluid (ECF - ANSWERThe fluid outside the body's cells
includes tissue
Limit on cell size - ANSWERan overly large cell cannot support itself, may rupture
For a given increase in diameter, volume increases more than surface area
Light microscope (LM) - ANSWERrevealed plasma membrane, nucleus, and
cytoplasm (fluid between nucleus and surface)
Transmission electron microscope (TEM) - ANSWERimproved resolution (ability to
reveal detail)
Scanning electron microscope (SEM) - ANSWERimproved resolution further, but
only for surface features
Basic components of a cell - ANSWERPlasma, Cytoplasm, Extracellular fluid
Plasma membrane - ANSWERBoundary of cell. Holds things together and controls
entry and exit of substances.
98% of membrane molecules are - ANSWERlipids
Phospholipids - ANSWERA molecule that is a constituent of the inner bilayer of
biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic
tail.
Cholesterol - ANSWER20% of the membrane lipids
Holds phospholipids still and can stiffen membrane
, Enzymes - ANSWERcatalyze reactions including digestion of molecules, production
of second messengers
Channel proteins - ANSWERallow hydrophilic solutes and water to pass through
membrane
some are always open, some are gated
Ligand-gated channels - ANSWERrespond to chemical messengers
Voltage-gated channels - ANSWERrespond to charge changes
Glycolipids - ANSWERAre complexes of carbohydrates and lipids
5% of the membrane lipids
Membrane proteins - ANSWER2% of the molecules but 50% of the weight of
membrane
Integral proteins - ANSWERpenetrate the hydrophobic core of the lipid bilayer, often
completely spanning the membrane (as transmembrane proteins).
Peripheral proteins - ANSWERAre proteins that are attached to the surface of the
membrane.
does not penetrate
tethered to the cytoskeleton
Functions of membrane proteins include: - ANSWERReceptors, second-messenger
systems, enzymes, channels, carriers, cell-identity markers, cell-adhesion molecules
Receptors - ANSWERbind chemical signals
Second messenger systems - ANSWERcommunicate within cell receiving chemical
message
Mechanically-gated channels - ANSWERrespond to physical stress on cell
Carriers - ANSWERbind solutes and transfer them across membrane
Cell-identity markers - ANSWERglycoproteins acting as identification tags
Cell-adhesion molecules - ANSWERmechanically link cell to extracellular material
Chemical first messenger - ANSWER(epinephrine) binds to a surface recepto
G protein - ANSWERrelays signal to adenylate cyclase which converts ATP to cAMP
(second messenger)
cAMP activates cytoplasmic kinases
Kinases - ANSWERAdd a phosphate group to a molecule
