All biochemical and cellular processes obey the laws of chemistry and physics
Biochemistry is not a special case. Therefore, in studying biochemistry, it is
necessary to consider the relevant laws that control possible reactions.
Activity 3.3.1: Medical History Visit #2
On the last visit, it was dete
Activity 3.3.1: Gasping For Air
Why can the human body last for only a few minutes without oxygen, yet can survive
for days without food or water? Remember the Rules of Three that we discussed at
the beginning of Unit 3. The body can last thr
Regulation of Enzymes
Control of any metabolic process depends on control of the enzymes responsible for
mediating the reactions involved in the pathway. Because regulating metabolic
pathways is critically important for living organisms, the ability to re
Examples of Protein Structures
Proteins fall into three general classes, based on their overall three-dimensional
structure and on their functional role: fibrous, membrane, and globular.
Fibrous proteins tend to be long, nar
Enzymes function by a wide variety of mechanisms. We will cover a few examples to
illustrate the means that enzymes use to catalyze reactions.
Peptide bond hydrolysis is a very common process. A wide variety of enzymes c
Nucleotides and Nucleic Acids
Nucleotides have a wide variety of functions. One major function is to provide the
thermodynamic driving force for a number of chemical reactions. This is especially
well-known for ATP, but GTP is also used for a variety of r
Vitamins and Coenzymes
Vitamins are compounds that are required in the diet, either because the organism
cannot synthesize them, or because the rate of usage by the organism typically
exceeds the rate of synthesis of the compound. In nearly all cases, onl
Why inhibit enzymes?
Enzyme inhibition is a common physiological process. Some aspects are fairly
obvious: in tissues that synthesize proteases, inhibitors are necessary to prevent
inappropriate proteolysis. A numbe
Introduction to Enzyme kinetics
Why study kinetics?
Kinetic information is useful for examining possible mechanisms for the
reaction. This is true for all types of reactions; kinetic principles are used to
understand both catalyzed and non-catalyzed react
Introduction to Enzymes
Open a can of soda. Breathe out. In both cases, a reaction occurs: the conversion of
carbonic acid to carbon dioxide and water.
In the case of the soda, the reaction occurs spontaneously and relatively slowly
Introduction to Protein Structure
Proteins are large heteropolymers usually comprised of 50 2500 monomer units,
although larger proteins are observed7. The monomer units of proteins are amino
acids. The primary structure is the sequence of monomer units i
The Structure of Water
Water is unusual
As discussed in more detail below, water2 molecules form strong intermolecular
interactions with one another. These interactions are actually very complex and are
not fully understood, and, as a result, computer sim
Proteins are not extended polypeptide chains. Instead, most proteins form compact
folded three-dimensional arrangements, with well-defined, specific structures.
Several types of non-covalent forces help maintain the folded structure.
1. Amino acids can be metabolized to produce energy. This is especially
important during fasting, when the breakdown of muscle protein is a major
2. Some amino acids act as neurotransmitters, and some act as st
Structure Determination and Sequence Analysis
Essentially all of the experimentally determined three-dimensional protein
structures have been solved by one of two methods: X-ray diffraction and Nuclear
Magnetic Resonance. Each method has advantages and di
Project 3.2.4: The Amylase
In Project 3.2.2 or Project 3.2.3, you investigated the basic structure of the digestive
system as well as the importance of enzymes in the chemical breakdown of food.
Our diet supplies us with the raw