ap bio unit 2e (the cell membrane)

what is a cell membrane made of?

phospholipids, proteins, carbs, cholesterol

how are membrane molecules held in place?

by weak hydrophobic interactions

what influences membrane fluidity?

temperature & the composition of fatty acids

in what type of cell is cholesterol found in its cell membrane?

only animal cells

what purpose does cholesterol serve in the cell membrane?

used to reduce fluidity at high temps & retain fluidity at low temps

what do proteins do in the membrane?

determines the function of the membrane

what are integral proteins?

proteins embedded within the phospholipid bilayer; channel, transport, receptor, recognition

what are peripheral proteins?

proteins attached loosely to the surface of a cell membrane that help with structure, cell signaling, & enzymes

what functions to membrane proteins have?

transport, enzymatic activity, signal transduction, intercellular joining, cell to cell recognition, attachment to cytoskeleton & ECM

what are glycoproteins?

protein w/ oligosaccharide; helps with cell signaling & recognition (ID tags)

what are glycolipids?

lipid w/ oligosaccharide; helps cells recognize e/o (ID tags) & maintain cell membrane structure

what is turgid?

sufficient water enters a plant cell, making it swollen w/ water (turgor pressure)

what flaccid

little water enters the cell, lacking turgor pressure (wilting)

what is plasmolysis

water exits the cell, causing the cell membrane to shrink

what is a transport protein?

helps ions & polar molecules move across the cell membrane

what is passive transport?

moving an item across a membrane w/o using ATP

what is active transport?

moving an item across a membrane using ATP

what is simple diffusion?

going from high to low

what is facilitated diffusion?

passive movement of ions & polar molecules through a transport protein

what is diffusion?

going from high to low concentration

what is osmosis?

diffusion of water

what is dynamic equilibrium?

molecules are evenly distributed, but they continue moving w/o change in concentration

what is hypertonic?

a lot of solute

what is hypotonic?

a lot of water

what is isotonic?

solution of equal concentration

what molecules can easily pass through the cell membrane?

small & hydrophobic molecules

what molecules need help passing through the cell membrane?

ions & polar molecules

what are channel proteins?

tunnels that allow polar molecules or ions to cross passively

what are carrier proteins?

bind to specific molecules & change shapes to move them across

what are receptor proteins?

bind to external signaling molecules to trigger reactions inside a cell (ex. enzymes)

what are recognition proteins?

use carb markers to identify cells

what is an aquaporin?

protein channels that rapidly transport water in & out of the cell

what is exocytosis

moving items out of a cell using energy

what is endocytosis

moving items into a cell using energy

what is phagocytosis

endocytosis of solids

what is pinocytosis

endocytosis of liquids

what is a cell membrane made of?

phospholipids, proteins, carbs, cholesterol

how are membrane molecules held in place?

by weak hydrophobic interactions

what influences membrane fluidity?

temperature & the composition of fatty acids

in what type of cell is cholesterol found in its cell membrane?

only animal cells

what purpose does cholesterol serve in the cell membrane?

used to reduce fluidity at high temps & retain fluidity at low temps

what do proteins do in the membrane?

determines the function of the membrane

what are integral proteins?

proteins embedded within the phospholipid bilayer; channel, transport, receptor, recognition

what are peripheral proteins?

proteins attached loosely to the surface of a cell membrane that help with structure, cell signaling, & enzymes

what functions to membrane proteins have?

transport, enzymatic activity, signal transduction, intercellular joining, cell to cell recognition, attachment to cytoskeleton & ECM

what are glycoproteins?

protein w/ oligosaccharide; helps with cell signaling & recognition (ID tags)

what are glycolipids?

lipid w/ oligosaccharide; helps cells recognize e/o (ID tags) & maintain cell membrane structure

what is turgid?

sufficient water enters a plant cell, making it swollen w/ water (turgor pressure)

what flaccid

little water enters the cell, lacking turgor pressure (wilting)

what is plasmolysis

water exits the cell, causing the cell membrane to shrink

what is a transport protein?

helps ions & polar molecules move across the cell membrane

what is passive transport?

moving an item across a membrane w/o using ATP

what is active transport?

moving an item across a membrane using ATP

what is simple diffusion?

going from high to low

what is facilitated diffusion?

passive movement of ions & polar molecules through a transport protein

what is diffusion?

going from high to low concentration

what is osmosis?

diffusion of water

what is dynamic equilibrium?

molecules are evenly distributed, but they continue moving w/o change in concentration

what is hypertonic?

a lot of solute

what is hypotonic?

a lot of water

what is isotonic?

solution of equal concentration

what molecules can easily pass through the cell membrane?

small & hydrophobic molecules

what molecules need help passing through the cell membrane?

ions & polar molecules

what are channel proteins?

tunnels that allow polar molecules or ions to cross passively

what are carrier proteins?

bind to specific molecules & change shapes to move them across

what are receptor proteins?

bind to external signaling molecules to trigger reactions inside a cell (ex. enzymes)

what are recognition proteins?

use carb markers to identify cells

what is an aquaporin?

protein channels that rapidly transport water in & out of the cell

what is exocytosis

moving items out of a cell using energy

what is endocytosis

moving items into a cell using energy

what is phagocytosis

endocytosis of solids

what is pinocytosis

endocytosis of liquids