Chapter 7

Metabolism

What is Metabolism?
Metabolism is the sum of all of the chemical reactions that take place in an organism.  There are three main objectives for metabolism:…
First Law of Thermodynamics
7.2: First Law of Thermodynamics
The First Law of Thermodynamics states that energy cannot be created or destroyed, only transformed. This can be demonstrated within a classic food…
Second Law of Thermodynamics
7.3: Second Law of Thermodynamics
The Second Law of Thermodynamics states that entropy, or the amount of disorder in a system, increases each time energy is transferred or…
Kinetic Energy
7.4: Kinetic Energy
Kinetic energy is the ability of an object in motion to do work or enact change and it can take on many forms. Water flowing down a waterfall has…
Potential Energy
7.5: Potential Energy
Potential energy is a form of energy that has the potential to do work—to be converted to kinetic energy. Energy can be stored in the form of…
Free Energy
7.6: Free Energy
Free energy—abbreviated as G for the scientist Gibbs who discovered it—is a measurement of useful energy that can be extracted from a…
Activation Energy
7.7: Activation Energy
Activation energy is the minimum amount of energy necessary for a chemical reaction to move forward. The higher the activation energy, the slower the…
Hydrolysis of ATP
7.8: Hydrolysis of ATP
The bonds of adenosine triphosphate (ATP) can be broken through the addition of water, releasing one or two phosphate groups in an exergonic process…
Phosphorylation
7.9: Phosphorylation
Phosphorylation—the addition of a phosphate group—is an important modification for cells to regulate protein function.  The…
Induced-fit Model
7.10: Induced-fit Model
Most chemical reactions in cells require enzymes—biological catalysts that speed up the reaction without being used up or permanently changed.…
Feedback Inhibition
7.11: Feedback Inhibition
Biochemical reactions are occurring constantly in cells, converting starting substances to different products, usually with the help of enzymes that…
Colorimetric Enzyme Assay
7.12: Colorimetric Enzyme Assay
Enzymes are biochemical catalysts that are essential for life. Enzyme assays are used to study the kinetic properties of enzymatic reactions,…
Medicine: Study of In Vivo Glucose Metabolism
7.13: Medicine: Study of In Vivo Glucose Metabolism
Obesity is the most important risk factor in the pathogenesis of type-2 diabetes which is characterized by insulin resistance. In this article,…
Immunology and Infection: A Simple Flow Cytometric Method to Measure Glucose Uptake and Glucose Transporter Expression
7.14: Immunology and Infection: A Simple Flow Cytometric Method to Measure Glucose Uptake and Glucose Transporter Expression
Monocytes function in the innate immune system and when activated, switch from using oxygen to sugar for energy.  In this study, flow cytometry…
Biology: Glucose Uptake Measurement and Response to Insulin Stimulation
7.15: Biology: Glucose Uptake Measurement and Response to Insulin Stimulation
A standard readout to quantify sensitivity to insulin is the rate of sugar uptake. In this article, human cultured muscle cells are stimulated…