Presentation on theme: "Chapter 7 Cell Structure and Function. Anton van Leeuwenhoek Father of the microscope - 1600s used lens technology fabric quality telescope same time."— Presentation transcript:
Chapter 7 Cell Structure and Function
Anton van Leeuwenhoek Father of the microscope s used lens technology fabric quality telescope same time 1st to see life in a drop of water (animalcules)
Robert Hooke st to examine plant tissue Resembled monasterys tiny rooms Cells
Matthias Schleiden all plants are made of cells
Theodor Schwann All animals are made of cells
Rudolf Virchow Cells come from other preexisting cells
The Cell Theory All living things are composed of cells Cells are the basic units of structure and function in living things New cells are produced from existing cells
What do all cells have in common? Cell membrane thin, flexible barrier surrounding the cell (protection) Cytoplasm fluid within the cell Genetic Material (DNA/RNA)
Major Groups of Organisms 1.Bacteria 2.Protists (amoeba, algae, seaweed) 3.Fungi 4.Plants 5.Animals
Basic Cell Types Prokaryotic Cells cell membrane cytoplasm genetic material (lack a nucleus) bacteria Cell membrane cytoplasm Genetic Material
7-3 The Cell Membrane Objectives: Describe the structure of the cell membrane Describe how substances move through the cell
Cell Membrane Structure: Lipids, Proteins, Carbohydrates Lipid bilayer Functions: 1.Regulates entry and exit of materials 2.Protection and support Carbohydrate chains act as identification cards
Fluids ICF = Intracellular Fluid (inside cell/cytoplasm) ECF = Extracellular Fluid (outside cell) Always dissolved particles in both of these fluids Dissolved particles = solutes Concentration of solutes can vary High = more solute Low = less solute
Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains Figure 7-15 The Structure of the Cell Membrane
Diffusion Movement of materials from a high concentration to a lower concentration until equilibrium is reached requires no energy = passive What materials diffuse across a cell membrane?
Permeability Ability of membrane to allow substances to penetrate/pass through Levels of permeability: Permeable- any solutes can pass through Semi-permeable/Selectively Permeable- certain solutes are selected to pass through Impermeable- nothing is able to pass through All cell membranes are selective = picky/choosy Impermeability is not an option cell would die! Why???
Osmosis Diffusion of water across a selectively permeable membrane Types of Solutions hypertonic - higher concentration of dissolved particles (solute) hypotonic - lower concentration of dissolved particles (solute) isotonic - identical concentration
Osmosis occurs b/c the solute is unable to pass through the membrane. Water can always pass through the membrane.
Problems in Organisms (Maintaining Homeostasis) Plants turgor pressure rigid vs. wilting Antibiotic effects on bacteria Single Celled Organisms contractile vacuole homeostasis Animals cells bathed in isotonic fluids blood
Facilitated Diffusion specific protein channels for specific substances that cannot diffuse on their own glucose channel
Facilitated Diffusion Protein channel Glucose molecules
Active Transport movement of materials from lower concentration to higher concentration requires energy = ATP
Molecule to be carried Active Transport
Molecule to be carried Molecule being carried Energy Figure 7-20 Active Transport-going against concentration gradient (low to high). Natural is from high to low (diffusion and facilitated diffusion).
Phagocytosis Large particles taken into cell Extension of cytoplasm engulfs large particles outside cell Pocket folds into cell with contents and breaks loose from cell membrane forming vacuole inside cell (in cytoplasm).
Other examples of active transport
Unicellular Organisms A single cell is the entire organism Includes all prokaryotes and some eukaryotes Examples include: algae, yeasts, bacteria
Multicellular Organisms Cells are interdependent (like a team) Cell specialization- separate roles for each type of cell (ex. Blood cell, nerve cell, muscle cell) Cells are specialized to perform particular functions within organism
Levels of Organization Individual cells tissues organs organ systems organism Tissue- group of similar cells that perform particular function Organ- groups of tissues working together Organ Systems- group of organs working together to perform specific function (11 major systems in human body)
Muscle cell Smooth muscle tissue Stomach Digestive system