If we place the potato in a sucrose solution with a similar solute concentration as a potato, then the least amount of water will diffuse into or out of the potato cells. This occurs because this scenario will be initially closest to an isotonic solution, allowing us to determine the solute concentration of a potato. Materials: * Knife/ Cork Borer * Seven 30 cm pieces of Dialysis tubing * Thirteen 250 mL Beakers * 15% Glucose Solution * Glucose Test Strips * 1% Starch Solution * Distilled water * Lugol’s solution * 25 mL of: * .2 M sucrose * .4 M sucrose * .6 M sucrose * .8 M sucrose * 1 M sucrose * Paper Towels * Clock * Potatoes * Plastic
Plants are the producers for an ecosystem. They photosynthesise carbon dioxide and water and produce energy in the form of carbohydrates and other molecules. Photosynthesis requires water, and plants gain water from the soil using mineral ions such as nitrate produced by the nitrifying bacteria. Hydrolysis of ATP releases energy for processes such as active transport of the nitrate ions (and others such as potassium etc) from the soil into root hair cells, a process that lowers water potential and is used to draw water into the plant from the soil. In leaves, photosynthesis involves the photolysis of water, a process that involves the attachment of two electrons to a magnesium ion in chlorophyll and the production of hydrogen ions from the breakdown of water.
They are traveling along the outer perimeter to help move the vital nutrients throughout the cell and convert them to substances used in the cell of the Elodea. 2. What is the typical size difference between animal cells and bacterial cells? A) Bacteria cells are much smaller. Animal cells have membrane bound organelles, bacteria do not so that makes them much bigger than a bacteria cell.
There are two ways that the cell can transport substances; passive transport processes and active transport processes. Passive transport processes are when the cell does not use any energy during the transport process. The other transport processes require energy from the cell’s reserves. These processes are called active transport processes’. Passive transport processes: Diffusion Diffusion is the movement of ions or molecules from regions of high to low concentration; down a concentration gradient.
Properties of Water Property | Importance | Examples | Solvent | Metabolic processes in all organisms rely on chemicals being able to react together in solution. | 70-95% of cytoplasm is water. Dissolved chemicals take part in processes such as respiration and photosynthesis in living organisms. | Liquid | The movement of material around organisms both in cells and on a large scale in multicellular organisms requires a liquid transport medium. | Blood in animals and the vascular tissues in plants use water as a liquid transport medium.
Understand the interactions of actin and myosin in muscle contraction and in “localized” muscle contraction (e.g. pseudopodia and cytoplasmic streaming) Understand the structure and function of cell walls in plants. What other kinds of cells have them? What kinds of molecules make up the extracellular matrix in animals? Where do they come from?
The exterior surface of the plasma membrane can contain carbohydrates. How are the peripheral proteins attached to membrane? Peripheral (extrinsic) proteins are associated with the surface of the bilayer surface via ionic interactions (electrostatic) and H bonds. They do not extend into the hydrophobic interior and can be removed by agents that disrupt ionic interactions and H bonds, such as high salt concentrations, urea, or extremes of pH. How do proteins associate with cell membrane?
Motor nerves-Carry messages from CNS to the effector 7. Effectors-muscles or glands 5. The nervous system works with another system called the endocrine system 6. Endocrine system: This system produces hormones in response to certain stimuli Identify the broad range of temperatures over which life is found compared with the narrow limits for individual species Ambient temperature is the temperature of the environment 1. Aquatic organisms 1.
The profitability of alternative crops (e.g. carrots) rises. 3. A poor potato harvest 4. Farmers expect the price of potatoes to rise (short-run supply falls).
AP Biology November 3, 2011 Lab 1: Diffusion and Osmosis Objectives: * Measure the water potential of a substance in a controlled experiment. * Determine the osmotic concentration of living tissue or an unknown solution from experimental data * Describe the effects of water gain or loss in animal and plant cells * Release osmotic potential to solute concentration and water potential Introduction: Diffusion is the process that allows particles or molecules to move from an area of high concentration to an area of low concentration. This process accounts for the movement of many small molecules across cell membranes. The rate of diffusion of particles will be affected by the steepness of the concentration gradient or the difference in concentration between two areas. Diffusion can only occur across a membrane if there is a concentration gradient and the membrane is passable.