The bilayer is selectively permeable which enables it to act as a barrier that keeps proteins, ions and other molecules where they are needed and prevents them from diffusing into areas where they are not (Wisegeek.com/bilayer. 2011). Small molecules can move through the layer automatically, this is diffusion from a high concentration to an area of low concentration, whereas water diffuses from highly concentrated areas to low concentrated areas. This process is known as osmosis and its purpose is to maintain equilibrium within the cell in order for it to function properly (Wisegeek.com/bilayer. 2011).
4. List the three fluid compartments and the percentage of total body water in each. a. Intracellular 62% b. Plasma 8% c. Interstitial 30% 5. Give an example of each of the following solutes: a. Ions/electrolytes sodium b. Colloids proteins c. Nonelectrolytes glucose 6.
Respiration has three steps you have the Glycolysis, Krebs Cycle, and Election Transport Chain. The glycolysis is outside the mitochondrion and then the krebs cycle happens in the matrix and the election transport chain happens in the inner membrane. Photosynthesis and respiration are reactions that complement each other in the environment. They are the opposite of each other. They work well
6. Binding of the myosin heads sequentially prevents _____________________ of the thin filament. 7. Name three roles for ATP in the contraction of muscle. a. Energizing the power stroke of the myosin cross bridge b. Disconnecting the myosin head from actin c. actively transporting calcium back into the SR 8.
b. What two characteristics must a membrane possess in order to generate and maintain electrical signals critical to nervous tissue? A cell membrane must possess ion transport proteins in the membrane and resting membrane potentials in order to generate and maintain electrical signals. Membrane Transport Proteins 4. What three membrane proteins are required if a membrane is to carry electrical impulses?
When a solution a cell is placed in has more more atoms than the cell has the solution is known as a hypertonic solution while a solution holding less water than the cell it is known as a hypotonic solution. OBJECTIVES: -Diffusion and osmosis move materials from an area of high concentration to an area of low concentration -Diffusion and osmosis will move in two directions at the same time -Glucose will move down the concentration gradient
“Compare and contrast the different methods molecules can either enter or exit cells” In this essay I am going to discuss and compare the methods that molecules enter and exit cells. There are various ways in which molecules enter and exit cells, and I am going to talk about the three main transport mechanisms: active transport, bulk transport and diffusion. Firstly I will briefly summarize each method with a short explanation to what it does and then I will go on to compare and contrast the three methods, to show a greater understanding of what I have learnt. The first method I am going to talk about is active transport. Active transport is the process where dissolved molecules move across the cell membrane from a lower to a higher concentration.
Function and role of Plasma membrane Functions of a membrane it's: 1. Selectively permeable barrier. 2. Structural, keeping the cell contents together. 3.
There are two types of respiration: Aerobic (using oxygen) and Anaerobic (no oxygen). Aerobic respiration produces carbon dioxide and water and releases energy. The equation is: C6H12O6 + 6O2 → 6CO2 + 6H20 + Energy ATP A cell cannot get its energy directly from glucose, so during respiration the energy released from the breakdown of glucose is used to make ATP (adenosine triphosphate). ATP is made from the nucleotide base adenine, combined with a ribose sugar and three phosphate groups. It carries energy around the cell to where it’s needed.
Diffusion is the tendency of molecules of a substance to diffuse from where it is more concentrated to where it is less concentrated. In general a substance will diffuse down its concentration gradient until concentrations on either side of the membrane is at equilibrium. This metabolic process is called passive transport because it is a spontaneous process and therefore the cell does not expend any energy to make it happen (Campbell. 1993). The diffusion of water across a selectively permeable membrane is known as a special case of passive transport called osmosis (Campbell.