Essay on An Investigation into the Factors which Affect Osmosis

The leaves of a plant are the main photosynthetic organs and are involved in gas exchange and water transportation throughout a plant (Evans et al, 17). A leaf typically consists of an upper and lower epidermis, the mesophyll cells, veins, guard cells and stomata. The mesophyll cells contains spongey cells which have large gaps between each cell to allow oxygen and carbon dioxide circulation. The mesophyll cells contain palisade cells, which are located beneath the upper epidermis. The palisade cells contain many chloroplasts, which are green organelles. Located in the internal layers of chloroplasts is the pigment chlorophyll which is involved in trapping the light energy in photosynthesis (Evans et al, 17).

The experiment of the lab was to demonstrate knowledge of the concepts of diffusion and osmosis. Diffusion is the movement of substances moving from a high concentration to a low concentration. For this lab the rate of osmosis was measured in concentration. The concentration stayed the same and increased through the experiment. At the beginning of the experiment the sacs were weighed to determine the tonicity of water throughout the experiment. Timing was also a factor each 15, 30, 45 minute interval the sacs were weighed and recorded. Each sac had a different amount of solution in them. The tonicity of the sacs was determined as well by the final weights and the final percent of gain or loss of water in the sacs.

Plant cells have selectively permeable membrane that allows selective substances to penetrate into the cell. Cell membranes are consisting of lipid layer that are made up of phospholipids. (Essays, UK.2013). These phospholipids are amphipathic in nature, which have phospholipids head and tail respectively. Phospholipids heads are hydrophilic and tails

In your laboratory notebook sum these two reactions to find the stoichiometric factor that relates moles of

A system is Material moving most stable when it has reached equilibrium. A out of the cell system will tend to go to equilibrium (lowest, accessible energy state) in the absence of added energy (Figure 2).

The reasoning behind this experiment is the examine whether the rate of osmosis is changed due to a change in temperature. It was hypothesized that the rate of osmosis will increase as the temperature of the sucrose is increased. The rate of osmosis was tested by using the different jars full of different temperate water and testing how high the water rose on an osmometer over a span of 20 minutes. An osmometer is a tool used to measure rates of osmosis. The different temperatures tested on a sucrose solution were 5 degrees Celsius, 20 degrees Celsius, and 37 degrees Celsius. Rates of osmosis were higher in the hot water than in the cold water and control. The results showed that the rate of osmosis increased as the temperature increased, henceforth the hypothesis was supported. In conclusion, the experiment showed how changes in temperature affect the rate of osmosis.

*Note: A recording mistake was made in the lab notebook, where the final product was supposed to be 0.05g (calculations above) and not 0.55g (calculations below).

Overall the mass of the potato slice for the groups went down during the experiment. The ranges of weight change warried from around 0.2 to 0.3 grams

4. Take a piece of dialysis(as cut earlier), find the mass of the dialysis, and the zero out the scale on

The purpose of this lab was to observe the osmosis rates and mass changes of dialysis tubes. To this three-dialysis tubes with differing sucrose levels were tested on their rate of osmosis and weighed at 15-minute intervals. The results found described that as the sucrose level increases the rate of osmosis increased as well.

This is made possible by the support lent to it by the slightly elastic cellulose cell wall. It will support a turgid cell enough to prevent it from bursting (see left). It is turgid cells such as this that provide a plant with its support. Animal cells on the other hand, do not have supporting cell walls, just cell membranes. As plants are always surrounded by water, it is vital for them to have cell walls, but animal cells, surrounded by blood (low water concentration), do not need as much support.

Effect of Sucrose Solution on Osmosis Aim: The aim of the experiment is to show how varying the concentration of sucrose solution affects osmosis by changing different molar solutions of sucrose and water and how it affects the potato. Introduction: In this investigation I will be exploring the effect of varying concentration of sucrose sugar solution on the amount of activity between the solution and the potatoes. Osmosis is the movement of water molecules across a partially permeable membrane from a high water concentration to a low water concentration.

In plants the cell membrane is surrounded by a cell wall. The cell wall is outside the cell membrane, and its purpose is to help the membrane protect and support the cell. Since the cell wall is very porous, water, oxygen,

This experiment was used to examine the hypothesis that: Osmosis is dependent on the concentrations of the substances involved.

If the solution contains only sucrose then the osmotic pressure will increase substantially. This would represent a hypotonic solution because more water molecules are entering the cell meaning the solution contains no invertase. If the osmotic pressure has a slight increase than the solution contains sucrose and invertase due to the rate of the sucrose being broken down, however the cell will overtime begin to shrink. If the osmotic pressure remains close to the same than the solution contains no sucrose, containing only water and invertase. We predicted that because the height of the fluid in the osmometer tubing was increasing only a little bit our blue solution was hypertonic and contained invertase and sucrose. The invertase was able to break down sucrose into glucose and fructose which were small enough to be able to leave the cell membrane. This would reflect a hypertonic solution. We predicted this would cause the cell to shrink in size and the height of the fluid would never increase.