Cell Membrane and Cell Transport

for example, in the sodium-potassium pump, 2 K (potassium) enter the pump, and ___?___ Na (sodium) exit the pump

3

vesicle transport ___________ require energy

DOES

what is the cell membrane composed of?

a double layer of phosholipids and proteins

define active transport

a transport that *requires energy*

proteins

act like "windows and doors" and as channels to carry or transport materials through the cell membrane

active transport is the transport of substances across a cell membrane that moves ______________ the concentration gradient

against

selectively permeable

allows only certain substances to pass through

____________ in cell membranes are the channel proteins that allow osmosis to occur

aquaporins

peripheral proteins

are attached on the surface (inner or outer)

integral proteins

are embedded completely through the membrane

carrier protein

bind a specific solute to be transported and undergo a series of structural changes to transfer the bound solute across the membrane

globular

can be peripheral (cell signaling/ communication) or integral (cell transport)

what does facilitated diffusion use?

carrier or channel proteins (an example is glucose molecules)

some active transports use _______________________ aka pumps

carrier proteins

what is embedded in animal cell membranes, but NOT plant cell membranes?

cholesterol

define facilitated diffusion

diffusion through selective pores or proteins

facilitated diffusion ____________ use energy

does NOT

passive transport moves _____________ the concentration gradient

down

the solute in diffusion moves __________ the concentration gradient

down

define protein pumps

enzymes pump materials into and out of the cell against the concentration gradient using ATP energy

antibody release from plasma B-cells is an example of endocytosis or exocytosis?

exocytosis

neurotransmitter release from neurons is an example endocytosis or exocytosis?

exocytosis

glucose moving into red blood cells is an example of which passive transport?

facilitated diffusion

in exocytosis, material is packed into a vesicle by the ______________________ and shipped to the cell membrane where it fuses with the membrane to release the contents outside the cell

golgi body (golgi apparatus)

glycolipids

have a carbohydrate sugar chain attached them. they help the cell to recognize other cells of the body (similar to glycoproteins).

osmosis moves from areas with __________ to _________ concentration

high concentration (low solute) to low concentration (high solute)

diffusion moves from areas of ___________ to _________ concentration

high to low

facilitated diffusion moves from ___________ concentration to ___________ concentration

high to low (still follows the concentration gradient)

how does cholesterol help the cell membrane?

it helps stabilize the cell membrane, so it is not too solid, not too fluid; it also helps with the "selectiveness" of the cell membrane- meaning it helps decide which materials to let in/ exit and which materials to not let in/ exit.

what does passive transport "use" to move until equilibrium is met?

kinetic energy

lysosomes are a product of endocytosis- they are vesicles with a __________ pH and hydrolytic enzymes to break down materials

low

active transport binds at _________ concentration and releases at __________ concentration

low; high

_____________ ions, such as Na⁺, K⁺, Mg²⁺, or Ca²⁺, require ion pumps or ion channels to cross membranes and distribute through the body

metal

molecules in cell membranes are constantly _____________________.

moving and changing (phospholipid movement allows for small particles to enter/exit).

what types of molecules can be diffused?

only small, *non-polar* molecules, such as oxygen and carbon dioxide, can diffuse easily across the membrane through the phospholipids. all polar molecules are transported by proteins using channel or carrier proteins

which transport uses energy?

passive

diffusion, facilitated diffusion, and osmosis are all types of what process?

passive process

channel protein

pores that are gated, meaning that they open and close, and thus regulate the flow of ions or small polar molecules across membranes. transport occurs faster than with carrier proteins

in an analogy, you could compare facilitated diffusion to something ______________ like a VIP entrance to a club

selective

fibrous proteins

serve as cell receptors to help cells communicate with their external environment through the use of signaling molecules like hormones.

endocytosis is used by _________________ organisms like amoebas and paramecium (protists) to obtain food

single-celled

the ___________ of the molecule, the _________________ of the molecule on either side of the membrane, and the molecule's lipid ___________________ all affect how fast/ when a molecule moves across a membrane

size; concentration; solubility

give some examples of protein pumps

soduim-potassium pump, calcium pump, proton pump

cell (plasma) membrane

surrounds outside of ALL cells; controls what enters or leaves the cell to maintain an internal balance called homeostasis; provides protection and support for the cell

define pinocytosis

takes *liquid* into the cell uisng vesicles

define phagocytosis

takes in a *solid* particle

define osmosis

the diffusion of water through a membrane

define endocytosis

the movement of a substance into a cell by a vesicle

define exocytosis

the process that takes place when waste and materials made in the cell leave the cell

define diffusion

the random net movement of particules

where does diffusion occur?

through the phospholipids of the membrane

phospholipid

true barrier that separates cell from surroundings

in endocytosis, material is taken into the cell by a forming a __________________ with the cell membrane around the material and then breaking loose

vesicle

some things are too large to move through proteins, so they need a __________ for transport

vesicle

hydrophobic

water hating (lipid tail)

hydrophillic

water loving (head)