Diffusion Lab Report

3. Does the rate of diffusion change over time? How might this affect your calculated diffusion

An example of active transport would be pushing a stroller up a hill. Passive transport is diffusion across a membrane requiring only random motion of molecules with no energy expanded by the cell. Another example of passive transport would be rolling a ball down a hill.

Diffusion is defined as the movement of molecules from an area of high concentration to an area of low concentration. The diffusion of water molecules through a semi-permeable(selectively permeable) membrane is osmosis. Semi-permeable means that some molecules can move through the membrane while others can not. Diffusion and Osmosis are passive forms of transport requiring no energy. Active Transport utilizes energy in the form of ATP. Water is a solvent that can dissolve a number of substances more than any other substance. Wherever water goes, through the ground or a body, it takes along valuable molecules. Water’s chemical composition causes it to be attracted to many different molecules and be attracted so strongly it disrupts the forces and dissolves it. Water can pass through the semipermeable membrane without any help but can change the solution, on the other side of the cell membrane, depending on how much it diffuses in and out.

diffusion is one of the passive transport processes. it is used in oxygen entering a cell and carbon dioxide leaving a cell. diffusion is the movement of particles such as atoms or molecules from a high concentration place in an area of a low concentration. this shows that they diffuse down the concentration gradient. the concentration gradient is a gradual change in the concentration of solutes in a solution as a function of distance through a solution. in biology a gradient results from an unequal distribution of particles across the cell membrane. When this happens solutes move along the concentration gradient until the concentration of the

By a form of passive transport called diffusion, across a concentration gradient. Water soluble substances such as sugars and inorganic ions diffuse very slowly, with no energy expenditure. It is a uniport mechanism and demonstrates saturation kinetics where the glucose specific receptors are all occupied and operating at max capacity.

Sometimes one substance is transported in one direction at the same time as another substance is transported in the other direction. This is called Co- transport. In Co-tansport one of the two substances are transported in the direction of their concentration gradient utilizing the energy derived from the transport of the second substance (mostly Na+, K+ or H+) down its concentration gradient. Active transport often takes place in the

The reason for it not requiring energy from another substance is the fact that the particle is in constant movement and is able to use its kinetic energy for diffusion. Diffusion occurs in the cell membrane where the membrane is fully permeable. In the case of the plasma membrane, the membrane is permeable to non-polar substances such as steroids and glycerol, as well as oxygen and carbon dioxide in solution. Diffusion can also occur through pores in the membrane. Water diffuses through these protein lined pores or can diffuse through spaces between the phospholipid molecules.

Another potential error, which might have occurred, is the temperature fluctuation throughout the experiment. The rate of osmosis will be affected if the temperature in inconsistent, as more heat increases rate of osmosis and cooler temperature decreases rate of osmosis.

Some molecules can pass into the cell by facilitated diffusion. This is passive due to the nature of diffusion and because the solute is moving down its

Diffusion is the movement of molecules from a region of higher concentration to a region of lower concentration. The rate at which molecules diffuse can be determined by the relationship of molecular weight and that rate of diffusion through a membrane. Hypothesis of this experiment is that the fluid with higher molecular weight will diffuse at a slower rate and distance.

In conclusion, the potato cube with the highest surface area to volume ratio (the 1x1x1 cube) had the fastest rate of diffusion as it had the largest percentage increase in mass. While all the other cubes of potato had larger increases in mass at face value compared to the smallest cube, the smallest cube had the largest overall gain in percentage. The results support my hypothesis that the smallest cube will have a higher rate of osmosis because it has a proportionally larger amount of surface area compared to its volume.

Showing an example of diffusion with the water molecules equally back and forth the semi-permeable membrane of the potatoes and the saucer of water. The hypertonic solution of salt water has given an example of osmosis. The water molecules passed through the semi-permeable membrane out of the potatoes but weren’t able to get back in as easily due to the salt blocking the membranes passage. This left the potatoes in the salt water saucer feeling flexible and spongy almost leaving the potato a little

All cells contain membranes that are selectively permeable, allowing certain things to pass into and leave out of the cell. The process in which molecules of a substance move from an area of high concentration to areas of low concentration is called Diffusion. Whereas Osmosis is the process in which water crosses membranes from regions of high water concentration to areas with low water concentration. While molecules in diffusion move down a concentration gradient, molecules during osmosis both move down a concentration gradient as well as across it. Both diffusion, and osmosis are types of passive transport, which do not require help.

2.2. Important factors to Osmosis and Diffusion include Temperature, Concentration and Surface area to volume ratio. Temperature can affect the rate in which a solute dissolves in a solution, higher temperature faster rate of Osmosis. This is caused by the molecules movements being faster in higher temperatures. Concentrations are

The movement of molecules have two forms of transport through the plasma membrane: active transport and passive transport. Active processes require energy, such as ATP, in order for the molecules to be transported. In active transport, the cell administers ATP.i Within passive processes no energy is required and changes n pressure and concentration are the driving forces. Processes such as simple diffusion, facilitated diffusion, osmosis, and filtration are characterized as passive transport, while solute pumps are a form of active transport. Each of these form of transports occur in the cells of all living organisms and are essential to life.