AP Biology Chapter 8

Chapter 8
1) What does the second law of transformation means?
It means every energy transfer or transformation increases the entropy of the universe. It’s like when we light a candle, the candle’s burning. The potential energy of candle is losing, but these potential energy changes into some disorder energy go back to universe.
2) What means free energy?
Free energy is the portion of system’s energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell.
3) what’s the name of ATP
Adenosine triphosphate. In the ATP, there are adenine (nitrogenous base), ribose (pentose sugar) and 3 phosphates.

Factors
1) Some metabolic pathways release energy by breakdown complex molecules to simpler compounds; these degradative processes are called catabolic pathways. Anabolic pathway is to consume energy to build complicated molecules from simpler ones. Catabolic pathways store energy and anabolic pathway release those energy.
2) Energy is the capacity to cause change. There are three different types of energy, kinetic energy, potential energy and chemical energy.
3) There’re two laws of transformation. One is the energy of the universe is constant, energy can be transferred and transformed, but it cannot be destroyed or created. It also known as the principle of conservation of energy. Second law is every energy transfer or transformation increases the entropy of the universe.
4) There are 3 things that can affect enzyme activity. They are temperature and PH which we conclude as environment. And cofactors, enzyme inhibitors.
5) In feedback inhibition, a metabolic pathway is switched off by the inhibitory binding of its end product to an enzyme that acts early in the pathway.
Summary:
An organism’s metabolism transforms matter and energy, subject to the laws of thermodynamics. The free-energy change of a reaction tells us whether or not the reaction occurs spontaneously. ATP powers cellular work by coupling exergonic reactions to endergonic reactions. Enzymes speed up metabolic reactions by lowering energy barriers. Regulation of enzyme activity helps control metabolism.

Diagram
This is an ATP cycle picture. It shows how ATP works in cell. Enery released by breakdown tractions (catabolism) in the cell is used to phosphorylate ADP, regenerating ATP. Chemical potential energy stored in ATP drives most cellular work.

Key terms
Metabolism: an emergent property of life that arises from interactions between molecules within the orderly environment of the cell.

Bioenergetics: the study of how energy flows through living organisms.

Chemical energy: the term people use to refer to the potential energy available for release in a chemical reaction.

Thermodynamics: the study of the energy transformations that occur in a collection of matter.

Free energy: is the portion of a system’s energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell.

Exergonic reaction: An exergonic reaction proceeds with a net release of free energy.

Endergonic reaction: An endergonic reaction is one that absorbs free energy from its surroundings.

Active site: only restricted region of enzyme molecule actually binds to the substrate, this region, called the active site.

Competitive inhibitor: they reduce the productivity of enzymes by blocking substrates from entering active sites.

Noncompetitive inhibitor: they do not directly compete with the substrate to bind to the enzyme at the active site; instead they impede enzymatic reactions by binding to another part of the enzyme.

Video: http://www.youtube.com/watch?v=Ki9Tly-A-Rc