Intro to cell II Flashcards
Lipid Bilayer PM hydrophobicity
Amphilic=Amphipathic
Hydrohobic lipids in inner
Hydrophilic groups face external
Integral membrane proteins
Traverse entire width of cell membrane
Peripheral membrane proteins
Attached to extracellular regions of PM noncovalently
What happens to proteins when separate lipid bilayer
Integral proteins associate with one leaflet or the other
Faces of PM
E and P faces
P face has many more interactions with proteins-actin
RBC membrane proteins
Stabilized by spectrin and other cytoskeletal proteins (actin)-why so many proteins are on P face
Hereditary spherocytosis
Spherical/less deformable/more susceptible to destruction by phagocytic cells-RBCs-spectrin mutations
-essentially use SPECTRINS to keep membrane shape and ensure no problems with extracellular osmolarity
Four types of membrane proteins
Linker/anchor
Transporter
Receptors-signalling
Enzymes
Brush border
Microvilli boarder
-example of one of mods PMs can have
Cell adherence is possible w/
Junctional complexes
Glycocalyx
Fuzzy coat on tips of microvilli
Enteric surface coat
Created from several glycosylated molecules at surface of cell
Glycosylation occurs in RER
Consists of glycolipids, glycoproteins, and proteoglycans
What stabilizes microvilli?
Actin-cytoplasm surrounds finger like projection of actin bundle
Terminal web
Filamentous complex at top of cells where actin of villi terminate
Myosin in microvilli
Move material down microvili
Terminal bars
identify locations of junctional complex
Microfilaments ar made of…
Actin-extend throughout cell
Microtubules
Extend through cytoplasm
Structural bas of centrioles
Form cilia and mitotic spindles
Made of tubulin
Grandular vs Agranular reticulum
RER vs SER
SEE structure+ function
Consists of expensive array of membrane tubules and enclosed cisterns-no ribosomes
Lipid and steroid biosynthesis+metabolize many substances
Also site of storage for divalent ion calcium-site of many heme linked proteins
RER
Cistern=ribsome membrane bounded space
Start in nucleus, go to RER, go to golgi (sorted for final dentition here)
rRNA dyeing
bind to costively-charged dyes and produce basophila
ER in sec cells
Sec cells can be loaded with RER
Golgi faces
Cis-attached to RER
Medial
Trans-Results in secretory vesicles/can also store secretory vesicles
How does transport between goggle cisternae occur
vesicle trafficing
Constitutive secretion
Contiual secretion of proteins
Distinct lack of storage/secretory granules
Regulated secretion
Large number s of granules accumulate-many sec vesicles
Secretion initiated by external stimuli
Early endosome pathway
Coated pit to coated vescile, then bind to cell surface receptor
(receptor mediated endocytosis)
-fuse with early endosome
Clathirin-protein that coats
What is an endosome
Endosomes-distinct organelles consisting of vesicles containing material that has entered cell
- early endosome-receptors and ligands are separated, and receptors often recycle to surface
- nutrients routes to lysoeom via late endosome where nutrients can be released from carrier proteins and made averrable to cell
Mitochorndira S+F
Double membrane-inner membrane has cristae
-many different shapes depends on cell needs
Oxidative phosphorylation to synthesize ATP
-Someting to do with cell death
Cristae numbers
Depends on energy needs
=more energy=more cristae
some many not even have cristae
Mito DNA makes
most mitorRNA, mito rtRNA
hydrophobic subunits of enzymes involve din oxidative phosphorylation
Most protein of mito are made by other DNA
Lysosomes
Seen by a specific stain
Packets of hydrolytic enzymes that become active at acidic pH
-sites of intracellular digestion
Eat external molecules as well as worn-out intracellular organelles
Also can eat entire cells (phagocytosis)
Hard to identify
Eosinophil
Found in circulating blood and in connective tissue-fight drastic infections
-have crystallline inclsions=HAMBURGER!
Peroxisomes
Distinct protein complements
- specific metabolic functions
- inclusions that are not easily seen by immunocytochem
- Cryalline core in EM=dense material in matrix
