cell physiology

physical isolation, metabolic isolation, sensitivity, structural support

functions of plasma membrane

passive

transport that does not require ATP

active

transport that requires ATP

diffusion, osmosis, filtration, dialysis, facilitated diffusion

types of passive isolation

temperature, size, solubility in a lipid, ability to ionize, presence of carrier

factors that affect diffusion

endocytosis and exocytosis

types of active transport

receptor mediated, pinocytosis, phagocytosis

types of endocytosis

true

t/f: phospholipid bilayer forms the basis of plasma membrane

false

t/f: plasma membrane is kept fluid by the presence of chitin wedged between phospholipids

true

t/f: most integral proteins pass entirely through the phospholipid bilayer of the plasma membrane

false

t/f: peripheral proteins are most often found attached to glycolipids

true

t/f: plasma membrane is permeable to CO2 and O2

true

t/f: plasma membrane is permeable to H2O

false

t/f: plasma membrane is permeable to ions and most nutrient molecules

true

t/f: rate of diffusion can be affected by temperature

false

t/f: hypertonic solution has a higher concentration of water molecules than a hypotonic solution

true

t/f: hypotonic solution has a lower concentration of solute than a hypertonic solution

true

t/f: blood cells placed in a hypertonic solution will crenate

false

t/f: it takes about 1 hour to complete a good session of hemodialysis

true

t/f: simple sugars, such as fructose, glucose, and galactose, are moved across the plasma membrane by the transporter protein GLUT-1

false

t/f: glucose transport via GLUT-1 is an active transport process

true

t/f: uptake of tiny droplets of extracellular fluid is termed pinocytosis

false

t/f: in the process of phagocytosis, the plasma membrane invaginates

false

t/f: role of ribosomes in protein synthesis is to carry out transcription

true

t/f: genes describe how to make proteins by putting the correct amino acids into a long chain in the correct order

A-U, G-C

RNA bases

A-T, G-C

DNA bases

permeability

the ease w which a substance may pass through a membrane

permeable

will allow substance to pass freely

semipermeable

will allow some substances to pass but not all

impermeable

will not allow substances to pass

passive membrane processes

methods that do not involve the expenditure of cell energy

diffusion, facilitated diffusion, osmosis, filtration, dialysis

passive membrane processes (5)

active transport (solute pumping), bulk transport

active membrane processes

active transport processes

methods in which cell energy is expended to move substances across the plasma membrane

diffusion

the movement of molecules or ions from areas of high concentration to areas of low concentration

concentration gradient

the difference between the high and low concentration

equilibrium

point of even molecular distribution

facilitated diffusion

transport of substances across the plasma membrane w the help of carrier molecules

osmosis

net movement of water across a selectively permeable membrane driven by a difference in solute concentrations on the two sides of the membrane

isotonic

the solutions being compared have equal concentrations of solutes

hypertonic

the solution w the higher solute concentration

hypotonic

the solution w the lower solute concentration

filtration

process by which water and solutes are forced across a body membrane or vessel wall by the hydrostatic pressure

dialysis

process by which small molecules are separated from larger ones by passing a solution through a semipermeable membrane

active membrane process

cell expends energy to move substances across the plasma membrane

active transport

similar to facilitated diffusion (involves carrier proteins); different than facilitated diffusion (substances move against concentration gradient); most important substances transported (amino acids and ions)

solute pumping

active transport aka...

bulk transport

large particles and macromolecules are transported through the plasma membrane

endocytosis and exocytosis

2 types of bulk transport

exocytosis

substances are moved from the cell interior to the extracellular space; includes hormone secretion, mucus secretion, neurotransmitter release, and ejection of wastes

endocytosis

substances are moved from the extracellular space to the cell interior; involves vesicle formation

phagocytosis, pinocytosis, and receptor mediated

3 types of endocytosis

pinocytosis

cell drinking; small droplets containing dissolved materials are taken in by the cell; important in cells that function in absorption

phagocytosis

cell eating; large or solid materials are taken in by the cell

receptor mediated endocytosis

active uptake of specific substances from the extracellular environment; plasma membrane invaginates in a method similar to pinocytosis; invagination is stimulated when specific molecules (ligands) bind to receptors (integral proteins) in the plasma membrane

sensitivity

ability to respond to a stimulus environmental change

irritable

sensitivity is aka...

transmembrane potential

measured difference of positive and negative charges across the plasma membrane from one side to the other

electrolytes

positive or negative charged ions

voltage

electrical potential energy resulting from the separation of oppositely charged particles (ions)

volt

unit used to describe the electrical potential; the higher the volts the greater the difference in charge

millavolt (mV)

used to measure transmembrane potential since it is so small; 1/1000th of a volt (1000 mV per volt)

genes

contains all the codons necessary to produce a given polypeptide

mRNA

messenger that carries info from the nucleus (DNA) to the cytoplasm and ribosomes

polypeptide

primary structure of a protein

mRNA

what transports amino acids to the ribosomes for protein synthesis?

methionine

1st amino acid in formation of proteins

integral proteins

embedded in the lipid bi layer (transmembrane protein)

glycoprotein

integral protein w carbohydrate group attached

carbohydrate

forms plate-like wedges that keep membrane fluid

glycolipid

lipid w carbohydrate attached

peripheral protein

not embedded in lipid bi layer

glycocaylx

sticky coat on cell surface

isotoic

solution w same concentration of water and solutes as cell cytoplasm

hypotonic

solution w few dissolved particles

hypertonic

solution w high solute concentration and low water concentration

invagination

folding in of plasma membrane resulting in the formation of vescicle

chemotaxis

movement of body toward chemical attractant

false

t/f: passive membrane does involve the use of energy

bolus

large amount instantly to bottom

true

t/f: net movement where equilibrium is reached occurs in diffusion

mole

6.022x10^23 atoms

true

t/f: diffusion takes place along the concentration gradient

nonpolar

nonpolar/polar: lipid- chains and head

polar

nonpolar/polar: water

false

t/f: facilitated diffusion does require the cell to expend energy

true

t/f: facilitated diffusion involves large insoluble substances like glucose and ions

true

t/f: polar will dissolve in water except when supersaturation

false

t/f: nonpolar dissolved in water

true

t/f: osmosis always goes toward solution w the higher concentration

true

t/f: osmosis is the water that flows from the solution w the lower solute concentration to the solution w the higher solute concentration

tertiary structure

functional form of protein

amino acid

building blocks of proteins

codon

3 letter word for individual amino acid on mRNA strand

alpha helix

spiral shaped secondary protein structure

replication

duplication of DNA

primary structure

sequence of amino acid that makes up protein

transcription

construction of mRNA

anticodon

3 letter word in tRNA