CELLULAR PHYSIOLOGY Flashcards
cells are organized into 3 main regions
nucleus cytoplasm plasma membrane
70-85%, principal fluid medium of the cell, where chemical reactions take place
water
10-20%, both structural and functional
proteins
proteins that form the cytoskeleton of the cellular organelles
structural proteins
proteins that act as enzymes to control metabolic functions
functional proteins
2% of cells mass, forms the cell membrane and intracellular membrane barriers that separate the cell components,
fats stored in cells are the main storehouse of energy giving nutrients
lipids
1% of cell mass, major nutrition of the cell, little structural function as part of glycoproteins
carbohydrates
provides inorganic chemicals for cellular reaction
ions
aqueous solution that contains organic molecules, organelles and inclusions
cytoplasm
a network of tubular and flat vesicular structures in the cytoplasm, connected to the nuclear membrane, highway of the cells
endoplasmic reticulum
ribosomes are attached to the cytoplasmic side of the membrane ,
site of the translation of mRNA and postranslational modification of proteins to be secreted from the cells
rough endoplasmic reticulum
no attached ribosomes, functions for the synthesis of lipids, site of steroid synthesis, site of detoxification process in other cells
smooth endoplasmic reticulum
complex structure containing mixture of proteins and RNA, sites of protein synthesis, found either attached to ER or floating free in the cytosol
ribosomes
stack of flattened membrane sac, provides processing and forms secretory vesicles containing proteins to be secreted through the cell membrane, packaging of the cells
golgi apparatus
powerhouse of the cell, site where ATP is generated through oxidative phosphorylation, bounded by a two-lipid bilayer membrane, contains DNA controlling replication
mitochondria
vesicular organelles formed from golgi apparatus, contains hydrolytic enzymes,
digestive system of the cell
lysosomes
dissolves bacterial cell membrane
lysozyme
binds iron before they promote bacterial growth
lysoferrin
Genetic disorder caused by absence of single lysosomal enzyme
seizures, muscle rigidity, blind, demented, and dead before the age of 5
Tay-Sachs Disorder
similar to lysosomes except it buds off from the endoplasmic reticulum, contains oxidative enzymes.
microbodies
peroxisomes
contractile elements in muscle cells
microfilaments
structural support
intermediate filaments
intracellular transport of vesicles, chromosome movement during mitosis, movement of cilia and flagella
microtubules
cilia
for locomotion, dynein responsible for the whiplike movement of the cilia
an autosomal recessive disorder in which dynein is missing in cilia and in males the flagella of sperm-infertile males
impaired mucociliary transport
kartagener’s syndrome
control center of the cell
control and promote reproduction of cell
nucleus
double membrane with spaces between called perinuclear cisterns
contains nuclear pores through which transport of proteins and mRNA occurs
nuclear membrane
staining structure inside the nucleus
site of ribosome synthesis
granules rich in RNA
most prominent and numerous in growing cells
Nucleolus
basophilic material composed of DNA and associated proteins (histones)
scattered throughout the nucleoplasm
condenses to form chromosomes when the cell divides
chromatin
separates intracellular contents from extracellular environment
lipid bilayer with associated proteins
plasma membrane
regulates transport of molecules into and out of the cell
selective permeability
restricts passages of some substances while permitting the passage of others
semipermeable
embedded in lipid bilayer
transmembrane proteins
channel or carrier protein
integral protein
bind to integral proteins
easily removed
enzyme or signal transducer
peripheral proteins
related to the effect of the solution to the volume of the cell
tonicity
solution with the higher concentration of solutes
hypertonic
solution with lower concentration of solutes
hypotonic
solution with equal solute concentrations
isotonic
occurs when a membrane separating 2 solutions is permeable to some but not all the molecules in solution
Gibbs donnan effect
hypotonic media: cells swell
transports osmotically active particles out of cells — decrease osmotic pressure and restore cell volume to normal
regulatory volume decrease
hypertonic media: cells shrink
transports osmolytes into cell — increase intracellular osmotic pressure - restores cell volume to normal
regulatory volume increase
spontaneous process by which a substances moves from a region of higher concentration to a region of lower concentration driven by thermal motion of molecules
diffusion
transport of substances down their concentration/electrochemical gradient using carrier proteins
does not require energy
carrier mediated diffusion
ex: glucose transporter
facilitated diffusion
substances and solvent move across the membrane driven by a hydrostatic pressure gradient
solute containing fluid pushed from a high pressure area to a lower pressure area
