Cell StructureCell Structure

Typical Structures Found in Typical Structures Found in Plant and Animal CellsPlant and Animal Cells

Provisions of Cell StructuresProvisions of Cell Structures

The structures within a cell The structures within a cell function in providing:function in providing:

Protection and supportProtection and support

Forming a barrier between the Forming a barrier between the cell and its environment.cell and its environment.

Building and repairing cell Building and repairing cell parts.parts.

Transporting materialsTransporting materials

Taking in, storing and Taking in, storing and releasing energyreleasing energy

Excreting wasteExcreting waste

Increasing in numberIncreasing in number

Cell WallCell Wall

The cell of plants, algae, The cell of plants, algae, fungi and most bacteria are fungi and most bacteria are enclosed in a cell wall.enclosed in a cell wall.

Cell Walls Cell Walls are tough, rigid are tough, rigid outer coverings that protect outer coverings that protect cells and give them shape.cells and give them shape.

Made mostly of:Made mostly of:

1.1. cellulose, a cellulose, a carbohydrate. .

2.2. Pectin-glue-like substance.Pectin-glue-like substance.

3.3. Lignin- compound that Lignin- compound that makes cell wall rigid.makes cell wall rigid.

Cell MembraneCell Membrane

The protective layer surrounding every The protective layer surrounding every cell is the cell is the cell membranecell membrane..In plant cells: located just inside the In plant cells: located just inside the cell wall.cell wall.In animal cells: forms the outer In animal cells: forms the outer covering of the cell.covering of the cell.

Function-Function-provide protection provide protection control the movement of materials control the movement of materials into and out of the cellinto and out of the cellAllows nutrients to move into the cell, Allows nutrients to move into the cell, while waste products leave.while waste products leave.““A barrier with doorways”A barrier with doorways”

CytoplasmCytoplasm

Cells are filled with a gelatin-like substance called Cells are filled with a gelatin-like substance called cytoplasm.cytoplasm.Constantly flows inside the cell membrane.Constantly flows inside the cell membrane.Region between the nucleus and the cell Region between the nucleus and the cell membrane.membrane.

Throughout the cytoplasm is a framework called Throughout the cytoplasm is a framework called the the cytoskeleton.cytoskeleton.Helps maintain its shape and enable some cells Helps maintain its shape and enable some cells to move.to move.The cytoskeleton is made up of thin, hollow The cytoskeleton is made up of thin, hollow tubes of protein and thin, solid protein fiberstubes of protein and thin, solid protein fibers

Manufacturing Proteins

One substance that takes part in nearly every cell activity is protein.

Proteins are part of cell membranes and are needed for chemical reactions that take place in the cytoplasm.

Protein FactoriesProtein Factories

Cells make their own proteins on small structures called ribosomes.Ribosomes receive directions from the hereditary material on how, when, and in what order to make specific proteins.Float freelyMany attached to the endoplasmic reticulum

Membrane-Bound Organelles

Within the cytoplasm of eukaryotic cells are structures called organelles, the largest of which is usually the nucleus.

• Ribosomes are considered organelles, but are not membrane-bound.

Nucleus- Control Center of CellNucleus- Control Center of Cell

• All celluar activities are directed by the nucleus.

• The nucleus contains long, threadlike, hereditary materials made of DNA.

• DNA is the chemical that contains the code for cell’s structure and activities.

A structure called a nucleolus also is found in the nucleus, and is where most ribosomes are made.

Chloroplasts- Energy ProducersChloroplasts- Energy Producers

In plant cells, food is made in green organelles in the cytoplasm called chloroplasts (KLOR uh plasts).Chloroplasts contain the green pigment chlorophyll.Captures the energy of sunlight which can be used to produce food for the cell.

MitochondriaMitochondriaThe Powerhouse of the Cell The Powerhouse of the Cell

• Mitochondria (mi tuh KAHN dree uh) Rod shaped structures that supply most of the energy for the cell.

• Releases energy by breaking down food into carbon dioxide and water.

Endoplasmic reticulum Endoplasmic reticulum Transportation System of the CellTransportation System of the Cell

• Endoplasmic reticulum is a series of clear tubular passageways.

• Lead out from the nucleus.

• Some lead to the cell membrane

• Others to all other areas of the cell.

• Carries proteins from one end of the cell to the other.

• The ER may be “rough” or “smooth.”

• Ribosomes are attached to areas on the rough ER.

• There they carry out their job of making proteins that are moved out of the cell or used within the cell.

• Smooth ER processes cellular substances such as lipids that store energy.

Golgi bodiesGolgi bodies

The Golgi bodies (GAWL jee) are stacked, flattened membranes.

After proteins are made in a cell, they are transferred to the Golgi bodies.

The Golgi bodies sort proteins and other cellular substances and package them.

VacuolesVacuolesStorage Tanks for CellsStorage Tanks for Cells

• Cells also have membrane-bound spaces called vacuoles for the temporary storage.

• A vacuole can store water, waste products, food, and other cellular materials.

LysosomesLysosomesClean up Crews for the CellClean up Crews for the Cell

Organelles called lysosomes (LI suh sohmz) contain digestive chemicals that help break down food molecules, cell waste, and worn-out cell parts.

Lysosomes also break down viruses and bacteria taken into a cell.