• http://www.youtube.com/watch?v=-zafJKbMPA8 start at 49 seconds (3min)

KEY CONCEPT Cells are the Basic unit of life.

• http://www.youtube.com/watch?v=u54bRpbSOgs 4min

A View of the Cell

Cellular Organization• Cell• Tissue – group of cells functioning together.• Organ – group of tissues functioning together.• Organ System – group of organs

functioning together.• Organism – group of organ systems

functioning together.

• The cell theory grew out of the work of many scientists and improvements in the microscope.

• Many scientists contributed to the cell theory.

• The cell theory grew out of the work of many scientists and improvements in the microscope.– Many scientists contributed to the cell theory.– More was learned about cells

as microscopes improved.

• The cell theory grew out of the work of many scientists and improvements in the microscope.– Many scientists contributed to the cell theory.– More was learned about cells

as microscopes improved.– The cell theory is a unifying

concept of biology.

The History of the Cell

• The Cell–The basic unit of an organism–Discovery made possible by the invention of the microscope

Microscopes and Cells

• 1600’s.–Anton van Leeuwenhoek first described living cells as seen through a simple microscope.

Microscopes and Cells

–Robert Hooke used the first compound microscope to view thinly sliced cork cells.

•Compound scopes use a series of lenses to magnify in steps.•Hooke was the first to use the term “cell”.

Microscopes and Cells• 1830’s.

–Mathias Schleiden identified the first plant cells and concluded that all plants

made of cells.

- Thomas Schwann made the same conclusion about animal cells.

• Early studies led to the development of the cell theory.• The Cell theory has three principles.

–All organisms are made of cells.

• Early studies led to the development of the cell theory.• The Cell theory has three principles.

–All organisms are made of cells.

–All existing cells are produced by other living cells.

• Early studies led to the development of the cell theory.– The Cell theory has three principles.

• All organisms are made of cells.

• All existing cells are produced by other living cells.

• The cell is the most basic unit of life.

Cell Theory:

• All organisms are

made up of one or more cells.

• The cell is the basic unit of organization of all organisms.

• All cells come from other cells all ready in existence.

COMMON CELL TRAITS

• A cell is the smallest unit that is capable of performing life functions.

COMPARING CELLS

• The size & shape of a cell relates to its function. (job it does)

• There are two cell types: eukaryotic cells and prokaryotic cells.– Eukaryotic cells have a

nucleus.– Prokaryotic cells do

not have membrane- bound organelles.

Two Basic Cell Types

Prokaryote– Lacks internal

compartments.– No true nucleus.– Most are single-

celled (unicellular) organisms.

– Examples: bacteria

• Prokaryotic cells lack a nucleus and most internal structures of eukaryotic cells.– All cells share certain characteristics.

• Cells tend to be microscopic.

• All cells are enclosed by a membrane.

• All cells are filled with cytoplasm.

Bacterium(colored SEM; magnification 8800x)

cell membrane

cytoplasm

Prokaryote

• Were here first & for billions of years the only living thing on Earth

• Reproduces only through asexual methods

Prokaryotic Cells(proh KAYR ee yah tihk)

• cells without membrane-bound structures

• EX: bacteria

pond scum

Story Time

• Mr. P (Phagocyte) + Mr. B (bacterium) = Mitochondria

» + =

Phagocyte

Eukaryotic Cells(yew KAYR ee yah tihk)

• cells with membrane-bound structures

• EX: animals, plants, fungi and protists

The Parts of The Eukaryotic CellBoundaries

Plasma Membrane -- Serves as a boundary

between the cell and its external environment.

-- Allows materials to pass in and out of the cell.

Animal Cell

• Several organelles are involved in making and processing proteins.– The nucleus stores genetic information.

The Parts of The Eukaryotic Cell: Controls

Nucleus• Regulates cell function.• Surrounded by a double-

layered membrane (nuclear enveloped) with large pores that allow materials to pass in and out of the nucleus.

• Contains chromatin – long tangles of DNA.

• Left cell nucleus is undergoing mitosis-nucleus has disintegated to prepare for division

Controls

Nucleolus•Found in the nucleus and responsible for ribosome production. Ribosomes are the sites of protein production.

The Parts of The Eukaryotic Cell: Assembly

CytoplasmThe jelly-like

material thatsurroundstheorganelles.

• protects the cell

• gives shape

• is made of cellulose

• A cell wall is found in plants, algae, fungi, & most bacteria.

CELL WALL

CELL MEMBRANE

• Outer covering, protective layer around ALL cells

• For cells with cell walls,the cell membrane is inside the cell wall

• Allows food, oxygen, & water into the cell & waste products out of the cell.

NUCLEAR MEMBRANE

• separates nucleus from cytoplasm

• controls movement of materials in & out of nucleus

NUCLEOLUS

• Aka “little nucleus”

• Found in the nucleus

CHROMATIN

• contains genetic code that controls cell

• made of DNA & proteins

The Parts of The Eukaryotic Cell: Transport

Endoplasmic reticulumFolded membrane that

acts as the cells delivery system

Smooth E.R. contains enzymes for lipid synthesis

Rough E.R. is studded with ribosomes for

protein synthesis.

• Several organelles are involved in making and processing proteins. (continued)– Ribosomes link amino acids to form proteins.

• Several organelles are involved in making and processing proteins..– Many processes occur in the endoplasmic

reticulum.

• Several organelles are involved in making and processing proteins.– Many processes occur in the endoplasmic

reticulum.– There are two types of endoplasmic reticulum.

• rough endoplasmic reticulum

• Several organelles are involved in making and processing proteins.– The nucleus stores genetic information.– Many processes occur in the endoplasmic

reticulum.– There are two types of endoplasmic reticulum.

• rough endoplasmic reticulum

• smooth endoplasmic reticulum

TransportGolgi apparatus (or

Golgi body)A series of flattened sacs where newlymade lipids and proteins from the E.R. are repackaged and shipped to the plasma membrane.

The Parts of The Eukaryotic Cell: Storage

Vacuoles•A sac of fluid surrounded by a membrane used to store food, fluid, or waste products.

• Other organelles have various functions.– Vacuoles are fluid-filled sacs that hold

materials.

StorageLysosomes

•Contain a digestive enzyme.

•Can fuse with vacuoles to digest food, or can digest worn cell parts.

•Also known as “suicide sacs” because they can also destroy the whole cell.

• Other organelles have various functions.– Lysosomes contain enzymes to digest material.

• Several organelles are involved in making and processing proteins..– Vesicles are membrane-bound sacs that hold

materials.

• Other organelles have various functions.– Mitochondria supply energy to the cell.

The Parts of The Eukaryotic Cell: Energy Transformers

Mitochondria•Produce the energy for the cell.

•Also known as the “powerhouse of the cell”.

•Has a highly folded inner membrane (cristae).

6) Energy Transformers

Chloroplasts-- Found in plant cells and some protists.-- Transforms light energy into chemical energy which is stored in food molecules.-- Contain chlorophyll – a green pigment that traps light energy and gives plants their green color.

The Parts of The Eukaryotic Cell: SupportCytoskeleton

•A network of thin, fibrous materials that act as a scaffold and support the organelles.

•Microtubules – hollow filaments of protein.

•Microfilaments – solid filaments of protein.

• Cells have an internal structure.– The cytoskeleton has many functions.

• supports and shapes cell

• helps position and transport organelles

• provides strength

• assists in cell division

• aids in cell movement

CYTOSKELETON

• scaffolding-like structure in cytoplasm

• helps the cell maintain or change its shape

• made of protein

The Parts of The Eukaryotic Cell: Locomotion

Cilia• Short,

numerous, hair-like projections from the plasma membrane.

• Move with a coordinated beating action.

Locomotion

FlagellaLonger, less numerous projections fromthe plasma membrane thatmove with a whiplike action.

The Parts of The Eukaryotic Cell: Cell Division

Centrioles– made of protein.– play a role in the

splitting of the cell into two cells.

– found in animal and fungi cells.

• Other organelles have various functions.

–Centrioles are tubes found in the centrosomes.

• Centrioles help divide DNA.

• Centrioles form cilia and flagella.

Composite Animal Cell

Composite Animal Cell

Plant Cell

• Plant cells have cell walls and chloroplasts.– A cell wall provides rigid support.

Boundaries

Cell Wall--surrounds the plasma

membrane of the cells in plans, bacteria, and fungi.

--plant cell walls contain cellulose while fungi cell walls

contain chitin.

• Plant cells have cell walls and chloroplasts.– A cell wall provides rigid support.– Chloroplasts convert solar energy to chemical

energy.