Name: Marion Paxton Diffusion Lab Introduction: In this lab you will observe the diffusion of a substance across a semi permeable membrane. Iodine is a known indicator for starch. An indicator is a substance that chances color in the presence of the substance it indicates. Watch as your teacher demonstrates how iodine changes in the presence of starch. **Prelab Observations: Describe what happened when iodine came into contact with starch. The cornstarch turned blue-black Procedure:
Premium Osmosis Concentration Iodine
TRANSPORT ACROSS MEMBRANE define diffusion and describe its role in nutrient uptake and gaseous exchange in plants and humans define osmosis and describe the effects of osmosis on plant and animal tissues define active transport and discuss its importance as an energy-consuming process by which substances are transported against a concentration gradient‚ as in ion uptake by root hairs and uptake of glucose by cells in the villi . A cell is surrounded by a layer of cell surface membrane. This phospholipid
Premium Cell wall Osmosis Cell membrane
Activity 6.2-Membranes Organize a Cell’s Activity Dissect a Plasma Membrane Objective: to understand the structure of a membrane 1. Why is the membrane described as a phospholipid bilayer? It is described as a phospholipid bilayer because there are two layers of phospholipid molecules. 2. How does the arrangement of the phospholipids form a bilayer? The phospholipids arranged in two layers so that the charged phosphate heads interact with the water on either side of the membrane‚ and the
Premium Cell membrane Lipid bilayer Cell
The effect of temperature on the cell membranes of beetroot cells and amount of pigment released. Apparatus • Corer size 4 • White tile • A Beetroot • Automatic Water Bath • Segregated knife • A thermometer • Stopwatch Method: • First take the white tile and the corer. Then collect a cylinder of beetroot by pushing the corer into the beetroot and withdrawing it. The cylinder remains inside the corer- so push it out with the end of a pencil. • Collect 3 cylinders
Premium Cell membrane Protein Cell
To investigate the effect of variation in temperature on the permeability of cell membranes using fresh beetroot Aims In this investigation‚ you will subject fresh‚ washed beetroot discs to different temperatures to investigate the effect of temperature on the permeability of the plasma membrane. Overview The beetroot discs will be placed in distilled water at different temperatures. You will compare the intensity of the beetroot pigment that has leaked out from the cells subjectively and possibly
Premium Cell membrane Laboratory glassware Gas
The different cell membrane transport mechanisms The cell membrane is referred to as a ‘fluid mosaic model’ because the protein part within the cell membrane used to be though of as an even layer spread over the outside and the inside of the phospholipid. Now we are starting to think that it is spread unevenly‚ more like a mosaic than a layer. The phospholipid part of the cell membrane is fluid; this means that its molecules are constantly moving about. Through the molecules constantly moving
Premium Protein Cell membrane Diffusion
The Lipid Barrier of the Cell Membrane‚ and Cell Membrane Transport Proteins The structure of the membrane covering the outside of every cell of the body is discussed in Chapter 2 and illustrated in Figures 2–3 and 4–2.This membrane consists almost entirely of a lipid bilayer‚ but it also contains large numbers of protein molecules in the lipid‚ many of which penetrate all the way through the membrane‚ as shown in Figure 4–2. The lipid bilayer is not miscible with either the extracellular
Premium Sodium Ion Diffusion
Describe the structure and function of each of the eukaryotic organelles. ”A eukaryotic cell is sectioned by internal membranes into different functioning categories called organelles. For example‚ the nucleus houses DNA‚ the genetic component that controls the cells activities. (Boundless. “Introduction” Boundless Biology). The Cytoplasm is the material between the cell membrane and the nucleus. It has a lot of responsibilities within the cell. It contains enzymes for breaking down waste and also
Premium Cell Organelle Eukaryote
through the epithelial cell membrane to enter into the epithelial cell’s cytoplasm – its charged cuz of side chains To get through the membrane the amino acid must cross the Simple columnar epithelial cells lining the apical surface of the small intestinal tract. These cells are impermeable to any harmful bacteria that may be ingested by the body‚ but permeable to necessary ions. Absorption of amino acids occurs through a process known as facilitated diffusion through membrane transporters (carrier protein)
Premium Protein Amino acid
At rest‚ a nerve cell maintains a difference in charge between the inside and the outside of the cell membrane. This difference in charge is continued by three factors. Firstly‚ in the cell membrane‚ there are sodium potassium ‘pumps’ crossing the membrane which are proteins that bring 2 potassium ions into the cell‚ for every 3 sodium ions it pumps out. As well as this‚ there are protein channels which allow potassium ions in the cell to flow out via facilitated diffusion. Potassium diffuses out
Premium Action potential Neuron Electric charge