Many cells face serious difficulty living in a hypotonic environment and adapt in various ways to prevent cytolysis due to excessive water movement. Plant cell walls are one such adaptation to osmosis. By applying pressure in the form of turgor pressure on the inside of the wall, plants can prevent further movement into the plant and thus avoid cytolysis. A particular plant cell is placed in an open container of water containing a 0.75 M solution of sucrose at 20°C. Calculate the turgor pressure required to allow the plant to be at equilibrium with the environment and prevent water entry into the plant cell.

24. On the basis of your knowledge of osmosis, predict what will happen to the water in Elodea cells.

Lactose transporter of E. coli is a well-studied proton driven cotransporter. It transports one lactose molecule together with one proton into the cell. Calculate the free energy change for transporting one more of protons into the cell? Membrane potential is -50 mV (inside is negative) and the pH = 7.2 inside the cell and the pH = 4.0 outside the cell. Temperature is 37 degrees celsius (310K). Remeber to convert pH to (H+) and express your answer as kJ/mol.

Discuss the physical properties of a membrane, the movement of its phospholipids and proteins– explain the fluid mosaic model.

Based on a hypothesis of the osmolarity of potato tissue, what results might be predicted from this experiment?

What is the role of lysozyme and a low ionic strength extraction buffer? Select all that apply. Cells absorb water from a low ionic strength extraction buffer, by osmosis, swell and lyse, releasing their contents Lysozyme breaks down bonds in the cellulose cell wall of plants, weakening the structure Cells release water into a low ionic strength extraction buffer by osmosis, shrink and lyse, releasing their contents Lysozyme is an enzyme found in lysosomes in cells Lysozyme breaks down bonds in the peptidoglycan cell wall of bacteria, weakening the structure Lysozyme is an antibiotic found in tears, saliva, human milk and mucus.

In eukaryotic cells, metabolic pathways occur in specific locations, such as the mitochondrion or the cytosol.What sort of transport processes are required as a result?

Mark the flow of water with an arrow for cells that have been placed in solutions of differing tonicity. Indicate what will happen to a plant and animal cell under each of these conditions. Direction of osmosis Plant cell Animal cell shape shape minor swelling The solute concentration outside the cell is isotonic (or equal) to the inside of the cell. No change swelling and lysis plasmolysis crenation Reset Zoom (a) Outside isotonic The solute concentration outside the cell is hypertonic to the inside of the cell. (b) Outside hypertonic The solute concentration outside the cell is hypotonic to the inside of the cell. (c) Outside hypotonic Oo Solute Cytosol ©2018 McGraw-Hill Education. Check m

Plate A = filter paper dipped into 5% solution of unknown Dye A %3D Plate B = filter paper dipped into 5% solution of unknown Dye B Both plates were incubated at 37°C. At the end of the 60 minute incubation period the diffusion rings for each dye were measured. The diffusion ring for Dye A = 40 mm. The diffusion ring for Dye B = 24 mm %3D Based on the results, which dye had the higher molecular weight? Explain your answer.

Explain (using the correct terminology and drawing an image) what happens to the cells in the following environments: A human blood cell (0.9% salt) is placed in a saltwater tank (27.5% salt). - A bacterial cell with 35% organic material in their cytoplasm is living in a tank filled with 35% sulfur. - A freshwater plant cell (75% water) is living in a pond that floods over.