220 likes | 484 Views
Organelles. Control: *Nucleus (plant and animal) Assembly, Transport, and Storage: *Nucleolus (plant and animal) *Endoplasmic reticulum (plant and animal) *Ribosomes (plant and animal) *Golgi apparatus (plant and animal) *Vacuoles (plant and animal)
E N D
Organelles • Control: *Nucleus (plant and animal) • Assembly, Transport, and Storage: *Nucleolus (plant and animal) *Endoplasmic reticulum (plant and animal) *Ribosomes (plant and animal) *Golgi apparatus (plant and animal) *Vacuoles (plant and animal) -one BIG one in plants; multiple small ones in animals *Lysosomes (plant and animal) • Energy transformations: *Chloroplasts (plant only) *mitochondria (plant and animal)
Nucleus • Contains most of eukaryotic cell’s genetic library (mitochondria and chloroplasts contain their own DNA…) • Largest organelle • Enclosed by nuclear envelope or membrane, which is a double membrane – each of which is a lipid bilayer!!! • Nuclear envelope has pores in it • Contains inactive DNA – chromatin
Nucleolus • Prominent structure in non-dividing nucleus • Ribosomal RNA and ribosomal subunits are made here
Endoplasmic reticulum – “highway system” • EXTENSIVE – accounts for more than half the total membrane system in eukaryotic cells • Name means “little net within the cytoplasm” • Smooth and rough e.r. are actually connected, not distinct, separate sections • Job is to transport materials quickly from one place to another in cell
Smooth e.r. • Functions in synthesis of lipids, metabolism of carbs, detoxification of drugs and poisons *Lipids – oils, phospholipids, steroids (sex hormones and adrenal hormones) *Liver cells – glycogen; gets converted to glucose phosphate which cannot leave cell, so e.r. makes enzyme that converts this to glucose *Detox – liver; adds hydroxyl groups to drugs, makes them soluble and able to be flushed out of body
Rough e.r. • Makes secretory proteins (ex. Insulin made by pancreatic cells) • Most are glycoproteins (proteins covalently bound to carbs) • Rough e.r. is also a membrane factory – grows by adding proteins and phospholipids; parts can be taken from here and added to other membrane systems using the vesicles for transport
Ribosomes“protein factories” • Sites of protein synthesis • Are made of rRNA and protein • Cells with high rates of protein synthesis have MANY ribosomes (human pancreas cell has MILLIONS of ribosomes) • Are “free” ribosomes in cytosol that make proteins for the cell that they are INSIDE of • Ribosomes that are attached to endoplasmic reticulum (bound) are making proteins for packaging and export OUTSIDE OF CELL
Golgi apparatus“Gift wrapper/UPS system” • Finishes, sorts, ships cell products • Golgi will modify products as needed – gives more variety by removing some monomers and substituting others
Vacuoles“Bank Vaults” or “trash cans” • Sites of storage in cells *good things stored – water, minerals, food etc. *bad things stored – broken down cell parts, waste
Lysosomes“suicide bags” • Membrane-bounded sac of hydrolytic enzymes • Different lysosomes break down each of the major classes of macromolecules – proteins, polysaccharides, fats, nucleic acids • Work best at pH of 5 • Used in autophagy – recycle the cell’s own organic material for use
Mitochondria and Chloroplasts“powerhouses” • Mitochondria – carry on cellular respiration – sites of energy production in cell (glucose broken down to produce ATP) • Chloroplasts – carry on photosynthesis – sites where sunlight, CO2 and water are converted into glucose
Other structural components of cell… • Cytoskeleton • Cilia and flagella
Cytoskeleton“hay in mud makes bricks” • Network of fibers extending into cytoplasm of cell • Provides structural support, and aids in cell motility and cell regulation • Made up of microtubules (thickest), microtubules (thinnest), and intermediate filaments
Cilia and Flagella“hairs and tails” • Cilia are short projections from cell body – hair-like • flagella are much longer – whip-like • Movement may not be for entire organism; may be part of a larger unit – ex. Cilia lining windpipe propel foreign substances out…
Organelles do not work alone… • Cell is a dynamic interaction of ALL of its parts – literally, the basic unit of life….