3A_Biomolecules

25th March 2010

__HOMEOSTASIS__

Definition: Despite change in external environment, the living system will still be able to maintain the equilibrium.

__Processes:__ - Osmosis - Diffusion - Active transport

1. Define 2. Explain 3. Give example.

//Living organisms obtain and process matter and energy.// - For example, plants photosynthesize to make food.

- In cells, energy is stored in mitochondria (Wrong: Mitochondria use glucose to generate/produce ATP/energy) - Energy is stored in the form of fats.
 * //Energy//** //is stored in the organization of matter.

//Living organisms use matter and energy to build and maintain body structures - Young mammals feed on mother's milk to grow. - Milk contains calcium that is used by the young to build bones. - Proteins help to build muscles or build structure in the body.

//Communities of organisms depend on the cycling of matter and the flow of energy// - Energy can be lost, but cannot be created or destroyed. - Can change from one form to another form, can flow from one system to another system.


 * This balance is achieved through various biogeochemical cycles and the processes of photosynthesis and cellular respiration - //focus is on ENERGY//

// 1. Why is the carbon molecule suitable for life as we know it? - Carbon has a valency of 4, it has four electrons free to bond with other atom, being able to form macromolecule out of other molecules, with different properties and functions. And form bonds with themselves.

2. Why is chemistry of water suitable for life. - All characteristics of water. //