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Chapter One Notes
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based on experimental evidence; explanations as valid as the data on which they are based and
are open to change
a standard technique for investigating the functioning of an organ is to observe what happens
when the organ is surgically removed or when its function is altered in a specific way

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Father of modern physiology - Claude Bernard - observed that the internal environment remains
constant despite changing conditions in the external environment
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integrating center = region of brain or spinal cord, or region of cells in an endocrine gland
a # of diff sensors can send info to a particular integrating center which can then integrate that
information and direct the responses of effectors = muscles or glands
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EX: after the AC has been on for a while, the room temp may fall below set point which causes
the AC to be turned off
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negative feedback - continuous ongoing processes
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The effectiveness of
some negative feedback loops is increased by positive feedback mechanisms that amplify the
actions of a negative feedback response
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when estrogen, secreted by ovaries, stimulates the
pituitary gland to secrete LH there is a positive feedback effect that creates an LH surge which
triggers ovulation
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Another ex: contraction of uterus and oxytocin
Neural and Endocrine Regulation
Homeostasis is maintained by two categories of mechanisms: 1) intrinsic (built into the organs
being regulated) 2) extrinsic (regulation of an organ by nervous or endocrine systems)
regulation by the endocrine system is achieved by secretion of chemical regulators = hormones
into the blood
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These target organs can be muscles or glands that act as effectors
Feedback Control of Hormone Secretion
Hormones are secreted in response to specific chemical stimuli (a rise in glucose concentration
stimulates insulin secretion from structures in pancreas called pancreatic islets or islets of
Langerhan)
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The secretion of a hormone can be inhibited by its own effects in a negative feedback manner
(negative feedback inhibition)
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insulin
Homeostasis of blood glucose --> several mechanisms when glucose starts to fall
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Second, the secretion of a hormone antagonistic to insulin, glucagon, increases stimulates processes in liver (breakdown of glucagon to increase glucose levels)

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Myofibers = syncytium
(multinucleate mass formed from the union of separate cells)
parallel arrangement of muscle fibers = ability to vary of "grade" the strength of muscle
contraction
CARDIAC MUSCLE
found only in heart where myocardial cells are short, branched and intimately interconnected to
form a continuous fabric
special areas of contact b/w adjacent cells stain darkly to show intercalated disks - couple
myocardial cells tog mechanically and electrically - no graded contraction; stimulation of cell
results in stimulation of all other cells
SMOOTH MUSCLE
digestive tract, blood vessels, bronchioles, ducts of urinary and reproductive systems
circular arrangement - produce constriction of lumen(cavity) when contracted
digestive tract also has longitudinally arranged layers
series of wavelike contraction of circular and longitudinal layers of muscle = peristalsis = pushes
food
NERVOUS TISSUE
consists of nerve cells, or neurons(specialized for generation&conduction of electrical events)
and supporting cells(provide functional&anatomical support) called glial cells
neuron - cell body(nucleus, metabolic center), dendrites (highly branched cytoplasmic
extensions that recieve input), axon(single cytoplasmic extension specialized for conducting
nerve impulses from cell body to another neuron or to an effector(muscle/gland) cell
glial cells bind neurons tog, modify extracellular env, influence nourishment and electrical
activity of neurons
EPITHELIAL TISSUE
consist of cells that form membranes which cover and line the body surfaces, and of glands,
which are derived from these membranes
exocrine glands(secrete chemicals to outside of body surface) & endocrine glands (secrete
hormones into blood)
Epithelial membranes classified by # of layers and shape of cells in upper layer
flat shape = squamous ; as wide as they are tall = cuboidal; taller than they are wide = columnar
one cell layer thick = simple membranes ; multiple layers = stratified membranes
membranes cover all body surfaces and line the cavity (lumen) of every hollow organ

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stratified membranes - protection ; simple membranes - transport of substances (lungs, small
intestine examples)
dispersed among columnar cells are specialized unicellular glands called goblet cells that secrete
mucus
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stratified epidermis of skin is keratinized or cornified by
contrast(b/c epidermis is dry and exposed to desiccating effects of air, the surface is covered
with dead cells filled with water resistant protein called keratin)
constant loss and renewal of cells
epithelial cells are closed packed an joined by junctional complexes
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The epithelium recieve nourishment from tissue beneath which
have large intercellular spaces for vessels and nerves - connective tissue
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basement membrane - induce polarity to cells of epithelial membranes
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Substances are transported in
specific directions across simple epithelial membranes
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When they divide one
daughter cell is attached to the basement membrane(renewing basal cell population) while the
other differentiates and migrated upward
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Collagen IV - made up of 6
polypeptide chains coded by 6 different genes
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Secretion of these cells are passed to outside of
epithelial membranes through ducts
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Acini are surrounded by tentacle like extensions of myoepithelial cells that contract and
squeeze secretions through ducts
exocrine glands - lacrimal (tear) glands, sebaceous glands(oil into hair), sweat glands
sweat glands (eccrine(salt solution for cooling) and apocrine glands(protein rich fluid for
nourishing bacteria - smell)
liver and pancreas = exocrine and endocrine glands
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Prominant also in reproductive tract
and digestive tract
CONNECTIVE TISSUE

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extracellular material(connective tissue matrix) b/w different types of connective tissue cells
varies in the four types of connective tissue: (1) connective tissue proper (2) cartilage (3) bone
(4) blood(half its volume is extracellular fluid, plasma)
Connective tissue proper: matrix=protein fibers&gel like ground substance
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Dense, regular connective tissue - collagenous
fibers oriented parallel to each other and densely packed(little room for cells and ground
substance) - tendons, connecting bone to bone, and ligaments, connecting bones tog at joints
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In each adipose cell, or adiposyte,
the cytoplasm surrounds a globule of fat and breaks it down
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Is a type of supportive and protective tissue called gristle
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The bone
forming cells, osteoblasts, surrounded by their calcified products become trapped within
cavities called lacunae -- become osteocytes
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Blood vessels lie within central canals surrounded by concentric rings of
bone lamellae with their trapped osteocytes
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2 Carbohydrates And Lipids
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Carbohydrates are a class of organic molecules that includes monosaccharides, disaccharides,
and polysaccharides -- based on characteristic ratio of carbon, hydrogen, and oxygen atoms
Lipids constitute a category of diverse organic molecules that share the property of being
nonpolar and insoluble in water
CARBOHYDRATES
CnH2nOn : contains twice as many hydrogen atoms than oxygen and carbon atoms
include simple sugars (monosaccharides) and longer molecules than contain a # of
monosaccharides joined together
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A simple formula does not
differentiate between structural isomers which have the same ratio but different structure -->
glucose, fructose
two monosaccharides joined covalently = disaccharide or double sugar --> sucrose, lactose
numerous monosaccharides joined tog = polysaccharide --> starch, glycogen, cellulose, chitin
cells that store carbs for energy minimize osmotic damage by joining glucose molecules together
to form polysaccharides glycogen or starch (b/c fewer of larger molecules less water is drawn in)
In the formation of disaccharides and polysaccharides, the separate subunits(monosaccharides)
are bonded together by a reaction call dehydration synthesis or condensation: (requires the
participation of enzymes) a hydrogen atom is removed from 1 monosaccharide and a hydroxyl

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group is removed from another - a covalent bond is formed between the 2 subunits as water is
produced
Liver and muscles can store excess glucose in the form of glycogen by dehydration synthesis
reactions
digestion reactions(the covalent bonds that join monosaccharides need to be broken) occur by
hydrolysis - when a covalent bond joining 2 monosaccharides is broken, a water molecule
provides the atoms needed to complete their structure
LIPIDS
includes several types of molecules that differ in chemical structure
common property : insoluble in polar solvents i
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Lipids consist of hydrocarbon chains
and rings which are nonpolar&hydrophobic
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condensation of 1 molecule of glycerol(3C alcohol) with 3 molecules of fatty acids
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If the C atoms within the hydrocarbon chain are joined by single covalent bonds=saturated
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Within the adipose cells of the body, triglycerides are formed as the carboxyl ends of fatty acid
molecules condense with the hydroxyl groups of a glycerol molecule - neutral fats
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If bound to nitrogen containing choline molecule = lecithin
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- micelles
The amphipathic nature also allows phospholipids to alter the interaction of water molecules
and thus decrease the surrounding surface tension- surfactants (prevents lungs from collapsing
due to surface tension forces)
Steroids:
nonpolar & insoluble in water
3 6C rings joined to 1 5C ring
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It is also the precursor molecule for bile salts and vitamin D

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The differences b/w the AA are due to differences in their functional
groups (R)
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Since
most of the tertiary structure is stabilized by weak bonds, this structure can easily be denatured
by changes of pH or by high temps
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1 Plasma Membrane and Associated Structures
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Many of the functions of cells are performed by particular subcellular structures known as
organelles
All cells share certain characteristics : all surrounded by a plasma membrane, and most posses
structures in fig 3
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organelles are subcellular structures within cytoplasm
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This barrier itself cannot be water
soluble = composed of lipids
plasma membrane and all membranes surrounding organelles are composed of phospholipids
and proteins - hydrophobic parts of the molecules huddle together in the center of the
membrane leaving polar parts exposed to water on both surfaces -- double layer of
phospholipids in the cell membrane

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hydrophobic middle prevents the passage of water and water soluble molecules and ions
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Membrane proteins are either peripheral or integral
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phospholipids and proteins are free to move laterally & proteins are not uniformly distributed constantly changing mosaic pattern - fluid mosaic model
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In addition to lipids and proteins, the membrane contains carbs attached to outer surface as
glycoproteins and glycolipids
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Phagocytosis
bulk transport of larger portion of the extracellular environment
white blood cells(neutrophils) and connective tissue cells (macrophages) perform amoeboid
movement - extending parts of cytoplasm to form pseudopods to move thru extracellular matrix
(depends on bonding of proteins called integrins(on plasma membrane) with proteins of matrix
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surround victim with pseudopods which join together and fuse, then pinches off and is now in a
food vacuole
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This is an imp immune process
Endocytosis
a process in which the plasma membrane furrows inward, instead of extending outward with
pseudopods
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m invaginates to produce a furrow
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Allows cell to engulf large mol like proteins
another type = receptor mediated endocytosis = involves smaller area of p
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3 BioEnergetics
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Bioenergetics = flow of energy in living systems
1st law of thermodynamics = energy can be transformed but cannot be created nor destroyed :
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The second law = the amount of entropy increases in every energy transformation - free
energy(available for work) decreases as entropy increases
ENDERGONIC AND EXERGONIC REACTIONS
chemical rxns that require an input of energy = endergonic rxn ; the products of endergonic
reactions have more free energy than the reactants
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The energy released by these rxns is used to drive the energy
requiring processes(endergonic) of the cell
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The energy released by most exergonic rxns is used to drive a particular endergonic rxn: the
formation of ATP from ADP and inorganic phosphate Pi
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The energy released from the breakdown of ATP is used to power cell processes
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These are coenzymes that function as
Hydrogen carriers because they accept hydrogen(become reduced) in one enzyme rxn and
donates hydrogens (oxidized) in a diff enzyme reaction
Each FAD can accept two electrons and bind two protons --> FADH2
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Chapter Five Notes
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The complete combustion of glucose
requires the presence of O and yields about 30 ATP for each molecule of glucose
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When a molecule is completely broken down into water and CO2, then this final
electron acceptor is O - aerobic cell respiration
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Oxygen is used in the final step
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Skeletal muscles often convert pyruvic acid into
lactic acid in anaerobic metabolism
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exergonic - portion of energy thats released is used to drive the endergonic reaction ADP + P ->
ATP
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(lactic acid fermentation or anaerobic metabolism)
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yields a net gain of two ATP molecules (produced by glycolysis) per glucose molecule
Red blood cells, which lack mitochondria, can use only the lactic acid pathway - this spares the
oxygen they carry for delivery to other cells
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CLINICAL APPLICATION - Ischemia refers to inadequate blood flow to an organ, decreasing
oxygen delivery
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People with this
will experience angina pectoris- pain in the chest and left/right arm due to increase blood levels
of lactic acid
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Instead, many organs store carbs in the form of
glycogen
the formation of glycogen from glucose is called glycogenesis --> glucose is converted to glucose
6-phosphate then to its isomer glucose 1-phosphate
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Reverse rxn: the enzyme glycogen phosphorylase catalyzes the breakdown of glycogen to
glucose 1-phosphate (phosphates are derived from inorganic phosphates, not ATP, so doesn't
require metabolic energy)
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This
process is called glycogenolysis
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Glucose 6 phosphate cannot leak out of the cell
because organic molecules with phosphate groups cannot cross plasma membranes
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The liver, however, has the enzyme, glucose 6-phosphatase, that can remove
the phosphate groups and produce free glucose
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The liver has the enzymes needed to
take pyruvic acid and convert them to glucose 6-phosphate (reverse of glycolysis)
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The conversion of noncarbohydrate molecules (lactic acid, AA, glycerol) through pyruvic acid to
glucose = gluconeogenesis
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This two way traffic b/w skeletal muscles and the liver = Cori Cycle
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3 Metabolism of Lipids and Proteins
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Triglycerides can be hydrolyzed into glycerol and fatty acids
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This involves the removal of the amine
group and the conversion of the remaining molecule into either pyruvic acid or one of the Krebs
cycle molecules
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When cellular ATP concentrations rise b/c more energy from food is
available than can be immediately used, ATP production is inhibited and glucose is converted
into glycogen and fat
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Amino Acid Metabolism
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healthy adults maintain a state of nitrogen balance in which amount ingested equals amount
excreted
when more AA are ingested than are needed the excess are not stored
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keto acids can be converted into AA by
addition of an amine group(found from cannibalizing another AA)
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glutamic acid is produced in the liver from the ammonia
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The metabolic pathway that removed amine groups from AA - leaving a keto acid and
ammonia = oxidative deamination
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the formation of glucose from AA or other noncarb molecules is called gluconeogenesis

Chapter Six Notes
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env
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env
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env
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m of the
epithelial cells and the glycoproteins&proteoglycans of the matrix, the basal lamina helps wed
the epithelium to its underlying connective tissue
On Plasma membrane = integrins(class of glycoproteins that extend from cytoskeleton within a
cell, thru p
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matrix --> adhesion molecule b/w cells and matrix; serve to
relay signals b/w

CATEGORIES OF TRANSPORT ACROSS PLASMA MEMBRANE
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selectively permeable
generally not permeable to proteins, nucleic acids, and other molecules needed for the
structure&function of the cell
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2 Diffusion and Osmosis
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nonpolar molecules, small polar but uncharged molecules can easily pass thru p
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m impermeable to charged inorganic ions such as Na+ and K+ --> ion channels
Some ion channels are always open but most are gated: a particular physiological
stimulo(binding of the channel to a specific chemical regulator) can open an otherwise closed
channel
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3 Carrier Mediated Transport
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cells must take up glucose, amino acids, and other organic molecules from extracellular matrix too large and polar to pass through membrane by simple diffusion - carrier proteins
(1) specificity (2) competition (3) saturation

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carrier proteins interact with specific molecules; if a carrier can transport two different AA then
they compete with each other - slower rate of transport; as the concentration of a transported
molecule goes up so does the rate of transport - but only up to transport maximum in which the
carrier transport is saturated

FACILITATED DIFFUSION
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transport of glucose
ATP not required
the carrier protein has a site that can bind specifically to glucose, and such binding causes a
conformational change in the carrier so that a pathway is formed for glucose to diffuse into the
cell
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e the Ca2+ pump, the proton pump, Na+/K+ pump
CA2+ PUMP:
located in plasma membrane of all cells and membrane of endoplasmic reticulum of striated
muscle cells
removes Ca2+ from cytoplasm
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This sudden rise in cytoplasmic Ca2+ serves as a
signal for diverse processes - release of neurotransmitters from axon terminals and muscle
contraction
SODIUM POTASSIUM PUMP:
found in all body cells
transports three Na+ out of the cell cytoplasm for every two K+ that they transport into the
cytoplasm
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Three functions: (1) steep Na gradient is used to provide energy for the coupled transport of
other molecules (2) the gradients for Na+ and K+ concentrations of nerve and muscle cells are
used to produce electrochemical impulses
active extrusion of Na is imp by preventing the inflow of water
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Hydrolysis of ATP by NA/K pump is used
indirectly

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if mol is moved in same direction as Na = cotransport or symport
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4 The Membrane Potential
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the inside of the cell is negative charged compared to the outside
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B/c
membrane is more permeable for K than any other cation, K accumulates within cell -- result:
each cell acts as a tiny battery with the positive pole outside the membrane and the negative
pole inside -- potential difference (measured in voltage)

Equilibrium Potentials
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the extent to which an ion contributes to the membrane potential depends on (1) its conc
gradient (2) its membrane permeability
b/c membrane is most permeable to K+, membrane potential is usu determined primarily by the
K+ gradient
If K+ were the only ion able to diffuse through the plasma membrane it would distribute itself
b/w the intracellular and extracellular compartments until an equilibrium was established
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Not enough K+ would accumulate within the cell to neutralize these anions so the inside of the
cell would be -90mV compared to outside of cell = equilibrium potential for potassium (Ek)
Na+ equilibrium potential = +66mV
Equilibrium potentials are useful to know b/c they tell us what happens to the membrane
potential when the p
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The resting neuron for
ex, has a membrane potential close to Ek b/c its membrane is most permeable to K+
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RESTING MEMBRANE POTENTIAL
the membrane potential of a real cell that is not producing impulses is known as the resting
membrane potential
if p
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As a result, its resting potential is close to Ek but somewhat less negative due to slight
inward diffusion of Na+ and slight outward diffusion of K+
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Influenced

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by many diff ions, it ranges from -65mV to -85mV (in neurons, averages to -70mV)
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Role of Na/K pump - not only counteracts leakages to keep relatively constant intracellular
concentrations of Na and K but contributes to the intracellular negative charge (this electrogenic
effect adds 3mV to membrane potential)

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