Organelle Memorization Flashcards
organelles
specialized structures within the cell that have characteristic shapes; perform specific functions in cellular growth, maintenance, and reproduction
centrosome
pair of centrioles plus pericentriolar matrix
centrioles
cylindrical structures, each composed of nine clusters of microtubular triplets arranged in a circular pattern
cilia
motile cell surface projections that contains 20 microtubules and a basal body
flagella
similar structure to cilia but much longer
moves an entire cell
only present in sperm
ribosomes
composed of two subunits containing ribosomal RNA and proteins; may be free in cytosol or attached to rough ER
endoplasmic reticulum (ER)
a network of membranes in the form of flattened sacs or tubules; extends from the nuclear envelope and projects throughout the cytoplasm
rough ER
continuous with the nuclear membrane and usually is folded into a series of flattened sacs
has ribosomes on its surface
synthesizes glycoproteins and phospholipids that are transferred to cellular organelles, inserted into the plasma membrane, or secreted during exocytosis
smooth ER
extends from the rough ER to form a network of membrane tubules
does not have ribosomes on the surface
synthesizes fatty acids and steroids; detoxifies drugs and other potentially harmful substances; stores and releases calcium ions, removes phosphate group from glucose-6-phosphate
function of Golgi complex
modifies, sorts, packages, and transports proteins received from the rough ER; forms secretory vesicles that discharge processed proteins via exocytosis into extracellular fluid; forms membrane vesicles that ferry new molecules to the plasma membrane; forms transport vesicles that carry molecules to other organelles, such as lysosomes
lysosomes
vesicle formed from Golgi complex; contains digestive enzymes
peroxisomes
similar in structure to lysosomes but smaller; contain oxidases, enzymes that can oxidize various organic substances
proteasomes
tiny barrel-shaped structures consisting of four stacked rings of proteins around a central core
mitochondria
consists of an external and an internal mitochondrial membrane, mitochondrial cristae, and mitochondrial matrix; new mitochondria form from preexisting ones
nucleus
consists of a nuclear envelope with pores, nucleoli, and chromosomes,, which exist as a tangled mass of chromatin in interphase cells
nuclear envelope
a double membrane that separates that nucleus from the cytoplasm
nuclear pores
openings that extend through the nuclear envelope
nucleoli
spherical bodies within the nucleus that function in producing ribosomes
plasma membrane
fluid mosaic lipid bilayer (phospholipids, cholesterol, and glycolipids) studded with proteins; surrounds cytoplasm
function of plasma membrane
protects cellular contents; makes contact with other cells; contains channels, transporters, receptors, enzymes, cell-identity markers, and linker proteins; mediates entry and exit of substances
cytoplasm
cellular contents between plasma membrane and nucleus - cytosol and organelles
function of cytoplasm
site of all intracellular activities except those occurring in the nucleus
cytosol
composed of water, solutes, suspended particles, lipid droplets, and glycogen granules
function of cytosol
fluid in which many of cell’s metabolic reactions occur
cytoskeleton
a network in the cytoplasm composed of three protein filaments: microfilaments, intermediate filaments, and microtubules
function of cytoskeleton
maintains shape and general organization of cellular contents; responsible for cell movements
function of centrosome
the pericentriolar matrix contains tubulins, which are used for growth of mitotic spindle and microtubule formation
function of cilia
moves fluids over cell’s surface
function of ribosomes
protein synthesis
Golgi complex
consists of 3-20 flattened membranous sacs called saccules; structurally and functionally divided into entry face, medial saccules, and trans face
function of lysosomes
fuses with and digests contents of endosomes, phagosomes, and vesicles formed during bulk-phase endocytosis and transports final products of digestion into cytosol; digests worn-out organelles (autophagy), entire cells (autolysis), and extracellular materials
function of peroxisomes
oxidizes amino acids and fatty acids; detoxifies harmful substances, such as alcohol and hydrogen peroxide and associated free radicals
function of proteasomes
degrades unneeded, damaged, or faulty proteins by cutting them into small peptides
function of mitochondria
site of aerobic cellular respiration reactions that produce most of a cell’s ATP; plays an important early role in apoptosis
function of nucleus
nuclear pores control the movement of substances between the nucleus and cytoplasm, nucleoli produce ribosomes, and chromosomes consist of genes that control cellular structure and direct cellular functions
