BIO 225 EXAMS 1 EXAMINERS SET QUESTIONS AND
ANSWERS SURE A+
✔✔types of feedback w/ descriptions - ✔✔negative: response opposes the stimulus
positive: response amplifies the stimulus to a fixed endpoint
feed-forward (anticipatory): triggers a change before the stimulus occurs, can be
conscious or subconscious
✔✔primary functions of
nucleus
cytoplasm
ER
ribosomes
mitochondria
plasma membrane - ✔✔nucleus: DNA --> transcription
cytoplasm: facilitates metabolic processes
ER: protein synthesis, transport, signaling
ribosomes: translation
mitochondria: cellular energy --> ATP
membrane: maintain composition and intra and extracellular fluids, regulates traffic in
and out, detects messengers at cell surface, links cells
,✔✔types of membrane proteins - ✔✔channel proteins
peripheral proteins: interact with membrane surface or integral proteins
integral proteins: involved in structural support, signaling, and transport
glycoproteins: have sugar chains attached
✔✔relationship between molecular properties and membrane permeability -
✔✔hydrophobic and small-uncharged pass through easily
large, ions, charged, and hydrophilic don't pass through
✔✔describe simple diffusion - ✔✔type of passive diffusion
depends on a concentration gradient
random dispersing process
molecules move both ways
movement due to intrinsic kinetic motion
✔✔factors that determine the rate of passive diffusion - ✔✔permeability
concentration gradient
temperature
surface area
size of molecule
distance (thickness of membrane)
✔✔key features of osmosis - ✔✔passive movement of water
direction of movement is determined by osmolarity
✔✔what is osmolarity
hyperosmotic
hypoosmotic
isosmotic - ✔✔the total concentration of solutes in a solution
depends on total number of molecules, not individual type
hyperosmotic: higher osmolarity, net water moves in
hypoosmotic: lower osmolarity, net water moves out
isosmotic: same osmolarity, water moves both ways
✔✔what is hydrostatic pressure - ✔✔pressure exerted by a fluid due to gravity or a
pump, directly proportional to the depth of fluid
✔✔facilitated diffusion
types of molecules
, gradients involved - ✔✔transmembrane proteins facilitate diffusion of some
polar/charged molecules across the membrane, down their gradients (concentration or
electrochemical)
use transporter proteins-bind substrate, conformational change, release
slow but highly specific
✔✔types of transporter proteins - ✔✔uniporter
symporter/cotransporter
antiporter/exchanger
✔✔types of gated channels, stimulus, function, importance - ✔✔ligand gated channels:
a single molecule binds to the receptor/channel regulating the opening and closing
voltage gated channels: regulated by the electrical state of the membrane, occurs due
to flow of charged ions
mechanically gated channels: regulated by physical change (pressure on touch
receptors)
✔✔primary active transport
energy and concentration gradient - ✔✔movement against electrochemical gradient
uses transporter proteins
uses energy directly- changing of ATP to ADP+P causes a conformational change in the
transporter
✔✔mechanism of the Ca 2+ pump - ✔✔Ca2+ binds to sights on the transporter
ATP hydrolyzes to ADP+P
transporter flips its shape
Ca2+ is released on other side
✔✔Na/K pump - ✔✔exports 3 Na+ and imports 2 K+ per cycle
contributes to a steep gradient of Na+ and K+ ions
important for electrochemical impulses, osmotic flow, regulating energy required at rest,
provides energy for secondary active transport
✔✔secondary active transport - ✔✔indirect energy input
depends on gradient established in primary active transport
energy needed for "uphill" movement of one substance obtained from "downhill"
movement of another
✔✔coupled transport - ✔✔antiporter or symporter
ANSWERS SURE A+
✔✔types of feedback w/ descriptions - ✔✔negative: response opposes the stimulus
positive: response amplifies the stimulus to a fixed endpoint
feed-forward (anticipatory): triggers a change before the stimulus occurs, can be
conscious or subconscious
✔✔primary functions of
nucleus
cytoplasm
ER
ribosomes
mitochondria
plasma membrane - ✔✔nucleus: DNA --> transcription
cytoplasm: facilitates metabolic processes
ER: protein synthesis, transport, signaling
ribosomes: translation
mitochondria: cellular energy --> ATP
membrane: maintain composition and intra and extracellular fluids, regulates traffic in
and out, detects messengers at cell surface, links cells
,✔✔types of membrane proteins - ✔✔channel proteins
peripheral proteins: interact with membrane surface or integral proteins
integral proteins: involved in structural support, signaling, and transport
glycoproteins: have sugar chains attached
✔✔relationship between molecular properties and membrane permeability -
✔✔hydrophobic and small-uncharged pass through easily
large, ions, charged, and hydrophilic don't pass through
✔✔describe simple diffusion - ✔✔type of passive diffusion
depends on a concentration gradient
random dispersing process
molecules move both ways
movement due to intrinsic kinetic motion
✔✔factors that determine the rate of passive diffusion - ✔✔permeability
concentration gradient
temperature
surface area
size of molecule
distance (thickness of membrane)
✔✔key features of osmosis - ✔✔passive movement of water
direction of movement is determined by osmolarity
✔✔what is osmolarity
hyperosmotic
hypoosmotic
isosmotic - ✔✔the total concentration of solutes in a solution
depends on total number of molecules, not individual type
hyperosmotic: higher osmolarity, net water moves in
hypoosmotic: lower osmolarity, net water moves out
isosmotic: same osmolarity, water moves both ways
✔✔what is hydrostatic pressure - ✔✔pressure exerted by a fluid due to gravity or a
pump, directly proportional to the depth of fluid
✔✔facilitated diffusion
types of molecules
, gradients involved - ✔✔transmembrane proteins facilitate diffusion of some
polar/charged molecules across the membrane, down their gradients (concentration or
electrochemical)
use transporter proteins-bind substrate, conformational change, release
slow but highly specific
✔✔types of transporter proteins - ✔✔uniporter
symporter/cotransporter
antiporter/exchanger
✔✔types of gated channels, stimulus, function, importance - ✔✔ligand gated channels:
a single molecule binds to the receptor/channel regulating the opening and closing
voltage gated channels: regulated by the electrical state of the membrane, occurs due
to flow of charged ions
mechanically gated channels: regulated by physical change (pressure on touch
receptors)
✔✔primary active transport
energy and concentration gradient - ✔✔movement against electrochemical gradient
uses transporter proteins
uses energy directly- changing of ATP to ADP+P causes a conformational change in the
transporter
✔✔mechanism of the Ca 2+ pump - ✔✔Ca2+ binds to sights on the transporter
ATP hydrolyzes to ADP+P
transporter flips its shape
Ca2+ is released on other side
✔✔Na/K pump - ✔✔exports 3 Na+ and imports 2 K+ per cycle
contributes to a steep gradient of Na+ and K+ ions
important for electrochemical impulses, osmotic flow, regulating energy required at rest,
provides energy for secondary active transport
✔✔secondary active transport - ✔✔indirect energy input
depends on gradient established in primary active transport
energy needed for "uphill" movement of one substance obtained from "downhill"
movement of another
✔✔coupled transport - ✔✔antiporter or symporter
