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• Prokaryotic


  In domains bacteria and archaea, small, bacteria contain a single chromosome composed of double stranded DNA- survival genes, cell wall
• Prokaryotic cells


  • No nucleus- DNA not enclosed only thrown in corned called nucleoid region, plasmids are non essential genes that reproduce independently, DNA transferred between bacterial cells by pili
• Eukaryotic


  Domain Eukarya , Big, Round/squarish, nucleus, some eukaryotes dont have cell walls
• Cell size


  • Can't be too small, have hold enough DNA and organelles to be able to sustain themselves, can't be too big: boundary functions as selective barrier to pass oxygen wastes, only so much area for traffic, at a certain point surface area is too small for the cell's increased volume
• Phospholipids


  Form micelles when dumped in water, amphipathic, form a bilayer, and move slightly
• Fluid Mosaic Model


  Proposed by Singer and Nicholson, membrane is a fluid structure, proteins embedded in it or on it, phospholipids, generalized picture, membranes of different cells have different structure, membrane is built by the endoplasmic reticulum (ER), protein in membrane have hydrophobic regions
• Cholesterol


  • Helps the membrane resist changes in fluidity, keeps phospholipids in place, prevents the close packing of the phospholipids, unsaturated fatty acids in phospholipid tails, reduces membrane fluidity at moderate temps by reducing phospholipid movement, low temps hinders solidification by disrupting regular packing
• Integral proteins


  Pass into nonpolar region of phospholipid layer/ placement maintained by polar vs non-polar section and by cytoskeleton, some proteins allow specific polar molecules to pass through membrane
• Surface proteins


  Never cross membrane, attached to integral proteins or to the polar surface of the membrane, in response to a decrease in temp, membrane will solidify more and proteins wont function, directional orientation
• Function of proteins in the Cell membrane

  • Transport-polar molecules move through membrane proteins
  • Enzyme- so rxns can take place
  • Receptor binding sites- bind a chemical messenger
  • Cell to cell recognition- ID tags that are specifically recognized by other cells
  • Cell to cell anchors- hold cells tgt with eachother
  • Cytoskeleton Anchors- bonds to proteins, keeps cell chape
• Transport across the membrane

  The only substances that don't require transport across the membrane are CO2 and O2, H2O protein is aquaporin
• Passive Transport


  Free- no cost, Simple diffusion: always from high -> low concentration, driven by the kinetic energy of molecules, no need for protein, more concentrated= faster diffusion, Facilitated diffusion: through special membrane proteins, can show saturation- mac speeds is # of available proteins, need a protein, can be a channel open all the time or a gate that can open and close, is only one direction, obey high- low concentration gradient
• Active Transport


  Needs energy-ATP , needs proteins, moved against concentration gradient uphill (low - high)
• Osmosis


  Doesnt need energy, diffusion of water across a semipermeable membrane, solute cannot cross but solvent can, concentration of solutions refers to the concentrations of solute in the water, so the higher the solute concentration the lower the water concentration, water move high h2O -> low H2O
• Hypertonic


  More concentrated
• Hypotonic


  Less concentrated
• Isotonic


  Equal concentrated
• Plasmolyzed


  Cell becomes shrunken
• Lysed


  Cell explodes or is broken open
• Pressure high animal cells will explode and plant cells will not. Plants have cell walls
• Endomembrane system


  Separates functions in cell, not all membranes involved are same, Consists of nuclear envelope, endoplasmic reticulum, Golgi apparatus, Lysosomes, Vesicles, Plasma membrane
• Nucleus


  Largest organelle, under microscopes, nucleus dark when stained, DNA- chromatin between division, chromosomes (chromatids) during division, cell division- makes daughter cells/ identical copies- stores information, required for long term of survival
• Nuclear membrane


  Double membrane called nuclear envelope, has pores for communication, to pass molecules RNA, proteins, ribosomal subunits, only present during interphase
• Nuclear lamina


  Protein filaments that maintain shape
• Nucleolus


  Dark area in nucleus, size and # varies, builds the ribosomal subunits, uses rRNA
• Ribosomes


  Makes proteins, large and small subunit, no membrane, solid, free cytoplasm and bound ER
• Endoplasmic Reticulum


  Folded membrane- creates a cavity separated from the cytoplasm
• Rough Endoplasmic Reticulum


  Makes proteins for export, surface facing cytosol is studded with ribosomes, makes glycoproteins, they're put together here, stored in RER cavity until exported, transitional produces vesicles, source of new membrane for cell, makes pieces and exports
• Smooth Endoplasmic Reticulum


  No ribosomes , makes stores and exports lipids, detoxifies poisons and drugs, store carbohydrates, glycogen, exact specialization varies with cell type, enzymes that make lipids, such as sex hormones
• Golgi Complex


  Modification, storage, shipping of products, also manufactures some polysaccharides in plant walls, often step after ER, sacs called cisterna, polarity, shipping and receiving sides, receiving=cis=next to ER, shipping=trans=next to cell membrane, molecules carried from one cisterna to next by vesicles, add signals to vesicle product to direct where to go
• Vesicles


  Temporary for movement within cell, endocytosis and exocytosis
• Vacuole


  Membrane sac-larger than vesicles, for storage, animal: intake food by phagocytosis, plants: stores molecules-proteins, develops osmotic pressure
• Lysosome


  Digestive compartments, sac with hydrolytic enzymes used to digest, the enzymes work best at ph 5, if lysosome breaks enzymes not strong since cell is 7, made by ER and golgi, single celled use lysosomes to digest food, Autophagy: Lysosome engulfs broken organelle from cell, Macrophages: animals have special type of lysosome that destroys invaders, Programmed destruction: lysosomes are also used for making developmental changes
• Autotrophs


  Make own energy from inorganic source
• Heterotrophs


  Need to digest other organisms
• Glucose


  ATP=$ for bodies
• Adenosine Triphosphate


  Immediate source of energy, must make it, energy gained by adding or removing phosphate, ADenosine diphosphate which is the energy 30 ADP+ 30P=30ATP
• Mitochondria


  # depends on need, sites of cellular respiration, needs O2, enclosed by two membranes, smooth outer and a folded inner, endosymbiosis, mom
• Photosynthesis


  Requires chloroplasts, light,water, CO2, plants makes sugars, Chloroplast uses every spectrum of light except green hence generic plant colour, made independently, only increase in number by self division, endosymbiosis
• Extracellular Matrix


  Support, adhesion, movement, recognition and regulation, contains glycoproteins on outer surface of cell, found in most tissues, mainly composed by glycoproteins and other carbohydrate-containing 'fibrous' molecules in network, elastin, collagen (most abundant protein, present in dermis, provides strong durable support for the overlying epidermis)