THE POWERHOUSE OF THE CELL

Microfilaments

cytoskeleton made of ACTIN muscle contraction CYTOPLASMIC STREAMING: directed flow of cytosol + organelles cell shape changes cell division --> actin-myosin contractile ring

Microtubules

cytoskeleton made of TUBULIN cell shape chromosome movements (segregation) cell motility (make up cilia) track for motor proteins

motor protein

moves vesicles along microtubules

mitochondria

cellular respiration TWO MEMBRANES outer membrane = boundary inner membrane = energy rxns SEMI-AUTONOMOUS organelle (w/ some of their own DNA/riboomes --> codes for some of their proteins) ENDOSYMBIOTIC theory alphaproteobacterium engulfed by early cell cristae

extracellular matrix (ECM)

collagen - main structural protein. forms flexible extracellular layer fibronectin - glycoprotein dimer. binds integrins + collagen. cell adhesion, wound healing. integrins - transmembrane receptors pass info about ECM

gap junctions

create gaps that connect ANIMAL cells membrane proteins from adjacent cells line up to form a CHANNEL

Plasmodesmata

create gaps that connect PLANT cells tubule of ER passes thru it

Intermediate filaments

cytoskeleton various components (keratin, lamin) structural support anchorage cell-type specific proteins

cellulose

microfibrils beta glucose monomer H-bonds b/w adjacent polymers --> microfibers plant cell walls

How do actin and myosin cause movement?

when myosin "head" attaches to actin + moves, actin filament slides (ATP hydrolysis) ex: cytokinesis (actin-myosin interactions pinch membrane in 2) cytoplasmic streaming in plants (a-m interactions move cytoplasm around cell)

How is cytokinesis different between animal and plant cells?

Animal cells: contractile ring --> pinches membrane in two plants: cell wall material is built in the middle of the cell to cause separation.

thylakoid membrane

highly folded membrane in center of chloroplast contains light-collecting pigments like CHLOROPHYLL site for PHOTOSYNTHESIS

cytoplasmic streaming

plants + fungal cells actin-myosin movements (microfilaments) directed flow of cytosol + organelles

stroma

fluid-filled matrix inside the inner membrane of the chloroplast

cristae

folds of the mitochondrial inner membrane that provide an increase in the surface area

kinesin

"walks" along microtubule track every "step" requires energy (ATP hydrolysis) attached to transport vesicle tail (two pronged), stalk, head (attached to microtubule)

major components of the plant cell wall?

MOSTLY POLYSACCHARIDES CELLULOSE microfibrils PECTIN - polysaccharide

cytoskeleton

Microfilaments Microtubules Intermediate filaments filamentous network of proteins structure, organization, movement

chloroplast

photosynthesis a kind of plastid. others include chromoplasts (pigments) possesses its own DNA + ribosomes (semi-autonomous) THREE MEMBRANES TWO SYSTEMS inner + outer membrane thylakoid stroma, granum

What macromolecules are found in the animal ECM?

polysaccharides (carbs) proteins (integrin, fibronectin) carbohydrate groups of glycoproteins

tight junctions

proteins in adjacent cell membranes line up + BIND to each other (stitches cells together --> forms watertight SEAL b/w the 2 plasma membranes) cell-cell attachment

signal sequences (no signal sequence? Amino terminal signal? Internal Signal?)

signal sequences on protein synthesized by free ribosomes (ribosomes not attached to rER) NO SIGNAL PEPTIDE to cytosol AMINO-TERMINAL SIGNAL to chloroplast/mitochondrion INTERNAL SIGNAL to nucleus

granum

stacks of thylakoids embedded in the stroma of a chloroplast