LAB EXERCISE: Diffusion and Osmosis Laboratory Objectives After completing this lab topic‚ you should be able to: 1. Describe the mechanism of diffusion at the molecular level. 2. List several factors that influence the rate of diffusion. 3. Explain why diffusion is important to cells. 4. Describe a selectively permeable membrane‚ and explain its role in osmosis. 5. Define hypotonic‚ hypertonic‚ and isotonic in terms of relative concentrations of osmotically active substances. 6. Discuss
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Research Project: Potato The potato originated in the South American Andes‚ but its heartland of wild genetic diversity reaches from Venezuela‚ Colombia‚ Ecuador‚ Peru‚ Bolivia‚ Argentina‚ Chile‚ Uruguay‚ Paraguay‚ southern Brazil‚ northward into Central America‚ Mexico‚ and the southwestern United States. Potato was first cultivated between 3 and 7 thousand years ago‚ some scientists believe they may have grown wild in the region as long as 13‚000 years ago. Potato is the third most important
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of a Potato Mishal Hasan Abstract Students in Biology find it difficult to understand the concept of tonicity and osmolarity in a real time situation. In this investigation‚ several concentrations of sucrose were used to determine the osmolarity of a potato. It was found that the concentration of sucrose was close to 3.6 in the potato used showing that it was isotonic. Anything above caused the potato to gain weight showing that it was a hypotonic solution and anything below caused the potato to lose
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Plasma membranes are selectively permeable. The purpose of this experiment is to reveal how a form of diffusion in a semipermeable membrane works by creating a real life simulation of a semipermeable plasma membrane. This is done by building an imitation of a caterpillar’s digestive tract using dialysis tubing and glassware. The first material in this experiment is a small beaker representing the head and crop of the caterpillar. This beaker is filled with both starch and the enzyme α-amylase. This
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Part A: Diffusion on a liquid in a liquid. I did an experiment with three different glasses of tap water from the faucet. All three cups measured the same which happened to be 13 cm from the top of the cup to the bottom of the cup. I let the water settle‚ and sit for about an hour so the temperature was the same for all three cups. I then placed one drop of food coloring into the first glass and waited for the coloring to reach the bottom. I calculated 93 seconds. I then went to the second glass
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"Do different concentrations of solutions determine the mass of a potato?" Introduction: The way to get the full results of this lab was through the process of osmosis. Osmosis is the movement of water across a membrane into a more concentrated solution to reach an equilibrium. When regarding cells osmosis has three different terms that are used to describe their concentration. The first of these words is isotonic. Cells in an isotonic solution show that the water has no net movement and the amount
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The Effect of Molecular Weight and Time on the Diffusion Rate of Potassium Permanganate‚ Potassium Dichromate‚ and Methylene Blue.1 Arantxa Alex Carpio Group 1 Sec. X – 4L March 24‚ 2015 ABSTRACT The effect of molecular weight and time on the rate of diffusion was determined using the agar-water gel test. A petri dish of agar-water gel with three wells was prepared and a prepared solution of each substance was dropped on each well; one with potassium permanganate (KMnO4)‚
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Simple diffusion The term simple diffusion refers to a process whereby a substance passes through a membrane without the aid of an intermediary such as a integral membrane protein. The force that drives the substance from one side of the membrane to the other is the force of diffusion. In order for substances to pass through a cell membrane by simple diffusion it must penetrate the hydrophobic core of the phospholipid bilayer. The types of molecules that can do this are themselves substantially
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Topic: Osmosis Materials: Potato cylinders‚ 20 percent sodium chloride solution‚ three test-tubes‚ test-tube rack‚ scalpel blade‚ Gel ink pen‚ syringe-10cm^3‚ Plastic ruler with mm‚ tile‚ forceps filter paper‚ Masking tape. Method: 1) Three test-tubes‚ A‚ B and C were labeled and initials of experimenters were applied with the date: January 29‚ 2013. 2) A syringe was used to put 10cm^3 of water in tube A and 5cm^3 in tube B along with 5cm^ 20 percent sodium chloride solution and 10cm^3 20 percent
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Diffusion is one of several transport phenomena that occur in nature. A distinguishing feature of diffusion is that it results in mixing or mass transport without requiring bulk motion. Thus‚ diffusion should not be confused with convection or advection‚ which are other transport mechanisms that use bulk motion to move particles from one place to another. In Latin‚ "diffundere" means "to spread out". There are two ways to introduce the notion of diffusion: either a phenomenological approach starting
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