Chow, Kit Mei
In chain of transformations beginning at the dawn of the universe, unclear fusion of hydrogen in the Sun releases potential energy which was created at the time of the Big Bang. Any living organism relies on an external source of energy, radiation from the Sun in the case of green plants; chemical energy in some form in the case of animals, to be able to grow and reproduce. Energy: as it pertains to an ecosystem; it’s an attribute of objects and system that is conserved in nature and as a capacity to do work.
The first law of thermodynamics states that an energy cannot be created or destroyed. Sunlight, motion, and heat are an unchanging amount of energy in the universe that is distributed. Energy can be converted from one form to different forms, but the total amount of energy in the universe is constant. Second law of thermodynamics is an expression of the universal law of increasing entropy, the entropy of an isolated system which is not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.
Activation energy is the minimum amount of energy that will get a chemical reaction to occur; enzymes lower it in metabolic reactions. Some reactions require a lot of activation energy, others do not.
Concentration gradient is a difference in the number per unit volume of molecules or ions between adjoining regions. Molecules tend to move down their concentration gradient-from a region of higher concentration to one of lower concentration. Concentration diffusion the net transport of molecules or ions from a region of higher concentration to one of lower concentration; it is gradual mixing of material by random molecular motion.
Passive transport is moving biochemical and other atomic or molecular substances across the cell membrane, through a channel inside a transport protein. The four main kinds of passive transport are diffusion, facilitated diffusion,...