INTRODUCTION TO CELLS

Robert Hooke naturalist, philosopher, inventor, architect.... (July 18, March 3, 1703) He was the first person to use the term “cells”.

Anton van Leeuwenhoek  perfected the simple microscope  He discovered bacteria in 1674 and four years later, he discovers protozoa.

Matthias Schleiden all plants are made of cells Cell Theory Theodore Schwann all animals are made of cells Rudolf Virchow all cells came from pre-existing cells

Cell Theory all living things are made up of cells cells are the basic units of structure and function in an organism new cells are produced from existing cells Matthias Schleiden concluded that all plants are made of cells (1838) Theodore Schwann concluded that all animals are made of cells (1839) Rudolf Virchow concluded that all cells came from pre-existing cells (1855)

Cell Specialization Cells in organisms are specialized to perform different tasks. Photos from Biology, Prentice Hall

Multicellular organisms are arranged from simple to complex according to their level of cellular grouping. celltissueorganorgan system organism The Levels of Organization Simple Complex

LevelFunctionExample  What is the benefit of being made of all of these cells? Nervous System Brain Nervous Tissue Neuron Levels of Organization Organ system Organ Tissues Cells Different organs function together Different tissues function together Similar cells function together Cells can perform special jobs

Cell Types PROKARYOTE  No membrane-bound organelles (nucleus)  Small ribosomes  Most cells are μm in size  Evolved 3.5 billion years ago  Found only in Archaebacteria and Eubacteria Kingdoms EUKARYOTE  Has membrane- bound organelles (nucleus)  Larger ribosomes  Cells can be between 2 - 1,000 μm in size  Evolved 1.5 billion years ago  Includes Protista, Fungi, Plantae and Animalia Kingdoms A unit of length equal to one thousandth (10 -3 ) of a millimeter

Cell Type: Prokaryotes  Prokaryotes, which includes all bacteria, are the simplest cellular organisms. They have genetic material but no nucleus. Typical bacteria cell

Cell Types: Eukaryotes  Eukaryotic cells contain a membrane- bound nucleus and numerous membrane -enclosed organelles (e.g., mitochondria, lysosomes, Golgi apparatus) not found in prokaryotes.

Examples of Eukaryotes

Different Types of Cells  Prokaryotic  Eukaryotic no nucleus protists, fungi, plants, animals only in bacteria small small ribosomes larger ribosomes very small organellesno organelles nucleus no nucleus small ribosomes organellesno organelles nucleus protists, fungi, plants, animals only in bacteria small umvery small 1-10um larger ribosomes

What Are the Parts of Cells  Both prokaryotic and eukaryotic cells have some things in common.  All cells have ¤cell membrane ¤cytoplasm ¤ribosomes ¤nuclear material cytoplasmribosomesnuclear materialcell membrane

Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains Section 7-3 Figure 7-12 The Structure of the Cell Membrane PHOSPHOLIPID BILAYER

ProkaryotesEukaryotes Cell membrane Contain DNA Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Animal CellsPlant Cells Centrioles Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Cell Wall Chloroplasts Section 7-2 Venn Diagrams

Animal Cell Centrioles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Golgi apparatus Smooth endoplasmic reticulum Mitochondrion Cell Membrane Ribosome (free) Ribosome (attached) Section 7-2 Figure 7-5 Plant and Animal Cells

Plant Cell Nuclear envelope Ribosome (attached) Ribosome (free) Smooth endoplasmic reticulum Nucleus Rough endoplasmic reticulum Nucleolus Golgi apparatus Mitochondrion Cell wall Cell Membrane Chloroplast Vacuole Section 7-2 Figure 7-5 Plant and Animal Cells

cytoplasm nucleus cell membrane chloroplast vacuole mitochondria cell wall ribosomes Parts of a plant cell cytoplasm: semi-liquid material that fills the cell (p. 175) nucleus: controls most cell processes, contains hereditary information (DNA) chloroplast: capture energy from sunlight and convert it into chemical energy (food), (photosynthesis occurs here) vacuole: sac-like structure that stores water, salts, foods, etc ribosomes: manufacture proteins mitochondria: convert chemical energy stored in food into ATP (cellular respiration occurs here) cell membrane: regulates what enters and leaves the cell, protection and support cell wall: outer layer in plant cells, support and protection endoplasmic reticulum golgi complex endoplasmic reticulum: transportation system throughout the cell Golgi complex: packages proteins

cytoplasm nucleus cell membrane chloroplast vacuole mitochondria cell wall ribosomes (p. 175) Plant Cell endoplasmic reticulum golgi complex

Cell Membrane Mitochondria Chloroplast Endoplasmic Reticulum Nucleus Lysosome Golgi Body Vacuole Ribosome Cell Wall Cell Organelles  Animal  Plant

Cell Video Q’s  How did they grow the little girl’s skin?  Can an organism live with only one cell?  Why did Hooke call the objects he viewed with microscope cells?  If all plants are made of cells, why do you think they vary in size and appearance?