Cell Transport Graphics to Interpret
Station 1
Answer these questions in your notebook using complete sentences! 1. What does this graph show?
2. What is the independent variable on this graph? 3. What is the dependent variable on this graph?
4. Explain the relationship between diffusion and temperature. Use 3 data points to back up your answer.
http://connormcgrady4b.edublogs.org/2011/11/10/osmosis-egg-lab/
Answer these questions in your notebook using complete sentences!
1. What does this graph show?
2. What is the independent variable on this graph? 3. What is the dependent variable on this graph?
4. Which solution caused the egg to take on mass? Use 3 data points to back up your answer. 5. Solutions can be hypertonic, hypotonic or isotonic. Which type of solution is the 15% salt
Cell Transport Graphics to Interpret
Station 3
Freshwater fish are hypertonic to their water environment and therefore, water is continually diffusing into the fish through the gill membranes into the blood. The gills are also permeable to respiratory gases, ammonia waste products, and ions. Therefore, while water moves in towards the higher osmotic pressure of the blood, sodium and chloride ions also diffuse out of the fish, moving down their concentration gradients to the external environment. Freshwater fish must expend energy to regulate this ion loss and fluid uptake. The continual uptake of water in
freshwater species is regulated by the kidneys which continually produce large amounts of dilute urine. Kidneys remove excess water and salts by producing urine.
Marine fish are hypotonic to their saltwater environment. They have less salt (ions) in them then the ocean they are in so water will want to leave their bodies. Fortunately, their gills are also a site of salt (ion) uptake. Special cells in gill contain sodium and chloride “pumps “in their membranes. These pumps are special enzymes that use energy to move the ions up their
concentration gradient to maintain their higher concentration in the body. Thus, osmoregulation is a process that requires the expenditure of much energy on the part of the fish--even when they appear to be inactive. This constant expenditure of energy to maintain an osmotic balance is a reason why proper nutrition and low stress levels are important for healthy fish.
A fish that appears bloated, or swollen up, has probably lost the ability of osmoregulation.
Answer these questions in your notebook using complete sentences! 1. Define hypotonic.
2. Define hypertonic.
Cell membrane receptor proteins help cells communicate with their external environment through the use of hormones, neurotransmitters and other signaling molecules. The receptor proteins are always found on the outer cell membrane surface. This is where hormones and neu-rotransmitters and other chemicals attach to the surface of the cell. Hormones change the activity of the cells. These receptor sites are how they affect the cells. There are different receptor sites for different hormones. One cell might have 20 different types of receptor sites while another might have just one. The type of receptor site it has, determines what type of hormone or neuro-transmitter can affect it. If insulin is secreted by the pancreas, this hormone will go out of the blood stream and if a cell doesn’t have any insulin receptor sites, the insulin will have not affect it. The cell with the insulin receptor site (called the target cell) will be affected by it.
Answer these questions in your notebook using complete sentences! 1. What are the functions of protein receptors?
2. What do hormones do to cells?
3. Explain how the insulin hormone decreases blood sugar using the following terms: Receptor, insulin, glucose, transports, and pancreas.
Cell Transport Graphics to Interpret
Station 5
Endocytosis is a process in which the cell membrane surrounds a substance and engulfs it, bringing it into the cell. Cells use endocytosis to move in large particles such as proteins and bacteria.
Exocytosis is a process in which the cell membrane expels a substance by fusing with a vesicle inside the cell and releasing its contents out of the cell. Cells use exocytosis to remove wastes and to release proteins made by the cells like enzymes, antibodies and hormones.
Answer these questions in your notebook using complete sentences! 1. Describe endocytosis.
2. Describe exocytosis.
3. Give two examples of substances cells move in using endocytosis. 4. Give two examples of substances cells move out using exocytosis.
What would you think if you were told a fish could die of dehydration while surrounded by water? As farfetched as it sounds, this is entirely possible. The cause of this phenomenon is osmosis, defined as the movement of water from an area of low solute concentration to an area of high solute concentration.
Saltwater fish spend their lives submerged in a solution containing a much higher concentration of solutes than is found in their body tissues. Due to their environment, marine fish are constantly losing water from their bodies through osmosis. These fish have therefore adapted many strategies to deal with this water loss. Saltwater fish drink water very frequently to bring it back into their bodies. Since drinking ocean water brings solutes into the body, fish have also developed a way to expel these solutes through their gills as well as through very concentrated urine.
If a fish with these adaptive strategies was to be placed in a freshwater
environment, they would not be losing water by osmosis but rather gaining it. If the fish continued to participate in its water-conserving practices, so much water
would enter the fish that it would explode! This is described as a fish in a hypotonic situation.
Answer these questions in your notebook using complete sentences! 1. Define osmosis.
2. Explain why water moves towards salt due to osmosis.
Cell Transport Graphics to Interpret
Station 7
Answer these questions in your notebook using complete sentences! 1. Define facilitated diffusion using the 4 steps above.
2. What type of molecule is being transported by facilitated diffusion in the diagram above?
Answer these questions in your notebook using complete sentences!
1. In the diagram above, which substances can’t cross a cell membrane by diffusion or osmosis?
2. Why can’t the molecules above cross the membrane? Give 2 reasons.
3. In the diagram above, which substances can move into a cell by osmosis? (Hint: define osmosis)
