Chapter 3 Power Point

Mrs. WetzelBiologyChapter 3 Power PointCell TheoryEarly Discoveries: Almost all cells are too small to be seen with the naked eye.

Prior to the discovery of the Microscope cells were unheard of.

The Dutch Eyeglass maker Zacharias Janssen and his father Hans. Get credit for making the first known Microscope.

Scientists who contributed to the Cell Theory Robert Hooke (1665) Used a three lens microscope to examine thin slices of cork. He observed that cork is make of tiny hollow compartments. The compartments reminded Hooke of the rooms at the Monastery, so he gave them the same name, cells.

Cork Cells What part of the cells was Robert Hooke seeing when he examined the cork?

Scientists who contributed to the Cell Theory Anton Van Leeuwenhoek (1674)- Was studying new methods for using lenses to examine cloth. As a result of his studies he made a much more powerful microscope than Hooke had been using. Leeuwenhoek was one of the first people the describe Living cells when he observed a drop of pond water.He called these Organisms AnimalculesScientists who contributed to the Cell Theory Building On Hooke & Leeuwenhoeks discoveries three more scientists added to the Cell TheoryMatthias Schleidon (1838) was the first to note that plants are made of cellsTheodore Schwann (1839) Concluded that ALL living things are made from cellsRudolph Virchow (1855) proposed that cells only come from other living cellsCell Theory* All living things are made of cells

*All cells come from other living cells

*The cell is the most basic unit of life. There is nothing living that is smaller than a cell Cell Theory* All living things are made of cells

*All cells come from other living cells

*The cell is the most basic unit of life. There is nothing living that is smaller than a cell Two types of CellsCells come in many different shapes and carry out many different jobs. However they all share some features. 1. Cells are all SMALL2. Cells all have a membrane of some sort to keep materials in or out3. Cells have cytoplasm on the inside4. Cells have genetic material

Two types of Cells; Prokaryotic & EukaryoticProkaryotic: Prokaryotic Cells are VERY small. Their DNA floats in the cytoplasmThey have no NucleusThey have no distinct Membrane Bound Organelles

Two types of CellsEukaryotic:Are larger than Prokaryotic CellsThey have a nucleusDNA (genetic material) Lives in the NucleusThey have Membrane bound OrganellesSome are unicellular, some are multicellular

Two types of CellsTwo types of CellsTwo types of CellsRelevancy CheckWhat Kingdoms have Eukaryotic Cells, Which ones have Prokaryotic? Prokaryotic EukaryoticCell StructuresCytoskeleton: Your Skeleton is made of bones that help keep all of your body parts in place. Eukaryotic Cells have a skeleton too.The CYTOSKELETON is the framework for the cell

CytoskeletonThree Parts of the cytoskeleton are:Microtubules-MovementMicrofilaments-Cell Division & movementIntermediate filaments- Cell strength

Cell StructuresNucleus:Stores and Protects the DNA of the Cell DNA contains genetic material and instructions for making proteinsIt is often called the brain of the cell

Cell StructuresEndoplasmic Reticulum:A network of folded membranes that helps in the production of proteins.Looks like a maze

Cell StructuresRibosomes:Tiny organelles that link amino acids together to form proteins.They are found on the ER, or floating in the cytoplasm

Ribosomes

Golgi Apparatus: Packages proteins for transport within the cell, or to destinations outside of the cell

Cell StructuresVesicles: Are small sacs that carry different molecules to where they are needed.

Cell StructuresMitochondrion: Supplies Energy for the cellBean shapedInner Membranes with many folds and compartmentsConverts food you eat into usable energy

Cell StructuresVacuole:A fluid Filled sac used for the storage of materials needed by the cellWater, nutrients, etc.

ANIMAL CELLS- Small vacuolesPLANT CELLS- LARGE Vacuole

Cell StructuresLysosome: Organelles that contain enzymesProtect a cell by attacking incoming bacteria and virusesBreaks down old cell parts

Cell StructuresCentriole: Shaped like tiny tubes in a circleHelp animal cells divide

Plant Cells Vs. Animal CellsPlant CellAnimal CellCell WallLarge VacuoleChloroplasts

CentriolesLysosomesPlant Cells Vs. Animal CellsPlant CellAnimal Cell

Plant Cells Vs. Animal CellsPlant Cell WallAnimal Cell MembraneCell Wall; Strong, rigid, layer that protects, supports, and shapes the cell. Some cell walls are very thickCell Membrane; a thin layer that separates the inside of the cell from the outside. It is selectively permeable. Cell Wall vs. Cell MembraneCell WallCell Membrane

Cell Membrane

Phospholipid Bilayer- Provides a selectively permeable protective covering for cellsAllows some materials to pass through, some can notThe cell membrane is referred to as a fluid mosaic model because the phospholipids are not rigid, they can move and slide

Cell MembranePhospholipid

Charged Phosphate groupGlycerol2 Fatty acid chains

Cell Membrane

A variety of Molecules are embedded among the phospholipids. Cholesterol: Molecules strengthen the cell membraneProteins: Channels that extend through the membrane helping materials to cross overCarbohydrates: act as identification. Allowing the cell to communicate with each other

Selective PermeabilityA selectively permeable membrane allows some, but not all molecules to cross.

Relevancy Check:What can you think of that has a selectively permeable membrane? #14A ________________ detects a signal molecule and carries out an action in response?

#14A ________________ detects a signal molecule and carries out an action in response?

Answer: Receptor #15A ________________ is a molecule that acts as a signal when it binds to a receptor.#15A ________________ is a molecule that acts as a signal when it binds to a receptor.

Answer: Ligand #16. A ligand that can cross a cell membrane can bind to an _____________ receptor.

#16. A ligand that can cross a cell membrane can bind to an _____________ receptor.

Answer: intracellular

#17. A ligand that can not cross a cell membrane can send a message to a cell by binding to a _______________receptor which then _____________shape.#17. A ligand that can not cross a cell membrane can send a message to a cell by binding to a _______________receptor which then _____________shape.

Answer: Membrane, Changes

Concentration GradientConcentration is the amount molecules of one type in an area. Few Molecules= Low concentrationLots of Molecules= High concentration.

Concentration of molecules can vary from one area to another. A Concentration Gradient is the difference in the concentration of a substance from one location to another. Relevancy CheckWhat in your daily life reminds you of a concentration gradient? Movement across the Cell MembraneWays molecules can move across the cell membrane (enter or leave a cell)1. Passive TransportA. Diffusion: The movement of molecules from an area of High concentration to an area of Low concentration (no energy needed)B. Osmosis: The movement of WATER molecules from an area of high concentration to low concentrationC. Facilitated diffusion: gets help from protein channels embedded in cell membrane Movement across the Cell MembraneWays molecules can move across the cell membrane (enter or leave a cell)1. Active Transport: Requires energy from the cell. Molecules move across the concentration gradient. From an area of low concentration to High concentration.A. Endocytosis- takes in large molecules of Phagocytosis is a type of endocytosis that Eats large moleculesB. Exocytosis opposite of endocytosis- large molecules exit the cellFacilitated Diffusion vs. Simple DiffusionFacilitated diffusion relies on Protein Channels to transfer larger ions across the cell membrane. It requires no energy from the cell because the molecule go from an area of high concentration to an area of low concentration.

OsmosisOsmosis The movement of water across a semi permeable membrane. Osmosis is the movement of water (red dots) through a semipermeable membrane to a higher concentration of solutes (blue dots).

Isotonic Isotonic Solution A solution that has the same salt concentration as the normal cells of the body and the blood.

When a cell is placed in an isotonic solution, the water diffuses into and out of the cell at the same rate. The fluid that surrounds the body cells is isotonic

HypertonicHypertonic Solution A Hypertonic solution contain a high concentration of solute in relation to the solution within the cell (e.g. the cell's cytoplasm). When a cell is placed in a hypertonic solution, the water diffuses out of the cell, causing the cell to shrivel up.

HypotonicHypotonic Solution A hypotonic solution contain A solution with a lower salt concentration than in normal cells

When a cell is placed in a hypotonic solution, the water diffuses into the cell, causing the cell to swell and possibly explode.

Active TransportActive Transport Active Transport requires the cell to use energy, usually in the form of ATP. Active Transport creates a charge gradient in the cell membrane. For example in the mitochondrion, hydrogen ion pumps pump hydrogen ions into the intermembrane space of the organelle as part of making ATP.

EndocytosisENDOCYTOSISEndocytosis (Endo (within) cytosis (cell) ) is a process in which a substance (e.g. proteins) gains entry into a cell without passing through the cell membrane.

Phagocytosis

ExocytosisEXOCYTOSISEndocytosis (Exo (exit) cytosis (cell) ) is a process in which a substance is exited from the cell without passing through the cell membrane. Examples of things that might be exited include secretion of proteins like enzymes, hormones and antibodies