9The Cell Theory One of the fundamental ideas of modern biology Includes 3 principles:1. All living organisms are composed of one or more cells2. Cells are the basic unit of structure and organization of all living organisms3. Cells arise only from previously existing cells
10Remember 2 major cell types ProkaryotesEukaryotes
12Prokaryotic cellsCells that do not contain a nucleus & membrane bound organellesProkaryotes contain DNA, but only a single, circular moleculeWhich kingdoms contain living organisms with only prokaryotic cells?
13PROKARYOTES UNICELLULAR ORGANISMS EXAMPLE= cyanobacteria Fossil 2 billion years old (left) and living (right). Note the similarities in appearance. Interspersed among the cyanobacteria colonies are chains of rod-shaped bacteria.
14Eukaryotic cells Contain a nucleus and membrane-bound organelles More advanced – organelles allow specialized cell functions to take place in different parts of the cell at the same timeWhich kingdoms contain eukaryotic cells?
15INTERNAL ORGANIZATION ORGANELLES:CELL COMPONENT THAT PERFORMS SPECIFIC FUNCTIONS FOR THE CELL
16Parts of the cell that both eukaryotes and prokaryotes have
17Most cells have a: Cell Wall Thick, rigid, mesh of fibers that surrounds the outside of the plasma membrane, protecting the cell and giving it supportWhich Kingdom does NOT have a cell wall??Make sure you know what each kingdom’s cell wall is composed of!!
18All cells have a: Plasma membrane Plasma membrane – flexible boundary that controls the movement of substances into and out of the cell
19Plasma Membrane The plasma membrane has selective permeability: Allows some substances to pass through while keeping others out
20Structure of the plasma membrane The plasma membrane can have this selective permeability because it is composed of a phospholipid bilayerPhospholipid bilayer = two layers of phospholipid molecules arranged with polar heads facing outside and nonpolar tails facing inside
22Plasma membrane continued… Proteins are embedded in the phospholipid bilayerHeld in place by polar (charged)/non-polar attractionsHelp cells recognize each otherRecognize & bind specific substancesMove substances in and out of cell
23The phospholipids create a “sea” in which other molecules can float, like apples floating in a barrel of water.
25All Cells Have CYTOPLASM: CELL GOO INSIDE CELL WHERE THE ORGANELLES ARE LOCATEDALSO CALLED CYTOSOL
26CytoplasmCytoplasm=semifluid material inside the cell’s plasma membraneIn prokaryotes, all of the cell’s functions take place directly in the cytoplasmIn eukaryotes, all of the cell’s functions take place within organelles in their cytoplasmCytoplasm
27CytoskeletonSupporting network of long, thin protein fibers that form a framework for the cell and provide an anchor for the organelles inside the cells
28CYTOSKELETON NETWORK OF LONG PROTEIN STRANDS IN THE CYTOSOL NO MEMBRANEAIDS IN MOVEMENT OF ORGANELLESMICROFILAMENTS:THREADS OF A PROTEIN CALLED ACTIN.SMALLEST STRAND MAKES UP CYTOSKELETON
29ASSIST IN MOVEMENT OF CHROMOSOME DURING CELL DIVISION MICROTUBLES:LARGEST STRANDSHOLLOW TUBESWHEN CELL IS ABOUT TO DIVIDE BUNDLES COME TOGETHER AND EXTEND ACROSS THE CELLSPINDLE FIBERS:THICK BUNDLESASSIST IN MOVEMENT OF CHROMOSOME DURING CELL DIVISION
31All cells have: RIBOSOMES MAKES PROTEINSMOST NUMEROUS ORGANELLE IN THE CELLNO MEMBRANE60% RNA AND 40% PROTEINS MAKE UP RIBOSOME'S
32PRODUCED & ASSEMBLED IN THE NUCLEOLUS Many Proteins are produced by a specialized cell, e.g. antibodiestransported and used elsewhere in the organismWHEN RIBOSOMES ARE ATTACHED TO ER:PROTEINS INSERTED TO MEMBRANESPROTEINS EXPORTED FROM CELLElectron Micrograph of ribosomes. The ribosomes operate in chains when translating a mRNA.
33Proteins (AA chains) being made by ribosomes from mRNA Proteins (AA chains) being made by ribosomes from mRNAOnce amino acids bond together to form a chain, it is now a protein, and can be used by the body.Simplified translation on the ribosome
34Translation = the language of nucleic acids translated to the language of proteins PROTEIN CHAINJHKJHKJHKJHKJHKJHKJHKJHKJHKJHKJHKJHKJHKRIBOSOMES Allow PROTEIN CHAINS to be made correctly
35Eukaryotes have organelles that prokaryotes do not have.
36NUCLEUS: LARGE NEAR CENTER OF CELL CONTAINS MOST OF CELLS GENETIC INFO DIRECTS MOST ACTIVITIES OF CELL
37NucleusIn eukaryotic cells, the central membrane-bound organelle that manages cellular functions and contains DNASurrounded by a nuclear envelope – a double membrane that has nuclear pores to allow substances in and out of the nucleus
38NUCLEAR MATRIX= PROTEIN SKELETON NUCLEAR ENVELOPE= DOUBLE MEMBRANE AROUND NUCLEUSCHROMOSOME= DENSELY PACKED (“X”) CHROMATINCHROMATIN= COMBO OF DNA & PROTEIN (stretched out chromosome)NUCLEAR PORE= SMALL HOLES (Doors)NUCLEOLUS= RIBOSOME SYNTHESIS, PRODUCTION
40ENDOPLASMIC RETICULUM (ER) A SYSTEM OF MEMBRANE BOUND SACS AND TUBULESINTRACELLULAR “HIGHWAY”MOLECULES MOVE FROM ONE PART OF CELL TO ANOTHER2 TYPES OF ER:SMOOTH ER= (no ribosomes)ROUGH ER= (COVERED W/RIBOSOMES)
41Endoplasmic reticulum Highly folded membrane system in eukaryotic cells that is the site for protein and lipid synthesis
42ROUGH ER:MAKE PROTEINSUSED FOR EXPORT OUT OF THE CELLALSO TO BE INSERTED INTO THE CELL MEMBRANESMOOTH ER:INVOLVED IN PRODUCTION (SYNTHESIS) OF STEROID GLAND CELLSREGULATION OF CALCIUM LEVELSBREAKDOWN OF TOXIC SUBSTANCES BY LIVER CELLS
44Golgi apparatus “UPS crew” Flattened stacks or sacs of membranes that modifies, sorts, and packages proteins into sacs called vesiclesVesicles can fuse with the cell’s plasma membrane to release proteins to the environment outside of the cell
45GOLGI APPARATUS PROCESSING PACKAGING SECRETING ORGANELLE SYSTEM OF MEMBRANES “PANCAKES”MODIFIES PROTEINS FOR EXPORT BY CELL
47Vacuoles “storage crew” Membrane-bound vesicle for temporary storage of materials such as food, enzymes, and wastes
48LYSOSOME “clean up crew” SMALLSPHERICAL ORGANELLEENCLOSE ENZYMES in a SINGLE MEMBRANESDIGEST PROTEIN, CARBS., LIPIDS, DNA, RNAWhen needed: OLD ORGANELLES, VIRUSES, BACTERIA THAT WERE INGESTEDRARE IN PLANT CELLS
49MITOCHONDRIA CONTAIN THEIR OWN DNA (circular) SURROUNDED BY A DOUBLE MEMBRANE
50Mitochondria “Power-house” “Mighty Mouse” Converts fuel (sugars) into the energy molecule ATP for the rest of the cell
51MITOCHONDRIA IN HUMAN LIVER CELL TRANSFER ENERGY FROM ORGANIC COMPOUNDS (pyruvate) TO ATP VIA CHEMICAL RXN’SATP = (AdenosineTriPhosphate) MOLECULE THAT MOST CELLS USE AS ENERGY CURRENCYCAR (MITOCHONDRIA)GASOLINE (CHEMICAL RXN)GAS + ENGINE = CAR STARTS (ATP MADE)CAR RUNS (ENERGY)MITOCHONDRIA IN HUMAN LIVER CELL
52SURROUNDED BY: 2 MEMBRANES CRISTAE: OUTER & INNER THE LONG FOLDS OF THE INNER MEMBRANEENLARGE SURFACE AREAWHERE CHEMICAL RXNS TAKE PLACE
53HOW CELLS MOVECELLS USE HAIRLIKE STRUCTURES THAT EXTEND FROM THE SURFACE OF THE CELLSHORT & IN LARGE QUANTITIES = CILIALONG & LESS NUMEROUS = FLAGELLA
54Cilia and Flagella Flagella Cilia Long, tail-like projection with a whiplike motion that helps a cell move through a watery environmentCiliaShort, numerous projections that look like hair and function in cell movement
55Plant cells have 3 structures that animal cell lack 1. Cell wall2. Chloroplasts3. Central vacuole
56ChloroplastDouble membrane organelle that captures light energy and converts it to chemical energy through photosynthesis
57Central vacuoleMembrane bound space that stores water; Aids in the rigidity of the cell