AP BIO - Cell Membrane Unit

cytoplasm

A gel-like fluid that fills the inside of a cell. Provides structure so cell parts can move freely

prokaryotic cell

a cell lacking a true nucleus and membrane-bound organelles. (ex. bacteria)

Nucleoid region

Where DNA in prokaryotic cells is located

Eukaryotic cell

A cell w/ nucleus and membrane-bound organelles (ex. plants/animals)

Cytosol

Fluid portion of cytoplasm w/o other parts of cell and suspends organelles

Plasma membrane

membrane found in ALL cells that separates the inside and outside. (Contains a phospholipid bilayer)

Nucleus

the organelle that houses/protects DNA and contains chromosomes

Nucleolus

Area of nucleus that creates ribosomes and synthesizes rRNA

Ribosomes

made of RNA and protein. Carries out protein synthesis

endomembrane system

network of membranes and organelles (nucleus, ribosomes, ER, golgi apparatus, vesicles, lysosomes, & plasma membrane) that create proteins/products for export

Smooth endoplasmic reticulum (ER)

lacks ribosomes; helps manufacture membranes, creates safe passage for movement with/ membrane, and helps with synthesis/hydrolysis of carbs, lipids, and detoxifiers

Rough endoplasmic reticulum (ER)

studded w/ ribosomes; helps with making/folding proteins for protein synthesis, manufacturing membranes, safe passageway for movement

glycoprotein

protein w/ carb/sugar attached; helps for cell recognition/signaling

golgi apparatus

modifies, sorts, and packages proteins and lipids for transport or secretion

central vacuole

large vacuole found inside plant cells. stores H2O and maintains turgor pressure in plant cells

peroxisome

small vesicles containing digestive enzymes for breaking down toxic material using H2O2

mitochondrion

powerhouse of the cell, site of cellular respiration and ATP production

chloroplast

organelle in plant cells where photosynthesis occurs

cytoskeleton

protein fibers that provide structured support, movement, and transport within cells.

microtubules

Thickest filaments that are a part of the cytoskeleton. Essential for cell shape, organelle positioning, etc.

microfilaments

thinnest filaments that are a part of the cytoskeleton. Essential for cell shape, movement, and division.

centriole

cylindrical structure made of microtubules; helps w/ organizing (spindle fibers) (animal cells)

flagella

long hair-like structure that enables movements (of cells)

cilia

short hair-like structure on surface of cell (sensory organelles)

cell wall

strong protective structure that surrounds a plant cell outside plasma membrane

extracellular matrix

network of proteins and other molecules that surround and give support to cells and tissues in the body. Also helps cells attach and communicate with nearby cells.

plasmodesmata

passageways that allow sharing b/w plant cells

tight junctions

creates a watertight, glue-like seal b/w cells

desmosomes

an “anchoring” junction that holds cells together with protein filaments like a staple

gap junctions

passageways that allow sharing b/w animal cells

selective permeability

membrane property that only allows select substances to enter or exit the cell

fluid mosaic model

describes the movement of phospholipid bilayer/plasma membrane and says that components move laterally within membrane

integral proteins

penetrate lipid bilayer, across whole membrane (molecule transport)

peripheral proteins

attached to membrane surface loosely (signaling)

diffusion

movement of molecules from high to low concentration. (passive transport)

concentration gradient

difference in the concentration of a substance across a space or membrane

passive transport

movement of substances across the membrane without energy input

hypertonic

solution with higher solute concentration

hypotonic

solution with lower solute concentration

isotonic

solution with equal solute concentration

osmosis

diffusion of water across a semi-permeable membrane

turgid

firm plant cell due to water gain in a hypotonic environment

flaccid

limp plant cell due to water loss in isotonic or hypertonic environment

facilitated diffusion

passive transport/diffusion of molecules through protein channels

active transport

movement of molecules against their concentration gradient using energy/ATP (uses integral proteins)

membrane potential

difference in electrical charge between inside and outside of cell

cotransport

active transport where one substance enables the movements of another

exocytosis

moving large molecules out of the cells (endomembrane system)

phagocytosis

endocytosis: cell-eating - large particles/cells

pinocytosis

endocytosis: cell-drinking - uptake of extracellular fluid

endocytosis

process of taking large molecules out of the cell