cell bio exam 2

free energy gradient

high to low, no energy required

diffusion

movement with free energy gradient

facilitated diffusion

movement aided by protein channels

active transport

movement aided against free energy gradient

diffusion is affected by

polarity

isotonic

net water movement

hypertonic

high salt concentration outside the cell, water rushes out

hypotonic

high salt inside the cell, water rushes in

channel protein

doesn’t change shape

carrier protein

integral, changes shape

direct active transport

energy from ATP

indirect active transport

energy from transport of another molecule powers the energy carrying of another

secretion

large molecules packing into secretory vesicles, vesicle of membrane

constitutive secretion

constant independent of signals

regulated secretion

vesicles accumulate and fuse with membrane via signal

exocytosis

the lumenal surface becomes cell membrane outer surface

calcium

often signals vesicle fusion

polarized

secretion can be

SNARE

coiled coil tethering proteins that guide vesicles to plasma membrane

SNAP

release SNARE after vesicle binds to plasma membrane

Endocytosis

steady state that balances endo and exocytosis

phagocytosis

pseudopod surrounds particles on outside of cell

clathrin independent pinocytosis

not specific, controls cell volume and surface area

clathrin dependent

molecule binds a receptor then receptors come together to form coated pits, clathrin forms on inner surface

endomembrane system

cell maufactures them itself, single membrane organelles

cisternae

sacs of ER

lumen

enclosed by ER

functions of ER

membrane biosynthesis, calcium function, carbohydrate metabolism, hydroxylation, membrane/ secreted protein

ER associated degredation

when misfolded proteins are detected and moved to cytosol

cis golgi network

CGN

medial cisternae

middle of golgi

trans golgi network

TGN

transition vesicles

vesicle that transports from ER to CGN, COPIII coated

shuttle vesicles

vesicles within golgi, COPI coated

transport vesicles

vesicles that leave the TGN, COPI or clathrin coated

on the membrane

where does glycosylation begin

lysosome

isolate digestive enzymes from rest of cell

regulated

secretion that requires secretory vesicles to fuse in response to a signal

plasmolyzed

plant cell that shrivles after being placed in a hypertonic solution

coated pit

transient sructure that forms at the plasma membrane during receptor-mediated endocytosis

triskelion

shape of clatherin molecules

exocytosis

the process of fusing vesicles to the plasma membrane

vsnare

protein on vesicles that help fuse a vesicle to its target

endocytosis

the engulfing of material brought into a cell

turgid

plant cell that swells when placed in a hypotonic solution

lumen

interior fluid of a vesicle or organelle

mannose 6 phosphate

Tag for signaling a protein to the lysosome

medial cisternae

Golgi sacs found in the center of the Golgi

transport

Vesicles leaving the TGN

signal sequence

Short amino acid sequence, usually at the N-terminus, that designates a polypeptide for cotranslational import

cis golgi network

Golgi sacs that vesicles encounter first

cytosol

The semiliquid portion of the cytoplasm; not an organelle

cotranslational import

The process of translating an mRNA and importing the growing peptide chain into the ER at the same time

vesicular transport

Golgi model that emphasizes small vesicles

COPI

Vesicle protein on shuttle and transport vesicles

autophagy

Occurs when a cell fuses lysosomes with other organelles in a form of self-digestion

O linked

Glycosylation that occurs on a serine or threonine (using an oxygen)

cisterae

Sacs of the ER

TOM

Transport protein found in the outer membrane of mitochondria

ER associated degradation

Process where misfolded proteins are taken from the ER into the cytosol for degradation

membrane

Protein type that is imported into the ER but has one or more domains pass through the membrane

TIC

Transport protein found in the inner membrane of chloroplasts

N linked

Glycosylation that occurs on asparagine (using a nitrogen)

posttranslational import

The process of importing a protein into an organelle after it has been translated

signalpeptidase

Protein in the ER membrane that cleaves off the signal sequence or a membrane or secreted protein

secreted

Protein type that is imported completely into the lumen of the ER

transition

Vesicles that move from ER to Golgi

glycosylation

The addition of carbohydrates to proteins

transgolgi network

Golgi sacs from which secretory vesicles arise

TOC

Transport protein found in the outer membrane of chloroplasts

BIP

Protein that binds to hydrophobic regions of other proteins to prevent large polypeptide aggregates

cisternal maturation

Golgi model that emphasizes changes to the cisternae over time

shuttle

Vesicles within the Golgi

hydroxylation

The addition of -OH to molecules to make them more soluble

calcium

Ion stored in the ER; often used in cell signaling

dolichol

Molecule that serves as the starting point for glycosylation

lumen

Interior of the ER (or other organelle)

COPII

Vesicle protein found on transition vesicles

SRP

Protein that binds to a short amino acid sequence on a new polypeptide chain and takes the ribosome to the ER

TIM

Transport protein found in the inner membrane of mitochondria