Biology- Movement across the Cell Membrane

Diffusion

Move from HIGH to LOW concentration - "passive transport" - "no energy needed" " Dawn" the concentration gradient

Exit ticket Active Transport

A. Movement of particles form low to high concentration THAT USES ENERGY

What is a major difference between active and passive transport? A. Active transport moves ions, while passive transport does not. B. Active transport requires energy, while passive transport does not. C. Active transport involves a concentration gradient, while passive transport does not. D. Active transport uses membrane proteins, while passive transport does not.

B. Active transports requires energy, while passive transport does not * Choices A, C, and D are incorrect because both types of transport move ions, involve concentration gradients and use membrane proteins (though mechanisms differ).

Endocytosis

- Brings extracellular material INSIDE the cell - Both endocytosis and exocytosis requires ENERGY

Ion and Molecular pumps

- Mechanisms of active transport - Uses ATP to move material against concentration gradient - Ions pumps move uncharged molecules - Molecular pumps move uncharged molecules Remember- passive transport occurs until concentrations of solutes are EQUAL - Energy is used to transport molecules across the membrane when the cell is NOT in equilibrium -LOW to HIGH

Active Transport

- Movement of particles from an area of LOW concentration to HIGH concentration. - Uses ATP as an energy source - Cells use active transport to build up a concentration gradient.

Concentration of Water

Direction of osmosis is determined by comparing total solute concentrations - Hypertonic - MORE solute, LESS water - Hypotonic - LESS solute, MORE water - Isotonic - EQUAL solute, EQUAL water

Exit Ticket Endocytosis

E. A form of active Transport where extracellular materials are taken INTO the cell by forming a membrane vesicle around it

Passive Transport

A process that Does not require energy to move molecule From a HIGH to LOW concentration

Cholesterol does not dissolve in blood and other water-based body fluids. To be transported throughout the body, it must be encased in lipoproteins, marcomolecules that are water-soluble. How can a call take in lipoproteins from its extracellular fluid? A. Exocytosis B. Endocytosis C. Molecular Pump D. Facilitated Diffusion

B. Endocytosis * Because B describes a vesicle being formed during active transport of materials into and out of the cell.

Facilitated diffusion

The movement of larger molecules like glucose through the cell membrane- larger molecules mu be "helped" - Proteins in the cell membrane form channel for large molecules to pass through - Proteins that form channels (pores) are called protein channels

Vesicles and exocytosis

- Vesicles (small membrane sacs that transport material through the cytoplasm) - Vesicles are produced in the Golgi apparatus and ER - Marcomolecules are transported within these vesicles - Exocytosis releases substances from the cell Neurotransmitters Hormones

Last session, we discussed the movement of fluids and molecules across the plasma membrane that did NOT require a source of energy. Passive transport moves materials down a ___________ _______________. The process stops when _____________ is reached within the cell.

1. Concentration gradient 2. Equilibrium 3. ATP NEW - Some cells require a concentration gradient to be created and maintained. - Others take in or expel materials too large to fit through a membrane protein. - This all requires ENERGY - Where does the cell get the energy for this???

Which of the following is not involved in the transport of molecules by facilitated diffusion? A. ATP B. Phospholipids C. Protein Channels D. Concentration gradient

A. ATP ATP - Is a source of energy, and facilitated diffusion does not require the input of energy,

Some plasma membranes contain channel proteins that help transport specific molecules, such as ions, across the membrane. Which of the following transport processes allow these channel proteins to function without energy expenditure? A.Diffusion B. Facilitated diffusion C. Active transport D. Osmosis

B. Facilitated Diffusion * The proteins are helping transport specific molecules, such as ions, across the membrane - WITHOUT ENERGY EXPENDITURE!

Exit Ticket Passive Transport

B. Transportation of material across a plasma membrane without using energy

The image shows a U-shaped tube with s semipermeable membrane separating the right and left sides. Each side is filled with equal volumes of water and different concentrations of solute. Which statement explains the change in water volume? A. Water moved to the tight side, where solute concentration was originally lower. B. Water moved to the right side, where solute concentration was originally higher. C. Water and solute moved to the right side, where solute concentration was originally lower. D. Water and solute moved to the right side, where solute concentration was originally higher.

B. Water moved to the right side, where solute concentration was originally higher * Water "followed" the solute and moved into the side with higher solute concentration. Osmosis equalizes the solute concentrations.

The diagram shows the movement of a substance across a plasma membrane. What is true about this process? A. It requires no energy. B. It is called exocytosis. C. It is a form of active transport. D. It stops when equilibrium is reached.

C. It is a form of active transport * the ion is being transported AGAINST the concentration gradient. The concentration gradient is being created and maintained with the input of energy. Explanation Choices A and D, are true of passive transport- incorrect - Choice B is incorrect because this picture doesn't involve vesicles, or exocytosis. - Choice C is correct-the ion is being transported AGAINST the concentration gradient. The concentration gradient is being created and maintained with the input of energy.

Exit Ticket Osmosis

C. Movement of water through a permeable membrane from area of high to low

Exit Ticket Exocytosis

D. A from of active transport where substance are released/expelled from the cell.

Osmosis is diffusion of water

Diffusion of water from; - High concentration of water to low concentration of water - Across a semi-permeable membrane In Osmosis, water moves from an area of higher water concentration to an area of lower water concentration.

Example of Facilitated diffusion

Glucose needs help from transport proteins to enter cells Without transport proteins, your cells would not receive enough glucose to power cellular respiration

Describe passive transport and give 2 examples of passive transport.

Passive transport is does not require energy to move the molecules from a high to low concentration. One example of passive transport is diffusion and the second example of passive transport is osmosis.