Chapter 4Chapter 4

Cells: The Basic Units of LifeCells: The Basic Units of Life

Section 1: Organization of LifeSection 1: Organization of Life

Every living thing has at least one cell Many living things exist as one cell

The average human has 100,000,000,000,000 cells!!!!

Every living thing has at least one cell Many living things exist as one cell

The average human has 100,000,000,000,000 cells!!!!

Cells: Starting Out SmallCells: Starting Out Small

Most cells are too small to be seen without a microscope

Many organisms exist as single cells, while others exist as multiple cells All multi-cellular organisms start out as a single cell

For multi-cellular organisms, not all cells look or act the same i.e. there are 200 different kinds of cells in your body

Most cells are too small to be seen without a microscope

Many organisms exist as single cells, while others exist as multiple cells All multi-cellular organisms start out as a single cell

For multi-cellular organisms, not all cells look or act the same i.e. there are 200 different kinds of cells in your body

Tissues (cells working together) and Organs (teams working together)

Tissues (cells working together) and Organs (teams working together)

Tissue - a group of cells that work together to perform specific job in the body Cells grouped together

Organ - two or more tissues working together to perform a specific job i.e. stomach, intestines, heart, lungs, and skin

Plants also have different organs i.e. stems, roots, and leaves

Tissue - a group of cells that work together to perform specific job in the body Cells grouped together

Organ - two or more tissues working together to perform a specific job i.e. stomach, intestines, heart, lungs, and skin

Plants also have different organs i.e. stems, roots, and leaves

Organ Systems (a great combination) and Organisms (independent living)

Organ Systems (a great combination) and Organisms (independent living)

Organ Systems - organs working together in groups to perform a particular job

Each system has its own special job to do i.e. digestive - breaks down food, nervous - sends

electrical impulses “messages” throughout the body

Organisms - anything that can live on its own There are two types:

1) unicellular - a single cell living on its own 2) multicellular - organisms that can only exist as a

group of cells

Organ Systems - organs working together in groups to perform a particular job

Each system has its own special job to do i.e. digestive - breaks down food, nervous - sends

electrical impulses “messages” throughout the body

Organisms - anything that can live on its own There are two types:

1) unicellular - a single cell living on its own 2) multicellular - organisms that can only exist as a

group of cells

The Big PictureThe Big Picture

Organisms can live on their own, but they usually do not live alone

Populations - a group of organisms that are of the same kind and that live in the same area

Organisms can live on their own, but they usually do not live alone

Populations - a group of organisms that are of the same kind and that live in the same area

Communities - two or more different populations living in the same area

Ecosystems - the community and all of the nonliving things that affect it i.e. water, soil, rocks, temperature, etc.

Communities - two or more different populations living in the same area

Ecosystems - the community and all of the nonliving things that affect it i.e. water, soil, rocks, temperature, etc.

Section 2: The Discovery of Cells

Section 2: The Discovery of Cells

Most cells are so tiny that they are not visible with the naked eye

The discovery of cells happened by accident The first person to see cells was not even

looking for them How did this lead to the discovery of many

different cell types?

Most cells are so tiny that they are not visible with the naked eye

The discovery of cells happened by accident The first person to see cells was not even

looking for them How did this lead to the discovery of many

different cell types?

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QuickTime™ and aTIFF (Uncompressed) decompressor

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Seeing the First CellsSeeing the First Cells In 1665, a British chemist named Robert Hooke built

a crude compound microscope He decided to look at a thin piece of cork To his amazement the cork looked like hundreds of

tiny boxes He named these boxes cells, which means little rooms in

Latin Amazed by his discovery, Hooke used his microscope

to look at feathers, fish scales, fly eyes, etc. Hooke believed that cells were only found in plants

In 1665, a British chemist named Robert Hooke built a crude compound microscope

He decided to look at a thin piece of cork To his amazement the cork looked like hundreds of

tiny boxes He named these boxes cells, which means little rooms in

Latin Amazed by his discovery, Hooke used his microscope

to look at feathers, fish scales, fly eyes, etc. Hooke believed that cells were only found in plants

Seeing Cells in Other Life-FormsSeeing Cells in Other Life-Forms

In 1673, a Dutch merchant named Anton van Leeuwenhoek used his hand made microscope to look at pond scum

He was amazed when he saw many small “creatures” swimming around He also looked at blood, tartar, and was the first

person to see bacteria

In 1673, a Dutch merchant named Anton van Leeuwenhoek used his hand made microscope to look at pond scum

He was amazed when he saw many small “creatures” swimming around He also looked at blood, tartar, and was the first

person to see bacteria

The Cell TheoryThe Cell Theory

In 1838 German scientist Matthias Schleiden , after many observations, concluded that all plant parts are made of cells

The next year, after many observations, German scientist Theodore Schwann stated that all animal tissues are made of cells

Schwann then wrote the first two steps of what would become the cell theory

In 1838 German scientist Matthias Schleiden , after many observations, concluded that all plant parts are made of cells

The next year, after many observations, German scientist Theodore Schwann stated that all animal tissues are made of cells

Schwann then wrote the first two steps of what would become the cell theory

About 20 years later, in 1858, Rudolf Virchow, a German doctor, saw that cells could not develop from anything except other cells

This completed the Cell theory, which states; 1) All organisms are composed of one or

more cell 2) The cell is the basic unit of life in all

living things 3) All cells come from existing cells

About 20 years later, in 1858, Rudolf Virchow, a German doctor, saw that cells could not develop from anything except other cells

This completed the Cell theory, which states; 1) All organisms are composed of one or

more cell 2) The cell is the basic unit of life in all

living things 3) All cells come from existing cells

Cell SimilaritiesCell Similarities

Cells come in many different shapes and sizes, and perform a variety of different functions

All cells have the following things in common: 1) Cell membrane - a barrier between the inside of

the cell and the cell’s environment 2) Hereditary material (DNA) - controls all of the

activities of the cell and contains the information for that cell to make new cells

Cells come in many different shapes and sizes, and perform a variety of different functions

All cells have the following things in common: 1) Cell membrane - a barrier between the inside of

the cell and the cell’s environment 2) Hereditary material (DNA) - controls all of the

activities of the cell and contains the information for that cell to make new cells

Cytoplasm and Organelles - the chemicals and structures that enable the cell to live , grow, and reproduce Cytoplasm - the gel like fluid of the cell

and everything in it Organelles - the individual structures

within the cell

Small size - most cells are too small to be seen with the naked eye

Cytoplasm and Organelles - the chemicals and structures that enable the cell to live , grow, and reproduce Cytoplasm - the gel like fluid of the cell

and everything in it Organelles - the individual structures

within the cell

Small size - most cells are too small to be seen with the naked eye

Benefits of Being MulticellularBenefits of Being Multicellular

Can you name some of the benefits of being multicellular?

Can you name some of the benefits of being multicellular?

Two Types of CellsTwo Types of Cells

Of all the many different kinds of cells that exist, they can only be divided into two groups 1) Prokaryotic - cells that do not have a nucleus

or membrane covered organelles 2) Eukaryotic - cells that have a nucleus and

membrane covered organelles

Of all the many different kinds of cells that exist, they can only be divided into two groups 1) Prokaryotic - cells that do not have a nucleus

or membrane covered organelles 2) Eukaryotic - cells that have a nucleus and

membrane covered organelles

Prokaryotic CellsProkaryotic Cells

The world’s smallest cells and include bacteria They DO NOT have a nucleus but they do have

DNA They have a single long, circular DNA molecule shape

like a rubberband They DO NOT have membrane covered

organelles, but they do have ribosomes Ribosomes assemble proteins for the cell

Prokaryotic cells (bacteria) were probably the first type of cell on Earth Some scientists think they have existed for about 3.8

billion years

The world’s smallest cells and include bacteria They DO NOT have a nucleus but they do have

DNA They have a single long, circular DNA molecule shape

like a rubberband They DO NOT have membrane covered

organelles, but they do have ribosomes Ribosomes assemble proteins for the cell

Prokaryotic cells (bacteria) were probably the first type of cell on Earth Some scientists think they have existed for about 3.8

billion years

Eukaryotic CellsEukaryotic Cells

All living things that are not prokaryotic cells are made of one or more eukaryotic cells

Have a nucleus and membrane covered organelles About 10 times larger than prokaryotic cells and

more complex Appeared about two billion years ago Contains linear shaped DNA molecules All eukaryotic cells have a cell membrane, and some

have an additional cell wall http://www.umanitoba

.ca/Biology/lab3/biolab3_1.html

All living things that are not prokaryotic cells are made of one or more eukaryotic cells

Have a nucleus and membrane covered organelles About 10 times larger than prokaryotic cells and

more complex Appeared about two billion years ago Contains linear shaped DNA molecules All eukaryotic cells have a cell membrane, and some

have an additional cell wall http://www.umanitoba

.ca/Biology/lab3/biolab3_1.html

Section 3: Eukaryotic Cells - The Inside Story

Section 3: Eukaryotic Cells - The Inside Story

Eukaryotic cells are very complex Everything, from the structures

covering the cells to the organelles inside them, performs a task that helps to keep the cell alive

Eukaryotic cells are very complex Everything, from the structures

covering the cells to the organelles inside them, performs a task that helps to keep the cell alive

Holding It All TogetherHolding It All Together Cell Membrane

All cells are covered by a cell membrane It is made of phospholipids

The membranes job is to 1) Keep the cytoplasm inside 2) Allow nutrients in and wastes out 3) Interact with things outside the cell

Cell Wall Provides strength and support to the cell membrane

It is made of cellulose

Plants and algae have cell walls Allows plants (i.e. trees) to defy gravity

Cell Membrane All cells are covered by a cell membrane

It is made of phospholipids

The membranes job is to 1) Keep the cytoplasm inside 2) Allow nutrients in and wastes out 3) Interact with things outside the cell

Cell Wall Provides strength and support to the cell membrane

It is made of cellulose

Plants and algae have cell walls Allows plants (i.e. trees) to defy gravity

The Cell’s LibraryThe Cell’s Library Nucleus

The largest and most visible organelle in a eukaryotic cell

Covered by a membrane through which materials can pass

The “control center” of the cell Stores DNA

DNA contains information on how to make all of the cells proteins

Every chemical reaction important to life involves some kind of protein

Contains the nucleolus Nucleolus stores materials used to make ribosomes

Nucleus The largest and most visible organelle in a

eukaryotic cell Covered by a membrane through which

materials can pass The “control center” of the cell Stores DNA

DNA contains information on how to make all of the cells proteins

Every chemical reaction important to life involves some kind of protein

Contains the nucleolus Nucleolus stores materials used to make ribosomes

Protein FactoriesProtein Factories

Ribosomes The smallest but most abundant organelles ALL cells have ribosomes Ribosomes attach amino acids together to make

proteins, because all cells need proteins to live Amino Acids - the building blocks of proteins

Ribosomes are not covered by a membrane

Ribosomes The smallest but most abundant organelles ALL cells have ribosomes Ribosomes attach amino acids together to make

proteins, because all cells need proteins to live Amino Acids - the building blocks of proteins

Ribosomes are not covered by a membrane

The Cell’s Delivery System The Cell’s Delivery System

Endoplasmic Reticulum - a membrane covered compartment that makes lipids and other materials for use inside and outside the cell It also breaks down drugs and other chemicals that could

damage the cell It is an internal delivery system

Substances enter the ER and can move from one place to another through it’s series of tubes

There are two types: 1) Rough ER - has ribosomes attached to it

Proteins made by these ribosomes enter the rough ER 2) Smooth ER

Endoplasmic Reticulum - a membrane covered compartment that makes lipids and other materials for use inside and outside the cell It also breaks down drugs and other chemicals that could

damage the cell It is an internal delivery system

Substances enter the ER and can move from one place to another through it’s series of tubes

There are two types: 1) Rough ER - has ribosomes attached to it

Proteins made by these ribosomes enter the rough ER 2) Smooth ER

The Cell’s Power PlantsThe Cell’s Power Plants

Mitochondria Produces most of the cell’s ATP (Adenosine

Triphosphate) Energy stored in food (glucose) is used to make ATP in the

mitochondria

Mitochondria are surrounded by two membranes The inner membrane has many folds and is where most of the

ATP is made Mitochondria must have oxygen to make ATP The main reason we breath air is to supply our mitochondria

with oxygen

Contains it’s own DNA

Mitochondria Produces most of the cell’s ATP (Adenosine

Triphosphate) Energy stored in food (glucose) is used to make ATP in the

mitochondria

Mitochondria are surrounded by two membranes The inner membrane has many folds and is where most of the

ATP is made Mitochondria must have oxygen to make ATP The main reason we breath air is to supply our mitochondria

with oxygen

Contains it’s own DNA

Chloroplast - “Green Structure” Produces sugar (glucose) from sunlight during

the process of photosynthesis. This sugar is used by the mitochondria in plants and

algae to produce ATP Chloroplasts are also surrounded by two

membranes and contain flatten sacks (thylakoids) stacked upon each other (grana), that contain chlorophyll Thylakoids contain a green pigment (chlorophyll)

that traps sunlight’s energy, which is used to make sugar (glucose)

This process is called photosynthesis Contains it’s own DNA

Chloroplast - “Green Structure” Produces sugar (glucose) from sunlight during

the process of photosynthesis. This sugar is used by the mitochondria in plants and

algae to produce ATP Chloroplasts are also surrounded by two

membranes and contain flatten sacks (thylakoids) stacked upon each other (grana), that contain chlorophyll Thylakoids contain a green pigment (chlorophyll)

that traps sunlight’s energy, which is used to make sugar (glucose)

This process is called photosynthesis Contains it’s own DNA

The Cell’s Storage CentersThe Cell’s Storage Centers

Vesicle - any membrane covered compartment used for storage or transport Vacuoles - membrane covered chamber where

water and other liquids are stored Plants cells have a very large vacuole Animal cells have vacuoles, but they are too small

to be seen Contractile vacuole - special type of vacuole

found in some freshwater unicellular organisms It allows the organism to “squeeze” excess water out

of it’s cell

Vesicle - any membrane covered compartment used for storage or transport Vacuoles - membrane covered chamber where

water and other liquids are stored Plants cells have a very large vacuole Animal cells have vacuoles, but they are too small

to be seen Contractile vacuole - special type of vacuole

found in some freshwater unicellular organisms It allows the organism to “squeeze” excess water out

of it’s cell

plantvacuolesfigure1.jpg.weblocplantvacuolesfigure1.jpg.webloc

Packages of DestructionPackages of Destruction

Lysosomes - special vesicles in animal cells that contain enzymes Enzymes - a type of protein that allows

chemical reactions to occur more quickly They destroy worn out organelles, get rid of wastes and

protect the cell from foreign invaders

Lysosomes - special vesicles in animal cells that contain enzymes Enzymes - a type of protein that allows

chemical reactions to occur more quickly They destroy worn out organelles, get rid of wastes and

protect the cell from foreign invaders

Plant or AnimalPlant or Animal

Plant Animal

•Outer boarder - Cell Wall

•Chloroplasts

•Large Central Vacuole

*Lysosomes

*Outside boarder - cell membrane