CELL THEORY Robert Hooke coined the term CELL

CELL THEORY Robert Hooke coined the term “CELL” after observing 1. All organisms are made cells. a microscope cork of under 2. Cells are the basic unit of organization 3. All cells come from preexisting cells. 2 Major groups: Prokaryotes Eukaryotes Typically larger Smaller Nucleus Cell membrane No nucleus Cytoplasm Membrane-bound Organelles are not DNA organelles membrane-bound Ribosomes DNA contained within DNA is free floating “Pro” in prokaryotes – nucleus evolved first Complex Simple “Eu” in eukaryotes – they Ex: plants, Ex: bacteria haveanimals a true nucleus

Flagellum – tail used for movement Cytoplasm – liquid inside the cell Rough Endoplasmic Reticulum Lysosome Chloroplast – plants, sitecell, of Cell Wall –brain plants, provides Ribosomes ––ofbreak Nucleus –fluid the Vacuole – filled space, – folded membranes, transport down waste material photosynthesis, green pigment structure and support protein synthesis manages cell function stores food and/or wastes system, with ribosomes Mitochondria powerhouse; Smooth Endoplasmic Cell Membrane –– aka plasma Microtubules partthe of nucleus, Golgi ––membrane sacs, Nucleolus – inside produces energy molecules food Reticulum – and folded membranes, membrane, boundary of from cell, cytoskeleton, structure modify repackage proteins produces ribosomes transport noofribosomes controlssystem, passage materials

Phospholipid Bilayer – 2 layers of phospholipids e Concentration Cell Membran– the amount of dissolved substances in a solution SELECTIVELY PERMEABLE Only “select” things can “permeate” (come through) the High concentration barrier Low concentration Same amount of dissolved substance but different amounts of solution The cell must be Gradient able to bring in nutrients Concentration – higher and remove wastes – just weanother do! concentration in one arealike than PASSIVE NO Ex: will be a higher There ENERGY – concentration Osmosis of perfume in down a the Facilitated Diffusion immediate area where it concentration was sprayed than anywhere gradient else in the room. Transport = movement across a membrane ACTIVE Diffusion –REQUIRES molecules spread out until there is ENERGY – an equal up distribution a concentration gradient

PASSIVE ACTIVE TRANSPORT OSMOSIS – diffusion of water REQUIRES molecules across a membrane. ENERGY!! FACILITATED Molecules are being moved across a DIFFUSION – “diffusiontowith help” Only water membrane from a low concentration molecules a high concentration (up the. Some gradient) molecules cannot pass (red) are through the membrane, they moving need assistance. across the membrane. Carrier Proteins in the Ex: membrane allow these Sodium-Potassium pump molecules to move across.

Hypertonic Hypotonic Isotonic Solution – The ––Outside concentrations thecellhas are the a lower higher same concentration inside and outside thaninside the cell. thecell. Water moves both inout into and of the out the cell of cell to the to cell – concentrations equalize the concentrations. are equal. Water Substance/material dissolved in water Cell remains swells may shrink. the and may burst. same.

Endocytosis Exocytosis Endo= =means Exo meansout into of(thinkentrance exit or export) or enter) Things that cannot pass through the membrane can be taken in or excreted through bulk transport. is Note: this considered ause it active bec nergy! e s e ir u q e r Vesicles Membrane containing folds in creating materialsafuse with the cell membrane, Pinocytosis – endocytosis of liquid opening vesicle containing the vesiclematerials. and releasing the. Phagocytosis materials. – endocytosis of solids