Chapter 7 A View of the Cell

Questions from Chapter 7 Outline

I. A View of the Cell” THE CELL THEORY THE CELL THEORY THE CELL THEORY A. The cell is the basic units of living organisms. B. Cell Theory 1. Robert Hooke: coined the term “cell”. He was actually looking at cell walls. 2. Anton Van Leeuwenhoek: developed the first microscope 3. Felix DuJardin: single cell organism are self-sufficient living organisms 4. Mathias Schleiden: botanist, stated all plants are made up of cells 5. Theordore Schwann: zoologist, stated all animals are made up of cells. 6. Rudoulf Virchow: stated all living cells come from other living cells. THE CELL THEORY THE CELL THEORY THE CELL THEORY

The Cell Theory C. They (Schleiden/Schwann) proposed that: All organisms are composed of one or more cells The cell is the basic unit of organization of organisms All cells come from preexisting cells

II. Microscopes A. Compound Light Microscope —can magnify up to 1,500 times—used to view living cells, small organisms and preserved cells B. SEM (scanning electron microscope) — can magnify up to 60,000 times—used to view surface of cells C. TEM (transmission electron microscope) —can magnify up hundreds of thousands of times—used to view structures inside the cell

III. Inside the Cell A. Felix DuJardin studied cells of single-celled organisms. He found they were self-sufficient living organisms.

B. Nucleus: made up of proteins, enzymes and hereditary material B. Nucleus: made up of proteins, enzymes and hereditary material. It is the “Control Center” of the cell. The nucleus directs all activities of the cell. C. Nucleolus: Plays an indirect role in making proteins. Found inside the nucleus. D. Nuclear Membrane: Enables the nucleus to maintain a different environment. E. Organelles: Organized structures within the cells. Term means “Little Organs”. They carry out life functions of the cell. Inside The Cell

IV. Cellular Framework and Movement. A. Cytoskeleton: framework of a cell. 2 Parts Microfilaments: Provides structural support and assist cell movement. Microtubules: help organelles move in the cell. MOVEMENT External appendages that aid in movement B. Flagella: whip like structure C. Cilia: hair like structure

V. Other Cellular Organelles. A. Chlorophyll: Green pigment in plants. B. Chloroplast: contains the green pigment used in photosynthesis. (only in plants) C. Cell wall: provides protection and support for the cell. (Plants only) D. Cell membrane or plasma membrane: found in plants and animals. Function is to regulate movement of materials in and out of the cell. “Gate keeper” and “Maintains Homeostasis” E. Nuclear membrane: Enables the nucleus to maintain a different environment.

More Organelles in the Cell F. Cytoplasm: clear gel-like material. Carries on anaerobic respiration. (Life functions are carried out in the cytoplasm) G. Golgi Bodies: Packages substances that are to be secreted from the cell. “Protein Package Station” H. Centrioles: (Animals only) important in reproduction and cell division I. Ribosomes: site for making proteins. “Protein Factory”

More Cell Organelles J. Endoplasmic Reticulum: Involved in protein production and transport. (2 types Smooth and Rough) Ribosomes attached to the Rough ER K. Mitochondria: site of cellular respiration “Power House” HAS ITS’ OWN DNA L. Vacuole: storage of food, enzymes and things needed by the cell. “Store House” ***Generally large in plant cells.*** M. Lysosomes: contain digestive enzymes sometimes referred to as “suicide sacs”

VI. Two Types of Cells Prokaryotes: nucleus not enclosed in a nuclear membrane. Eukaryotes: have organelles and nucleus is enclosed in a membrane.

VII. Cellular Levels of Organization. Cells Tissues Organs Organ System Organism

VIII. The Plasma Membrane A. In order for cells to live, they must be in balance with the environment around them. This balance is homeostasis. B. It is the job of the plasma membrane to maintain homeostasis “steady state” C. It allows a steady supply of nutrients such as glucose, amino acids, lipids….etc to pass in and out of the cell.

Maintains Homeostasis By: IX. Plasma Membrane Maintains Homeostasis By: A. Selective permeability: Allows some molecules to pass through while keeping other out. ex. screen in window on a house B. Cells exist in a water environment (inside &outside) water can flow freely in and out of the cell

X. Structure of the Plasma Membrane A. Phospholipid (double layer) p. 177 1. Polar Head (phosphate) (head is hydrophilic…-love water) 2. Nonpolar Tail (fatty acid) (tail is hydrophobic…-avoids water) B. The model of the plasma membrane is called the fluid mosaic model —because it is flexible (it can move and flow), also transport proteins in the membrane move materials (food/waste)…

Word Bank for Video “Cells, the Building Blocks of Life” Prokaryote DNA Microtubles Homeostasis Diffusion Flagella Lysosomes Mitochondria Glucose Active Transport Endoplasmic Reticulum Golgi Bodies Coenzymes Cytoplasm Ribosomes Stimuli Cell Enzymes Vacuoles Cilia Chloroplasts Eukaryote Chloroplasts Photosynthesis Nucleus ATP