Question 3

How do the Laws of Thermodynamics relate to the biochemical processes that provide energy to living systems? And, what are enzymes, how are they regulated, and how do they control metabolism? [Chapter 6]

Metabolism, Energy, and Life (read pages 87-96)

1. The chemistry of life is organized into metabolic pathways. Summarize what these are, and how they function?
2. How do organisms transform energy?
3. Energy transformations must follow the Laws of Thermodynamics. Describe the first two of these laws and how they relate to organisms.
4. Free energy is what organisms use to maintain life, how is this done so the organism does not reach equilibrium?
5. ATP links exergonic and endergonic chemical reactions. What is the structure of ATP and how does it work?

Enzymes (read pages 96-100)

1. Enzymes are proteins that are catalysts. These molecules run chemical reactions in cells and make it possible for cells to carry out chemical reactions by lowering energy barriers.

2. Enzymes are substrate specific. (Analogy: enzymes are like keys and the substrate is like a lock) Give some examples of enzymes and their substrates.

3. The active site is an enzymes catalytic center.

4. A cell’s physical and chemical environment affects enzyme activity. Make a list of these and describe how they impact the enzymes.

The Control of Metabolism (read pages 101-103)

1. The first enzyme in a metabolic pathway is often an allosteric enzyme. These enzymes have two active sites, one of which acts like a switch to turn the molecule on or off.

2. Enzymes are found is specific places inside a cells

3. Higher levels of organization result in emerging properties. Thus, organization is the key to understanding the chemistry of life.

John C. Murphy	Science
Phone:  (815) 436-3200, ext. 2120
jmurphy@learningcommunity202.org

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