Biology
- Cellular Transport
Cellular Transport? Sounds like something off of a Syfi movie, doesn't it? But this ladies and gentlemen, is real!There are four different types of Cellular Transport: diffusion, osmosis, facilitated diffusion, and active transport. The purpose...
- Osmosis Experiment
Here are the photos illustrating the change in flexibility of the potato strips depending on whether water moved in or out by osmosis: ...
- # 26 Surface Area To Volume Ratios, Investigating Diffusion
As the radius of a cell ? from 1x to 3x (left), the surface area ? from 1x to 9x, and the volume ? from 1x to 27x. Source: Nature Education As a cell increases in size, there is less surface area in proportion to its volume. Relatively there...
- # 25 Passive And Active Transport Across Cell Membranes
Substances can enter or leave a cell in 2 ways: 1) Passive a) Simple Diffusion b) Facilitated Diffusion c) Osmosis (water only) 2) Active a) Molecules b) Particles I. Passive transport across cell membranes 1. Diffusion Molecules and ions move...
- #23.2 Cell Membranes And Transport - Syllabus 2016
4.1 Fluid mosaic membranes 4.2 Movement of substances into and out of cells The fluid mosaic model introduced in 1972 describes the way in which biological molecules are arranged to form cell membranes. The model has stood the test of...
Biology
Diffusion and Osmosis
Movement in a and out of cells (some key terms):
Diffusion: the movement of a substance from a high concentration to a lower one as a result of their random movement.
Give an example of diffusion
Osmosis: The diffusion of water molecules from a dilute to a more concentrated solution through a semi-permeable membrane. In effect it is the diffusion of water molecules from a high to a lower concentration. Note that water molecules are small and can pass through the small pores in the partially permeable membrane.
Experiments to illustrate Osmosis
Visking tubing has very small pores and so represents the membrane of a cell. Sugar solution was placed in the Visking tubing and this was sealed at one end. The other end (top) was sealed around a glass tube. The tubing was then placed in a beaker containing distilled water. Record the level of water in the glass tube attached to the Visking tubing every two minutes.
(ref p 24)
Collect and tabulate the data. Then plot a suitable graph to illustrate the data and state and explain any conclusions that you can make.
Potato Experiment:
Cut three equal size strips of potato, measure their length, and place one in distilled water, one in sugar solution and the last one in salt solution. After 30 minutes measure the length of the strips and comment on the flexibility/stiffness of them.
Write a method, tabulate the data and state with an explanation the conclusions that can be made from the data.
- Cellular Transport
Cellular Transport? Sounds like something off of a Syfi movie, doesn't it? But this ladies and gentlemen, is real!There are four different types of Cellular Transport: diffusion, osmosis, facilitated diffusion, and active transport. The purpose...
- Osmosis Experiment
Here are the photos illustrating the change in flexibility of the potato strips depending on whether water moved in or out by osmosis: ...
- # 26 Surface Area To Volume Ratios, Investigating Diffusion
As the radius of a cell ? from 1x to 3x (left), the surface area ? from 1x to 9x, and the volume ? from 1x to 27x. Source: Nature Education As a cell increases in size, there is less surface area in proportion to its volume. Relatively there...
- # 25 Passive And Active Transport Across Cell Membranes
Substances can enter or leave a cell in 2 ways: 1) Passive a) Simple Diffusion b) Facilitated Diffusion c) Osmosis (water only) 2) Active a) Molecules b) Particles I. Passive transport across cell membranes 1. Diffusion Molecules and ions move...
- #23.2 Cell Membranes And Transport - Syllabus 2016
4.1 Fluid mosaic membranes 4.2 Movement of substances into and out of cells The fluid mosaic model introduced in 1972 describes the way in which biological molecules are arranged to form cell membranes. The model has stood the test of...