ObjectivesObjectives 1. Describe and explain the three parts 1. Describe and explain the three parts

of the cell theoryof the cell theory

2. Determine why cells are so small2. Determine why cells are so small

3. Compare and contrast the structure 3. Compare and contrast the structure of Prokaryotic and Eukaryotic Cellsof Prokaryotic and Eukaryotic Cells

4. Describe the structure of the cell 4. Describe the structure of the cell membranemembrane

Cell FeaturesCell Features

Group ChallengeGroup Challenge

What are 5 characteristics of the What are 5 characteristics of the cell?cell?

Why are cells so small?Why are cells so small?

Group ChallengeGroup Challenge

How are cells made?How are cells made?

What do cells make up?What do cells make up?

What protects the cell?What protects the cell?

Cell TheoryCell Theory

Schleiden, Schwann, and VirchowSchleiden, Schwann, and Virchow

1. All living things are made of one or 1. All living things are made of one or more cellsmore cells

2. Cells are the basic units of structure 2. Cells are the basic units of structure and functionand function

3. All cells arise from existing cells3. All cells arise from existing cells

Common Features of CellsCommon Features of Cells

Cell Membrane – encloses the cell Cell Membrane – encloses the cell and separates the cell interior from and separates the cell interior from outside the cell. Regulates what outside the cell. Regulates what comes in and out of the cell. comes in and out of the cell.

Cytoplasm – region of cell within the Cytoplasm – region of cell within the membrane that includes the fluid, membrane that includes the fluid, cytoskeleton, and all organelles cytoskeleton, and all organelles except the nucleus.except the nucleus.

Common Features of CellsCommon Features of Cells

Cytoskeleton – the cytoplasmic Cytoskeleton – the cytoplasmic network of protein filaments that network of protein filaments that play a role in cell movement, shape, play a role in cell movement, shape, and division.and division.

Ribosomes – a cell organelle Ribosomes – a cell organelle composed of RNA and protein composed of RNA and protein synthesis.synthesis.

ProkaryotesProkaryotes

Smallest and simplest cellSmallest and simplest cell Single celled, lacks a nucleus and Single celled, lacks a nucleus and

other internal compartmentsother internal compartments Therefore can’t carry out many Therefore can’t carry out many

specialized functionsspecialized functions• Example BacteriaExample Bacteria

Characteristics of ProkaryotesCharacteristics of Prokaryotes

Can Exist in a broad range of Can Exist in a broad range of environmentsenvironments

Enzymes and Ribosomes are free to move Enzymes and Ribosomes are free to move around in the cytoplasm.around in the cytoplasm.

No internal structures to divide the cellNo internal structures to divide the cell Single circular molecule of DNASingle circular molecule of DNA Have a cell wall that provides structure Have a cell wall that provides structure

and support and made of polysaccharidesand support and made of polysaccharides Cell wall can be surrounded by a capsule Cell wall can be surrounded by a capsule

which enables cell to cling to other objectswhich enables cell to cling to other objects

Characteristics of ProkaryotesCharacteristics of Prokaryotes

Many Prokaryotes have a flagella.Many Prokaryotes have a flagella. Flagella – a long threadlike structure Flagella – a long threadlike structure

that protrude from the cells surface.that protrude from the cells surface.

What is the function of a flagellaWhat is the function of a flagella

Prokaryotic CellProkaryotic Cell

Eukaryotic CellsEukaryotic Cells

The first cells with compartmentThe first cells with compartment Eukaryotic Cells have a nucleusEukaryotic Cells have a nucleus

• Nucleus is an internal compartment that Nucleus is an internal compartment that houses the cells DNAhouses the cells DNA

• The Eukaryotic Cell has membrane The Eukaryotic Cell has membrane bound organellesbound organelles

Eukaryotic cell DNA is organized into Eukaryotic cell DNA is organized into chromosomeschromosomes

Large RibosomesLarge Ribosomes

CytoskeletonCytoskeleton

Provides the interior framework of an Provides the interior framework of an animal cellanimal cell

3 Types of Cytoskeleton Fibers3 Types of Cytoskeleton Fibers Actin Fibers – Play a major role in Actin Fibers – Play a major role in

determining the shape of animal cells by determining the shape of animal cells by pushing and pullingpushing and pulling

Microtubules – Act as a highway system Microtubules – Act as a highway system for transportation of information from the for transportation of information from the nucleus to different parts of the cellnucleus to different parts of the cell

Intermediate Fibers – Provide a frame on Intermediate Fibers – Provide a frame on which the ribosomes and enzymes can be which the ribosomes and enzymes can be confirmed to specific regions of the cell.confirmed to specific regions of the cell.

The Cell MembraneThe Cell Membrane

Cell membranes are not rigid but Cell membranes are not rigid but fluidfluid

Fluidity is caused by lipids which Fluidity is caused by lipids which form the foundationform the foundation

Selectively PermeableSelectively Permeable

Made of PhospholipidsMade of Phospholipids

PhospholipidsPhospholipids

Lipid made of a phosphate group and Lipid made of a phosphate group and two fatty acids.two fatty acids.

Polar Head and Two Non-Polar tailsPolar Head and Two Non-Polar tails Phospholipids arranged in a bi-layerPhospholipids arranged in a bi-layer