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13. Understand the transportation of potassium and sodium across plasma membranes. (p. 10 bottom right, p. 20 bottom right, p. 21 diagram)

Exercise 1: Cell Transport Mechanisms and Permeability: Activity 3: Simulating Osmotic Pressure Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. Which of the following is true of osmosis? You correctly answered: c. It is a type of diffusion. 2. Which of the following occurs when a hypertonic solution is added to cells? You correctly answered: d. The cells shrink. 3. The variable that affects osmotic pressure is You correctly answered: a. the concentration of nondiffusing solutes. 4. The net movement of water would be into the cell in a You correctly answered: b. hypotonic solution.

Introduction: Cell membranes contain many different types of molecules which have different roles in the overall structure of the membrane. Phospholipids form a bilayer, which is the basic structure of the membrane. Their non-polar tails form a barrier to most water soluble substances. Membrane proteins serves as channels for transport of metabolites, some act as enzymes or carriers, while some are receptors. Lastly carbohydrate molecules of the membrane are relatively short-chain polysaccharides, which has multiple functions, for example, cell-cell recognition and acting as receptor sites for chemical signals.

List three criteria cells use to select materials to enter or leave the cell. Then explain the role of each criterion in determining the type of transport a cell will use for different sized molecules. For instance, small molecules move across the membrane by diffusion, given they are moving with the concentration gradient.

1.Discuss the structure of the plasma membrane and explain the process of active and passive transport through the membrane.

b. Describe the role of primary active transport with regard to potassium (K+) and hydrogen (H+) ion movement.

Students have grouped together in their Anatomy Lab using three different types of Sucrose Bathing Solutions and three different deshelled chicken eggs. Students will learn the permeability of the cell membrane by studying the ability of a shell-less chicken egg to absorb the various sucrose bathing solutions. Students can see how membranes can regulate a cell’s interaction with its environment. The deshelled egg is semi-permeable, meaning that some molecules easily move across the cell membrane, some cannot. A cell membrane can transport materials through two general forms: Simple diffusion and Facilitated diffusion. Principles of Medical Physiology states “Facilitated diffusion, it is generally much faster than simple diffusion. Glucose and other large uncharged hydrophilic molecules have extremely slow rates of simple diffusion across the lipid bilayer but they cross the membrane much faster through facilitated diffusion.” Osmosis can be defined as the

Exercise 1: Cell Transport Mechanisms and Permeability: Activity 2: Simulated Facilitated Diffusion Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. Molecules need a carrier protein to help them move across a membrane because You correctly answered: d. they are lipid insoluble or they are too large. 2. Which of the following is true of facilitated diffusion? You correctly answered: c. Movement is passive and down a concentration gradient. 3. Examples of solutes that might require facilitated diffusion include You correctly answered: d. all of the above. 4. Which of the following would not affect the rate of facilitated diffusion? You correctly answered: a. the amount of intracellular ATP

3. Explain your prediction for the effect Na+ Cl- might have on glucose transport. In other words, explain why you picked the choice that you did. How well did the results compare with your prediction?

In this lab, neutral red was used as a pH indicator. The color changes from yellow to red in a basic solution to an acidic solution. The neutral red dye was applied to Saccharomyces Cerevisiae. When the S. Cerevisiae cells come in contact with the neutral red dye, the dye gets to the cell by crossing the cell membrane. The cell membrane is the outer surface of the cell that functions as a barrier. The outside of the cell membrane is made of lipid and membrane proteins (Hardin, 2012). It is selectively permeable, which means only select ions and molecules can pass through it by transport. Membrane transport can be actively or passively moving a substance from side of the membrane to another (Hardin, 2012). Passive transport does not require energy to move molecules across the cell membrane. Diffusion is a form of passive transport that moves molecules across the membrane from an area of higher concentration to an area of lower concentration. Osmosis, diffusion, and facilitated diffusion are all examples of passive transport. Active transport requires energy to move molecules across the membrane from areas of lower concentration to higher concentration. It requires energy because it pushes sodium ions (Na+) and potassium ions (K+) (Hardin, 2012). When the dye entered the cell, it also showed its location. Sodium azide (Na+N3-) is a metabolic inhibitor that blocks the flow of electrons along

3. Describe gas transport across the plasma membrane. Passes through bilayer by diffusion and journeys along the concentration gradient. Uses gradient energy.

All organisms need to exchange particles such as food, waste, gas and heat with their surroundings. there are two different types of ways in which substances can enter or/and leave a cell. these ways are called Passive and Active. with in these there are different processes for example, in passive process there are diffusion, facilitated diffusion and osmosis and in the active process there is molecule and particle. in this assignment I am going to discuss all of these processes starting with diffusion.

b.) In chemiosmotic production of ATP, hydrogen ions move through ATP synthase implanted in membrane to produce energy, membrane covers increase surface area and hydrogen ions gradient established across membrane. In inter and intracellular signaling, through exocytosis, chemical signals were released, antibodies activate immune function and receptors in membrane chemical signals pass through the membrane. In

Cells, the smallest functional unit in an organism, contain several organelles and carry out functions of life. The cell membrane is an organelle that holds the cell’s contents, and it allows for certain molecules to pass through, which is why it is referred to as selectively permeable. Diffusion and osmosis are two main transport methods for moving molecules across a cell’s membrane. Diffusion takes place when molecules move from an area of high concentration to low concentration. The same process occurs with water molecules, only it is called osmosis. By conducting an experiment with four different activities, the goal is to

Exercise 1: Cell Transport Mechanisms and Permeability: Activity 5: Simulating Active Transport Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. The movement of sodium and potassium maintained by the Na+ -K+ pump You correctly answered: e. requires energy and is against a concentration gradient. 2. The sodium-potassium pump is classified as a(n) You correctly answered: a. antiporter. 3. The sodium-potassium pump moves _____ sodium ions and _____ potassium ions simultaneously. You correctly answered: b. 3, 2 4. Solutes that require active transport for movement might be too large to pass or might be You correctly answered: a. lipid insoluble.