2 THE CELL THEORY(DEVELOPED AFTER THE DISCOVERY OF THE MICROSCOPE AND THE CELL)HAS THREE PARTS:1. ALL ORGANISMS ARE COMPOSED OF CELLS.2. CELLS ARE THE BASIC UNIT OF LIFE – they are thesmallest structures that show all the characteristics of life.3. CELLS ARISE FROM OTHER PRE-EXISTING CELLS.
3 PROKARYOTIC EUKARYOTIC ALL ORGANISMS ARE COMPOSED OF CELLS.DOES THIS MEAN ALL ORGANISMS – EVEN BACTERIA, VIRUSES, PLANTS & ANIMALS?Most organisms are MULTICELLULAR = composed of many cells. These are the two types ---THE TWO TYPES OF CELLS:PROKARYOTIC EUKARYOTIC
4 HERE’S THE INFO……………..YOU DECIDE!!! THE VIRUS DEBATEHERE’S THE INFO……………..YOU DECIDE!!!THEY ARE COMPOSED OF ONLY A PROTEIN COAT AND DNA or RNA.THEY CANNOT LIVE WITHOUT A HOST (ANOTHER PROKARYOTIC OR EUKARYOTIC CELL).3. THEY CAN PERFORM ONLY SOME OF THE CHARACTERISTICS NECESSARY FOR LIFE.
5 WHAT ARE THE CHARACTERISTICS OF LIFE? What makes some things living and others nonliving?1. MOVEMENT – Must be able to move food into its body, distribute it to all parts of the body, and eject wastes.2. METABOLISM AND HOMEOSTASIS – Must be able to make energy from compounds and build tissues. Must know how much is required to keep the body in balance.3. RESPONSIVENESS – Must be able to respond to the environment – “fight or flight”.4. GROWTH AND DEVELOPMENT – Grow by taking in raw materials and using them to synthesize new cells.5. REPRODUCTION – Ability to produce offspring to produce new generations.6. ADAPTATION – Features that fit them into their environment and help them survive.
6 2. CELLS ARE THE BASIC UNIT OF LIFE WHAT IS A CELL COMPOSED OF? ALL CELLS HAVE CERTAIN CHARACTERISTICS:Surrounded by a membrane = PLASMA OR CELL MEMBRANEThis membrane separates them from the outside environment.BUT…. It does allow some things in….this makes it SEMI-PERMEABLE.WHAT ARE SOME THINGS IT LETS IN?
7 “ALSO KNOWN AS THE CELL MEMBRANE” THE PLASMA MEMBRANE“ALSO KNOWN AS THE CELL MEMBRANE”STRUCTURE:Two layers (bilayer) of PHOSPHOLIPIDS AND PROTEINS- Semi- permeable: allows in/out oxygen, carbon dioxide, proteins, glucose, water – some with the use of ENERGY other withoutFUNCTION:-Separate cell from external environment-Barrier to keep some materials out and allow others in; controls what enters and leaves
8 2. ALL CELLS INCLUDE – DNA - Since they must reproduce and make proteins for their functioning. The DNA in cells is SEGREGATED into a DNA- containing region.
9 3. All cells contain – CYTOPLASM Cytoplasm is a “jello” (jelly) like substanceIt contains:Water, salts and organic compoundsIt is located inside the CELL MEMBRANE and between the cell membrane and NUCLEAR MEMBRANE.It is in constant motion – bathing and moving the cell structures.
10 Cell Functions/Jobs A. Digestion B. Secretion – release enzymes and other chemicalsC. Metabolism or RespirationD. ExcretionE. AbsorptionF. ReproductionG. Response To StimulusH. Synthesis – making of proteins and other substances
11 Cells contain subparticles known as ORGANELLES. WHICH ORGANELLES AND THE NUMBER A CELL CONTAINS DEPENDS UPON THE TYPE OF CELL THAT IT IS.EACH ORGANELLE HAS ITS OWN SPECIFIC STRUCTURE AND FUNCTION.
12 THE CELL ORGANELLES NUCLEUS STRUCTURE -CONTAINS THE GENES (DNA) ALSO KNOWN AS CHROMATIN (NONDIVIDING CELL) OR CHROMOSOMES (DIVIDING CELL)-SURROUNDED BY A DOUBLE LAYERED MEMBRANE WITH PORES CALLED THE NUCLEAR MEMBRANE- CONTAINS THE NUCLEOLUSFUNCTIONCONTROLS THE MAKING OF NEW CELLS-CONTROLS THE MAKING OF PROTEINS- ALSO KNOWN AS THE “BLUEPRINTS”
13 NUCLEOLUS STRUCTURE Located within the nucleus, spherical Contains RNA and proteinsFUNCTION- Produces ribosomes (l0,000/min.)
14 RIBOSOMES STRUCTURE FUNCTION Made of 2 subunits of protein and RNA - No membrane, spherical- Located on the Endoplasmicreticulum andin the cytoplasmFUNCTION- protein synthesis
15 ENDOPLASMIC RETICULUM STRUCTURE:Consists of a network of tubes that are continuous with the nuclear membraneTWO TYPES:SMOOTH ER – does NOT contain ribosomesFunction = making lipids, breakdown of carbohydrates, muscle contraction, and detoxification of drugs and poisonsROUGH ER – contains ribosomes on its surface (outside)Function = site of PROTEIN production and Transport of proteins
16 GOLGI BODY OR APPARATUS STRUCTUREA series of flattened, membranous sacs (looks like pita bread)- Located near the ERFUNCTIONPackages and stores proteins- Sends proteins to the cell membranefor EXPORT in small spherical structurescalled VESICLES.
17 LYSOSOMESALSO KNOWN AS “SUICIDE SACS”STRUCTURE Sphere shaped, membrane bound organelles located in the cytoplasm - Contain DIGESTIVE ENZYMES - More commonly found in animal cells FUNCTION Break down and digest old cell parts, bacteria, food particles - Play a role in early development
18 “Powerhouses of a cell” MITOCHONDRIA“Powerhouses of a cell”STRUCTURE:Double membrane structure. The outer membrane is smooth, while the inner membrane is folded, these folds are called CRISTAE.- The inner most area is called the Mitochondrial matrix.FUNCTION:Cellular RespirationGlucose is changed to water, carbon dioxide and energy (known as ATP) which the cell can use for its many functions.
19 PLASTIDSPlastids are PLANT organelles that store chemical energy. They include:AMYLOPLASTS – which store starchLEUCOPLASTS – which store starch, proteins, and lipidsCHROMOPLASTS – which contain color pigmentsCHLOROPLASTS – which contain the green pigment, CHLOROPHYLL
20 CHLOROPLASTS STRUCTURE: Chloroplasts have a double membrane. The outer membrane is smooth, while the inner membrane forms stacks called THYLAKOIDS. Thylakoids may be joined together to form GRANA.These membranes are bathed in a fluid called STROMA.FUNCTION:PHOTOSYNTHESIS – converting carbon dioxide and water with the help of sunlight into SUGAR and OXYGEN.
21 VACUOLES STRUCTURE: Found mainly in plant cells larger than vesicles - Single membrane, spherical-May take up to 90% of a plantcells areaFUNCTION:Store food, excess water, toxins, enzymes, and waste products.- Digest food and waste- Pump excess water out of cells
22 CYTOSKELETON (Cell Framework) STRUCTURE:Composed of microtubules and microfilaments (protein tubes and threads)FUNCTION:-Microtubules – shape, support and help move organelles around the cell- Microfilaments – muscle contraction, cytoplasmic streaming, and changes in cell shape
23 CILIA AND FLAGELLA STRUCTURE: -Extensions of cell membranes Composed of microtubules in a “ 9 + 2” pattern-Driven by ATP-Cilia: numerous and short-Flagella: one or two to a cell and longerFUNCTION: MOVEMENT OF THE CELLCilia - move back and forth like an oarFlagella – move in a whip-like fashion“9
24 Found only in PLANT CELLS CELL WALLFound only in PLANT CELLSSTRUCTURE:composed of CELLULOSE- Two walls thick- contains poresFUNCTION:- Protect, strengthen and allow certain materials in and out
25 PROKARYOTIC CELLS Include bacteria and some algae DO NOT contain all the structures found in eukaryotic cells.Size micronsNucleus No, circular DNARibosomes YesCell Wall YesOther Organelles NoCilia/Flagella Yes
27 DIFFERENCES BETWEEN EUKARYOTIC AND PROKARYOTIC CELLS EukaryoticProkaryoticRepresentative organismPlant and animal cellsBacteria and some algaeSize10-50 microns1-10 micronsNucleusYesNoRibosomesCell WallPlant onlyOther OrganellesCilia/Flagella
28 DIFFERENCES BETWEEN PLANT AND ANIMAL CELLS Animal PlantSize10-20 microns30-50 micronsShapeIrregularSquare/RectangularCell WallNoYesLysosomeRareChloroplastVacuoleSmall or absentLarge/90% of cellCilia/FlagellaBothMostly absentexcept sperm
29 3. All cells come from pre-existing cells. SPONTANEOUS GENERATIONLiving things can arise from nonliving things.BIOGENESISLife comes from life.EXPERIMENTATIONREDI EXPERIMENT – 1600’S
31 ORGANELLES – subparticles of cells BIOLOGICAL HEIRARCHYATOMSMOLECULES/COMPOUNDSORGANELLES – subparticles of cellsCELLSTISSUES – group of cells that perform the same function (Example: Four types - Muscle tissue, epithelial tissue, connective tissue, nerve tissue)ORGANS – group of tissues that perform the same function (Example: Stomach – muscle, epithelial, nerve, connective tissue)ORGAN SYSTEMS – group of organs that work together to perform the same function (Example: Digestive System)ORGANISM – group of organ systems that work together to perform a function