Cell
● Nucleus
○ Nucleolus makes ribosomes
○ Assembled ribosome is 70S sedimentation band
■ Ribosomes in soma of neurons
○ Proteins in nucleus contain nuclear localization sequence
■ How proteins enter nucleus
● Epithelial
○ Squamous squished
○ Cuboidal
○ Columnar
○ Stratified = not lined up linearly
○ Pseudostratified is wacky looking non linear columns
○ Transitional just looks fucked up (like stratified squamous + stratified columnar)
○ Epithelial connected by tight junctions
■ Not immune privileged
■ Attached to basement membrane via cell-to-cell attachment
■ BBB attached by tight junctions
○ Epithelial produce mucus in lungs
■ Specifically goblet cells
○ Pneumocytes II produce surfactant in lungs
■ Type of epithelial
○ GI epithelial cells do lots of mitosis
● Golgi go cis → trans golgi
● Smooth ER involved in detox and lipid formation
● Transport within cell
○ ER → Golgi or plasma membrane is anterograde
○ Golgi/plasma membrane → ER is retrograde
● ETC in inner mitochondrial membrane for eukaryotes
○ ETC in cell membrane of prokaryotes
○ Creates 32 ATP
○ Last step creates water from O2
○ Uses NADH as energy
● Phospholipids
○ Cell membrane made of phospholipids with cholesterol
○ Held together by London Dispersion Forces
○ Tail has many double bonds = unsaturated = reduces intermolecular interactions
= decrease forces holding it = increase membrane fluidity
■ Saturated (single bonds) decrease membrane fluidity
○ Peroxisomes bound by lipid bilayer
■ Membrane-bound
■ Other membrane bound organelles: nucleus, mitochondria, chloroplasts,
lysosomes, vacuoles, vesicles
● Lysosomes show radioactivity or fluorescence
, ● Lysosomes have degradative enzymes that function at low pH
○ Lysosome is acidic lumen w digestive enzymes
○ For hydrolysis of macromolecules and infectious agents
○ Dynamic properties most rapid in phospholipids within plane of membrane
○ Phospholipid is 2 fatty acids ester-linked to 1 glycerol + charged head
● Storage lipids made of 3 fatty acids ester-linked to 1 glycerol
○ Neutral fat
○ Aka triacylglycerol
● Ceramide made of 3 fatty acids ester-linked to 1 sphingosine
○ Cell signaling
● Sphingomyelin is 2 fatty acids ester-linked to 1 sphingosine + charged head
○ Insulator in myelin sheath of axons
○ Cell signaling
● Mitochondria
○ Affected most by thyroid
○ Heteroplasmy is variability of mitochondria composition in cell
■ From self-replication and cell division
○ DNA mutations cause mitochondrial disorders
■ Nonsense mutation = nonfunctional
■ Missense affects shape and function
○ Inner membrane has foldings called cristae
● Membrane
○ Resting membrane potential depends on
■ Differential distribution of ions across membrane
■ Active transport processes
■ Selective permeability of phospholipid bilayer
● NaCl does not readily diffuse through, but water can via osmosis
○ Fluidity lowered by trans glycerophospholipids
■ Increase melting point
■ Glycerophospholipids have 2 fatty acid tails
● Cytoskeletal System
○ Microfilaments made from actin
■ Smallest
■ Linked with cytokinesis and phagocytosis
○ Intermediate filaments made from actin
■ Mid size
■ No movement; give structure
○ Microtubules made from tubulin
■ Largest
■ Form flagella and cilia
● Cilia and pseudopodia unique to protists and eukaryotes
● Flagella for prokaryotes
■ Dynein: motor protein that moves along microtubules towards center of
cell
, ■ Kinesin: uses ATP hydrolysis to move along microtubules towards
peripheral of cell
● Plasma Membrane
○ Hydrophobic (steroids/cholesterol) can pass bc inside is hydrophobic (tails)
■ Hydrophilic need transporter to cross membrane
■ So hydrophilic (like AA) get stuck on surface of plasma membrane
○ Sphingolipids
■ Ceramide
■ Sphingomyelin
■ Cerebroside
■ Ganglioside
○ Cholesterol keeps phospholipids in membrane from clumping
■ Cholesterol only in esterified form in ER and Golgi
■ Golgi only in eukaryotes
■ Cholesterol is precursor to bile salts
○ Myelin sheath speeds up signal propagation
■ Faster conduction with myelin sheath than without
■ Increases magnitude of potential difference during action potential
■ Saltatory conduction of action potential
● Saltatory conduction is when action potentials jump between
nodes
■ Myelin discontinuous at nodes of Ranvier
■ Myelin also helps electric signals to dissipate slower
○ Action potentials form at axon hillock (unmyelinated)
■ Voltage gated sodium channels
● If VGSC are blocked, AP is prolonged
○ Bc delays the repolarization phase back to resting
membrane potential
● Action potential, first thing that happens is VGSCs open at axon
hillock
○ Calcium influx and neurotransmitter release does not
happen until action potentials arrive at axon terminals
■ APs are all or nothing
○ Ungated channels maintain resting membrane potential
○ Graded potentials in cell body/dendrites
■ NOT axon
○ Schwann cells have high fat concentration
■ Form myelin sheath
■ Part of PNS
○ Satellite cells surround neurons
■ Part of PNS
○ Sensory neurons are afferent
■ Enter spinal cord on dorsal side
○ CNS neural cells
, ■ Astrocytes form BBB and regulate brain function
■ Microglia are macrophages
● Present antigens to immune system
● Activate other immune cells (B and T)
● Initial immune response
■ Ependymal are line ventricles
■ Oligodendrocytes are lipids that form myelin sheath around neurons
○ Synaptic transmission mediated by neurotransmitter vesicles
■ Not dependent on myelin at synaptic bouton
○ Cytoskeleton mediates neurotransmitter migration
○ Cili move fluid in lungs, ependymal (nervous system), uterus
○ Microvilli move food in small intestine
○ Peripheral proteins bound with electrostatic interactions
○ Cell junctions
■ Gap junctions allow direct communication
● Cytoplasmic channels between adjacent cells
■ Desmosomes bind adjacent cells by cytoskeletons
■ Tight junctions on outermost epithelium
■ Plasmodesmata cell-cell junctions in plants only
■ Hemidesmosomes attach epithelial cells to underlying layers
○ Steroids have 3 6-member rings and 1 5-member ring
■ Squalene is precursor of steroids/cholesterol
■ Terpenes are steroids
● Isoprene units
○ Lipid bilayer formation spontaneous, increases entropy
■ Clumping increases entropy
● Ports
○ Sodium potassium port is antiport
■ Primary active transport
■ Against concentration gradient
○ Sodium channel closes with depolarization
■ Greater concentration inside
○ But if you use sodium ionophore, it disrupts Na/K gradient
■ = decreased production of ATP
○ Potassium channel opens with repolarization
○ Hyperpolarization: potential more negative than resting
■ From Cl- in and K+ leaving
● Facilitated diffusion needs transport protein
○ Down concentration gradient
○ Transport affinity is a property of amino acid transport protein = does not change
● GABA opens ligand-gated channel
● Clathrin is vesicle-coating protein for endocytosis
● Nucleus
○ Nucleolus makes ribosomes
○ Assembled ribosome is 70S sedimentation band
■ Ribosomes in soma of neurons
○ Proteins in nucleus contain nuclear localization sequence
■ How proteins enter nucleus
● Epithelial
○ Squamous squished
○ Cuboidal
○ Columnar
○ Stratified = not lined up linearly
○ Pseudostratified is wacky looking non linear columns
○ Transitional just looks fucked up (like stratified squamous + stratified columnar)
○ Epithelial connected by tight junctions
■ Not immune privileged
■ Attached to basement membrane via cell-to-cell attachment
■ BBB attached by tight junctions
○ Epithelial produce mucus in lungs
■ Specifically goblet cells
○ Pneumocytes II produce surfactant in lungs
■ Type of epithelial
○ GI epithelial cells do lots of mitosis
● Golgi go cis → trans golgi
● Smooth ER involved in detox and lipid formation
● Transport within cell
○ ER → Golgi or plasma membrane is anterograde
○ Golgi/plasma membrane → ER is retrograde
● ETC in inner mitochondrial membrane for eukaryotes
○ ETC in cell membrane of prokaryotes
○ Creates 32 ATP
○ Last step creates water from O2
○ Uses NADH as energy
● Phospholipids
○ Cell membrane made of phospholipids with cholesterol
○ Held together by London Dispersion Forces
○ Tail has many double bonds = unsaturated = reduces intermolecular interactions
= decrease forces holding it = increase membrane fluidity
■ Saturated (single bonds) decrease membrane fluidity
○ Peroxisomes bound by lipid bilayer
■ Membrane-bound
■ Other membrane bound organelles: nucleus, mitochondria, chloroplasts,
lysosomes, vacuoles, vesicles
● Lysosomes show radioactivity or fluorescence
, ● Lysosomes have degradative enzymes that function at low pH
○ Lysosome is acidic lumen w digestive enzymes
○ For hydrolysis of macromolecules and infectious agents
○ Dynamic properties most rapid in phospholipids within plane of membrane
○ Phospholipid is 2 fatty acids ester-linked to 1 glycerol + charged head
● Storage lipids made of 3 fatty acids ester-linked to 1 glycerol
○ Neutral fat
○ Aka triacylglycerol
● Ceramide made of 3 fatty acids ester-linked to 1 sphingosine
○ Cell signaling
● Sphingomyelin is 2 fatty acids ester-linked to 1 sphingosine + charged head
○ Insulator in myelin sheath of axons
○ Cell signaling
● Mitochondria
○ Affected most by thyroid
○ Heteroplasmy is variability of mitochondria composition in cell
■ From self-replication and cell division
○ DNA mutations cause mitochondrial disorders
■ Nonsense mutation = nonfunctional
■ Missense affects shape and function
○ Inner membrane has foldings called cristae
● Membrane
○ Resting membrane potential depends on
■ Differential distribution of ions across membrane
■ Active transport processes
■ Selective permeability of phospholipid bilayer
● NaCl does not readily diffuse through, but water can via osmosis
○ Fluidity lowered by trans glycerophospholipids
■ Increase melting point
■ Glycerophospholipids have 2 fatty acid tails
● Cytoskeletal System
○ Microfilaments made from actin
■ Smallest
■ Linked with cytokinesis and phagocytosis
○ Intermediate filaments made from actin
■ Mid size
■ No movement; give structure
○ Microtubules made from tubulin
■ Largest
■ Form flagella and cilia
● Cilia and pseudopodia unique to protists and eukaryotes
● Flagella for prokaryotes
■ Dynein: motor protein that moves along microtubules towards center of
cell
, ■ Kinesin: uses ATP hydrolysis to move along microtubules towards
peripheral of cell
● Plasma Membrane
○ Hydrophobic (steroids/cholesterol) can pass bc inside is hydrophobic (tails)
■ Hydrophilic need transporter to cross membrane
■ So hydrophilic (like AA) get stuck on surface of plasma membrane
○ Sphingolipids
■ Ceramide
■ Sphingomyelin
■ Cerebroside
■ Ganglioside
○ Cholesterol keeps phospholipids in membrane from clumping
■ Cholesterol only in esterified form in ER and Golgi
■ Golgi only in eukaryotes
■ Cholesterol is precursor to bile salts
○ Myelin sheath speeds up signal propagation
■ Faster conduction with myelin sheath than without
■ Increases magnitude of potential difference during action potential
■ Saltatory conduction of action potential
● Saltatory conduction is when action potentials jump between
nodes
■ Myelin discontinuous at nodes of Ranvier
■ Myelin also helps electric signals to dissipate slower
○ Action potentials form at axon hillock (unmyelinated)
■ Voltage gated sodium channels
● If VGSC are blocked, AP is prolonged
○ Bc delays the repolarization phase back to resting
membrane potential
● Action potential, first thing that happens is VGSCs open at axon
hillock
○ Calcium influx and neurotransmitter release does not
happen until action potentials arrive at axon terminals
■ APs are all or nothing
○ Ungated channels maintain resting membrane potential
○ Graded potentials in cell body/dendrites
■ NOT axon
○ Schwann cells have high fat concentration
■ Form myelin sheath
■ Part of PNS
○ Satellite cells surround neurons
■ Part of PNS
○ Sensory neurons are afferent
■ Enter spinal cord on dorsal side
○ CNS neural cells
, ■ Astrocytes form BBB and regulate brain function
■ Microglia are macrophages
● Present antigens to immune system
● Activate other immune cells (B and T)
● Initial immune response
■ Ependymal are line ventricles
■ Oligodendrocytes are lipids that form myelin sheath around neurons
○ Synaptic transmission mediated by neurotransmitter vesicles
■ Not dependent on myelin at synaptic bouton
○ Cytoskeleton mediates neurotransmitter migration
○ Cili move fluid in lungs, ependymal (nervous system), uterus
○ Microvilli move food in small intestine
○ Peripheral proteins bound with electrostatic interactions
○ Cell junctions
■ Gap junctions allow direct communication
● Cytoplasmic channels between adjacent cells
■ Desmosomes bind adjacent cells by cytoskeletons
■ Tight junctions on outermost epithelium
■ Plasmodesmata cell-cell junctions in plants only
■ Hemidesmosomes attach epithelial cells to underlying layers
○ Steroids have 3 6-member rings and 1 5-member ring
■ Squalene is precursor of steroids/cholesterol
■ Terpenes are steroids
● Isoprene units
○ Lipid bilayer formation spontaneous, increases entropy
■ Clumping increases entropy
● Ports
○ Sodium potassium port is antiport
■ Primary active transport
■ Against concentration gradient
○ Sodium channel closes with depolarization
■ Greater concentration inside
○ But if you use sodium ionophore, it disrupts Na/K gradient
■ = decreased production of ATP
○ Potassium channel opens with repolarization
○ Hyperpolarization: potential more negative than resting
■ From Cl- in and K+ leaving
● Facilitated diffusion needs transport protein
○ Down concentration gradient
○ Transport affinity is a property of amino acid transport protein = does not change
● GABA opens ligand-gated channel
● Clathrin is vesicle-coating protein for endocytosis
