anatomy and physiology UWEC BIOL 214 Exam 1 Answers

carbohydrates

primary components of bread and candy

lipids

organic compound that includes cholesterol

protein

inlcudes enzymes

ATP

the energy currency of the cell and is made from glucose

cell shape: squamous

thin, flat, scaly

cell shape: discoid

disc-shaped

egg cells

very large, 100 um diameter

__% of membrane molecules are lipids

98

glycolipids

-5% of the membrane lipids
-phospholipids with short carb chains on extracellular face
-contributes to glycocalyx (carb coating on cell surface)
-COMPLEX CARB STUCK ONTO A LIPID

where is a proton found and what is its charge?

the nucleus +1

where is a neutron found and what is its electrical charge?

the nucleus 0

where is an electron found and what is its charge?

orbitals -1

proton defintion

positively charged particles in the nucleus of atoms

atom definiton

smallest piece of an element with the chemical and physical properties of the element

energy defintion

puts matter in motion

electron definition

negatively charged particle with a very small mass

ion

charged atoms that hace either lost or gained electrons

matter

examples are solids, liquids, and gases

element

made up of atoms and have the same atomic number

molecule

two or more atoms that are bonded together by covalent bonds

neutrons

particles in the nucleus with a mass of 1 AMU and no charge

valence

electrons in the other energy levels of atoms, involved in bonding

glucose

building blocks of carbs

steroids

a lipid that includes sex hormones

amino acids

building blocks of a protein

nucleic acids

DNA and RNA are examples

carbohydrates (glucose)

the single most important fuel source for body cells

lipids

used to insulate the body and found in all cell membranes

proteins

primary components of meat and cheese

RNA

is single-stranded and found in the cytoplasm of cells

DNA

is double-stranded and found in the nucleus of cells

cell theory (4 parts)

-all organisms are composed of cells and cell products
-an organisms structure AND function are due to activities of the cell
-cells only come from pre-existing cells
-cells of all species exhibit biochemical similarities

cell definition

simplest structural and functional unit of life

cell shape: cuboidal

squarish-looking

cell shape: columnar

taller than wide

how can a cell shape appear differently?

if it is viewed in a different type of section (longitudinal vs. cross section)

cell shape: polygonal

irregular angular shapes, multiple sides

cell shape: stellate

star-like

cell shape: spheroid to ovoid

round to oval

cell shape: fusiform

thick in the middle, thin at ends

cell shape: fibrous

thread-like

length of nerve cells

very long, can be over 1 meter long

limit of cell size

an overly large cell cannot support itself, it may rupture

for a given increase in diameter, ___ increases more than ___ ___

for a given increase in diameter, volume increases more than surface area

volume is proportional to...

cube of diameter

surface area is proportional to...

square of diameter

light microscope

shows plasma membrane, nucleus, and cytoplasm
+BACKBONE OF HISTOLGY

transmission electron microscope (TEM)

improved resolution

scanning electron microscope (SEM)

improved resolution further than TEM, but only for surface features

plasma membrane

-surrounds cell and defines boundaries
-made of proteins and lipids
-governs interactions with other cells
-controls passage of materials in and out of cell
-has intracellular and extracellular faces

cytoplasm

interior of a cell
(organelles, nucleus, cytoskeleton, inclusions, and cytosol)

extracellular fluid (ECF)

fluid outside of cells includes tissue (interstitial fluid)

phospholipids

-amphipathic molecules arranged in a bilayer
-hydrophilic phosphate heads face water on each side of membrane
-drift laterally, keeping membrane fluid

cholesterol

-20% of the membrane lipids
-holds phospholipids still and can stiffen membrane

membrane proteins

-2% of the molecules but 50% of the weight of the membrane

integral proteins

-penetrate membrane
-transmembrane proteins pass completely through
-hydrophilic regions contact cytoplasm, extracellular fluid
-hydrophobic regions pass through lipid of the membrane
-some drift in the membrane, others are anchored to the cytoplasm

peripheral proteins

-adhere to one face of the membrane (do not penetrate it)
-usually tethered to the cytoskeleton

function of membrane proteins

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

membrane protein
receptors

bind chemical signals

membrane protein
second messenger systems

communication within the cell
-receiving chemical message

membrane protein
enzymes

catalyze reactions including digestion of molecules, production of second messengers

channel proteins

allow hydrophilic solutes and water to pass through membrane
-some are always open, some are gated

channel proteins
ligand-gated channels

respond to chemical messengers

channel proteins
voltage-gated channels

respond to charge changes

channel proteins
mechanically-gated channels

respond to physical stress on cell
ex: inner ear cells

carriers

bind solutes and transfer them across the membrane
-pumps-carriers that consume ATP

membrane proteins
cell-identity markers

gylcoproteins acting as identification tags

membrane proteins
cell-adhesion molecules

mechanically link to cell to extracellular material

G-proteins

-take a small extracellular signal and amplify it intracellularly
-chemical first messenger (epinephrine) binds to a surface receptor
-surface receptor changes shape and initials chemical reactions inside of cell

2 common secondary messengers

-cAMP
-Ca2+

up to __% of drugs work through G proteins and second messengers

60

if there is a weak signal stuck on the outside of the cell, there will be a _____ _____ on the inside

strong signal

when something changes shape....

it changes function

glycocalyx

fuzzy coat external to plasma membrane
-carb moieties of glycoproteins and glycolipids
-unique in everyone BUT identical twins

functions of glycocalyx

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

microvilli

extensions of membrane (1-2um)
-GIVES 15-40 TIMES MORE SURFACE AREA
-specializes cells absorption

how do microvilli appear on some absorptive cells?

a brush border, very dense

what do some microvilli contain?

actin filaments that are tugged towards the center of the cell to get more contents into the cell

with faster transport, you can absorb more ____ quicker

nutrients

motile cilia

beat in waves sweeping material across a surface in one direction
-50-200 on each cell
-beat freely within a saline layer at cell surface

Cl pumps pump Cl- into ECF
Na+ and H2O follow
-mucus floats on top of saline layer

where can you find cilia?

respiratory tract, uterine tubes, ventricles of brain, ducts of testes

cystic fibrosis

heredity disease in which cells make chlorine pumps, but fail to install them in the plasma membrane
-chlorine pumps fail to create adequate saline layer on cell surface
-instead of recycling mucus, they keep the bacteria filled mucus
-HIGH RISK OF PNEUMONIA

what causes cystic fibrosis?

thick mucous plugs pancreatic ducts and respiratory tract

what are the symptoms of cystic fibrosis

-inadequate digestion of nutrients and absorption of oxygen
-chronic respiratory infections
-life expectancy of 30

flagella

tail of sperm, only functional flagellum in humans
-whip-like structure with axoheme identical to cilium's
-much longer than cilium
-stiffened by coarse fibers that support the tail
-movement is snail-like
-no power stroke or recovery strokes

Pseudopods

continually changing extensions of the cell that vary in shape and size
-can be used for cellular locomotion, capturing foreign particles
*temporary extension of a cell

Pseudo=

fake/false

Do passive mechanisms require ATP?

no!

where does the energy come from for passive mechanisms?

random molecular motion of particles provide necessary energy

examples of passive mechanisms

filtration, diffusions, osmosis

carrier-mediated machanisms

use a membrane protein to transport substances across membrane

filtration

particles are driven through membrane by physical pressure
ex:
-filtration of water and small solutes through gaps in capillary walls
-allows delivery of water and nutrients to tissues
-allows removal of waste from capillaries in kidneys

simple diffusion

net movement of particles from place of a high concentration to a lower
-doesn't require a membrane
-substances can diffuse through a membrane if the membrane is permeable to the substance

what causes simple diffusion?

constant, spontaneous molecular motion (molecules collide and bounce off each other)

what factors affect diffusion rate?

1- temp (higher temp=faster diffusion)
2- molecular weight (bigger=slower)
3- steepness of concentration gradient
4- membrane surface area (more surface area, the faster)
5- membrane permeability (higher permeability, faster diffusion)

osmosis

net flow of water through a selectively permeable membrane (water moves from a more concentrated area to a side where its less concentrated)

what does solute particles do when they can't pass through the membrane?

they draw water from the other side

what is crucial consideration for I.V. fluids?

osmosis... osmotic imblances underlie diarrhea, costipation, and edema

aquaporins

channel proteins in membrane specialized for water passage
(water can diffuse thru phospolipid bilayers, but osmosis is enhanced by these)
CELLS CAN SPEED OSMOSIS BY INSTALLING MORE AQUAPORINS

osmotic pressure

the pulling force, it increases as the amount of nonpermeating solute rises (ex: salt or protein)