The CellThe cell is the smallest unit of life that can

carry out life processes.

Discoveries Leading to The Cell TheoryRobert Hooke – 1665 -observed cork

through a light microscope.Anton Van Leewenhoek – 1675 -

observed LIVING cells. Matthias Schleiden – 1883 –plants are

made of cells.Theodor Schwann – 1839 –animals are

made of cells

The Cell TheoryThe cell theory states that:

1.all living organisms are made of one or more cells,

2.cells are the basic units of structure and function,

3.cells come only from pre-existing cells.

Prokaryotic CellProkaryotic-

cells that do not have a nucleus and internal membrane-bound structuresMost unicellular

organisms are prokaryotes.

Bacteria

Eukaryotic CellEukaryotic-

Cells that do have a nucleus and internal membrane-bound structures.Most

multicellular organisms are eukaryotes.

Yeast and algae (unicellular, eukaryotes)

Plant and animal

Cytoplasm – Gel like material that protects, supports and suspends organelles.

Features Common to Cells:

Features Common to Cells:Cell membrane – Flexible, semi-permeable membrane

that allows some materials in and keeps others out. This helps to maintain cellular homeostasis.

Nucleus

“Command center”Surrounded by a

nuclear envelopeContains genetic

material: chromatinchromosomes

Chloroplast – green pigments of plant cells

Examples:Chloroplast – Located in plant cells, some bacteria,

and protists. Capture light energy to produce and store food Contain chlorophyll-green pigment that traps light

energy

Cell wallRigid outer

covering PLANT CELLS

Located outside the cell membrane

Provides support and protection

Animal Cell

Plant Cell

Parts of the Cell

Cytoskeleton – tiny fibers that give structure and support to the cell.

Features Common to Cells:

Ribosomes– site where proteins are made

• Can be found floating in the cytoplasm or attached to endoplasmic reticulum

Rough Endoplasmic Reticulum (RER)

Series of folded membranes allow a large amount of work to be done in a small amount of space

Transportation unit for the cell

Rough Endoplasmic Reticulum (RER)Ribosomes attachedProtein synthesis

Smooth Endoplasmic ReticulumSeries of folded membranes allow a large amount

of work to be done in a small amount of spaceTransportation unit for the cell• Smooth Endoplasmic Reticulum (SER)

– Produce and store lipids

Golgi ApparatusVesicles

Flattened tubular membranes

Packaging plantModify, sort,

package, and transport proteins throughout the cell

VACUOLESStorage sacs

Temporary storage of materialsStore food,

enzymes, waste

Plant cells have one large vacuole.

Animal cells have many small vesicles.

LYSOSOMESContain digestive

enzymesDigest excess or

worn organelles, food particles, viruses, and bacteria

Surrounded by membrane that prevents it from destroying the cell

Can burst causing cell death

Chapter 4MitochondriaCellular respiration -converts food into

energyCell “Powerhouse”Number of mitochondria depends upon the

function of the cellEx: muscles cells have more mitochondria than

fat cells

Centriole

Help with cell reproduction

Only found in animal cells

Cilia and FlagellaAid in movement

and feedingComposed of

microtubulesCilia-short,

numerous hair-like projections that move in a wavelike motion

Flagella-long, whip-like projections

Plant cell vs. Animal Cell

Plant vs Animal cells Animal Cell vs. Plant cell

Animal Cell DO contain centrioles. DO NOT contain a cell wall or plastids.

Plant Cell DO contain a cell wall, plastids, and a large

central vacuole.

DO NOT contain centrioles