INTRODUCTION TO CELLS
Jan 13, 2016
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, 1635 - 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 1632-1723
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
Cell Theory
Theodore Schwann
all animals are made of cells
Rudolf Virchow
all cells came from pre-existing cells
Cell Theory
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 Virchowconcluded 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.
cell tissue
organ organ system
organism
The Levels of Organization
Cell Type: ProkaryotesProkaryotes, which includes all bacteria,
are the simplest cellular organisms. They have genetic material but no nucleus.
Typical bacteria cell
Cell Types: EukaryotesEukaryotic cells
contain a membrane-bound nucleus and numerous membrane -enclosed organelles (e.g., mitochondria, lysosomes, Golgi apparatus) not found in prokaryotes.
Different Types of CellsProkaryotic Eukaryotic
no nucleus
protists, fungi, plants, animals
only in bacteria
small
small ribosomeslarger ribosomes
very small
organellesno organelles
nucleusno nucleus
small ribosomes
organellesno organelles
nucleus
protists, fungi, plants, animals
only in bacteria
Small very 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 Cellscytoplasm: semi-liquid material that fills the cellcell 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 proteinsmitochondria: convert chemical energy stored in food into ATP (cellular respiration occurs here)
nucleolusnuclear 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.
VesicleA small bubble that is used by the cell for organizing cellular substances. They are involved in metabolism & enzyme storage