Cell Organelles
Plasma Membrane comprised of a phospholipid bilayer and embedded proteins Outer surface has oligosaccharides separates the cells s contents from its surroundings
Cytosol the fluid Cytoplasm cell interior, everything outside the nucleus but within the cell membrane, includes the organelles, cytosol, and molecules and ions dissolved or suspended in the cytosol
Nucleus: contains DNA Nucleoplasm, Nuclear Matrix thick fluid, fills the nucleus, network of protein fibres provide internal structure and support Nucleolus denser region containing RNA, protein, and chromatin Nuclear Envelope surrounds the nucleus, protects DNA Nuclear Pore Complexes intricate protein ring surrounds each pore, regulates the entry and exit of certain large macromolecules
Nucleus
Ribosomes made of ribosomal RNA and protein, carry out protein synthesis, composed of two subunits Endoplasmic Reticulum extensive membranes in the form of tubules and sacs, that separates the internal compartments from the cytosol
Smooth Endoplasmic Reticulum lacks ribosomes metabolic processes including synthesis of lipids, metabolism of carbohydrates, and detoxification of drugs and poisons (liver) Rough Endoplasmic Reticulum has ribosomes attached synthesis of proteins by ribosomes, folding of proteins inside RER, attachment of carbohydrate (oligosaccharide) to protein to get glycoproteins
Endoplasmic Reticulum
Golgi apparatus Flattened membranous sacs, vesicles nearby, Has a cis-face (receiving side of GA) and transface (shipping side of GA) Cis face near the ER, with vesicles transporting material from ER to Golgi. Transport vesicles Products of the ER are modified and stored and then sent to other destinations. Makes some polysaccharides. Trans face near cell membrane. Secretory vesicles.
Golgi Apparatus Cis face receiving side of Golgi apparatus Trans face shipping side of Golgi apparatus Vesicles: Bud like sacs that form from ER and Golgi apparatus, and transport materials around cell, and secrete to exterior
Lysosomes membrane bound sac containing hydrolytic enzymes digests macromolecules, has an acidic environment, Autophagy - carry out recycling for cell Phagocytosis - also involved in digestion when single celled organisms engulf smaller organisms Autodigestion - also involved in destroying the cell when a large number of lysosomes open up into the cell (cell suicide/apoptosis)
Lysosome: formation and function 6. 7. 1. 2. 3. 4. 5. 1. Transport vesicle containing inactive hydrolytic enzymes buds off the ER membrane. 2. Golgi apparatus activates hydrolytic enzymes. 3. Lysosomes containing active enzymes bud off the Golgi membrane. 4. Autophagy A lysosome engulfs a damaged organelle. 5. Hydrolytic enzymes digest particles engulfed by lysosomes; breakdown products pass across lysosome membrane into cytosol. 6. Phagocytosis a food vacuole pinches off of the plasma membrane enclosing a food particle 7. Food vacuole fuses with lysosome.
Vacuoles vacuoles are larger than vesicles various functions; food vacuoles formed by phagocytosis, contractile vacuoles pump excess water out of the cell, plant cells have a large central vacuole enclosed by a membrane called a tonoplast central vacuole holds important organic compounds, some vacuoles contain pigments, major role in growth by elongation
Chloroplasts enclosed by a double membrane, have their own ribosomes, and a small amount of DNA, they reproduce themselves, inner and outer membranes separated by a narrow intermembrane space, inside is another membrane system in the form of flattened sacs called thylakoids, stacks of thylakoids make up a granum, the fluid surrounding the thylakoids/grana is the stroma, the membrane encloses thylakoid space found only in plants and algae, site of photosynthesis, convert solar energy to chemical energy by absorbing sunlight and using it to drive the synthesis of organic compounds from carbon dioxide and water,
Chloroplasts
Mitochondria found in all cells, including plants and animals, enclosed by a double membrane, have their own ribosomes and a small amount of DNA, they reproduce themselves. inner membrane is highly folded into cristae, two internal compartments intermembrane space and mitochondrial matrix enclosed by the inner mitochondrial membrane membranes have a collection of proteins embedded in them sites of cellular respiration, catabolic process that generates ATP by extracting energy from sugars, fats and other fuels with the help of oxygen
Mitochondrion
Peroxisomes single membrane compartment, contain enzymes that transfer hydrogen to oxygen producing H2O2 as a by-product, organelle also contains the enzyme that converts H2O2 to water, (Sound familiar?) they detoxify alcohol and other harmful compounds (in the liver)
Other Plastids Amyloplasts Plastid that stores starch Chromoplast Plastid that stores pigments
Cell Wall Distinguish plant cells from animals cells, (although prokaryotes, fungi, and some protists also have cell walls) protects the plant cell, and maintains its shape, prevents excessive uptake of water, much thicker than the plasma membrane, made of cellulose
Cell Wall
ECM Extracellular Matrix glycoproteins, mostly collagen forms strong fibres outside the cell, interwoven with other glycoproteins (proteoglycans) form large complexes
Cytoskeleton There are three types: microtubules, microfilaments, and intermediate filaments give mechanical support to the cell and maintain its shape, provide anchorage for many organelles, involved in cell motility, cytoplasmic streaming
Cilia specialized arrangements of microfilaments, that beat for locomotion, or function to move fluid over the surface of the tissue if the cell is held in place usually occur in large numbers on the cell surface (0.25 um) in diameter Flagella specialized arrangement of microfilaments, that beat for locomotion, usually a cell has one or a few per cell, undulating motion
Endomembrane system Many membranes are part of the endomembrane system. Either through direct physical continuity, or by transfer of membrane segments as tiny vesicles. Includes the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, various kinds of vacuoles, and the plasma membrane