Amino Acid Catabolism
Amino acids contain an element not found in carbohydrates or fatty acids,
namely nitrogen. Where does that nitrogen ultimately come from?
Source of Amino Acids for Catabolism
1) Digestion of Dietary Proteins
Most U.S. adults consume
Structure Based Drug Design
Protein Folding and Stability
How does the linear sequence of amino acids fold into a 3-dimensional structure?
1. What forces a polypeptide to fold?
2. What determines the three-dimensional structure of a protein?
3. What is th
Protein Structure and Function
Proteins are the most important molecules inside every living cell, tissue, organand inside the human body. Proteins do everything: They control our thinking, they
regulate all our physiological reactions, they metabolize ca
The electrons in NADH and FADH2 are ultimately transferred to O2 to make
However, the electrons first go through a series of oxidation-reduction
reactions appropriately called the electron transport chain.
To understand the
The most important proteins are enzymes
Enzymes are proteins that act as catalysts for chemical reactions in living systems.
Oxidation of Glucose
C6H12O6 + 6O2
6CO2 + 6H2O
G = -686 kcal / mole dont need to know number for test. (i.e.
The twenty amino acids found in proteins can be used by enzymes to catalyze reactions.
Example: HIV Protease
1. Acid Catalysis
a. Stabilize oxyanion of carbonyl
b. Protonate the leaving group
2. Base Catalysis
Domains and Protein Evolution
How do we get multi-domain proteins?
Domains evolved first.
e.g. NAD binding domain.
Both enzymes below require NAD therefore have to have some part of protein that
binds NAD. Alcohol dehydrogenase has to bind alcohol and NAD
Degradation of Phenylalanine
Caused by a deficiency of phenylalanine hydroxylase
PKU can also be caused by a deficiency of the reductase.
Phenylalanine hydroxylase is a mixed-function oxidase because one atom of
oxygen is incorporate
Tricarboxylic Acid Cycle
If the end product of glycolysis, pyruvate is oxidized further, the cell could
recover much more energy.
Under aerobic conditions the TCA cycle is used to oxidize pyruvate.
The energy released in the oxidation is stored in the red