November 19, 2015 Bell Work: What is a concentration gradient? Objective: The student will be able to… Distinguish between active and passive transport. Explain the function of a sodium-potassium pump and explain its importance. Describe endocytosis and exocytosis.

Today in History 1863 President Abraham Lincoln delivered the Gettysburg Address as he dedicated a national cemetery at the site of the Civil War battlefield in Pennsylvania. 1919 The Senate rejected the Treaty of Versailles.

Attendance and Passes

Cell Transport Active Transport

Active Transport The transport of a substance across the cell membrane against its concentration gradient. Requires the use of energy Supplied by ATP adenosine triphosphate

Active Transport Can use carrier proteins, but transports substances against their concentration gradient Called pumps

Sodium Potassium Pump Found in animal cells In a complete cycle, it transports three sodium ions out of a cell and two potassium ions into a cell Na+ (sodium) K+ (potassium) Carrier protein

Sodium Potassium Pump Sodium ions have a higher concentration outside of the cell Potassium ions have a higher concentration inside a cell Actively transports both sodium and potassium Energy used to power the sodium potassium pump is ATP

Sodium-Potassium Pump Three sodium ions inside the cell bind to the sodium potassium pump. A phosphate group is removed from ATP and also binds to the pump. The pump changes shape, transporting the 3 Na+ ions across the cell membrane and releasing them outside the cell. Pump is exposed to the surface of the cell. 2 K+ ions outside the cell bind to the pump. The phosphate group is released causing the carrier protein to change shape. The pump is exposed to the inside of the cell. The 2 K+ ions are transported across the cell membrane and released inside the cell.

Sodium Potassium Pump

Movement in Vesicles Many substances are too large to be transported by carrier proteins Proteins Polysaccharides Moved across the membrane in vesicles

Endocytosis Movement of a substance into a cell by a vesicle Cell membrane forms a pouch around a substance. Pouch closes and pinches off from the membrane to form a vesicle May fuse with lysosomes or other organelles.

Endocytosis

Exocystosis Movement of a substance from the inside of a cell to the outside of a cell Vesicles fuse with the cell membrane, releasing their contents. Use exocytosis to export proteins that are modified by the Golgi Apparatus

Exocytosis

Membrane Receptor Proteins Proteins used to communicate with other cells in the body

Receptor Proteins A protein that binds to a specific signal molecule, enabling the cell to respond the signal molecule Most are embedded in the lipid bilayer of the cell membrane The portion of the protein that fits the signal molecule faces the outside of the cell

Function of Receptor Proteins Changes in permeability When coupled with an ion channel, the binding of a signal molecule to the receptor protein causes the ion channel to open. Important in the nervous system

Function of Receptor Proteins

Functions of Receptor Proteins Second Messengers When activated, acts as a signal molecule in the cytoplasm Amplifies the signal of the first messenger Can change function of the cell by: Activating enzymes Triggering a series of biochemical reactions in a cell Change permeability by opening ion channels in the cell membrane.

Function of Receptor Proteins

Function of Receptor Proteins Enzyme Action Act as an enzyme When a signal molecule binds to a receptor protein, it may speed up chemical reactions inside the cell Activate other enzymes Triggers other chemical reactions within a cell

In Da Club- Membranes and Transport

Vocabulary Worksheet Complete the Worksheet

Cell Transport Worksheet Complete the questions using a complete sentence.

Ticket Out What is active transport?