CELL STRUCTURES AND THEIR FUNCTIONS Flashcards
smallest units of life
cells
chemical reactions that occur within cells
cell metabolism
outermost component, encloses cytoplasm and forms the boundary between material components
cell membrane
structure of the plasma membrane, phospholipids form a double layer of molecules
fluid mosaic
O2 and CO2, pass directly through phospholips bilayer
cell membrane passage
movement of substance into and out of the cell
membrane transport
two methods of membrane transport
active and passive
no energy required
passive transport
require energy (ATP)
active transport
solute tends to move to an area where it is in higher concentration - low concentration
diffusion
types of diffusion
simple diffusion
osmosis
facilitated diffusion
filtration
unasisted, solutes are lipid soluble materials
simple diffusion
simple diffusion of water, highly polar waste easily crosses plasma membrane
osmosis
substances require a protein carrier for passive transport
facilitated diffusion
water and solutes are forced through a membrane by fluid or pressure
filtration
classes of cell membrane channels
leak channels and gated channels
allow ions to pass through
leack channels
limit the movement of ions across the membrane
gated channels
force required to prevent the movement of water
osmotic pressure
types of osmosis
hyptonic
isotonic
hypertonic
has a lower concentration of solute and higher concentration of water
hyptonic
concentrations of various solutes and water are the same on both sides
isotonic
higher concentration of solutes and lower concentration of water
hypertonic
mediated trasnport process, involving membrane proeins such as channels or carrier protein to move substance across the cell membrane
facilitated diffusion
utilizes memebrane proteins to move substances across the cell membrane
active transport
the malfunctions of active transport can lead to serious health conditions
cystic fibrosis
involves the active transport of one substance across the cell membrane, establishing a concentration agent which provides energy for moving a second substances
secondary active transport
diffusing subtance moves in the same direction
cotransport
diffusing substance moves in a direction opposite
countertransport
uptake of material through the cell membrane by the formation of a vesicle
endocytosis
often used for endocytosis when said particles are ingested
phagocytosis
much smaller vesicles are formed, contain liquid rather than solid
pinocytosis
release of substances from the cell through the fusion of a vesicle with the cell membrane
exocytosis
stages of mitosis
interphase
prophase
metaphase
anaphase
telophase
located at the center of the cell, contains genetic materials or DNA
nucleus
3 regions of nucleus
nuclear envelops
chromatin
nucleoli
acts as a barrier of the nucleus, has a phospholipid membrane and nuclear pores
nuclear envelope
condenses to form chromosomes when the cell divides
chromatin
diffuse bodies with no surrounding membrane, found within the nucleus
nucleoli
where proteins are produced, may be attached to other organelles
ribosomes
series of membranes forming sacs and tubules
endoplasmic reticulum
attached w ribosomes
rouch endoplasmic reticulum
without ribosomes
smooth endoplasmic reticulum
golgi complex, closely packed stacks of curved membrane-bound sacs, collect, modifies, packages, and distributes proteins and lipids
golgi apparatus
small membrane bound sac that transport or stores meterials, pinch off form golgi apparatus
secretory vesicles
membrane bound vesicles formed from the golgi apparatus, contain a variety of enzymes that function as intracellular digestive systems
lysosomes
small membrane bound vesicles containing enzymes that break down fatty acids, amino acids, and hydrogen peroxide
peroxisomes
small organelles with inner and outer membranes separated by a space, powerhouse of the cells, carries out reactions, provides ATP
mitochondria
folds in inner membranes
cristae
internal framework of the cell, consists of protein structures that support the cell, holds organelle in place and enable the cell to change shape
cytoskeleton
protein structures
microtubulues
microfilaments
intermediate filaments
hollow structures formed from protein subunits
microtubules
small fibrils formed from protein subunits that structurally support
microfilaments
fibrils that structurally support (smaller)
intermediate fibrils
centrosome is a specialized area of cytoplasm close to the nucleus where microtubule formation occurs
centrioles
project from the face of cells, vary in number, capable of mmoving, cylindrical structures, numerous on surface cells
cilia
extensions of the cell membrane supported by mirofilaments, not actively move as cilia and flagella do, abundant on surface cells that line the kidney and intestine
microvilli
process by which information stored in the genes of DNA molecules directs the manufacture of the various proteins of our cells
gene expression
sequences of nucleotides that provide a chemical set of intructions
genes
occurs in the nucleus, information stored in a region of the DNA is ised to produce a complementary mRNA
transcription
nucleotide sequence of the molecule is ised to determine the composition of a polypeptide chain, precursor to protein
translation
groups of three nucelotides, each specifies a particular amino acid, 64 possible mRNA, 20 amino acids
codons
