2 I. CellsA. What is a cell? 1. Cell – the smallest unit of matter that can carry on all the processes of life
3 I. CellsB. Who first discovered the cell? 1. Anton van Leeuwenhoek – first to observe cells 2. Robert Hooke – used the light microscope to observe cork a. First person to call the shapes inside of organisms “cells”
4 I. Cells3. Rudolph Virchow – studied cell reproduction and discovered that all cells come from other pre- existing cells.
5 I. Cells4. Mathias Schleiden – studied plants and discovered that all plants are made of cells 5. Theodor Schwann – studied animals and discovered that all animals are made of cells
6 I. CellsC. What is the cell theory? 1. The cell theory was developed by theories of Hooke, Virchow, Schleiden, and Schwann. a. The cell is the basic unit of organization for organisms. b. All organisms are made of one or more cells. c. All cells come from other pre-existing cells.
7 I. Cells2. With better microscopes, scientists observed that cells contained specialized structures. a. Organelles – cells parts that perform a specific job or function for the cell
8 I. CellsD. Cell Diversity! 1. Your body alone contains 200 different cell types! 2. Cells Organisms can be classified by the number of cells they are made up of. a. Unicellular Organism – single celled organism Example: bacteria, yeast b. Multicellular Organism – organism made up of many cells Example: plants, animals
9 I. Cells 1. Nucleus 2. Nucleolus 3. Chromatin 4. Cell membrane E. How are cells classified based upon the presence/absence of organelles? 1. Eukaryotic Cells – cells with a membrane-bound nucleus and organelles a. Examples: plant and animal cells1. Nucleus2. Nucleolus3. Chromatin4. Cell membrane5. Organelles
10 I. Cells 2. DNA 3. Cell membrane 1. Ribosomes 4. Cell wall 2. Prokaryotic Cells – cells with no membrane-bound nucleus or organelles (except ribosomes) a. Examples: bacteria2. DNA3. Cell membrane1. Ribosomes4. Cell wall
11 I. CellsLeft: Colorized micrograph of a prokaryotic cell of the bacterium.Right: Colorized micrograph of a eukaryotic cell of the green algae.
12 I. Cells 3. Review: Cell Type Nucleus? Organelles? Uni or Multicellular?ProkaryoticEukaryotic
13 Plasma (Cell) Membrane II. Cell BoundariesPlasma (Cell) MembraneFunction:Surrounds cellAllows things in and out (homeostasis)Fact:Selectively permeable – allows water and nutrients in and waste outMade of phospholipidsFound in:ProkaryotesEukaryotes
14 2. Cell wall 1. Cell membrane II. Cell Boundaries Cell Wall Function: Surrounds cell membrane to provide extra support and protectionFact:Made of cellulose in plantsFound in:ProkaryotesEukaryotes (plants)2. Cell wall1. Cell membrane
15 III. Cell Control Nucleus Nucleus Nucleus Function: Controls the organellesContains DNAFact:“Command center” or “brain” of the cellMost prominent structureFound in:EukaryotesNucleus
16 III. Cell Control Chromatin Function: Condense to form chromosomes in nucleusFact:Strands of DNA that look like spaghettiFound in:Eukaryotes
17 III. Cell Control Nucleolus Nucleolus Nucleolus Function: Makes ribosomesFact:Found inside the nucleusFound in:EukaryotesNucleolus
18 III. Cell Control Ribosomes Ribosomes Function: Makes proteins Fact: Made of RNACan be free or attached to ERFound in:EukaryotesProkaryotesRibosomes
19 III. Cell Control Nuclear Envelope/Membrane Function: Controls what enters/exits the nucleusFact:Surrounds the nucleusFound in:Eukaryotes
20 IV. Cell Assembly Cytoplasm Function: Suspends/holds organelles Site of chemical reactionsFact:Contains clear gel-like fluid called cytosolFound in:EukaryotesProkaryotes
21 IV. Cell Assembly Rough Endoplasmic Reticulum (ER) Function: Produces proteinsFact:Helps move molecules throughout the cellFound in:Eukaryotes
22 IV. Cell Assembly Smooth Endoplasmic Reticulum (ER) Function: Produces lipids (steroids)Detoxifies poisonsFact:Helps move molecules throughout the cellFound in:Eukaryotes
23 IV. Cell Assembly Golgi Golgi Apparatus Function: Processes, packs, and secretes proteins and lipidsFact:Works closely with ERFlattened stack of membranesFound in:EukaryotesGolgi
24 IV. Cell Assembly Vacuole Vacuole Function: Stores food, water, waste, proteins, carbsFact:Helps maintain homeostasisFound in:Eukaryotes (plants have a LARGEvacuole)Vacuole
25 IV. Cell Assembly Lysosome Lysosomes Function: Uses enzymes to digest old organelles and foreign objects (bacteria, viruses)Fact:“Suicide sacs”Found in:EukaryotesLysosome
26 IV. Cell AssemblyEver wonder how a tadpole gets rid of its tail and grows legs????It’s lysosomes digest the cells in the tail, and these molecules are released to build different cells, like legs!
27 V. Energy Transformers Chloroplast Chloroplast Function: Capture light (solar energy) andconvert it to chemical energyduring photosynthesisFact:Glucose is the sugar madeFound in:Eukaryotes (plants)Chloroplast
28 V. Energy Transformers Mitochondria Mitochondria Function: Breaks down food into ATP energy during cellular respirationFact:“Powerhouse” of the cellFound in:EukaryotesMitochondria
29 VI. Support & Locomotion CytoskeletonFunction:Maintains the shape & supports the cellFact:Made of microfilaments & microtubulesFound throughout the cytoplasmFound in:EukaryotesProkaryotes
30 VI. Support & Locomotion CiliaFunction:Movement of cells or fluidsFact:Short hair-like fibersFound in:EukaryotesProkaryotes
31 VI. Support & Locomotion CiliaFlagellaFunction:Movement of cellsFact:Long hair-like fibersFound in:EukaryotesProkaryotesFlagella
32 VII. Levels of Organization A. Organization: Organelles Cells Tissues Organs Organ systems Organisms
33 VIII. THE CELL MEMBRANEA. A cell’s survival depends on the cell’s ability to maintain the necessary conditions inside itself.1. Maintaining these constant internal conditions is called homeostasis.
34 VIII. THE CELL MEMBRANEB. Cell Membrane – flexible boundary between the cell and its outside environment1. Allows water and nutrients to enter the cell and wastes to leave the cell.WaterCell Membrane
35 VIII. THE CELL MEMBRANE2. Selectively Permeable – allowing some materials to pass while keeping others outa. Example: A spaghetti strainer allows water, but not spaghetti to pass through
36 VIII. THE CELL MEMBRANEC. What is the cell membrane made up of? 1. Phospholipids – diglyceride with a phosphate group attached
37 VIII. THE CELL MEMBRANEa. Phospholipid Bilayer – the cell membrane is TWO layers thick
38 VIII. THE CELL MEMBRANEb. Phospholipids have a polar “head” and non polar “tail”.- Polar “heads” are attracted to water, sugars, and proteins.
39 VIII. THE CELL MEMBRANE- Non-polar “tails” repel water, sugars, and proteins.- Resulting in a selectively permeable membrane.
40 VIII. THE CELL MEMBRANE2. Proteins are embedded in the cell membrane to recognize substances that can enter and exit the cell.
41 VIII. THE CELL MEMBRANE3. Cholesterol stabilizes the membrane by preventing lipids from sticking together.
42 VIII. THE CELL MEMBRANED. Fluid Mosaic Model - describes how phospholipids can move around like a fluid and the proteins make a pattern
43 VIIII. Cell TransportA. What types of materials need to cross the cells membrane? Water, nutrients, oxygen, waste B. In cells, particles always move to reach equal concentrations. 1. Concentration Gradient – unequal distribution of particles
44 VIIII. Cell TransportC. Types of Transport 1. Passive Transport – movement of any substance across a membrane WITHOUT the use of chemical energy. a. Occurs from high to low concentration, with the concentration gradient.
45 VIIII. Cell Transportb. Types of Passive Transport - Diffusion – movement of molecules across a selectively permeable membrane; occurs from high to low concentration, with the concentration gradient.
46 VIIII. Cell Transport- Example: Oxygen diffuses into the bloodstream because of a high pressure in the lungs.
47 VIIII. Cell Transport- Osmosis – movement of water across a selectively permeable membrane; occurs from high to low concentration, with the concentration gradient.
48 VIIII. Cell Transportc. How are larger and strongly charged molecules, such as glucose, able to pass through the cell membrane more quickly than they should? - Facilitated diffusion – passive transport of large particles across a membrane with the help of proteins; occurs from a high to low concentration, with the concentration gradient - Example: Sugars, Amino AcidsGlucosemoleculesLowConcentrationCellMembraneHighProteinchannel
50 VIIII. Cell Transport2. Types of Solution – How does the water “know” which way to move? a. Hypertonic Solution – (high solute concentration) more water on the inside of the cell than the outside of the cell. - Water moves OUT of the cell. - Size of the cell = shrinks (plasmolysis)CellOvertimeH2O + NaCl Solution
51 VIIII. Cell Transportb. Hypotonic Solution – (low solute concentration) more water on the outside of the cell than the inside of the cell. - Water moves INTO the cell. - Size of the cell = swells - Cytolysis = animal cells burst - Turgor Pressure = water pushes against cell wall in plantsCellOvertimeH2O + NaCl Solution
52 VIIII. Cell Transport - Water moves in and out of cell equally. c. Isotonic Solution – equal concentration of water and solute inside and outside the cell- Water moves in and out of cell equally.- Size of cell = stays the sameCellOvertimeH2O + NaCl Solution
53 VIIII. Cell Transport Criteria Inside Cell Outside Cell Where is there more solvent (water)?hypertonichypotonicWhere is there more solute (salts, dissolved substances)?
55 VIIII. Cell Transport3. Diffusion is a powerful process, however, sometimes cells need to move materials in the opposite direction. a. Active Transport – proteins are used to move ions or molecules against the concentration gradient, using ATP energy. - Occurs from areas of low to high concentrations. - Examples: minerals, nutrients
56 VIIII. Cell Transport4. Types of Active Transport a. Endocytosis – process when a cell surrounds and takes in materials from the environment - Example: White blood cell engulfing a bacterium.
57 VIIII. Cell Transport- Two types of Endocytosis - Pinocytosis – movement of liquids into a cell - Phagocytosis – movement of solids in a cell
58 VIIII. Cell Transportb. Exocytosis – the explusion (exit) or secretion of material out a cell - Example: Cell getting rid of waste.
59 VIIII. Cell Transportc. Although endocytosis and exocytosis are different, the two processes often work TOGETHER.