chapter three Flashcards
membranes
fundamental component that makes a cell a cell, defines inside of cell from outside of cell, tissues that line a cavity, separate the cellular interior from extracellular environment
what are the functions of the cell (plasma) membrane or plasmalemma?
physical barrier, gateway for exchange, communication, cell structure
physical barrier
separates intracellular fluid and extracellular fluid
gateway for exchange
regulates exchange between intracellular compartments and interstitial fluid
communication
signals surrounding cells and senses extracellular environment
cell structure
anchor cytoskeleton, form tissues
what can substances move through?
non-polar molecules (fatty acids, vitamins A, D, E, K, steroids), oxygen, carbon dioxide, water
what can substances not move through?
ions (sodium, potassium, calcium, hydrogen), polar molecules (polysaccharides, amino acids, glucose, nucleic acids)
is water polar or non-polar?
polar
integral
any protein that is physically embedded in the membrane
transmembrane (integral)
all transmembrane proteins are integral, but not all integral are transmembrane
peripheral
not integral, not transmembrane, closely associated with the membrane but not embedded in membrane
what are eukaryotic cells?
human cells
where are eukaryotic cells divided?
on the inside with organelles
cell theory
cell is made of many different components
cytosol
the semi-liquid portion of the cytoplasm not occupied by organelles
cytoplasm
the interior of a cell other than the nucleus
nucleus
internal organelle that contains the genetic material for cellular reproduction
mitochondria
“powerhouse of the cell”; a double-membrane organelle that produces the ATP through oxidative phosphorylation (membrane bound structure)
endoplasmic reticulum
flat series of membrane layers that specializes in secretion of substances
rough (granular) ER
has ribosomes on the surface for protein synthesis, molecules enter ER and are packed for secretion from the cell (neurotransmitter & hormones) (make & secrete proteins)
smooth (agranular) ER
no ribosomes, used for sorting of molecules, specializes in lipid synthesis, calcium storage, makes lipids (steroids)
Golgi complex
set of flat, stacked, membranous sacs that process raw material transported from the ER into finished products, sorts and directs the finished product to their final destination
cytoplasmic vesicles
lysosomes, peroxisomes, transport vesicles