* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download CH 7 Cell Structure and Function
Survey
Document related concepts
Embryonic stem cell wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Polyclonal B cell response wikipedia , lookup
Microbial cooperation wikipedia , lookup
Cell growth wikipedia , lookup
Adoptive cell transfer wikipedia , lookup
Neuronal lineage marker wikipedia , lookup
Artificial cell wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell culture wikipedia , lookup
State switching wikipedia , lookup
Cell-penetrating peptide wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cell (biology) wikipedia , lookup
Transcript
DO NOW: Why do you think cells weren’t discovered until 1665? Do you think people can ever see cells with the naked eye? Explain your answer. Objectives: 1. State the cell theory. 2. Describe how the different types of microscopes work. 3. Distinguish between prokaryotes and eukaryotes. LIFE CAN BE FOUND AS… • SINGLE CELLULAR ORGANISMS • MULTI-CELLULLAR ORGANISMS HOW DID WE FIND OUT ABOUT THE CELL? • Robert Hooke (in 1665) • 1st person to describe cells • Observed cork (plant cells) with a microscope ANTON VAN LEEUWENHOEK • 1673 • First to observe: – Protists in pond scum – Blood cells, bacterial cells, and yeast cells. • Cells are the basic unit of life! MATTHIAS SCHLEIDEN In 1838, concluded that all plant parts were made of cells THEODOR SCHWANN • In 1839, concluded that all animal tissues were made of cells • Schwann cells cover nerve cells RUDOLPH VIRCHOW • In 1858, stated that all cells could form only from other cells Review: Biologists and Their Discoveries That Led to The Cell Theory Matthias Schleiden • First to observe “cells” by looking at cork through a light microscope • Discovered living organisms in water through the use of a simple microscope • Plants made of cells Theodor Schwann • Animals made of cells Rudolph Virchow • Cells come from existing cells Janet Plowe • Cell membrane is a defined physical structure Robert Hooke Anton van Leeuwenhoek What is the Cell Theory? • The cell theory states: –All living things are composed of cells. –Cells are the basic units of life. –New cells are produced from pre - existing cells. • Is It current? –YES! – http://www.youtube.com/watch?v=4OpBylwH9DU&feature=youtu.be Light Microscopes • Light passes through a specimen • Two lenses form image • Limitations: – Magnifies only 1000 times – Cells are transparent – Dyes or stains are needed to help see structures Electron Microscopes • Beams of electrons focused by magnetic fields • Reveal details 1000 times smaller than light microscope • Can only visualize nonliving, preserved cells and tissues Cell Size • Cells are too small to be seen w/out a microscope (25um) • Exceptions • Amoeba (.5 mm) • Human egg cell (size of a grain of sand) • Cell Membrane: • Cell boundary • Selectively Permeable • Cytoplasm: • Fluid inside cells • Holds organelles in place Parts of a Cell • Organelles: (little organs): • Structures that perform specific functions within the cell. • DNA: Genetic instructions TWO CATEGORIES FOR DISTINGUISHING CELL TYPE • Prokaryotic • Eukaryotic PROKARYOTE • • • • • • Small and simple (0.2 -2.0 µm) No nucleus Cell membrane & cytoplasm Ribosomes May have cell wall Grow, reproduce, respond to change • May use flagella/cilia for movement • Example: • Bacteria DNA is floating around and not in a nucleus! EUKARYOTE • Vary in shape • Highly specialized • Have a nucleus and membrane bound organelles • Cell membrane and cytoplasm • DNA is found in the nucleus • Some single-celled • Many multi-celled • Examples: • All plants, animals, fungi, and many protists DNA enclosed in a nucleus! Examples of Cells Amoeba Bacteria Nerve Cell Red Blood Cell Nucleus • Eukaryotic cells • Often most prominent structure in center of cell • Controls cell processes • Stores DNA • Codes for new proteins Binucleate and Multinucleate Cells: • Cells with more than one nucleus • Examples: –Cells that destroy bone –Some liver cells –Skeletal muscle cells Nuclear Envelope Surrounds nucleus • Double membrane layer • Pores allow material to move in and out of the nucleus Chromatin • Found in Nucleus • String of DNA • Condenses to form chromosomes during cell division Chromosomes • Location? – Nucleus (seen during cell division) • Description? – Condensed chromatin • Function? – Compacted DNA – Pass genetic info to following generations Nucleolus • Dark spherical mass inside the nucleus • Involved in the Assembly of ribosomes Cytoplasm Gel-like substance between membrane + nucleus • Holds organelles • Transport of materials Cytoskeleton Location? • Nucleus to cell membrane Description? • Protein filaments • Microtubules (cell support) • Microfilaments (cell division, movement) Function? • Maintain shape/support • Cell movement • Flagella and cilia Cilia & Flagella • Extensions of cell • Cilia – hair-like projections • Flagella- One or two, longer whip-like structures • Cell movement Flagella Cilia Cilia & Flagella Centrioles • Found Outside nuclear envelope • Only in animal cells • They Help separate chromosomes during cell division Endoplasmic Reticulum (E.R.) • Extension from Nuclear envelope • Rough E.R. – Ribosomes • Smooth E.R. – No ribosomes • Function? • Transport materials • Rough E.R. modify proteins • Smooth E.R. make lipids Ribosomes • Found In nucleus, cytoplasm, and Rough E.R. • They Produce proteins based on instructions found in DNA Protein Assembly Golgi Apparatus • Found Near E.R. and nucleus • Function? • Further package proteins after E.R. • Proteins then sent to final destinations • Outside of cell or to other organelles Lysosome • Location? • Cytoplasm • Rare in plant cells • Function? • Contain enzymes that break down food into nutrients for cell • Also a “cell cleaner” • Break down old organelles Plant Vacuole • Location? • Cytoplasm • Description? • Plant cells • Single, large saclike structure • Function? • Store nutrients • Pressure in plant vacuole aid in support of plant cell (lack of water – wilting) Vacuoles • Location? • Cytoplasm • Description? • Animal & Protists • Multiple vacuoles • Small saclike structures • Function? • Store nutrients • Remove excess water from cell (contractile vacuole) Chloroplasts (Cellular solar plants) • Location? • Cytoplasm of plants • Some protists & bacteria • Function? • Photosynthesis: • Use energy from sunlight to make glucose Mitochondria (Cellular power plants) • Location? • Cytoplasm • More in muscle cells • Function? • Cellular Respiration: • Release energy (ATP) from glucose Plant Mitochondria Human Liver Cell Mitochondria Cell Wall • Location? • Outer most boundary in plant, bacteria and fungi cells • Function? • Support and protection • Maintain cell shape Cell Membrane • Location? • Outer boundary of cells • Function? • Regulates what enters & exits • Supports organelles & provides barrier • Construction? • Lipid bilayer, also containing proteins and carbohydrates • Semipermeable Lesson Overview Cell Structure The Properties of Membranes • Made of phospholipids • Lipid bilayer (double layer) • Hydrophobic fatty tails cluster inside • Hydrophilic heads face out towards water Lesson Overview Cell Structure The Fluid Mosaic Model: • Membranes embedded w/ proteins & carbs • Can move around and “float” among lipids • Proteins form channels and pumps that help to move material across the cell membrane • Organelles: (4) vesicle (2) nucleus (3) ribosome (1) nucleolus (5) rough E.R. (6) Golgi apparatus (7) Cytoskeleton (8) smooth ER (9) mitochondria (10) vacuole (11) cytoplasm (12) lysosome (13) centrioles Plant Cell vs. Animal Cell Animal vs. Plant Cells Homework: DO NOW: Which of the following best describes a living cell? A) A building block B) A complex factory C) Can perform all life processes D) All of the above Explain your choice. Objectives: 1. Describe the processes of diffusion and osmosis. 2. Compare and contrast passive and active transport. Types of Cellular Transport Passive Transport Cell doesn’t use energy Diffusion 2. Facilitated Diffusion 3. Osmosis 1. Weeee!!! high low Active Transport Cell does use energy Protein Pumps 2. Endocytosis 3. Exocytosis 1. This is going to be hard work!! high low Lesson Overview Cell Structure Passive Transport: • Movement of molecules from one side of the membrane to the other • No additional energy • Maintains balance in the cell (homeostasis) Lesson Overview Cell Structure Passive Transport Includes: • Diffusion • The movement of solute particles from a high concentration to low • Facilitated diffusion • Using proteins as channels to help pass certain molecules through the membrane • Osmosis • Diffusion of water through the membrane using aquaporins (water channel proteins) Passive Transport: Facilitated Diffusion A B Facilitated diffusion: Diffusion of specific particles through transport proteins found in the membrane Used to transport large, Facilitated Diffusion diffusion (Lipid charged, or water (Channel Bilayer) molecules that can’t Protein) regularly pass through the membrane Carrier Protein Passive Transport: Facilitated Diffusion Cellular Transport From a- Glucose molecules High Concentration Cell Membrane Low Concentration Protein channel Through a Go to Section: Transport Protein Lesson Overview Cell Structure Osmosis: An Example of Facilitated Diffusion • Osmosis: Movement of water through cell membranes • Aquaporins: Transport proteins that allow water to pass through the membrane. Osmotic Pressure Osmotic pressure: Movement of water out of or into a cell exerting a force. For organisms to survive, they must have a way to balance the intake and loss of water. Examples: Water and nutrients enter plant cells through osmosis. When a wilted plant is watered, osmosis makes the plant firm again. How Organisms Deal with Osmotic Pressure •Bacteria and plants have cell walls. •A protist has contractile vacuoles. •Salt water fish pump salt out of their specialized gills so they do not dehydrate. •Fish eggs lack water channels. •Animal cells are bathed in blood. •Kidneys keep the blood isotonic by remove excess salt and water. Lesson Overview Cell Structure Active Transport: Protein Pumps • Active transport: Movement from low concentration to high • Certain molecules or ions need special transport proteins called protein “pumps,” to cross the membrane. • Examples: • Calcium, potassium, and sodium ions Active Transport: Endocytosis Endocytosis: Taking bulky material into a cell • • • • • Uses energy Cell membrane in-folds around food particle creating a vesicle “cell eating” Forms food vacuole & digests food This is how white blood cells eat bacteria (phagocytosis) Active Transport: Endocytosis and Exocytosis Lesson Overview Cell Structure Endocytosis: Phagocytosis and Pinocytosis • Phagocytosis: Cell eating • Pinocytosis: Cell drinking Lesson Overview Cell Structure Exocytosis: • Cells releasing large amounts of material from the cell • The membrane of the vacuole surrounding the material fuses with the cell membrane, forcing the contents out of the cell What is Homeostasis? Cells work best if they have the correct: Temperature Water levels Glucose concentration Mechanisms in the body keep the cells in a constant environment. Homeostasis: The maintenance of a constant environment in the body. organisms Organism: Anything that can perform life processes. Unicellular organism: Organism made of a single cell. Carry out all life processes in one cell Multicellular organisms: Consist of specialized cells that depend on each other for the organism to survive. The Diversity of Cellular Life Cells differ in size, shape and function Differences in cells arise from the way cells are specialized to perform certain tasks. The Discovery of the Cell Unicellular Organisms Sometimes the cell IS the organism Bacteria, protists, yeast Demonstrate all characteristics of living things including homeostasis These organisms dominate life on earth in terms of numbers! The benefits of being multicellular Larger Size Prey for fewer predators. Wider variety of prey. Longer Life Not limited to life span of a single cell. Specialization Each type of cell has a particular job Organism more efficient Cell communication is essential to Multicellular Life Cell Specialization: Cells throughout an organism can develop in different ways to perform different tasks Cells working together Tissue: Group of cells working together to perform a specific function. Animals have 4 basic types of tissues: Connective tissue Epithelial tissue Muscle tissue Nerve tissue Plants have 3 types of tissues: Vascular tissue Dermal tissue Ground tissue Tissues Working Together Organ: Two or more tissues working together to perform a specific function. Ex for animals: Heart, stomach, intestines, brain, lungs Ex for plants: Leaves, stems, and roots Tissues working together Organ system: Group of organs working together to perform a particular function. Examples in animals: Digestive system Respiratory system Cardiovascular system Examples in plants: Leaf systems Root systems Stem systems Levels of Organization 1st level- the cell 2nd level- tissue (group of similar cells that perform the same function) 3rd level- organ (groups of tissues that work together) 4th level- organ system (a group of organs that work together to perform a specific function) Structure and Function Structure is the arrangement of parts in an organism. Function is the job that the part does. In organisms, structure and function are related. Cellular Communication Vital for organ systems to work. Cells use chemical signals (hormones) that pass from one cell to another. To respond to one of these chemical signals, a cell must have a receptor to which the signaling molecule can bind. Some cells form connections, or cellular junctions, to neighboring cells. Exit Ticket: What is the main difference between a unicellular organism and a multicellular organism in the way life processes are carried out? Cell Membrane Review 1.All cells have a cell membrane 2.Functions: a.Controls what enters and exits the cell to maintain an internal balance called homeostasis b.Provides protection and support for the cell Cell Membrane Structure 1. Lipid Bilayer: Two layers of phospholipids ▫ Phosphate head is polar (water loving) ▫ Fatty acid tails non-polar (water fearing) ▫ Proteins embedded in membrane 2. Selectively permeable: Allows some molecules in and keeps other molecules out Phospholipid Lipid Bilayer Structure of the Cell Membrane Outside of cell Proteins Lipid Bilayer Transport Protein Carbohydrate chains Phospholipids Inside of cell (cytoplasm) Go to Section: Types of Cellular Transport • Passive Transport Cell doesn’t use energy 1. Diffusion 2. Facilitated Diffusion 3. Osmosis • Weeee!! ! high low Active Transport Cell does use energy 1. Protein Pumps 2. Endocytosis 3. Exocytosis This is going to be hard work!! high low Lesson Overview Cell Structure Passive Transport: • Movement of molecules from one side of the membrane to the other • No additional energy • Maintains balance in the cell (homeostasis) Lesson Overview Cell Structure Passive Transport Includes: • Diffusion • The movement of solute particles from a high concentration to low • Facilitated diffusion • Using proteins as channels to help pass certain molecules through the membrane • Osmosis • Diffusion of water through the membrane using aquaporins (water channel proteins) Lesson Overview Cell Structure Passive Transport: Diffusion Passive Transport: Facilitated Diffusion A B • Facilitated diffusion: Diffusion of specific particles through transport proteins found in the membrane Facilitated Diffusion ▫ Used to transport diffusion (Lipid large, charged, or (Channel Bilayer) water molecules that Protein) can’t regularly pass through the membrane Carrier Protein Passive Transport: Facilitated Diffusion Cellular Transport From a- Glucose molecules High Concentration Cell Membrane Low Concentration Protein channel Through a Go to Section: Transport Protein Lesson Overview Cell Structure Osmosis: An Example of Facilitated Diffusion • Osmosis: Movement of water through cell membranes • Aquaporins: Transport proteins that allow water to pass through the membrane. • Why do water molecules have a tough time passing through the cell membrane? Lesson Overview Cell Structure How Osmosis Works Selectively permeable barrier (membrane) Lesson Overview Cell Structure How Osmosis Works • Isotonic: Same concentration on both sides • Hypertonic: Concentrated solution • Hypotonic: Dilute solution http://glencoe.mcgrawhill.com/sites/0042561336/student_view0/chapter3/how _osmosis_works.html Osmotic Pressure Osmotic pressure: Movement of water out of or into a cell exerting a force. For organisms to survive, they must have a way to balance the intake and loss of water. Examples: Plasma surrounds red blood cells Water and nutrients enter plant cells through osmosis. When a wilted plant is watered, osmosis makes the plant firm again. Osmotic Pressure How Organisms Deal with Osmotic Pressure •Bacteria and plants have cell walls. •A protist has contractile vacuoles. •Salt water fish pump salt out of their specialized gills so they do not dehydrate. •Fish eggs lack water channels. •Animal cells are bathed in blood. •Kidneys keep the blood isotonic by remove excess salt and water. Osmotic Pressure Lesson Overview Cell Structure Active Transport: Protein Pumps • Active transport: Movement from low concentration to high • Certain molecules or ions need special transport proteins called protein “pumps,” to cross the membrane. • Examples: • Calcium, potassium, and sodium ions Active Transport: Endocytosis • Endocytosis: Taking bulky material into a cell • Uses energy • Cell membrane in-folds around food particle creating a vesicle • “cell eating” • Forms food vacuole & digests food • This is how white blood cells eat bacteria (phagocytosis) Active Transport: Endocytosis and Exocytosis Lesson Overview Cell Structure Endocytosis: Phagocytosis and Pinocytosis • Phagocytosis: Cell eating • Pinocytosis: Cell drinking Lesson Overview Cell Structure Exocytosis: • Cells releasing large amounts of material from the cell • The membrane of the vacuole surrounding the material fuses with the cell membrane, forcing the contents out of the cell DO NOW: 10/14 The cell is surrounded by a cell membrane, which regulates what enters and leaves the cell. Why is it important to regulate what moves into and out of a cell? Objectives: 1. Explain how unicellular and multicellular organisms maintain homeostasis. 2. Describe the 4 levels of organization in living things. Cells work best if they have the correct: Temperature Water levels Glucose concentration Mechanisms in the body keep the cells in a constant environment. Homeostasis: The maintenance of a constant environment in the body. Organism: Anything that can perform life processes. Unicellular organism: Organism made of a single cell. Carry out all life processes in one cell Multicellular organisms: Consist of specialized cells that depend on each other for the organism to survive. Cells differ in size, shape and function Differences in cells arise from the way cells are specialized to perform certain tasks. Unicellular Organisms Sometimes the cell IS the organism Bacteria, protists, yeast Demonstrate all characteristics of living things including homeostasis These organisms dominate life on earth in terms of numbers! Larger Size Prey for fewer predators. Wider variety of prey. Longer Not Life limited to life span of a single cell. Specialization Each type of cell has a particular job Organism more efficient Cell communication is essential to survival Cell Specialization: Cells throughout an organism can develop in different ways to perform different tasks Tissue: Group of cells working together to perform a specific function. Animals have 4 basic types of tissues: Connective tissue Epithelial tissue Muscle tissue Nerve tissue Plants have 3 types of tissues: Vascular tissue Dermal tissue Ground tissue Organ: Two or more tissues working together to perform a specific function. Ex for animals: Heart, stomach, intestines, brain, lungs Ex for plants: Leaves, stems, and roots Organ system: Group of organs working together to perform a particular function. Examples in animals: Digestive system Respiratory system Cardiovascular system Examples in plants: Leaf systems Root systems Stem systems 1st level- the cell 2nd level- tissue (group of similar cells that perform the same function) 3rd level- organ (groups of tissues that work together) 4th level- organ system (a group of organs that work together to perform a specific function) Structure is the arrangement of parts in an organism. Function is the job that the part does. In organisms, structure and function are related. Vital for organ systems to work. Cells use chemical signals (hormones) that pass from one cell to another. To respond to one of these chemical signals, a cell must have a receptor to which the signaling molecule can bind. Some cells form connections, or cellular junctions, to neighboring cells.