function of epithelial tissues
sheets of cells, cover, line, and form glandular tissue
nonexcitable
avascular
adherant to basement membrane
regenerative
simple epitheleal cells
1 layer
stratefied epithealeal cells
multiple layers
squamous
flat, allow for rapid diffusion
cuboidal
cube shaped
simple squamous examples
endothelium: lining of blood vessels
mesothelium: lining of thoracic and abdominal cavities
simple cuboidal
primarily secratory
pseudostratefied
often secretory, often modified
simple columnar
primarily secratory, gut, intestine, goblet cells
transitional
urinary bladder, ureter, and urethral linings
stratified squamous
mult layers, primarily for protection, upper and lower GI tract, skin
4 classes of conective tissue
- fibroblasts–> connective tissue proper
- chondroblasts –>cartilage
- osteoblasts –> bone
- hemocytoblasts –> blood
connective tissue is..
the most abundant in the body highly vascularized lots of extracellular stuff
connective tissue matrix
fluid fibers proteoglycans
collagen
triple chain structure glycine, proline, hydroxyproline
clinical collagen problems
scurvy: vitamin C deficiency, needed to make hydroproline to form proline
osteogensis imperfecta: severe bony deformities
GAGs
give bone shock absorbing properties
loose connective tissues
mesenchyme: embryonic connective tissue areolar: under epithelia, packages organs, mast cells migrate thru it adipose: fat, small spaces between cells reticular:liver, lymph noders, bone marrow, spleen. compartmentalizes cells within organs
dense connective tissue
regular: tendons, ligs, apaneuroses. -neatly aligned collagen fibers, strong irregular: dermis, organ capsules, fascia. -oriented in different directions, forces can be resisted in mult directions elastic: BV walls, trachea, bronchi, vocal cords, ligamentum flavum
hyaline cartilage
ends of long bones, costal cart of nose, trach, larynx shock absorption
fibrocartilage
IV discs, pubic symphysis, menisci
elastic cartilage
ext ear, epiglottis
bone
oesteocytes in lacuna, not much fluid in matrix
blood
lots of matrix, few cells
reaction rate depends on
-[] of reactants and products -temp -AE -catalysts (enzymes)
allosteric modulation
2 binding sites (functional and regulatory), needs a modulator molecule to bind to enzyme and change shape so that ligand can fit in functional site
covalent modulation
covalent binding of phosphate group (from ATP) to a protein which changes its shape and allows for the binding of ligand
protein kinase
cleaves phosphate from ATP and sticks it onto proteins
phosphotases
takes phosphate off things
Glycolysis
breakdown of glucuse anaerobic 2 net ATP splits glucose into 2 pyruvate fuel: carbs (anarobic) *in order to break down fat, breakdown of carbs is required
needs: 2 ATP, 2 NAD+, glucose, 4 ADP, 4 phosphates
makes: 4 ATP, 2 pyruvates, 2 NADH, 2 ADP
cytoplasm
lactic acid and glycolysis
2 molecules of lactic acid for every 1 molecule of glucose broken down
if O2 is available…
moves onto krebs cycle (aerobic)
is O2 isnt available…
fermenatation and conversion to lactic acid
pros/cons of glycolysis
ineffiecient can produce a lot of ATP quickly decays and fatigues if >~2mins
the hydrolysis of 1 mole of ATP yields
7 kcals of energy per mole
prep step of krebs
pyruvate —> acetylCoA
krebs cycle
makes: NADH, ATP, CO2, FADH2
fuel: fat is more effective, carbs, protein (last resort)
mitochondrial matrix
electron transport chain
products: 3 ATP per ADP (10) and 2 ATP per NAD2H (2)
final electron acceptor: oxygen
end product: water
diffusion
movement of molecules from high concentration to low due to random thermal motion
net flux occurs
down a [] gradient
ion channels
non gated: move via simple diffusion
ligand gated: also acts as a receptor, ligand binds, channels open
voltage gated: closed till a change in voltage occurs
mechanically gated:like cilia in ears, req a physical movement to open gates
phospholipid bilayer
stable but fluid
amphipathic: hydrophobic and hydrophilic ends (tails: phobic, heads: philic)
cholesterol
maintains and adds stability to the membrane
simple diffusion
non mediated, no energy required, rate: Fick eqn
molecule mvmt thru channels
small diffuse more easily, dont need pores/channels
polar have a hard time
inside of the cell tends to be -, + ions move in freely
facilitated diffusion
reqs a carrier molecule
no energy expended, can only occur down the gradient
glucose into skeletal muscle
facilitated diffusion mechanism saturation
as [] increases in solute, the flux will plateau at a certain point when all transporters are being used
pumps
transport things against the gradient (low to high)
primary acive transport
binding site in the protein is changed, costs energy, moves across [] gradients
secondary active transport
no direct utilization of ATP, cotransporters, depends on the maintence of the [] gradient
allosteric modulation by sodium in high concentration
release of sodium in low concentration
moves against gradients
brings 2 things into the cell (sodium and whatevers being transported)
endo and exocytosis
transports bigger things into and out of the cells
types of endocytosis
phagocytosis
pinocytosis
receptor mediated endocytosis
fibroblasts
connective tissue
chondroblasts
cartilage
osteoblasts
bone
hemocytoblasts
blood