Recommended
More Related Content
What's hot
What's hot (20)
Viewers also liked
Viewers also liked (16)
Similar to Cellular Transport: Structure and Function
Similar to Cellular Transport: Structure and Function (20)
Recently uploaded
Recently uploaded (20)
Cellular Transport: Structure and Function
- 1. Structure and Function of Cells:Structure and Function of Cells: Cellular TransportCellular Transport All About You Teacher Education Course 2013-2014
- 2. Key Take-Away and Unifying Themes Key Take-Away • We will write it at the end of this lesson Objectives • Explain why cellular transport is important • Identify the parts of a solution and what affects concentration • Determine movement of substances across a cell membrane by comparing concentrations in- and outside the cell • Use data to describe how cellular transport affects efficient cell size
- 3. What do cells need to do to survive? Metabolism • includes chemical reactions that convert energy from food to energy for life processes, like moving, repairing, and growing • cells take in essential materials such as oxygen and glucose, a food source for cells • cells get rid of waste such as carbon dioxide and lactic acid, a waste product from when a cell breaks down food with little oxygen • many substances, like water, flow into and out of the cell
- 4. Cellular Transport In order to undergo metabolism, a cell must undergo cellular transport • constant flow of materials into and out of cells through the cell membrane, or the semi-permeable outer covering of the cell A B C
- 5. Concentration Look at the first scenario and predict the outcome of the second scenario:
- 6. Concentration Look at the first scenario again and predict the outcome of this third scenario:
- 7. Concentration A solution is made up of two parts: solute and solvent The concentration of a solution indicates the amount of solute dissolved in a solvent Consider the image on the right •What is the solution? •What is the solvent? •What is the solute? •Which cup has the highest concentration? •Which cup has the lowest concentration?
- 8. Active and Passive Transport Materials can move into and out of a cell with the use of energy (active transport) or without the use of energy (passive transport) Whether the cell uses active or passive transport depends on the concentration gradient, or the concentration of the substances outside of the cell (extracellular environment) compared to the concentration of the substances inside the cell (intracellular environment)
- 9. Active and Passive Transport Equilibrium occurs when the concentration of the solute in the extracellular environment is balanced with the concentration of the solute in the intracellular environment Equilibrium is reached in passive transport Equilibrium is not reached in active transport
- 10. Active and Passive Transport
- 11. Diffusion and Osmosis Diffusion is a type of passive transport where the substances move from an area of high concentration to an area of low concentration Osmosis is the term used for the diffusion of water across a cell membrane
- 13. Activity How does cellular transport affect efficient cell size?
- 14. Key Take-Away and Unifying Themes What is the key take-away of this lesson? How does this lesson relate to • The characteristics of life? • Form fits function? • Homeostasis?
Editor's Notes
- A normal red blood cell looks like a disk with a pinched-in center. If water can move into and out of the cells, the cells will have just enough water to carry out life processes and retain their normal shape (B). If water is only allowed to flow out of cells, the cells will shrivel and ultimately die (A). If water is only allowed into cells, the cells will burst and ultimately die (C).
- If we add 200 ml of blue dye (the solute) into 1000 mL of water (the solvent), we will get a blue dye solution that has a concentration of 200mL/1000mL or 2/10 (first scenario). If we add 200 mL more blue dye than the original solution, the solution will have a higher concentration of blue dye: 400mL/1000mL or 4/10. The result is a darker blue color (second scenario).
- If we add 200 ml of blue dye (the solute) into 1000 mL of water (the solvent), we will get a blue dye solution that has a concentration of 200mL/1000mL or 2/10 (first scenario). If we dilute the original solution by adding 1000mL more water than the original solution, the outcome is a lower concentration of blue dye: 200mL/2000mL or 1/10. The result is a lighter blue color (third scenario).
- What is the solution? The colored water. What is the solvent? The water. What is the solute? The food coloring. Which cup has the highest concentration? The second cup because it has the highest ratio of solute dissolved in the solvent, thus giving it a darker color. Which cup has the lowest concentration? The third cup because it has the lowest ratio of solute dissolved in the solvent, thus giving it a lighter color.
- In active transport, cellular transport requires the use of energy. Energy is typically used when solutes are moved against the concentration gradient, or from an area of low concentration to an area of high concentration. Equilibrium is not reached inside these systems. Equilibrium occurs when the concentration of the solute in the extracellular environment is balanced with the concentration of the solute in the intracellular environment. Refer to the top row: the cell (intracellular environment) contains seven solute particles and the solution in the beaker has three solute particles. The transport of these solutes into the cell moves against the concentration gradient because they are move from an area of low concentration to an area of high concentration, thus requires energy. For example, in the gut, the extracellular environment is rich with glucose right after we eat. No matter the concentration of glucose intracellular environment, it has to continually pump glucose in so we have energy reserves. In this environment, energy is required to move glucose because it moves from an area of low concentration to an area of high concentration. In passive transport, cellular transport does not require the use of energy. Energy is typically not used when substances are moved with the concentration gradient, or from an area of high concentration to an area of low concentration. Equilibrium is reached inside these systems. It is important to note that there is still movement of substances when equilibrium is reached, but the net movement of solutes is 0. In other words, for a system in equilibrium, if one solute particle moves from the inside to the outside of the cell (from the intracellular environment to the extracellular environment), then one solute particle has to move from the outside to the inside of the cell (from the extracellular environment to the intracellular environment). Refer to the figure in the bottom row: the cell (intracellular environment) contains 0 solute particles and the solution in the beaker (extracellular environment) contains 10 solute particles. These solutes move through the cell membrane without the use of energy until equilibrium is reached. The cell and solution in the beaker both contain five solute particles.
- Click on the images to link to the online animation. Start the animation at the scenes that are suggested on this slide. It would be helpful to mute the narration and facilitate the animation on your own so that you can monitor the content that the students receive.
- In this activity, students will be using three different sized gelatin cubes, which represent three different sized cells. The gelatin cubes contain phenolphthalein, and indicator, and ammonia, a base, which together gives the cubes a vivid pink color. When the phenolphthalein comes in contact with an acid, such as vinegar, it will change from pink to clear. Students will imagine that the vinegar is an essential part of the gelatin cube’s “metabolism” and the vinegar will undergo passive transport from the extracellular environment (high concentration area) to the intracellular environment (low concentration area). Students will be measuring the time it takes for each gelatin cube to completely change from pink to clear. The cube that takes the shortest amount of time to change color will be the most efficient.
- Recall that our cells and organelles undergo chemical reactions that convert energy from food to energy for life processes, like moving, repairing, and growing. Many of the substances that are necessary for metabolism are minute compared to the human scale. Water, oxygen and glucose are examples of molecules that travel into the cell. Water, carbon dioxide, and lactic acid are examples of molecules that travel out of the cell. If our cells were too big compared to these necessary substances, it would take a long time for the cells and organelles to undergo metabolism. Thus our cells need to be small—microscopic—in order to be an efficient system for metabolism.