1. Fundamentals of Biochemical Reactions Flashcards
What is the free energy equation? (dletaG =…)
ΔG = ΔG°΄ + RTln(Products / Reactants)
Keq = ?
Products over Reactants
deltaG of ATP -> ADP + Pi
-7.3 kcal / mol
deltaG of ATP -> AMP +PPi
-10.9 kcal / mol
deltaG of PPi -> Pi + Pi
-4.0 kcal / mol
Normal pH of blood?
pH = 7.37 - 7.43
Kidneys remove H+ from the blood in the form of ____, and reabsorb _____
H+ removed as NH4+ HCO3- is reabsorbed
What are the 6 enzyme classes?
- Oxidoreductases
- Trasferases
- Isomerases
- Lyases
- Ligases
- Hydrolases
What do Lyases do?
Add or remove atoms to or from a double bond.
What do Lygases do?
Form C-O, C-S, C-N, or C-C bonds with the hydrolysis of ATP
Metal ions that act as cofactors (5)
- Copper (Cu)
- Iron (Fe)
- Magnesium (Mg)
- Selenium (Se)
- Zinc (Zn)
Optimal temperature for most human enzymes
37 degrees celcius
Optimal pH for most human enzymes (range, excludes pepsin)
pH between 4-8
Proton pump inhibitors affect what enzyme?
H+/K+ ATPase
Where is H+/K+ ATPase found, and what is its function?
Found in the Parietal Cells lining the gastric lumen
Pumps H+ into the lumen where it combines with Cl- to become HCL
What disease of the stomach can omeprazole cause, and what are its symptoms?
Hypochlorhydria
Symptoms:
- Reduced absorbtion of nutrients
- Increased sensitivity to food poisioning
- Reduction of gastric enzyme efficiency (especially pepsin, gastric amylase, and gastric lipase)
Binding of Noncompetitive vs Uncompetetive inhibitors
Noncompetetive:
Binds to either the empty Enzyme or the Enzyme-Substrate complex at a site other than the substrate binding site
Uncompetitive:
Binds to only the Enzyme-Substrate complex at a site other than the binding site.
In conceptual terms, what does Km represent?
The amount of substrate, in moles, needed to reach 1/2 Vmax
Characteristics of Competitive inhibition
- No Effect on Vmax
- Increase in Km
- Larger substrate concentration needed to achieve 1/2 Vmax
Characteristics of Noncompetitive inhibition
- Decrease in Vmax
- Km stays the same (the arch moves down)
- Inhibitor effects cannot be overcome by increasing substrate concentration. (Vmax is lowered)
Characteristics of Uncompetitive inhibition
- Km and Vmax are decreased by the same factor, resulting in paralel LB graphs
What is the example given in the slides of a chelating agent?
EDTA: Ethylene Diamine Tetraacetic Acid

Symptoms of lead poisioning?
- Irritability
- Sideroblastic Anemia
- Abdominal pain
- Headaches
What two medications are given for lead poisoning?
How do these work?
- Ca-EDTA
- Dimercoprol
Lead likes EDTA more than Calcium does, so it binds preferetially to the EDTA and forms Pb-EDTA, which is excreted out of the body.
Dimercoprol attaches to the regions of enzymes affected by lead that lead would like to attach to - thus slowing the effects of lead toxicity.
Enzyme Inactivation resembles which type of inhibiiton?
Noncompetitive
Vmax decreases, but Km stays the same.
(There are less enzymes to do the reaction quickly, but affinity stays the same)
What are the four enzymatic markers for MI?
- Troponin (Specifically cTn-I)
- CK-MB (Muscle Brain Creatine Kinase)
- LDH-1 (Lactate Dehydrogenase)
- AST/SGOT1 (Aspartate aminotransferase / Serum Glutamate oxaloacetate transaminase)
* Note: These are presented in order from quickest to present to longest to present.
When is Troponin the most sensitive for an MI?
10-24 hours following MI
Enzyme related to the diagnosis of Bone Disease
Alkaline phosphatase
The reality is a bit more complex than this, but this enzyme is present in bone, and is freed when there is damage. This enzyme is also a marker for liver disease.
Enzymes related to the diagnosis of Obstructive Liver Disease
Sobitol Dehydrogenase
Lactate Dehydrogenase (LDH - 5)
Enzyme related to the diagnosis of Prostatic Cancer
Acid Phosphatase
Enzyme related to the diagnosis of Acute pancreatitis
Amylase / Lipase
Enzymes related to the diagnosis of Muscular Distrophy
Aldolase
Helps convert glucose into energy in muscle cells
ASH
(I have no idea what this is)
Enzyme related to the diagnosis of Liver Disorder
CK-MM
Creatine Kinase - Muscle
WITH ALSO HAVING HIGH
ALT AST
What is the graph shape for Michaelis Menton graphs?
Hyperbolic
What is the graph shape for Allosteric enzyme kinetics?
Sigmoidal