3A_Biomolecules

Homeostasis
Definition: Despite a change in the external environment, the internal environment will still maintain an equilibrium. key words: maintaining equilibrium living systems changing environments

Processes that help maintain the equilibrium: Osmosis: the net movement of water molecules move from higher water potential to lower water potential across a semi-permeable membrane to reach an equilibrium. Diffusion Active Transport Passive Transport

In order to understand the processes, we learn about cells: The basic building blocks of living things organelles: - nucleus (nucleolus, nucleus pores) - mitochondria - smooth endoplasmic reticulum - rough endoplasmic reticulum - golgi apparatus - cell membrane

Universal Statements: Examples: (in-class activity)
 * **Energy** is stored in the organization of matter : //we store extra, unused energy in our bodies as fats **energy is stored in the form of fats, which comes from the food that we eat, fatty acids-> lipids. mitochondria uses glucose to generate energy by producing ATP** //
 * Living organisms use matter and energy to build and maintain body structures **we drink milk, which contains calcium, which is used to build bones, teeth, etc. It also contains proteins, which help to build muscles in the body.**
 * Living organisms obtain and process matter and energy
 * The structure of a molecule always dictates its function: //different cell types in the human body have different structures/shapes due to their different functions. For example, our red blood cells lack a nucleus and many other organelles, as they (the organelles) are not needed required to carry oxygen (their purpose)//
 * The structure and function of biological living systems obeys the laws of thermodynamics.
 * Communities of organisms depend on the cycling of matter and the flow of energy **note: not the food chain. Energy CAN be lost- as heat. It cannot be created, or //destroyed//. Energy can flow from one system/organism to another.**
 * The constant flow of energy and cycling of matter in the biosphere leads to a balanced or steady state: //the water cycle, carbon cycle **:D** //

//(note: italics- my answers; bold- answers discussed in class; normal- original question/statement)//

Boils down to: This balance is achieved through various biogeochemical cycles and the processes of photosynthesis and cellular respiration - //focus is on ENERGY//
 * 1) Are we just chemicals?
 * 2) Are we what we eat?
 * 3) **Why is the carbon molecule suitable for life as we know it?**
 * 4) **Why is the chemistry of water suitable for life?**

Carbon has a valency of four, so it has 4 free electrons to bond with other molecules, allowing it to become many different macromolecules with many different properties and functions. It also has the ability to bond with itself (unlike water etc.) (Fats are so stable due to carbon.)

Water: all the characteristics in the powerpoint.

(definition, explain, example)

tomorrow (1 block): Carbohydrates, proteins, lipids. Should be able to answer the 'you will need to' s. with notes from biowikispace and biozone.