Aryl Diazonium Ion Formation and Stability

Diazonium Ion Synthesis and Stability Comparison

The synthesis of an aryl diazonium ion begins with an aniline ({{c1::Ar–NH₂}}), which may possess substituents such as a tert-butyl group. This transformation is achieved via N-nitrosylation/diazotization, typically employing NaNO₂, HCl, H₂O at approximately 0 °C.

Reaction Mechanism and Intermediate

This process first yields an N-nitrosamine intermediate, which subsequently decomposes to form the desired aryl diazonium ion ({{c1::Ar–N₂⁺}

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Biochemistry Essentials: Protein Folding, Hemoglobin, and Glycan Structure

Protein Structure and Function Fundamentals

Proteins are at the center of all biological processes. They catalyze reactions, regulate pathways, transport molecules, and form most of the structural framework of cells.

Core Principle: Structure → Function.

Historical Milestones in Protein Science

  • Hsien Wu (1931): Showed that denaturation destroys non-covalent interactions, leading to unfolding and loss of function.
  • Bernal & Hodgkin (1934): X-ray diffraction of pepsin revealed that proteins are ordered,
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The Core Biomolecules: Carbohydrates, Proteins, and More

Carbohydrates

Definition

Optically active polyhydroxy aldehydes or ketones, or compounds that yield these upon hydrolysis.

General Formula and Name Origin

General Formula: Cₓ(H₂O)ᵧ

Name Origin: The name comes from “carbo” (meaning carbon) and “hydrate” (meaning water).

Classification of Carbohydrates

TypeDefinitionExamples
MonosaccharidesCannot be hydrolyzed further into simpler units.Glucose, Fructose, Ribose
OligosaccharidesYield 2–10 monosaccharide units upon hydrolysis.Disaccharides: Sucrose,
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Cellular Metabolism: Energy, Lipid Synthesis, and Gene Regulation

Fatty Acid Oxidation

Fatty acids carry more energy per carbon because they are more reduced. They also carry less water along because they are nonpolar. In contrast, glucose and glycogen are for short-term energy needs and quick delivery, with fat stored in adipose tissue.

Lipids are transported in the blood as chylomicrons. Unsaturated fatty acids have a bent structure.

Glycerol Activation

  • Glycerol kinase activates glycerol at the expense of ATP.
  • Subsequent reactions recover more than enough ATP to
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Human Metabolism Essentials: Pathways & Disorders

Carbohydrate Metabolism Fundamentals

Glycolysis: Key Outputs

  • Products: 2 Pyruvate, 2 ATP, 2 NADH

Carbohydrate Classification

  • Monosaccharides: Glucose, Fructose, Galactose
  • Disaccharides:
    • Lactose (Glucose + Galactose)
    • Sucrose (Glucose + Fructose)
  • Polysaccharides: Glycogen, Starch

Glycosylation vs. Glycation

  • Glycosylation: Enzymes add carbohydrates to proteins.
  • Glycation: Non-enzymatic attachment of glucose to proteins (e.g., HbA1c = glycated hemoglobin).

Blood Glucose Regulation

  • Low Blood Glucose: Glucagon activates
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Glycogen Metabolism: Synthesis and Breakdown

Glycogen Metabolism: Synthesis and Breakdown

Glycogen, the storage form of glucose, is a branched polymer crucial for energy regulation in the body. Both glycogen and starch store glucose for future metabolic needs. In animals, glycogen provides a rapidly accessible source of glucose, especially for tissues like the brain and red blood cells, which heavily rely on glucose as their primary energy source. While other tissues can utilize fatty acids or amino acids for energy, a constant supply of glucose

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