Diffusion 30/3/12

1)What is concentration gradient?
When there is a different concentration of molecules in a substance, there will be a concentration gradient. 


2)What is Diffusion?
Diffusion is the movement of molecules from a higher concentrated area to a less concentrated area.


3)Movement of molecules with respect to concentration gradient.
It moves from a higher concentrated area to a less concentrated area.


4)What are the factors that affect Diffusion?
1)The size of the chemical driving force.
2) The surface area of the membrane.
3) The permeability of the membrane.

How diffusion works video journal 30/3/12

What is diffusion?
Diffusion is the process where molecules move from a higher concentrated area to a lower concentrated area.

When will this process stop?
 It stops when all the molecules are evenly distributed.

Do molecules even stop moving?
No they do not, they always move.

What are the factors that determine the rate of diffusion?
It is affected by temperature, size of molecules and the steepness of the concentrated gradient.

Can you name some examples of diffusion in a living organism?
Gaseous exchange between the lungs and the surroundings.
Mineral salts enter the root cell when the root cell takes in water from the soil.

Task 6 23/3/12

TASK 6

Functions of cell parts 

Nucleus: Control all activities in the cell and also contains genetic information passed down from one generation to another.

Nucleur membrane: Regulate in and out movement of only specific substances. It also. In animal and plant cells, it holds the nucleus together and also acts as a security check for the nucleus.

Chromatin: Packs long strands of DNA in Compact form and also strengthens and assists replication and transcription during cell division.

Cytoplasm: Maintains the shape and consistency of the cell and also stores many chemicals that are inevitable for life.

Cell membrane: Controls the movement in and out of the cell and also anchors the cytoskeleton.

Vacuole: Stores food and nutrients in the cell, maintains pH, removes unwanted material in our body and also destroys invading bacteria.

Mitochondria: Produce energy, helps in the building of certain kinds of drought and also stores calcium ions

Chloroplast: Helps the plant to make food.

Cellulose cell wall: Protects the cell, provides support for the cell and is also a filter.  

Task 4&5 23/3/12

TASK 4&5

http://www.enchantedlearning.com/subjects/plants/cell/anatomy.GIF

http://www.enchantedlearning.com/subjects/animals/cell/anatomy.GIF

Task 3 23/3/12

TASK 3

PLANT CELL	ANIMAL CELL
- have cell wall	- does not have cell wall
- have only 1 big vacuole	- have 1 or many small vacuoles
- rectangular in shape	- irregular in shape
- leaves cell contains chloroplast	- all cells do not contain chloroplast
- plant cells are larger in size	- animal cells are smaller in size

Task 2 23/3/12

TASK 2

Similarities between plant and animal cell

-Both have cell membranes

-Both have nucleus

-Both have Mitochondra

-Both have Ribosomes

-Both have Golgi Apparatus

Task 1 23/3/12

Task 1	Task 1
Prokaryote cells	Eukaryotic cells
Smaller cells	Larger cells
Always unicellular	Often multicellular
No nucleus	Have nucleus
DNA is circular	DNA is linear
No cytoskeleton	Have cytoskeleton
Cell division is by binary fission	Cell division is by mitosis
Reproduction is always asexual	Reproduction can be asexual or sexual