♥ Oh2Bernadette

Sunday, September 28, 2008 { 2:03 PM }

Bio notes .
The notes that i'm posting will be on Chapters 3 and 4 only, cause Chapter 5 and 6 is on X_X , and Chapters 13~15 can be found in archives.
If any of you got important notes that i have not posted, please contact Ophe :D

Chapter 3: Transport.

Diffusion
-The net movement of molecules from a region of higher concentration to a region of lower concentration.
(E.g. Perfume sprayed in the bedroom will eventually be smelt in the living room as the molecules have moves by diffusion.)

Osmosis
-Net movement of water molecules from a solution of higher water potential to a solution of lower water potential across a partially-permeable membrane.
-Has to be about water.
-High to low water potential.
-Partially permeable membrane.

Transport in Plants
-Plants have 2 transport tubes called the xylem and phloem
-Xylem: Transports water & mineral salts from the roots to the leafs.
-Phloem: Transports food.
-Transpiration causes the "pull" that brings/moves the water and mineral salts up the xylem.

Transport in Animals
-Blood travels in blood vessels.
-Blood contains a mixture of red blood cells, white blood cells and platelets suspended in a pale yellow liquid called plasma.
-Plasma: 90% water , transports water, dissolved food, waste products, minerals, antibodies, blood clotting proteins, hormones.
-Platelets: Broken pieces of cells that help to clot blood.
-Red blood cells: Bi-concave
No nucleus
Lives for 120days
Produced in the bone marrow
-White Blood cells:
Phagocyte
Digests bacteria
Lymphocyte
Produces antibodies that stick to bacteria to be
digested by the Phagocyte.

Chapter 4 : Digestion

-Food must be digested as most of the food that we eat consists on large, insoluable molecules such as starch,protein and fat that cannot diffuse through the cell membrane into our blood.
-These large and insoluable molecules have to be broken down into smaller soluble molecules which can then be absorbed into the bloodstream

Digestion: The process of breaking down food into smaller soluble molecules.

Enzymes
-Special types of proteins produced by our body for bringing about or speeding up certain chemical reactions in our body.
Please save this picture then zoom in to view :D. I'm too lazy to continue -.-