BIO 156 Chapter 3 Part 1 Powerpoint

8/14/2019 BIO 156 Chapter 3 Part 1 Powerpoint

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BIO 156

Chapter 3


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Microscopes: Illuminating the Structure of


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Microscopes fall into two broad categories:

1. light microscopes

uses ordinary visible light to illuminate the specimen

can magnify objects from 100 to 400 times theiroriginal size

2. electron microscopes

uses a beam of electrons to create a visual image ofthe specimen

can enlarge objects 100,000 times their original size


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An Overview of Cell


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The cell consists of two main compartments.

1. The nuclear (nucleus) compartment2. The cytoplasmic compartment


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The nuclear (nucleus) compartment

The nucleus contains the genetic information thatregulates the structure and function of all eukaryoticcells.

The cytoplasmic compartment

The cytoplasmic compartment is home to thecytoskeleton.

The cytoskeleton is a network of tubules and filaments.

The cytoskeleton also binds to enzymes in metabolicpathways


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The Structure and Function of the Plasma


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The plasma membrane is the outermost boundary of the

Phospholipid

Protein

Cholesterol


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Phospholipids


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Protein Structure


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Protein Structure Continued


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Cholesterol


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The plasma membrane consists of lipids, protein, andcarbohydrate.

Lipids (fats) are biochemicals characterized by their lack ofwater solubility.

Human cells have thousands of different types of proteins,each type structurally and functionally unique.

Amino acids are small organic molecules that join bypeptide bonds, forming peptides and proteins.

The lipids of the plasma membrane form a double layer inwhich many of the proteins float freely.


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The plasma membrane is essential to cellular homeostasis.

The plasma membrane regulates the flow of molecules

and ions into and out of the cell.

The plasma membrane is selectively permeable


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Molecules move through the plasma membrane in five ways.

1. Diffusion

3. Active Transport --molecules are also activelytransported across the membrane

3. Endocytosis

4. Exocytosis

6. Carrier Proteins and Diffusion

8. Osmosis


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Diffusion: The movement ofmolecules from high to low

concentrations.


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Active Transport: Molecules are also actively transportedacross the membrane.


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ATP: Adenosine Tri-Phosphate


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Endocytosis: Large molecules and cells are ingested by

endocytosis.


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Exocytosis: Cells alsoregurgitate materials,releasing large molecules.


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Osmosis: The diffusion of water across the plasma membraneis known as osmosis.

Whenever two fluids with different concentrations of soluteare separated by a selectively permeable membrane, thefluid will flow from one to the other, moving down theconcentration gradient.In humans, osmosis helps regulate the concentration of

fluid surrounding the cell.


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End of Chapter 3, Part 1

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BIO 156 Chapter 3 Part 1 Powerpoint