1. Chapter 4 Cell Structure

2. 4.1 Studying Cells

3. Cells are small
1-100 mm
Small size maximizes surface area to volume ratio.
Required the development of microscopes
First light microscopes developed in 1600’s.
Anton Van Leeuwenhoek first observed tiny living organisms.
Robert Hooke first used term “cells”.

5. Cell Theory developed from centuries of observations
1800’s Schleiden and Schwann developed Cell Theory
1. All organisms are made of cells
2. Cell is basic unit function of organisms
3. Cells com form preexisting cells.
Virchow first described cell division

6. Cell Structure All cells contain outer phospholipid plasma membrane
DNA chromosomes
Cytoplasm

8. 4.2 Prokaryotic Cells

9. The presence of a cell nucleus
All cells contain DNA as its hereditary material
Prokaryotes simplest cell lacking a membrane bound nucleus or other organelles
DNA coiled in a circular chromosome
External structure include cell wall and flagella.
Include Bacteria and Archaea

11. 4.3 Eukaryotic Cells

12. Larger more complex cells
Membrane bound nucleus found in all Eukaryotes
Linear coiled chromosomes
Other organelles with specialized function.
Ribosomes (also in Prokaryotes) – assemble proteins
Mitochondria – produce energy
Peroxysomes – help metabolize lipids and amino acids
Vacuoles store and transport materials

14. Plant cells Contain Cell wall Chloroplast – site of photosynthesis
Large central vacuole which stores water
Lack Centrioles and Lysosomes

15. 4.4 Endomembrane System

16. Membrane extensions of the nuclear membrane
Rough Endoplasmic reticulum contain ribosomes
Smooth Endoplasmic reticulum lack ribosomes
Golgi Apparatus – Assist in protein modification and storage
Vesicles help transport materials between these structures