Cells Cellular basis of life Cell theory Cells = basic structural and functional units of life Organelles control biochemical activities Cells Variation: size, shape, function  Same basic parts Epithelial cells, fibroblasts, erythrocytes Cells that connect body parts, form linings, or transport gases Skeletal muscle cell, smooth muscle cells Cells that move organs and body parts Fat cell Cell that stores nutrients Macrophage Cell that fights disease Nerve cell Cell that gathers information and control body functions Sperm Cell of reproduction  Sperm membrane Fluid mosaic model Phospholipid bilayer: plasma membrane as exceedingly thin structure, composed of a double layer, or bilayer, of lipid molecules with protein molecules “plugged in” or dispersed in it Associated molecules- Cholesterol - Proteins: integral, peripheral- Carbohydrates Glycocalyx (sugar covering) is used to describe the fuzzy, sticky, carbohydrate-rich area at the cell surface Plasma Membrane:  Membrane proteins Transport- Channel/pore: has consistently open pore- Carrier: not always open… specific for certain substances Enzymatic activity Signal transduction Intercellular joining: 2 cells attaching Cell-cell recognition: recognizing self cells or bad cells Attachment to cytoskeleton and ECM- Acting as anchor for shape inside cell- Acting as anchor outside of cell Membrane junction Tight junctions: proteins fuse together to create impermeable seal of digestive tract  Impermeable junctions: nothing can pass between cells Desmosomes: provide mechanical anchoring of two cells, much stronger than tight Anchoring junctions: strongly link adjacent cells together so they don’t tear Gap junctions: proteins within adjacent cells that create pores  For ions, oxygen trans- Communicating junctions: leave quick passages for transport Membrane transport: active and passive transport processes, compare and contrast simple diffusion, facilitated diffusion, and osmosis relative to substances transported, direction, and mechanism.  Selectively permeability: allows some substances to pass while excluding others  Passive processes: without requiring any energy Diffusion: movement of solutes from high concentration  low concentration (ex: rolling a rock down a hill)- Simple: moving down the concentration gradient without help (ex: O2 and CO2) Osmosis: simple diffusion of a solvent (ex: h2o) Dialysis: simple diffusion of solutes (ex: salt)- Facilitated: provide a mechanism to move but no energy Ex) channel/ pore transport Filtration: high  low pressure (passive) Osmolarity: the total concentration of all solute particles in a solution- Isotonic solution: same solute/water concentration- Hypertonic solutions: higher concentration of solutes outside than inside cell (cell shrink)- Hypotonic Solutions: lower concentration of solutes outside than inside (cell bursts) Active processes: Require energy (ATP must be present) Active transport: low concentration  high concentration (against concentration gradient)- Primary: directivity requires ATP- Secondary: doesn’t require energy, but only occurs if primary established a concentration gradient  Vesicular transport: things brought into, exported, moved within the cell- Exocytosis: movement of substances outside of cell (exported/released)- Endocytosis: cells bring things into cell (engulf) Phagocytosis: large, solid particles (cell eating) Pinocytosis: small, liquid (cell drinking) Receptor mediated: large amounts of one substance - Transcytosis: in, through, and out of cell- Vesicular trafficking: movement of substances within a singular cell Resting membrane potential Difference in electrical charge within a membrane  All cells are polarized  Voltage across membrane: caused by distribution of cations and anions - Inside = -- Outside = + Cytoplasm (cell forming material): material between the plasma membrane and the nucleus  Cytosol: viscous, semitransparent fluid in which other cytoplasmic elements are suspended Organelles: metabolic machinery of the cell, each type of organelle carries out a specific function for the cell  Inclusions: chemical substances that may or may not be present, depending on cell type Organelles Mitochondria (threadlike): power plants of cell… produce ATP- 1 = mitochondrion- ATP- mtDNA: this is the name of mitochondria’s own DNA, you can get thisonly from the mother  Ribosomes - Produce proteins… protein synthesis- Tiny globs of proteins - Attached ribosomes: protein production that are going to be part of membranes or that are going to be used outside of cell  Endoplasmic reticulum: continuous with membrane - Rough: has ribosomes attached to it, initial site of protein in protein synthesis, cell-lipid synthesis- Smooth: involved in detox of drugs, production of some lipids  Golgi apparatus- Modification/packaging/concentration of protein- Can add sugars/other things to proteins Lysosomes- Contain particular digestive enzymes- Acid hydrolysis - Break down bad things- Can be bad for the cell  Endomembrane system- System of organelles that work together to produce, store, and export biological molecules and to degrade potentially harmful substances Peroxisomes- Filled with enzymes that detoxify certain chemicals- Different mixture of chemicals that do same job as lysosomes  Centrosomes- Anchors microtubules  Centrioles- Found at back of ____- Provide movement of flagella and cilia Cellular extensions- Capable of moving themselves Cilia: move in coordinated way to move particles Flagella: (ex: sperm)… only cell in human body that has flagella, propels itself through environment - Microvilli: foldings of plasma membrane, seen in cells for absorption, increase surface area, enhance absorption Ex) cells that line digestive tract, not exactly mobile elements  Nucleus Nuclear envelope: double membrane, four layers of phospholipids - Nuclear pores allow things to get out of nucleus - Double membrane- Nuclear pores Nucleoplasm:  Nucleoli: sites where ribosomal subunits are assembled, large in growingcells that are making large amounts of tissue proteins  Chromatin: nuclear DNA, proteins, and a little RNA- Cellular DNA- Histones: provide a physical means for packing the very long DNA molecules in a compact,