Cell Physiology Flashcards
what does function of cells depend on
-strucutral properties
4 major subdivisions of the cell
-plasma membrane encloses the cell
cytoplasm
-organelles
-nucleus
plasma membrane functions`
-physical isolation
-regulation of exchange with the environment
-sensitivity to environment
-structural support
centrosome and centrioles
-2 centrioles in cytoplasm at right angles
-essential for movemnt of chromsomes during cell division
-organization of microtubules in cytoskeleton
phospholipid bilayer
-hydrophillic heads
-hydrophobic tails
-barrier to ions and water soluble compounds
integral proteins
-within membran
peripheral proteins
-bound to inner or outer surface of the membrane
anchoring proteins
-attch to inside or outside structures
-recognition particles
-label cells as normal or abnormal
enzymes
catalyze reactions
receptor proteins
carrier proteins
-transport specific solutes through membrane
channels
-regulate water flow and solutes passing through membrane
gated channels
-open or close to regulate passage of substance
membrane carbohydrates
-proteoglycans, glycoproteins and glycolipids that extend outside the cell membrane and form a sticky coat called the glycocalyx
glycocalyx
-sticky coat formed by membrane carbs
function of glycocalyx
-lube and protection
-anchoring and locomotion
-specificity in binding
-recognition in immune response
cytoplasm
-all material in the cell and outside the nucelus
cytosol
-intracellular fluid
-contains dissolved materials
-nutrients ions and waste products
-high protein and potassium
-low carbohydrate, lipid, AA and sodium levels
organells
-structures with specific functions
non membranous organelles
-no membrane
-direct contact with cytosol
-include the cytoskeleton, centiroles, ribsomes, proteasomes, microvilli, cilia, and flagella
membrane organelles
-isolated from cytosol by plasma membrane
-nucleus, ER, Golgi, lysosomes, peroxisomes, mitochondria
cytoplasmic inclusions
-non-membranous organelle
-masses of insoluble materials in the cell
-some consist of glycogen or lipid droplets
cytoskeleton
-structural proteins for shape and strength
-microfilaments, intermediate filaments, microtubukes
-non membranous organelle
microfilaments
-thin filaments composed of actin
-mechanical strength
-interact with other ptoreins to adjust consistency of cytosol
-interact with thick filaments of mysoin for muscle contraction
intermediate filaments
-mid sized between microfilaments and microtubules
-durable
-stengthen the cell and maintain shape
-stabalize position of organelles
-stabalize cell position
microtubules
-large, hollow tibes of tubulin proteins
-attach to centrosome
-strengthen cell and anchor organelles
-change cell shape
-move organelles within the cell with the help of motor protein (kinesin and dynein)
–form spindle apparatus to distribute chromsomes
-formes centrioles and cilia of organelles
microvilli
-increase SA for absorption
-attach to cytoskeleton
centrioles
-form spindle apparatus during cell division
-centrosome - cytoplasm next to nucleus that surrounds centrioles
cilia
-slender extensions of plasma membrane
-move fluids across the cell surface
-primary cilia - non motile, for sensing environment
-motile cilia - found on cells lining the respiratory and repro tract
-flagellum - whip like extension of cell membrane
ribosomes
-synthesize proteins
-small and large ribosomal units
-contain ribosomal RNA
free ribosomes
-in cytoplasm
-manufacture proteins that enter cytosol directly
fixed ribosomes
-attached to ER
-manufacture proteins that enter ER for packaging
proteasomes
-organelles that contain proteases
-disassemble damaged proteins for recycling
six types of membranous organelles
-nucleus, ER, Golgi, lysosomes, peroxisomes, mitrochondrag
golgi
-storage, altercation and packaging of secretory products and lysosomal enzymes
mitochondria
-produce 95% of the ATP required by the cell
-smooth outer membrane
-folds of inner membrane = cristae
-cirstae surrounded my fluid matric
-take glucose to produce ATP
-ABCD = Anabolism, biosyntheis, catabolism, degreadation
ER
-contain cistenae
-syntehsis of proteins, carbs, lipids
-storage of cynthesied molecules and materials
-transport of materials within ER
-detoxification of drugs or toxins
nucelus
-control of metabolism
-storage and processing of genetic information
-control of protein synthesis
smooth endoplasmic reticulum
-no attached ribosomes
-synthesizes: phospholipids and cholesterol, steroid hormones, glycerides, glycogen
rough endoplasmic reticulum
surface covered with ribosomes
-active in protein adn glycoprotein synthesis
-folds proteins into secondary and tertiary structures
-encloses products in transport vesicles for delivery to golgi
golgi apparatus functions
-modifies and packages secretions for release from cell
-adds or remobes carnphydrated to or from proteins
-renews or modifes the plasma membrane
lysosomes
-enzyme containing vesicles
-produced by golgi apparatus
-primary lysosomes: contain inactiev enzymes
-secondary lysosomes: formed when primary lysosomes fuse with damaged organelles and enzymes are activated
-function to destroy bacteria, break down molecules and recycle organelles
peroxisomes
-small, enzymes containing vesicles
-produced by division of existing peroxisomes
-break down organic compounds such as fatty acids
recipe for ATP
-glycolysis - glucose –> pyruvic acid in cytosol and mitochondria absorb pyruvate molecules
-CAC - mitochondrial matrix, break down pyruvate
-ETC - inner mitochondrial membrane
plasma membrane restricts material based on
-size
-electrical charge
-molecular shape
-lipid solubility
passive transport
-diffusion
-facilitated diffusion
-sometimes carrier mediated transport
active transport
-requires energy
-vesicular and sometimes carrier mediated transport
facotrs influencing diffusion
-distance particle has to move
-ion and molecule size (smeller = faster)
-temperature (higher - faster)
-concentration gradient (steeper = faster)
-electrical forces (opposites attract, like charges repel)
simple diffusion allows what to cross
-lipid solublem dissolved gases, water
channel mediated diffusion
-water soluble compounds and ions
-affected by size, charge, and inteaction with channel walls
osmosis
-difsuison of water across selectively permeable membrane
-volume may increase in one side to maintain equilibirum concentration
hydrostatic pressure
-pressure of standing fluid water on membrane
osmotic pressure
-force with which pure water moves into a solution as a result of solute concentration
-hydrostatic pressure is the pressure needed to block osmosis
water moves until ________=_________
osmotic pressure = hydrostatic pressure
why does osmosis occur more rapidly than solute diffusion
-water can cross through aquaporins
-aquaporins outnumber solute channels
osmolarity
-total solute concentration in a solution
tonicity
-decreibes how solution affects cells
isotonic, hypotonic, hypertonic
-isotonic, does not cause osmotic flow
-hypotonic - lower solute concentration than the cell
-hypertonic - higher solute concentration than the cell
when considering both tonicity and osmolarity what can happen to cell
-isotonic - nothing
-hypotonic - cell increases water which can lead to rupture
-hypertonic solution - cell loses water and may shrink
specificity of carrier mediated transport
-one transport protein, one set of substrated
saturation limits of carrier mediated transport
-rate depends on avaliabilit of transport proteins and substrates
regulation of carrier mediated transport
-cofactors such as hormones affect activity of carriers
symport
-cotransport
-two substances move in the same direction at the same time
antiport
-one substance moves in while another moves out
faciliated diffusion
-passive
-down concentration gradient
-carrier mediated
-transport molecules to large to fit through channel proteins such as glucose and AA
-molecule bind, receptor changed shape, molecule passes
-receptor site is specific to certain molecules
active transport carrier mediated
-proteins move substrated against concentration gradients
-energy needed
-ion pumps move ions
-exchange pumps move two ions in opposite directions at the same time
-ATP needed to work against concentration gradient
primary active transport
-pumping solutes against a concentration gradient using ATP
-sodium potassium exhange pump
-one ATP oowers the movement of three soidum ions out and two potassim ions inse
secondary active transport
-ATP is required to establish a concentration gradient of one substance in order to passively transport another
-Na concentration gradient drives glucose transport into cells
-ATP used to pump Na back out
what is vesicular transport needed for
-too large for carriers and channels
does endocytosis require ATP
yes
3 types of vesicular transport
-receptor mediated endocytosis
-pinocytosis
-phagocytosis
vesicular mediated endocytosis
-receptors (glycoproteins) bind target molecules
-receptors and their ligands migrate to clathrin coated pits of plasma membrane to enter cell
-some receptors assocuaated with membrane lipids and small indentations called caveolae
pinocytosis
-endosomes drink extracellular fluid
phagocytosis
-psudeopodia engulfed in phagosomes
exocytosis
-cell vesicles fuses with plasma membrane and releases materials to ECF
-also adds specific components to membrane
how do cells undergo cellular differentiation
-turning off genes not needed by that cells
-this also allows for fifferent types of cells such as liver cells, fat cells and nuerons
mitosis is controlled by
-genetics
cell division stimulated by
-internal factors (M phase promoting factor - MPF)
-extracellular chemical factors like growth facots such as hormones peptides and nutrients
cell division inhibited by
-repressor genes
-naturally worn out telomeres
cell cycle overview
cancer overview
