INTRODUCTION TO CELLS
History of the Cell Robert Hooke, 1665 Anton von Leeuwenhoek, 1674 Matthias Schleiden, 1838 Theodor Schwann, 1839 Rudolph Virchow, 1855 Janet Plowe, 1931
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.
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 A group of cells work together 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 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 Smallvery small larger ribosomes Simple complex
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 cell wall: outer layer in plant cells, support and protection (p. 175) cell membrane: regulates what enters and leaves the cell, protection and support nucleus: controls most cell processes, contains hereditary information (DNA) Nucleolus: organelle that produces ribosomal RNA Nuclear membrane: phospholipid bilayer that surrounds a nucleus 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) nucleolus nuclear membrane
Golgi modifies, sorts, & packages other material from the ER 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, & proteins into small molecules that can be used by the rest of the cell. It is also involved in breaking down organelles that have outlived their usefulness.
Cytoskeleton: Helps the cell maintain its shape & is involved in movement.
Plastid: Found in plants. They are sites for storage of important chemical compounds. They contain pigments that determine the cell’s color.
Vesicle A small bubble that is used by the cell for organizing cellular substances. They are involved in metabolism & enzyme storage