Unit 2 Review

basic structure of the cell

includes the plasma membrane, cytoplasm with organelles, nucleus

cell

The __________ is the basic unit of life

protects, supports

The plasma membrane _______________ and ________________ through production and secretion of various kinds of molecules

regulates

The plasma membrane __________________ the movement of material into and out of the cell.

communication

__________________- cells produce and receive electrical and chemical signals (signal transduction)

metabolism, energy

cell _____________ and __________________ release (using the plasma membrane)

inheritance

each cell contains DNA. Some cells are specialized to gametes for exchange during sexual intercourse.

plasma membrane

separation of intra/intercellular materials

intracellular

within the cell

intercellular

between cells

extracellular

outside the cell

membrane potential

difference of charge across the membrane by regulation of ion concentrations

outside

which side of the membrane is more positive?

glycocalyx

combinations of carbs and lips and proteins on the outer surface of the membrane

glycolipd

carb with a lipid

glyprotein

carb with a protein

phospholipids

the bilayer is made up of ____________?

polar

_______________ heads facing water in the interior and exterior of the cell (charge)

hydrophillic

water loving heads are __________________

hydrophobic

water hating tails a re __________________

nonpolar

_______________ tails face each other (charge)

cholesterol

interspersed among phospholipids; helps stabilize the membrane

fluid nature

The plasma membrane's ________________ ___________________ allows distribution of molecules within the membrane

automatically

phospholipids are __________________ reassembled if the membrane is damaged thanks to the membrane's fluid nature

fuse

the fluid nature of the membrane allows membranes to ________________ with each other

intrinsic

another word for integral

integral proteins

proteins that extend deeply into the membrane, often extending from one surface to the other

channels

integral proteins can form _____________________ through the membrane

extrinsic

another word for peripheral

integral proteins

peripheral proteins are attached to _________________ __________________- at either the inner or outer surfaces of the lipid bilayer

function

______________ is determined by the protein's shape and chemical characterisitcs

marker molecules

glycoproteins and glycolipids;
allow cells to identify one another or other molecules

marker molecules

____________________ help with immunity, sperm recognizing oocyte, and intracellular communication

integrins

membrane-bound proteins

channel proteins (integral)

hydrphillic region faces inward; charge dtermines molecules that can pass through.

nongated ion channels

always open; responsible for the permeability of the plasma membrane to ions when the plasma membrane is at rest

gated ion channels

channels that can be open or closed

ligand gated

ion channel that opens in response to small molecules that bind to proteins of glycoproteins

voltage gated

ion channel that opens when there is a change in charge across the plasma membrane

receptor molecules

proteins in membranes with an exposed receptor site

receptor molecules

can attach to specific ligand molecules and act as an intercellular communication system

ligands

attachment of _____________ to receptors causes a change in shape of the channel protein; the channel opens or closes

cystic fibrosis

what disease is a defect in genes causing defects in channel proteins?

membrane permeability

drugs used to alter ______________________ ___________________ through attachment to channel protein-linked receptors

G protein

a receptor linked to a ______ _____________________ can alter the activity on the inner surface of the plasma membrane (leads to intracellular chemical signals that affect cell function)

hormones

Some _____________________ function like a receptor linked to a G protein

enzymes

some act to catalyze reactions at the outer/inner surface of the plasma membrane

dipeptides

surface cells of the small intestine produce enzymes that digest ____________________.

carrier proteins

integral proteins move across the membrane

carrier proteins

have specific binding sites, protein changes shape to transport ions or molecules

movement across the membrane

diffusion, osmosis, and filtration are all way for _______________________

mediated transport mechanisms

facilitated diffusion, active transport, secondary active transport

diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

concentration (density) gradient

difference between two points

viscosity

how easily a liquid flows

osmosis

diffusion of water (solvent) across a selectively permeable membrane

osmotic pressure

for required to prevent water from moving across a membrane by osmosis

isomatic

solution and solvent have the same solute concentration

hypertonic

less water, more concentration in a substance compared to the other solution

hypotonic

more water, lower concentration in the substance compared to the other solution

hyperosmotic

solution with a greater concentration of solute

hypoosmotic

solution with a lesser concentration of solute

isotonic

no shrink or swell

hypertonic solution

cell shrinks

crenation

cell shrinking

hypotonic solution

the cell swells

lysis

cell swelling

filtration

works like a sieve

filtration

depends on the pressure difference on either side of the partition

greater, lower

Moves from an area of ___________ pressure to an area of ________________ pressure in filtration

filtration

urine formation in the kidneys is an example of ?

mediated transport

involves carrier proteins or channels in the cell membrane

specificity

for a specific type of molecule

competition

"fighting" among molecules of a similar shape to attach to a receptor

saturation

rate of transport limited to number of available carrier proteins

low, low, limited

when the concentration of x molecules outside the cell is __________, the transport rate is _________________ because it is ______________ by the number of molecules available to be transported

more, more, increases

when __________________ molecules are present outside the cell, as long as there are enough carrier proteins available, ____________________ molecules can be transported, therefore the transport rate _________________.

limited, rate

the transport rate is ________________ by the number of carrier proteins available and by the __________ at whidch each carrier protein can transport solutes.

saturated, increase

when the number of molecules outside of the cell is so large that all of the carrier proteins are occupied, the system is _________________ and the transport rate can no longer _____________________.

water soluable, electrically charged

mediated transport mechanisms move large ________________ ________________ or ___________________ _________________ molecules across the plasma membrane.

in, out

amino acids and glucose go __________, manufactured proteins go ____________.

facilitated diffusion

carrier or channel-mediated, passive

active transport

requires ATP

active transport

rate of transport depends on concentration of substrate and ATP

active transport

Na/K pumping charged molecules across the membrane to create a electrical potential is an example of what type of transport?

secondary active transport

ions or molecules move in same or different direction

symport

same

antiport

different

higher

Na is ____________ outside the cell (active)

carrier

Na moves back into the cell by a _____________ protein that also moves glucose

concentration gradient

The _________________ ___________________ for Na provides the energy required to move glucose against its concentration gradient.

endocytosis

internalization of substances by formation of a vesicle

endocytosis

All of the following are examples of __________________:
- phagocytosis
- pinocytosis
- receptor-mediated endocytosis

phagocytosis

cell eating

pinocytosis

cell drinking

receptor-mediated endocytosis

binding of ligands to receptors triggers vesicle formation

exocytosis

accumulated vesicle secretions expelled from the cell

exocytosis

All of the following are examples of ______________________:
- secretion of digestive enzymes by pancreas
- secretion of mucous by salivary glands
- secretion of milk by mammary glands

cytoplasm

composed of cytosol, cytoskeleton, cytoplasmic inclusions and organelles

cytoplasm

cellular material outside the nucleus, but inside the plasma membrane