ANATOMY & PHYSIOLOGY I WORKSHEET I Plasma Membrane and Cellular Transport Structure of the Plasma Membrane 1. Why do you think it is important to have a membrane surrounding each of our trillions of cells? Expect varying answers‚ but the idea is have the students understand the plasma membrane separates the cells from their environment and each other while also regulating the material within each cell. 2. What are two distinctive physical features of phospholipids? Heads are polar (water soluble
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In 1947‚ experiments in which small quantities of Ca2+ ions were injected directly into the cell showed that an increase in intracellular calcium led to skeletal contractions. However it was not until the early 1960s when the way calcium ions were stored in cells became clearer thanks to work from Ebashi and Lipmann. (Burgoyne and Petersen‚ 1997). Calcium signalling determines whether or not a cell is activated. It is determined by calcium-ON and calcium-OFF mechanisms. Calcium-ON is responsible
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dendrite -> soma -> axon -> synapse Lecture 2 – Chapters 4 & 5 Ion channels and signalling - ions are separated by cell membrane; when ion channels are opened‚ ions flow -> generating electrical signals -> so neurons can communicate info through these electrical signals - neurons generate a constant negative voltage across membrane: the rmp - an AP abolishes the –ve rmp‚ making membrane potential transiently positive - we can record and measure ion currents using electrophysiology - hyperpolarization
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Introduction Cells have to interact with their environment‚ chemicals and water and in order to do so they must be able to move across the cell membrane and the cell. The movements within a cell are called Diffusion. When molecules move across a cell membrane it is known as Osmosis. Diffusion is the process by which molecules of a substance move from areas of higher concentration of that substance to areas of lower concentration. Diffusion can be the transfer of anything anywhere. However‚
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cell. The heart was no longer providing blood flow with the rich oxygen and glucose to the mitochondria‚ which is needed for the production of ATP. Without ATP it was only a matter of a few moments before the active transport pumps in the plasma membrane had stopped. This seize of activity had now allowed for sodium to begin leaking out of the cells and potassium to leak in. Joseph’s lungs could no longer expel harmful carbon dioxide from his body‚ or bring important oxygen in. Cells were dying.
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Impulses: Activity 9: The Action Potential: Putting It All Together Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. Sensory neurons respond to an appropriate sensory stimulus with a change in membrane potential that is You correctly answered: b. graded with the stimulus intensity. 2. If the depolarization that reaches the axon is large and suprathreshold‚ the result in the axon is You correctly answered: c. action potentials at higher frequency
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Transportation Overview Directions: Read page 362-374 and use your notes to help you answer the following questions. 1. Illustrate and describe the structure of the cell membrane using figure 2.8 on page 362. 2. What does selectively permeable mean (pg. 363)? A: Selectively permeable means that some substances can pass through the cell membrane while others cannot pass through. 3. What is diffusion and why does it occur? A: The movement of solutes in a solution from high to low concentrations. Diffusion
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Cells must move materials through membranes and throughout cytoplasm in order to maintain homoeostasis. The movement is regulated because cellular membranes‚ including the plasma and organelle membranes‚ are selectively permeable[1]. The purpose of an automatic flow of molecules is to create equilibrium on each side of the membrane. In order for molecules to pass through the membranes‚ there must be pores. The size of the pore determines what molecules can cross. Due to the size and polarity‚ only
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INTRODUCTION: Osmosis is defined as the net movement of water or any other solutions molecules from a region in which they are highly concentrated to a region in which they are less concentrated. This movement must take place across a partially permeable membrane such as a cell wall‚ which lets smaller molecules such as water through but does not allow bigger molecules to pass through. The molecules will continue to diffuse until the area in which the molecules are found reaches a state of equilibrium‚ meaning
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OCR BIOLOGY UNIT F221 Blood tests 1. Put a band (tourniquet) around the arm to make the vein stand out 2. Clean the area around the vein with an alcohol based solution 3. Push a sterile needle‚ attached to a sterile syringe into the vein 4. Pull back the plunger of the syringe to suck the blood into the syringe 5. When the necessary volume of blood has been extracted‚ remove the syringe and needle‚ loosen the tourniquet and press a small ball of cotton wool over the
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