Diffusion And Osmosis Lab Report

1. Cell Membrane - A cell membrane in a cell is like the turnstiles and gates of a baseball stadium. The cell membrane is selectively permeable and the turnstiles or gate only let people with a ticket into the stadium 2. Cell Wall - The cell wall in a cell is just like the support beams of a baseball stadium.

endocytosis- When larger molecules are able to enter the cell. 15. Energy-is what causes objects to carry out their tasks. 16. energy

This lab uses a lake simulation to study how the addition of nutrients and toxins can affect the lake, its inhabitants and the surrounding area. There is a strong focus on the addition of Phosphorous and added toxins because both are key elements in growth in lakes. The Virtual lake includes these five simulated species; green algae, cyanobacteria, bosmina, daphnia, and trout. There are two types of phytoplankton in the lake model, green algae and cyanobacteria. Green algae are a very diverse group that are photosynthetic, aquatic, plant like organisms that have a very simple reproductive structure.

More specifically the aim was to investigate what effect 40% and 70% ethanol solutions had on a B. Vulgaris cell membrane and then compare them to the same test with distilled water. It was hypothesised that the ethanol solution would increase the membrane permeability. From the results the hypothesis can be supported. The topic of cell membranes have been extensively researched, meaning that there is no limit to information and sources of information of the subject. The effects of alcohols on membrane have also been researched quite extensively.

Rationale The cell membrane, also called the plasma membrane is found in all cells and separates the extracellular side of the cell from the cytosolic side (Cell membrane (plasma membrane), 2023). The purpose of the cell membrane is to communicate with the cell’s external environment, to contain the cell’s contents and to control the transport of molecules in and out of the cell. Diffusion is the passive movement of molecules from an area of high to low concentration.

Part A: Osmosis practical task Aim: To observe the effects of osmosis in rhubarb cells. Hypothesis: Water will be extracted out of the cells in the salt solution causing the cells to look different to the cells in the freshwater solution. Materials: Rhubarb Distilled water in a dropping bottle Salt solution in a dropping bottle Microscope, slides, and coverslips Forceps and razor blades or scalpel Paper Towel Method: Clean and dry a slide and coverslip.

Exploration Title: Effect of Temperature on rate of Osmosis Submitted By: Abdulkarim Kamal Date Submitted: October 19th 2015 Subject: Biology HL Teacher: Mr. Nick   Aim: This is an investigation to determine the relation between temperature of a solution (sucrose) and the rate of osmosis Scientific Context: Osmosis is defined a passive transport process in which a fluid diffuses across a semi-permeable membrane, from an area of high solute concentration to an area of low solute concentration and vice-versa. There are various factors that could potentially influence the rate of osmosis; these factors include volume, concentration, and temperature. If all external factors that may interfere with rate of osmosis are controlled, the results will show equal amounts of fluid on both sides of the barrier (membrane); this is known as an “isotonic” state.

In this lab we used two processes called Diffusion and Osmosis. Diffusion is the movement of molecules from areas of high concentration to areas of low concentration. Diffusion is a process that requires no energy and involves smaller non-polar molecules. In Figure 1 you can see the molecules spreading throughout the glass from the area of high concentration, so that the areas with low concentration are filled evenly as well. The other process was osmosis.

Explain how different substances are transported across a plasma membrane. You must include simply and facilitated diffusion, osmosis, active transport and bulk transport (endocytosis and exocytosis). Plasma membrane plays a vital role in every the cell by protecting the cell and all cell organelles from its surroundings. Plasma membrane is mainly composed of phospholipids and proteins and it is selectively permeable.

More specifically the aim was to investigate what effect 40% and 70% ethanol solutions had on a B. Vulgaris cell membrane and then compare them to the same test with distilled water. It was hypothesised that the ethanol solution would increase the membrane permeability. From the results the hypothesis can be supported. Cell membranes are a core aspect of understanding cells which helps to understand humans and other living creatures. Therefore the topic of cell membranes has been extensively researched, meaning that there is no limit to information and sources of information of the subject.

The three major parts of the cell are the cell membrane, the nucleus, and the cytoplasm. The cell membrane functions as a selective semipermeable membrane and separates the cell from its external environment and from the neighboring cells. It also regulates the passage or transport of certain molecules into and out of the cell, and prevents the passage of others. The nucleus can be defined as the most important organ organelle within the cell. Its functions are to control cellular activities and to facilitate cell division.

INTRODUCTION: In this experiment I was testing for antimicrobial sensitivity of Staphylococcus epidermidis by using the Kirby-Bauer Diffusion test. The three antibiotics utilized in this lab were: gentamicin, novobiocin, and penicillin. I determined the effectiveness of the antibiotic by observing and measuring the zone of inhibition for each antibiotic.

Osmosis Lab Report Research Question: How does the change in the concentration of a sucrose solution affect the process of osmosis in a potato cell by measuring its mass? Background information: 1 Osmosis is the process by which a liquid passes through a semi-permeable membrane, moving from an area with a high concentration of water to a low concentration of water. There are various factors that affect osmosis such as: concentration, surface area and temperature. The concentration of solutions can affect the rate of osmosis, as there is more difference in the concentration of the solutions, which means osmosis, will take place quicker. Surface area could affect osmosis based on the ease by which molecules can get through the semi-permeable

Cell membrane- the blue outside layer on my model: The cell membrane is made up of a phospholipid bilayer. The membrane excludes, takes in, and excretes various substances, all in specific amounts. In addition, they must able to communicate with other cells. The plasma membrane needs lipids, which make a semi-permeable barrier between the cell and its environment. It also needs proteins, which are involved in cross-membrane transport and cell communication.

Biology Design Practical Joshua Edwards What are effects of the volume of a potato and the amount of weight it loses when placed in salt solution? Introduction This design practical uses a potato’s surface area to volume ratio to see what affects it has on osmosis in different concentrations. Osmosis is the movement of water molecules through a cell membrane into an area of a higher solute concentration. The movement goes the way of the solvent with more solute because the lower solute concentration is drifting through balancing the ratio of solute per solvent (En.wikipedia.org, 2018).