Chapter eight: introduction of metabolism

An enzyme can convert one or more product molecules. The enzyme shown here converts two substrate molecules to two product molecules.

Main questions:
1. Most cells cannot harness to perform work because?
A: heat can never be used to do work.
2. If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to?
A: add more of the enzyme.
3. Some bacteria are metabolically active in hot springs because?
A: their enzymes have high optimal temperatures.

Main Facts:
1. Energy can be transferred and transformed, but it cannot be created or destroyed.
2. There are three forms of energy: Kinetic, Potential, and Activation energy.
3. Every energy transfer or transformation increases the entropy of the universe.
4. For a process to occur spontaneously, it must increase the entropy of the universe.
5. ATP hydrolysis in several ways to perform the three types of cellular work-chemical, transport, and mechanical.

Summary:

Key terms:
1. Allosteric regulation: is the term used to describe any case in which a protein's function at one site is affected by thebinding of a regulatory molecule to a separate site.

2. Competitive inhibitors: A substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics.

3. Noncompetitive inhibitors: A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing the enzyme's shape so that the active site no longer functions effectively.

4. Feedback inhibition: A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.

5. Activation energy: The amount of energy that reactants must absorb before a chemical reaction will start.

6. Enzyme: A macromolecule serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction.

7. Catalyst: A chemical agent that increases the rate of a reaction without being consumed by the reaction.

8. Phosphorylated: Referring to a molecule that is covalently bonded to a phosphate group.

9.Exergonic reaction: A spontaneous chemical reaction, in which there is a net release of free energy.

10. Free energy: The portion of a biological system's energy that can perform work when temperature and pressure are uniform throughout the system.

Video: http://www.youtube.com/watch?v=VbIaK6PLrRM&feature=related