Presentation on theme: "INTRODUCTION TO CELLS. Robert Hooke naturalist, philosopher, inventor, architect.... (July 18, 1635 - March 3, 1703) In 1665 Robert Hooke publishes his."— Presentation transcript:
INTRODUCTION TO CELLS
Robert Hooke naturalist, philosopher, inventor, architect.... (July 18, March 3, 1703) In 1665 Robert Hooke publishes his book, Micrographia, which contains his drawings of sections of cork as seen through one of the first microscopes (shown at right). He was the first person to use the term cells.
Anton van Leeuwenhoek In 1673 Anton van Leeuwenhook perfects the simple microscope and observes cells and microorganisms. He discovered bacteria in 1674 and four years later, he discovers protozoa.
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
Cell Types PROKARYOTE No nucleus No membrane-bound organelles Small ribosomes Most cells are μm in size Evolved 3.5 billion years ago Found only in Archaebacteria and Eubacteria Kingdoms EUKARYOTE Has nucleus Many organelles 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
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.
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 mvery small 1-10 m 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
cytoplasm nucleus cell membrane chloroplast vacuole mitochondria cell wall ribosomes Parts of Cells 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
Parts of Cells cell membrane mitochondria ribosome Golgi apparatus nucleus cytoplasm Endoplasmic reticulum lysosome Golgi apparatus: modifies, sorts and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or secretion outside the cell Endoplasmic reticulum: site where lipid components of the cell membrane are assembled, along with proteins and other materials that are exported from the cell lysosome: digests lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell; also involved in breaking down organelles that have outlived their usefulness