What is the relationship between SA v ratio and diffusion time?

Explanation: When the cell increases in size, the volume increases faster than the surface area, because volume is cubed where surface area is squared. When there is more volume and less surface area, diffusion takes longer and is less effective.

What is the extent of diffusion?

Extent of the concentration gradient: The greater the difference in concentration, the more rapid the diffusion. The closer the distribution of the material gets to equilibrium, the slower the rate of diffusion becomes.

What does vinegar represent in agar cubes?

As an acid, vinegar has a large number of hydrogen ions. When the hydrogen ions come into contact with the pH indicator, the solution changes color. Fill a clear container with vinegar to a 3-cm depth. Place one agar cube of each size in the vinegar, making sure the blocks are submerged.

What is the principle of agar well diffusion method?

Agar well diffusion method is widely used to evaluate the antimicrobial activity of plants or microbial extracts [32], [33]. Similarly to the procedure used in disk-diffusion method, the agar plate surface is inoculated by spreading a volume of the microbial inoculum over the entire agar surface.

How do you do agar diffusion test?

In this method, the test agar plate is swabbed with a standardized concentration of the test organism, and then paper disks containing a defined antibiotic concentration are placed on the lawn of bacteria. After overnight incubation, the diameter of the zone of inhibited growth around the disk is measured.

Which cell shape is best for diffusion?

For example, the rectangular prism and tree resembled a geometric shape more so than the pineapple and the oval as both of these shapes had faster diffusion rates.

Why does diffusion occur?

Diffusion occurs when particles spread. They move from a region where they are in high concentration to a region where they are in low concentration. Diffusion happens when the particles are free to move.

How does surface area and volume affect diffusion?

When a cell’s surface area increases, the amount of substances diffusing into the cell increases. As volume and surface area increase, the volume increases faster, so much so that the surface area available to allow substances in halves each time the cell volume doubles.

What do the agar cubes represent in this lab?

The agar cubes represent biological cells. The volume of the cube correlates to the cytoplasm and the surface area of each cube to the cell membrane. All living cells are dependent on diffusion processes for survival. These processes transport materials across the cell membrane into and out of the cell.

What is agar diffusion methods?

Agar diffusion. Also known as agar contact method, it is the least-employed one of the techniques. It involves the transfer by diffusion of the antimicrobial agent from the chromatogram (PC or TLC) to an agar plate previously inoculated with the microorganism tested.

How is the rate of diffusion in an agar cell determined?

The rate of diffusion that occurs highly dependent on the size of the cell, specifically their area and their volume. So the experiment is designed to find out the relations between the volume of the agar cell and the rate of diffusion.

How does diffusion occur in a biological cell?

Biological cells can only survive if materials can move in and out of them. In this Snack, you used cubes of agar to visualize how diffusion changes depending on the size of the object taking up the material. Diffusion occurs when molecules in an area of higher concentration move to an area of lower concentration.

Why does the volume of agar cells increase?

This can be justified because when the length of each agar block which has the shape of cube increases, the volume will definitely be larger.

Why is sodium hydroxide diffused into an agar cell?

Hence, when the volume of the agar block gets larger, there will be a greater distance for the sodium hydroxide solution to be diffused into the cell, thus resulting in bigger region not penetrated by the sodium hydroxide solution.