Chapter 6 A Tour of the Cell

“Faith is a fine invention when

gentlemen can see, but microscopes are

prudent in an emergency.”

Emily Dickinson

Question ? Can cells be seen with the

naked eye?

Light Microscope - LM

Light MicroscopeOccular Lens

Objective Lens

Stage with specimen

Light Source

Magnification

Resolution

Limitations - LM

Electron Microscopes

TEM SEM

Advantages

Disadvantages

Transmission Electron Microscope - TEM

TEM Limitations

Scanning Electron Microscope - SEM

Excellent views of surfaces. Produces 3-D views. Live specimens possible.

Limitations Lower magnifications than

the TEM.

Cell Biology or Cytology

Cyto = cell - ology = study of

Should use observations from several types of microscopes to make a total picture of how a cell is put together.

Other Tools for Cytology

Cell Fractionation

Cell Fractionation

Chromatography

Electrophoresis

History of Cells

History of Cells 1833 - Robert Brown,

discovered the nucleus. 1838 - M.J. Schleiden,

all plants are made of cells. 1839 - T. Schwann,

all animals are made of cells. 1840 - J.E. Purkinje, coined

the term “protoplasm”.

Cell Theory

R. Virchow

Types of Cells Prokaryotic –

Eukaryotic -.

Both Have:

Prokaryotic Eukaryotic

Nucleus

Prokaryotic

Eukaryotic

Why Are Cells So Small?

Basic Cell Organization

Animal Cell

Plant Cell

Membrane

Cytoplasm or Cytosol

Organelle

Organelles - function

You must be able to:

Nucleus

Structure

Nuclear Membrane

Nuclear Pores

Nucleolus

Chromatin Chrom: colored - tin: threads

Nucleus - Function

Ribosomes

Subunits

Locations Free in the cytoplasm -.

Membrane bound -

Endomembrane System

Endomembrane System

Endoplasmic Reticulum

Structure of ER

Types of ER Smooth ER:

Rough ER:

Golgi Apparatus

Structure Has 2 Faces Cis face –

Trans faceface - -

Function of Golgi Bodies

Golgi Vesicles

Lysosome

Function

Lysosomes

Vacuoles

Protists

Plants

Function

Function: Plant vacuole

Microbodies Peroxisomes:

Glyoxysomes:

Enzymes in a crystal

Mitochondria .

Inner Membrane

Function

Mitochondria

Chloroplasts

Inner or Thylakoid Membranes

Function

Chloroplasts

Plastids

Examples Amyloplasts/ Leucoplasts –

Chromoplasts -

Ergastic Materials

Cytoskeleton

Functions

Components

Intermed. Microtubules Microfilament Filaments Hollow Solid Cables Tubulin Actin (Keratin) Dynein Cilia/Flagella Muscle Anchors Contraction Organelles Cell Division

Microtubules

Tubulin .

Microtubules

Microtubules

Cilia and Flagella

Cilia and Flagella

Dynein Protein

Centrioles

Basal Bodies

Basal Body

MTOCs

Microfilaments

Microfilaments are stained green.

Functions

Intermediate Filaments

Functions

Cytoskeleton

Cell Wall

Plant Cell Walls

Primary Wall

Secondary Wall

Middle Lamella

Cell Walls .

Extracellular Matrix - ECM

Intercellular Juctions

Plasmodesmata

Intercellular Juctions

Tight Junctions

Desmosomes

Gap Junctions

Summary Answer: Why is Life cellular

and what are the factors that affect cell size?

Be able to identify cellular parts, their structure, and their functions.