POP Quiz What did Robert Hooke contribute to science? Who refined microscope lenses to increase the ability of the microscope? Who believed that organisms were made of cells? List the three parts of the cell theory

Answers Came up with the word “cells”. Anton van Leeuwenhoek Schleiden and Schwann All organisms are composed of one or more cells; the cell is the basic unit of organization; all cells come from other living cells.

Microscopes as windows into the cells Chapter 7.1

Objectives TLW compare the operation of a compound light microscope with that of an electron microscope TLW learn the name and function of the various parts of a compound microscope.

Vocabulary Focus Compound Microscope Scanning Electron Microscope (SEM) Transmission Electron Microscope (TEM)

Section 7.1 Summary – pages 171-174 The Development of Light Microscopes Compound light microscopes use a series of lenses to magnify objects in steps. These microscopes can magnify objects up to 1 500 times. Section 7.1 Summary – pages 171-174

Development of Electron Microscopes The electron microscope was invented in the 1940s. This microscope uses a beam of electrons to magnify structures up to 500 000 times their actual size.

Development of Electron Microscopes There are two basic types of electron microscopes. The scanning electron microscope (SEM) scans the surface of cells to learn their three dimensional shape. The transmission electron microscope (TEM) allows scientists to study the structures contained within a cell.

SEM Pictures

TEM The transmission electron microscope (TEM) is capable of magnifications of 100,000 times. Unlike the scanning electron microscope, which uses reflected electrons, the TEM uses electrons passing through a very thin slice of the specimen. TEMs are especially useful in studying the structure of cells, and in crystallography.

Show me what you know Identify the type of microscope you would use to view each of the following: A group of cells in a thin layer of onion The details of the surface of a human hair. The organelles inside a cell.

Two Types of Cells Chpt 7.1

Objectives Distinguish between prokaryotic and eukaryotic cells

Vocabulary Focus Prokaryote Eukaryote Organelle

Two Types of Cells Prokaryotic Cells: Cells that do not contain internal membrane- bound structures. Example: bacteria Eukaryotic Cells : Cells that contain membrane-bound structures (organelles). Example: Plants and animals

Two Types of Cells The membrane-bound structures within eukaryotic cells are called organelles. Each organelle has a specific function that contributes to cell survival.

Prokaryotic Cell

Eukaryotic Cell