UC A&P1 Hedderson - CH 3

true

T or F: Cells are responsible for all structural and functional properties of a living organism

true

T or F: understanding cells is important for understanding workings of the human body, mechanisms of disease, and rationale of therapy

Cells

____ are the simplest structural and functional unit of life

cell theory

The idea that all living things are composed of cells and that all cells come from other cells defines

true

T or F: Cells of all species exhibit biochemical similarities

200

about how many types of cells are found in the human body?

squamous

(type of cell) thin, flat, scaly

cuboidal

(type of cell) square looking

Columnar

(type of cell) taller than wide

polygonal

(type of cell) irregularly angular shapes, multiple sides

stellate

(type of cell) star-like

spheroid to ovoid

(type of cell) round to oval

discoidal

(type of cell) disc-shaped

fusiform

(type of cell) thick in the middle, tapered towards the ends

fibrous

(type of cell) thread-like

plasma membrane

border of the cell; surrounds cell, defines boundaries, made of proteins and lipids

cytoplasm

A cytosol fluid inside the cell in which the organelles are suspended, and where the cytoskeleton and inclusions are found.

cytosol

Fluid portion of cytoplasm

extracellular fluid

Fluid outside of cells includes tissue (interstitial) fluid

false

T or F: the plasma membrane has only an intracellular face

function of plasma membrane

-defines cell boundaries

-governs interactions with other cells

- controls passage of materials in and out of cell

lipids

98% of the plasma membrane molecules are ____

75%

percentage of membrane lipids that are phospholipids

Amphipathic

phospholipids are ______, meaning that they have a hydrophilic head and a portion of hydrophobic tails

20%

percentage of plasma membrane lipids that are cholesterol

cholesterol

_____ holds phospholipids still and can stiffen the plasma membrane

5%

percentage of plasma membrane lipids that are glycolipids

glycolipids

phospholipids with short carbohydrate chains on extracellular face

glycocalyx

the carbohydrate coating on a cell's surface

integral, peripheral

membrane proteins consist of ____ proteins and _____ proteins

integral

____ proteins are those that penetrate the membrane and pass completely through

amphipathic

integral proteins are ______ since they have hydrophilic regions that contact cytoplasm and extracellular fluid, and a hydrophobic region that passes through the lipid membrane

true

T or F: some integral proteins drift in the membrane while others are anchored to the cytoskeleton

peripheral

_____ proteins adhere to one face of the plasma membrane and are usually tethered to the cytoskeleton

membrane proteins

functions of ____ include:

- receptors, second-messenger systems, enzymes, channels, carriers, cell-identity markers, cell-adhesion molecules

receptor

(membrane protein) binds chemical signals

second messenger systems

(membrane protein) communicate within the cell receiving chemical message

enzymes

(membrane protein) catalyze reactions including digestion of molecules

enzymes

responsible for the production of secondary messenger systems

channel proteins

(membrane protein) that allow hydrophilic solutes and water to pass through the membrane, some are gated and some are always open

ligand-gated

_____ channels respond to chemical messengers

voltage-gated

____ channels open or close in response to changes in membrane potential / charge changes

mechanically gated

____ channels that respond to physical stress on the cell and receptors

nerve, muscle

channel proteins are crucial to ___ and ___ function

carrier

___ proteins bind solutes and transfer them across membranes

pumps

carrier proteins that consume ATP

cell-identity markers

glycoproteins acting as identification tags

cell-adhesion molecules

mechanically link cell to extracellular material

cAMP

main secondary messenger

G

the ____ protein relays a signal to adenylate cyclase which converts ATP to cAMP

cAMP

____ activates cytoplasmic kinases

phosphate groups

kinases add _______ to other enzymes to turn some on and some off

Glycocalyx

carbohydrate coating on cell surface

glycocalyx functions

Functions:

- protection, cell adhesion, immunity to infection, fertilization, defense against cancer, embryonic development, transplant compatibility

microvilli

extensions of the plasma membrane that serve primarily to increase a cell's surface area by 15-40x

absorption

the best developed microvilli specialized in ___

actin filaments

protein fibers of microvilli that are tugged toward the center of the cell to milk absorbed contents into the cell

cilia

Hairlike projections that extend from the plasma membrane

function of cilia

to act as antenna for monitoring nearby conditions, help with balance in inner ear, and light detection in retina

sensory cells of the nose

multiple nonmotile cilia are found on the _____

ciliopathies

defects in structure and function of cilia

motile cilia

cilia found in respiratory tract, uterine tubes, ventricles of brain, ducts of tests

motile cilia

usually 50-200 of these on each cell that help sweep materials across cell surface

axoneme

core of motile cilium

axoneme structure

2 central microtubules surrounded by a ring of 9 pairs that anchor cilium to the cell as part of the basal body

dynein arms

responsible for the bending of cilium that uses ATP as energy

cyctic fibrosis

hereditary disease in which cells make chloride pumps but fail to install them in the plasma membrane, thick mucus plus pancreatic ducts and respiratory tract

chloride pumps

responsible for creating adequate saline layers on the cells surface for cilia to function correctly

30

what is life expectancy for cystic fibrosis?

incomplete digestion of nutrients and absorption of oxygen, chronic respiratory infections

what is the result of thick mucus plugs on pancreatic ducts and respiratory tract in individual's with cystic fibrosis?

flagella

whiplike tails found in one-celled organisms to aid in movement

flagella

tail of sperm is a _____

false

T or F: cilia are much longer than flagella

true

T or F: flagella are stiffened by coarse fibers that support the tail

true

T or F: flagella movement has no power stroke, unlike cilia

pseudopods

continually changing extensions of the cell that vary in size and shape, utilized in cellular locomotion and capturing foreign particles

selective permeability

A property of a plasma membrane that allows some substances to cross more easily than others

Passive

____ mechanisms require no ATP since the random motion of particles provides necessary energy

filtration, diffusion, osmosis

examples of passive membrane mechanisms

active

_____ mechanisms require active transport and vesicular transport and consume ATP for membrane transport

carrier-mediated

_____ mechanisms use a membrane protein to transport substances across a membrane

filtration

particles are driven through membrane by physical pressure

true

T or F: filtration of water and small solutes through gaps in capillary walls allows for the delivery of water and nutrients to tissues and removes waste from capillaries in the kidneys

simple diffusion

net movement of particles from place of high concentration to place of lower concentration

down

substances diffuse ___ their concentration gradient

increase

_______ diffusion rate through a membrane due to:

- increased temp/increase motion of particles

- decreased MW

- bigger concentration difference

- more membrane surface area

- more permeability

osmosis

net flow of water through a selectively permeable membrane from areas of low solute concentration to areas of high solute concentration

diarrhea, constipation, edema

Name three symptoms of osmosis imbalance.

aquaporins

channel proteins that facilitate the passage of water

osmotic pressure

hydrostatic pressure required to stop osmosis

false

T or F: the osmotic pressure decreases as the amount of nonpermeating solutes rises

reverse osmosis

process of applying mechanical pressure to overide osmotic pressure

Tonicity

The ability of a solution surrounding a cell to affect the cells fluid volume and pressure in the cell

nonpermeating solutes

Tonicity depends on the concentration of _______

hypotonic solution

Solute concentration is less than that inside the cell; cell gains water

hypertonic solution

Solute concentration is greater than that inside the cell; cell loses water

isotonic solution

a solution whose solute concentration is equal to the solute concentration inside a cell; no cell change

False

T or F: when a solute is released from the carrier protein on the opposite side of the membrane, the solute is changed

true

T or F: transport proteins are specific for particular solutes where the solute binds to a receptor site on a carrier protein

increases

as the solute concentration increases, the rate of transport _____ but only to a certain point