7-2 Cell Structure
Objectives:
1)   Students know that all cells are surrounded by a membrane that regulates their interaction with the environment.
2)   Students know the roles of the golgi apparatus and the endoplasmic reticulum in the production of proteins
3)   Students can explain how the cytoskeleton or cell wall gives a cell its shape.
4)   Students know that energy is provided by the mitochondria

Eukaryotic Cell

The Nucleus
•   The nucleus contains all the cell ’ s DNA.
•   These are the coded instructions for making proteins and other important molecules.

The Nucleus

Maintenance of the Cell
•   Vacuoles store materials in plant and animal cells
(eukaryotic)
•   A central vacuole helps support plant cells.
•   Typically found in plant cells

Vacuole

Vacuole

Vesicles
•   Vesicles are found in both plant and animal cells
(eukaryotic).
•   Used for storage and transport
•   In the picture, the vesicle is transporting proteins to the golgi apparatus

Lysosomes
•   Digestive enzymes contained in a membrane
•   Used to break down nutrients into more usable pieces and recycling old organelles.

Lysosomes

•   A network of protein filaments that provides the cell with support, aids with transport within the cell, and helps move materials to different parts of the cell.

Cytoskeleton

Building Proteins
•   Proteins are assembled on Ribosomes
•   New proteins are carried to the Golgi
Apparatus in vesicles.
•   The Golgi Apparatus modifies, sorts, and packages proteins to be sent outside the cell or to different parts of the cell itself.

Organelles that Build Proteins

Ribosomes
•   Organelle that makes proteins by following the instructions found on messenger RNA.
•   Found in the rough
ER (Endoplasmic
Reticulum)

Ribosomes

Endoplasmic Reticulum
•   Divided into two sections:
•   The Rough ER, is covered in ribosomes and is involved in protein synthesis
•   The Smooth ER does not have ribosomes and is involved in specialized tasks: blood purification in liver cells, for example.

Endoplasmic Reticulum (ER)

Golgi Apparatus

Golgi Apparatus
•   Looks like a series of flattened membranes.
•   This organelle modifies, sorts, and packages proteins for use inside or outside the cell.

Organelles that provide energy
•   Chloroplasts are only found in plants and convert solar energy to food.
•   Mitochondria convert food energy into compounds the cell can use.

Chloroplasts

Mitochondria

Cell Boundaries
•   Cell Walls are found in plant cells
(eukaryotes) and prokaryotes.
•   Cell walls are a strong supporting layer.
•   Made of cellulose which is a tough material.

Cell Membranes
•   All cells have a cell membrane.
•   Made of two rows of lipids called the Lipid
Bilayer.
•   These lipids are arranged with their
“ water loving ” heads on the outside and “ water fearing ” tails on the inside.

Cell Membrane
•   The hydrophilic heads and the hydrophobic tails of the lipids in the cell membrane make the cell membrane
“ selectively permeable ”

Selectively Permeable
•   “ Selectively
Permeable ” means that some substances can pass through the membrane and others cannot.

“ Fluid Mosaic ”
•   The cell membrane is called a “ Fluid
Mosaic ” because it contains proteins
(some with carbohydrates attached) that float around in it as if it were a fluid