4 - Enzymes 1 Flashcards
What are the basics of Enzyme activity?
Enzymes
❖ Because enzymes are selective for a particular substrate, a
cell determines which metabolic pathways will occur by
regulating which enzymes are synthesized.
❖ The molecule at the beginning of a reaction is called a
substrate while the molecule(s) produced is called a
product.
❖ Most biological processes need enzymes in order to occur
at the required rate
❖ Enzymes promote the same reaction over and over without being used up
What are common enzyme types?
Enzymes
What is an Isozyme and what is its importance?
Enzymes
Isozymes are Enzymes that Catalyze the Same Reaction, But Differ in their Primary Structure and/or Subunit Composition.
Densitometric patterns of the LDH isozymes in serum of patients diagnosed with myocardial infarction or acute hepatitis. Isozymes, differing slightly in charge, are separated by electrophoresis on cellulose acetate, visualized using a chromogenic substrate, and quantified by densitometry. Total serum LDH activity is also increased in these patients.
What are the classes of Enzyme cofactors?
Enzymes
Approximately 1/3 of all enzymes contain tightly bound metal ions and are termed metalloenzymes.
Co-enzymes are Types of Co-factors that are Frequent Participants in Metabolic Reactions. (CoA)
Prosthetic Co-factors are all covalently bound. These include Heme, Flavin, and Retinal.
Clinical significance?
Enzymes
Many Coenzymes, Cofactors & Prosthetic Groups Are Derivatives of B Vitamins.
Hydroxyproline formation:
Vitamin deficiency symptoms correlate with their enzyme cofactor function. Scurvy, a vitamin C deficiency, is characterized by bleeding gums, loose teeth, and poor wound healing, all due to weak connective tissue. The collagen in these tissues is deficient in hydroxyproline since vitamin C, ascorbic acid, is required to hydroxylate proline residues in procollagen. Without hydroxyproline, the collagen triple helix denatures at body temperature.
What was the past mechanistic understanding of enzymes?
Enzymes
The cyan box describes allosteric effects.
What is the current mechanistic understanding of enzymes?
Enzymes
Induced fit model
What are common modes of enzyme action?
Enzymes
- Catalysis can occur on a bound substrate without a stable covalent interaction between enzyme and substrate
- In other cases, a covalent intermediate is formed on, and then released from, the enzyme
- In still other cases, all catalytic action takes place on a coenzyme, which forms a covalent bond with the substrate.
What are factors that affect enzymatic reactions?
Enzymes
What are Pro-enzymes and Pro-hormones?
Enzymes
What are the types of enzyme specificity?
Enzymes
- Absolute Specificity: The enzyme is specific for the particular reaction (as opposed to a substrate).
- Group Specificity: The enzyme is specific for a group of molecules with related structure or the enzyme acts only on molecules that have specific functional groups such as amino, phosphate, and methyl groups.
- Linkage Specificity: Enzyme that is specific for a type of chemical bond regardless of the rest of the molecular structure. Enzyme phosphotases dephosphorylates its substrate.
- Stereo-Chemical Specificity: The enzyme is specific for particular steric or optical isomer.
What are some methods to determine enzyme effect?
Enzymes
How do you determine the catalytic activity of an enzyme experimentally?
Enzymes
What is a metabolic pathway in relation to enzymes?
Enzymes
A metabolic pathway is a series of two or more reactions that are coupled together by common intermediates. Since free energy changes are summative for all coupled pathway reactions, the continual addition of fuel to a catabolic pathway (extraction of energy) and the continual removal of pathway products (CO2 and H2O) result in a large negative ΔG.
How are metabolic pathway enzymes regulated?
Enzymes
In case you want more knowledge on enzymes I guess lmao
Enzymes
