Semester Exam: organelles and functions Flashcards
Cystoplasm
between plasma membrane and nucleus
includes: cytosol, cytoplasmic organelles, and inclusions
membranous organelles
mitochondria perioxisomes lysosomes endoplasmic reticulum golgi apparatus
nonmembranous organelles
cytoskeleton
centrioles
ribosomes
mitochondria
Double-membrane structure with shelflike cristae
Provide most of cell’s ATP via aerobic cellular respiration
Contain their own DNA and RNA
ribosomes
contain protein and rRNA
protein synthesis
free ribosomes synthesize
soluble proteins
membrane bound ribosomes (on rough ER) synthesize
proteins to be incorporated into membranes or exported from the cell
Endoplasmic reticulum
tubes and membranes enclosing cisternae
continuous with nuclear membrane
rough and smooth
Rough ER
covered in ribosomes
makes secreted proteins, integral proteins, and phospholipids
Smooth ER
tubules arranged in a looping network
golgi apparatus
Stacked and flattened membranous sacs
Modifies, concentrates, and packages proteins and lipids
Secretory vesicles leave trans face of Golgi stack and move to designated parts of cell
Lysosomes
membranous bags containing digestive enzymes
digest, degrade, and break down unwanted items
endomembrane overall function
Produce, store, and export biological molecules
Degrade potentially harmful substances
peroxisomes
Membranous sacs containing powerful oxidases and catalases
Detoxify harmful or toxic substances
Neutralize dangerous free radicals
Cytoskeleton
Elaborate series of rods throughout cytosol
Microtubules
Microfilaments
Intermediate filaments
microfilaments
Dynamic actin strands attached to plasma membrane
microfilaments are involved in
Involved in cell motility, change in shape, endocytosis and exocytosis
Intermediate Filaments
Tough, insoluble ropelike protein fibers
Resist pulling forces on the cell and attach to desmosomes
Microtubules
Dynamic hollow tubes
Most radiate from centrosome
Determine overall shape of cell and distribution of organelles
Motor Molecules
Protein complexes that function in motility
powered by ATP
Centrosome
“Cell center” near nucleus
Generates microtubules; organizes mitotic spindle
Contains centrioles
centrioles
Small tube formed by microtubules
Cilia and flagella
Whiplike, motile extensions on surfaces of certain cells
Contain microtubules and motor molecules
Cilia move substances across cell surfaces
Longer flagella propel whole cells
Microvilli
Fingerlike extensions of plasma membrane
Increase surface area for absorption
Core of actin filaments for stiffening
nucleous
contain DNA
blueprints for cellular proteins
nuclear envelope
Double-membrane barrier containing pores
nuclear envelope:
outer layer, inner layer, pores
Outer layer is continuous with rough ER and bears ribosomes Inner lining (nuclear lamina) maintains shape of nucleus Pore complex regulates transport of large molecules into and out of nucleus
Nucleoli
Dark-staining spherical bodies within nucleus
Involved in rRNA synthesis and ribosome subunit assembly
