* Double-membrane structure with inner shelflike cristae
* Provide most of cell's ATP via aerobic cellular respiration
– Requires oxygen
* Contain their own DNA, RNA, ribosomes
* Similar to bacteria; capable of cell division called fission
What is Mitochondria
100
What is the power house of the cell
What is Mitochondria
100
The outer most part of a cell.
What is cell membrane or outer membrane
100
• Protein complexes that function in motility
* Powered by ATP
What is Motor Proteins
100
– Whiplike, motile extensions on surfaces of
certain cells
– Contain microtubules and motor molecules
– Cilia move substances across cell surfaces
– Longer flagella propel whole cells
What is Cilia and flagella
200
• Granules containing protein and rRNA
• Site of protein synthesis
• Membrane-bound organelles (forming rough ER) synthesize proteins to be incorporated into membranes, lysosomes, or exported from cell
What is Ribosomes
200
• Stacked and flattened membranous sacs
• Modifies, concentrates, and packages proteins and lipids from rough ER
• Transport vessels from ER fuse with convex cis face; proteins modified, tagged for delivery, sorted, packaged in vesicles
What is Golgi Apparatus
200
• Elaborate series of rods throughout cytosol; proteins link rods to other cell structures
– Three types
• Microfilaments
• Intermediate filaments
• Microtubules
What is Cytoskeleton
200
• "Cell center" near nucleus
• Generates microtubules; organizes mitotic spindle
• Contains paired centrioles
– Barrel-shaped organelles formed by
microtubules
• Centrioles form basis of cilia and flagella
What is Centrosome and Centrioles
200
• Centrioles forming base called basal bodies
• Cilia movements alternate between power stroke and recovery stroke ! current at cell surface
• Primary cilia
– Single, nonmotile projection on most cells
– Probe environment for molecules receptors can recognize; coordinate intracellular pathways
What is Cilia and Flagella
300
• Interconnected tubes and parallel membranes enclosing cisterns
• Continuous with outer nuclear membrane
• Two varieties: – Rough and Smooth
What is Endoplasmic Reticulum (ER)
300
• Membranous sacs containing powerful oxidases and catalases
• Detoxify harmful or toxic substances
• Catalysis and synthesis of fatty acids
• Neutralize dangerous free radicals
– Oxidases convert to H2O2
– Catalases convert H2O2 to water and oxygen
What is Peroxisomes
300
• Thinnest of cytoskeletal elements
• Dynamic strands of protein actin
• Each cell has a unique arrangement of strands
• Dense web attached to cytoplasmic side of plasma membrane is called terminal web
– Gives strength, compression resistance
• Involved in cell motility, change in shape, endocytosis and exocytosis
What is Microfilaments
300
• Microvilli
– Minute, fingerlike extensions of plasma membrane
– Increase surface area for absorption – Core of actin filaments for stiffening
What is Cellular Extensions
400
• External surface studded with ribosomes
• Manufactures all secreted proteins
• Synthesizes membrane integral proteins and phospholipids
• Assembled proteins move to ER interior, enclosed in vesicle, go to Golgi apparatus
What is Rough ER
400
• Sphericalmembranousbagscontainingdigestive enzymes (acid hydrolases)
– "Safe" sites for intracellular digestion
• Digest ingested bacteria, viruses, and toxins
• Degrade nonfunctional organelles
• Metabolic functions,e.g.,break down and release glycogen
• Destroy cells in injured or nonuseful tissue (autolysis)
• Break down bone to release Ca2+
What is Lysosomes
400
• Tough, insoluble, ropelike protein fibers
• Composed of tetramer fibrils
• Resist pulling forces on cell; attach to desmosomes
• E.g., neurofilaments in nerve cells; keratin filaments in epithelial cells
What is Intermediate Filaments
400
• Double-membrane barrier; encloses nucleoplasm
• Outer layer continuous with rough ER and bears ribosomes
• Inner lining (nuclear lamina) maintains shape of nucleus; scaffold to organize DNA
• Pores allow substances to pass; nuclear pore complex line pores; regulates transport of large molecules into and out of nucleus
What is The Nuclear Envelope
400
• Largest organelle; genetic library with blueprints for nearly all cellular proteins
• Responds to signals; dictates kinds and amounts of proteins synthesized
• Most cells uninucleate; skeletal muscle cells, bone destruction cells, and some liver cells are multinucleate; red blood cells are anucleate
• Three regions/structures
What is Nucleus
500
• Network of tubules continuous with rough ER
• Its enzymes (integral proteins) function in
– Lipid metabolism; cholesterol and steroid- based hormone synthesis; making lipids of lipoproteins
– Absorption, synthesis, and transport of fats
– Detoxification of drugs, some pesticides, carcinogenic chemicals
– Converting glycogen to free glucose
– Storage and release of calcium
What is Smooth ER
500
Overall function
– Produce, degrade, store, and export biological molecules
– Degrade potentially harmful substances
• Includes ER, Golgi apparatus, secretory vesicles, lysosomes, nuclear and plasma membranes
What is Endomembrane System
500
• Largest of cytoskeletal elements; dynamic hollow tubes; most radiate from centrosome
• Composed of protein subunits called
tubulins
• Determine overall shape of cell and distribution of organelles
• Mitochondria, lysosomes, secretory vesicles attach to microtubules; moved throughout cell by motor proteins
What is Microtubules
500
• Dark-staining spherical bodies within nucleus
• Involved in rRNA synthesis and ribosome subunit assembly
• Associated with nucleolar organizer regions
– Contains DNA coding for rRNA • Usually one or two per cell
What is Nucleoli
500
• Threadlike strands of DNA (30%), histone proteins (60%), and RNA (10%)
• Arranged in fundamental units called
nucleosomes
• Histones pack long DNA molecules; involved in gene regulation
• Condense into barlike bodies called chromosomes when cell starts to divide