3A_Biomolecules


 * Definition of homeostasis**

Despite the change in external environment of living things or living systems, living systems will maintain equilibrium.

Processes that help maintain equilibrium

-Osmosis --> molecules move from a region of higher water potential to a region of lower water potential across a permeable cell membrane till it reaches equilibrium. -Diffusion -Active transport


 * Communities of organisms depend on the cycling of matter and the flow of energy:**

In a forest, when organic compounds decompose, the nutrients will seep into the soil and be absorbed by living plants. Living plants will then be eaten by herbivores and the energy will be transferred from the plants to the deer. When the deer get eaten by a bear or lion, the energy is again transferred--although of a decreased amount--from the deer to the bear or lion. When the lion or bear dies, the decomposed meat is again decomposed into nutrients and will be absorbed as energy again. Cycling of matter such as Water Cycle and Carbon Cycle are needed for organisms to drink water.

Energy is stored in the form of fats.
 * Energy is stored in the organization of matter:**

Milk contains calcium that is used to build and maintain bones in our body. The proteins in milk can also help build muscles.
 * Living things use matter and energy to build and maintain body structures:**

Wrong statement: Food chains are flows of energy because energy cannot be created or lost. Energy can be lost as heat. Lost: //destroyed

Carbon has a valency of 4 and have the ability to bond with 4 different other molecules to form macromolecules. Carbon can also combine with itself to form double bonds that are very hard to break down. Carbon can create many different structures for different functions. Water can also change in densities when it changes its state of matter. Like ice floats in water, which is very important for life on Earth.//