Fotosintesis

HOW ORGANISMS OBTAIN ENERGY?
Energy is the ability to do work. The flow and transformation of Energy in the universe is studied by Thermodynamics.
Law 1: Conservation of energy. Example: energyfood converts into chemical energy it is not destroyed or disappears.
Law 2: Energy cannot be converted without the loss of usable energy. This loss is called entropy. Example: food chains amount ofenergy decreases from one level of the pyramid to another.
Classification of organisms by the way they obtain energy: autotrophs and heterotrophs.
Metabolism: is all the chemical reactions that takeplace in the cells of an organism.
Metabolic pathway: series of reactions linked together in which the product of one reaction is the substrate of another. Example: digestion, nervous impulses.
A)Catabolic metabolism: release energy by breaking down larger molecules into smaller ones. Example: respiration.
B) Anabolic metabolism: uses the energy released by the catabolic pathways to buildlarger molecules from smaller ones. Example: photosynthesis.
REACTIONS:
PHOTOSYNTHESIS
light
6 CO2 + 6 H2O C6H12O6 + 6 O2RESPIRATION

ATP UNIT OF CELLULAR ENERGY
Energy exists in many forms: light, mechanic, thermal, chemical. In living organisms, chemical energy is stored in biomolecules. Example: chemical energy inmuscles turn to mechanic energy in muscular contraction with the use of ATP (adenosine triphosphate)
ATP structure: most abundant molecule and is made of an adenine base, a ribose sugar and 3 phosphategroups.

ADENOSINE GROUP

ATP function: releases energy when the bond between the second and third phosphate groups is broken, forming Adenosine Diphosphate (ADP) and a free phosphate group.Energy is stored in the bond of the phosphate formed when ADP receives a phosphate and becomes ATP.

PHOTOSYNTHESIS
Phase 1: light dependent reactions, light energy is absorbed and converted into...