3A_Biomolecules

Lesson: 25 March

Homeostasis Define homeostasis: Ability of living systems to maintain equilibrium despite the change in external environment

Processes:Osmosis- water molecule moving from a higher water potential to a lower water potential through a partially permeable cell membraneActive transportDiffusion Definition, Explain the processes, give example in living systemUnderstanding cell membrane allows you to understand the processes.

**ENERGY, MATTER & ORGANISATION -** BIOMOLECULES //** Living systems are complex and highly organized, and they require matter and energy to maintain this organization. **//

Human body stores energy in fats. Mitochondria generates ATP from glucose.
 * Energy is stored in the organisation of matter.**

Milk is fed on by young mammals for: Calcium Protein helps to build muscles/ structures in body.
 * Living organisms use matter and energy to build and maintain body structure**


 * Living organisms obtain and process matter and energy

The structure of a molecule always dictates its function.

If molecule has a double bond e.g. fats, then it is more stable and harder to break down.

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**

Flow of energy: Energy can be lost (e.g. heat energy to surroundings), but it cannot be destroyed. Energy can change from one form to another, can flow from one system to another, can flow from one organism to another (e.g. eating beef from cow converts to muscles for ourselves).
 * The constant flow of energy and cycling of matter in the biosphere leads to a balanced or steady state.**

Questions: Why is carbon molecule suitable for life as we know it? Carbon has a valency of 4, so it has 4 free electrons to bond with 4 other atoms, hence forming a macro-molecule out of one atom, with different properties and functions. All organic molecules (e.g. lipids, proteins) are carbon-based.

Why is water suitable for life as we know it? Water has its own properties

What is carbohydrate? Structure -> function? Forms it takes? How are the forms made?