Chapter 1.2 Microscopes allow us to see inside the cell

BEFORE, you learned Some organisms are

unicellular, and some are multicellular

A microscope is necessary to study most cells

The cell theory describes the cell as the fundamental unit of life

NOW, you will learn

About different types of microscopes

About prokaryotic and eukaryotic cells

How plant and animal cells are similar and different

Chp 1.2 pg 18

Think About

How small are cells?

MICROMETER (1µm) = 1

1,000,000 of a meter

17,000 bacteria cells lined up

would fit across a dime

Chp 1.2 pg 18

The Microscope is an Important Tool

Chp 1.2 pg 18-19

In light microscopes, LENSES bendthe LIGHT to make objects appear

BIGGER than they are.

. . .. . .

. … .. ..

Mixed Bacteriaas seen under a light

microscope

Modern LightMicroscopes can magnify objects

up to 1000x!

The Microscope is an Important Tool

Chp 1.2 pg 18-19

Cell samples aretreated with dyes

to make structuresin the cells easier

to see.

The Microscope is an Important Tool

Scanning Electron Microscope (SEM)

Transmission Electron

Microscope (TEM)

Chp 1.2 pg 19

Can produce imagesas small as

0.00002µm (micrometers)

In both SEM and TEM, tiny particles called ELECTRONS, not LIGHT areused to produce images.

The Microscope is an Important Tool

SEM & TEM Light Microscope

Chp 1.2 pg 19

Electrons, not light used to produce images

Light used toproduce images

Used to see the Details of the parts of cells

Used to see someParts of the cells

CANNOT be used to study LIVE cells

Allow scientists tostudy LivingCells

Used to observe

Microbes that can not

be seen with

just your eyes

Chp 1.2 pg 19

Looking at Organisms with a SEM:

1) Cell samples must be coated in a heavy metal.

2) The electrons bounce of the coating and are read by a detector.

3) The detector produces a 3-D image of the surface.

Chp 1.2 pg 19

Looking at Organisms with a TEM:

1) Sample must be sliced extremely thin.

2) Electrons pass through a thin section.

3) Images appear 2-D

Cells are Diverse

Chp 1.2 pg 20

Cell Membrane:Encloses the insideof each cell andprotects it.

Cytoplasm:Gelatin-likematerial insidethe cellmembrane

Genetic Material: Allows the cell toreproduce.

Cells are Diverse

Chp 1.2 pg 20

Genetic Information

PROKARYOTIC CELLS: Genetic Information is located in theCytoplasm

Cells are Diverse

Chp 1.2 pg 20

Genetic Information

EUKARYOTIC CELLS: Genetic Information is separated from the cytoplasm by a membrane.

The ORGANELLE that containsmost of the genetic materialis called the NUCLEUS

Plants and Animals Have Eukaryotic Cells

Nucleus

Usually the largest organelle in the cell.

Stores the instructions a cell needs to function.

Chp 1.2 pg 21

Plants and Animals Have Eukaryotic Cells

Plants have Cell Walls

A tough outer covering that lies just outside the cell membrane.

Protects and supports cell.

Chp 1.2 pg 21

Chp 1.2 pg 23

Structures that Process Information (Plants & Animals)

Ribosomes: Use informationto build important proteins

Organelles that Provide Energy (Plants)

Chp 1.2 pg 23

Chloroplast: Energy from sunlight is used to make sugars.

Organelles that Provide Energy (Plants & Animals)

Chp 1.2 pg 23

Mitochondria: Organellesthat use oxygen to get energyfrom processing food.

Organelles that Process and Transport (Plants & Animals)

Chp 1.2 pg 23-24

Golgi Apparatus: Takes materials made by the Endoplasmic Reticulum and finishes processing them.

Endoplasmic Reticulum: Makes parts of cell membrane and transports materials

Organelles for Storage, Recycling, and Waste

Plant Cells: Vacuoles Animal Cells: Lysosomes

Chp 1.2 pg 24

vacuole