Cell Transport

Cell Transport

Diffusion is the net movement of particles from an area of high concentration to an area of low concentration in other words the particles move from an area where there are more of them to an area where there are fewer.

Diffusion is a type of Passive Transport because no energy is needed to move the particles because they are already in motion.

Concentration refers to the amount of a substance in an area.

Diffusion can occur more quickly when concentration, temperature, or pressure are high because the particles collide more often.

Examples of Diffusion in the body

1. Oxygen diffusing from the lungs into the blood so it can be carried and diffused into the cells.
2. Carbon Dioxide from the cells in the body to the blood and then the lungs so it can be diffused out to the environment.

Facilitated Diffusion is also Passive Transport because no energy is required. Facilitated Diffusion is similar to Diffusion because the particles will move from high to low concentrations. It is different from Diffusion because Facilitated Diffusion will use proteins embedded in the membrane to move particles into and out of the cell.

Example of Facilitated Diffusion in the body

1. In Animals, stored Glycogen (a polysaccharide) will be broken down into Glucose (monosaccharide) and will move into the blood and then transported into the cells through proteins in the membrane.

Write a Summary ______

______

Define:

1. Diffusion -______
2. Facilitated Diffusion-______

On Lab, page 1 answer 1,4,5 (wait on 2,3)

Page 2 answer what’s in the bag? 1,2

Make predictions 1,2,fill out data table

Complete post lab and use colors for number 5.

Osmosis

Water is important to maintaining homeostasis in living organisms. Water helps to breakdown biomolecules in the process of Hydrolysis. Water is used by plants in photosynthesis to make Glucose. Water also keeps organisms hydrated.

The movement of water is passive and called Osmosis. Water will move from high concentrations to areas of lower water concentrations or down the gradient. Think about a spill on the counter and a paper towel. Why does the water get absorbed by the paper towel? Because it is the area of no water concentration?

Three conditions of osmotic solutions

1. Isotonic- equal amounts of water in the cell and in the environment. Water is still moving but the rate is equal so you cannot detect a difference in concentration. Animal cells prefer this condition because they do not have large vacuoles or a cell wall to contain the excess water.
2. Hypotonic- there will be more water in the environment than inside the cell. Therefore the cell must have more dissolved stuff in it called solutes than the environment has in it. This is the condition plant cell prefer because water is used during photosynthesis and plants will lose water during transpiration. If plants do not have water, they cannot make their food.

Example of Hypotonic in the human body

When a person suffers from kidney failure they cannot remove excess water from the blood so there body fills up like a water balloon. The dialysis machine filters the blood removing excess water and waste since the kidneys are no longer functioning.

In plants, Hypotonic causes TURGOR PRESSURE- the central vacuole swells and the cell becomes hard.

In animals, Hypotonic causes CYTOLYSIS-the animal cell swells and then bursts.

1. Hypertonic-neither plants nor animals want to lose water. Hypertonic conditions occur when there is more solute in the environment and the cell will lose water trying to hydrate the environment. In animals this would occur if we drank salt water.

In plants, Hypertonic causes PLASMOLYSIS- the plant cell central vacuole shrinks and the cell collapses.

In animals, Hypertonic causes CRENATION-the animal cell will shrivel up and collapse in on itself.

Write a Summary ______

Osmosis and Tonicity

Define osmosis. ______

In which direction does water move across membranes, up or down the concentration gradient? ______

Define these 3 terms:

1. isotonic-

1. hypertonic-

1. hypotonic-

Use arrows to show the direction of water movement into or out of each cell. Color and label the cell in an isotonic environment light blue, the hypotonic environment yellow, and the hypertonic environment light green.

Match the description or picture with the osmotic condition:

Active Transport

Active transport moves particles from an area of low concentration to an area of high concentration. This is also called moving up or against the gradient.

Active transport will use pumps, vesicles, and proteins to push the substances up/against the concentration gradient.

Two types of Active Transport that use Vesicles:

Endocytosis- in this process the cell surrounds a substance outside in the environment by extending the cell membrane around the substance and then pinches it off and brings the substance inside.

Ex:

Two types of endocytosis :

a.Pinocytosis- means the cell is drinking.

b.Phagocytosis-means the cell is eating..engulfing materials

Exocytosis- the opposite of Endocytosis. Instead of taking in materials using vesicles it will expel materials by having the vesicles fuse with the membrane and release the contents to the environment.

ACTIVE TRANSPORT using proteins as pumps

Proteins in the membrane will use ATP to have energy so it can pump Calcium, Potassium, and Sodium ions across the membranes against the concentration gradient. It takes ATP to move substances in the opposite direction of the concentration gradient. The NA+/K+ (sodium-potassium) pump is used to move ions across a membrane.

Write a Summary ______

______

Transport Requiring Energy

What type of transport is represented by the following picture? ______

What energy is being used? ______

In which direction (concentration gradient), is the movement occurring? ______

Describe the two types of Endocytosis? ______

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