# data[].attributes.headline
Dehami, Pulathi, Sinali, Tharana, Isala, Disala, Modika

# data[].attributes.subject
Dehami, Pulathi, Sinali, Tharana, Isala, Disala, Modika

# data[].attributes.body
Dehami and Pulathi

# data[].attributes.body
Modika

# data[].attributes.body
Tharana and Disala

# data[].attributes.body
Sinali and Isala

# data[].attributes.body
Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.

Dehami

# data[].attributes.body
Dehami

# data[].attributes.body
Active transport is net movement of particles from a region of low concentration to a high concentration.

Tharana

# data[].attributes.body
Tharana

# data[].attributes.attachment_link.title
GCSE Science Revision Biology "Active Transport"

# data[].attributes.body
The factors which affect the rate of diffusion includes -temperature, Diffusion distance, concentration gradient and surface area : volume

Isala

# data[].attributes.body
https://youtu.be/HLdNTvY2UkM

Isala

# data[].attributes.body
Higher the temperature, the more kinetic energy the particles will have, so they will move and collide even more quickly and would diffuse even more quickly!

Sinali

# data[].attributes.body
The diffusion distance is a factor which affects the diffusion rate.If the diffusion distance is high then the diffusion rate decreases, on the other hand if the diffusion distance is low then the diffusion rate increases.

Sinali

# data[].attributes.body
Alveoli is made out of a single-celled wall and the capillaries are also made up of singled cell walls ,thus it decreases the diffusion distance, while increasing the diffusion rate!

Sinali

# data[].attributes.body
Procedure -
Prepare a  2 cm deep layer of agar jelly.
Add potassium permanganate to it.
Then it turns to purple colour.
Next, cut out three cubes of side lengths 2 cm 1 cm and 0.5 cm.
Place each cube in dilute hydrochloric acid and observe the time taken for the jelly to turn colourless.

Observation-
The cube with the largest surface area to volume ratio quickly becomes colourless

Conclusion-
When there is low surface area to volume ratio diffusion is increased. When there is higher surface area to volume ratio diffusion is decreased.

Isala

# data[].attributes.body
-The greater the difference in concentration on either side of the membrane, the faster movement across it will occur

-This is because on the side with the higher concentration, more random collisions against the membrane will occur

Sinali

# data[].attributes.body
-The bigger a cell or structure is, the smaller its surface area to volume ratio is, slowing down the rate at which substances can move across its surface

-Many cells which are adapted for diffusion have increased surface area in some way – e.g. root hair cells in plants (which absorb water and mineral ions) and cells lining the ileum in animals (which absorb the products of digestion)

Isala

# data[].attributes.body
https://youtu.be/qNk3GMAZLm4

Isala

# data[].attributes.attachment_link.title
Factors Affecting the Rate of Diffusion | 9-1 GCSE Biology | OCR, AQA, Edexcel

# data[].attributes.body
For living cells, the precept of the movement down a concentration gradient is the same, but the cell is encircled by a cell membrane, which can constrain the free movement of the molecules.

The cell membrane is somewhat permeable – this implies it enables some molecules to cross easily, but others with difficulty or not at all
The easiest sort of choice is established on the size of the molecules.

Diffusion assists living organisms to:
|Collect many of their requirements.
|Get rid of numerous of their waste products.
|Carry out gas exchange for respiration.

Pulathi

# data[].attributes.body
It is also important to understand that diffusion is quite often how molecules move in and out of our cells through the cell membrane.

For example, the diagram above demonstrate a cell surrounded by nutrients (red dots). We can see that on the left, there are a lot more nutrients outside the cell than inside the cell.

By diffusion, the nutrients will diffuse into the cell (from higher to lower concentration) until the number of nutrients inside and outside the cell are balanced.

Pulathi

# data[].attributes.body
Osmosis is the net movement of water from a region of high water potential to a region of low water potential across a semi permeable membrane.

# data[].attributes.headline
Demonstrating the effect of osmosis on RBCs (Red Blood Cells)

# data[].attributes.subject
Demonstrating the effect of osmosis on RBCs (Red Blood Cells)

# data[].attributes.body
Procedure-
Take 3  boiling tubes and add 1 cm3 of fresh blood sample into each.
Then add 10 cm3 of distilled water into one test tube, 0.85% NaCl into another test tube and 3% of NaCl to the last test tube. Mix them well and keep for 20 minutes.
Then observe under a microscope.

Observation-
-In the first test tube osmosis occurs from outside to inside of thee cells. This causes the RBCs to burst.
-In the second test tube osmosis does not occur because both the solutions have the same water potential. Therefore there is no change in shape in the RBCs
-In the third test tube osmosis occurs from inside to outside. So RBCs shrink.

# data[].attributes.body
https://www.youtube.com/watch?v=fxAxsOa_icE

# data[].attributes.body
https://www.youtube.com/watch?v=xU0u7jpmeP8

Pulathi

# data[].attributes.headline
What Are The Factors That Affect Osmosis 

# data[].attributes.subject
What Are The Factors That Affect Osmosis 

# data[].attributes.body
Factors that are affecting osmosis are temperature , water potential gradient and surface area to volume ratio

# data[].attributes.attachment_caption
in this picture here is an example of osmosis in warmer temperature 

# data[].attributes.body
As you see in the picture warmer the temperature the faster that osmosis occurs .

# data[].attributes.body
-Energy is needed because particles are being moved against a concentration gradient, in the opposite direction from which they would naturally move (by diffusion)

-Examples of active transport include:

*uptake of glucose by epithelial cells in the villi of the small intestine and by kidney tubules in the nephron

*uptake of ions from soil water by root hair cells in plants

Disala

# data[].attributes.body
https://www.youtube.com/watch?v=bQZ0heYYSl0

Disala

# data[].attributes.attachment_link.title
Active transport and end of topic check - GCSE Biology (9-1)

# data[].attributes.body
Surface area will increase the speed of reaction as the greater the surface of the solid reactants, the more particles are required to expose and ‘cover’ the capacity of the solid. Increased surface area results in an increased chance of collisions between reactant particles.

# data[].attributes.body
when the water potential gradient is high the rate of osmosis also high

# data[].attributes.body
https://www.youtube.com/watch?v=qqe2NhQt8bY

# data[].attributes.body
THANK YOU!!
HOPE YOU ALL LEARNED SOMETHING FROM OUR PRESENTATION!