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Organic Compounds in the Body

Sep 4, 2025

Overview

This lecture reviews organic compounds in the body, with a focus on amino acids, proteins, enzymes, and the importance of temperature and pH in enzyme function.

Classes of Organic Compounds

  • Organic compounds contain carbon (C), hydrogen (H), and oxygen (O) chemically bonded together.
  • Main types include carbohydrates (like glucose), fats, and amino acids.
  • Amino acids are unique as they also contain nitrogen (N) in an amino group (NHâ‚‚).

Amino Acids and Proteins

  • There are 21 individual amino acids in the body.
  • Amino acids link together by chemical bonds to form proteins.
  • The two main classes of proteins are structural proteins (hair, collagen, nails) and functional proteins.

Functional Proteins: Enzymes and Hormones

  • Functional proteins include enzymes and hormones.
  • Enzymes are proteins that control all chemical reactions in the body.
  • Each enzyme is specific to one type of chemical reaction.

Protein Structure and Function

  • The sequence and type of amino acids determine the protein's identity.
  • Each amino acid carries an electrical charge, influencing protein folding.
  • The shape (3D structure) of a protein determines its function.
  • Altering the sequence or folding changes function, possibly disabling the enzyme.

Enzyme Activity and Body Conditions

  • Enzymes work optimally at normal body temperature (98.6°F).
  • Fever (high temperature) or hypothermia (low temperature) alters enzyme shape and reduces function.
  • Shape change from heat or pH changes can prevent enzymes from working.

pH and Enzyme Function

  • Body pH must be maintained between 7.35 and 7.45 for optimal enzyme activity.
  • Lower or higher pH alters enzyme shape, disrupting chemical reactions, especially in the brain.
  • Acids or bases (like hair treatments) change pH and thus protein shape.

Key Terms & Definitions

  • Organic Compound — Molecule containing carbon, hydrogen, and oxygen.
  • Amino Acid — Building block of proteins, contains C, H, O, and N.
  • Protein — Chain of amino acids bonded together.
  • Enzyme — Protein that speeds up and controls chemical reactions in the body.
  • pH — Scale measuring acidity/basicity; blood pH must stay between 7.35-7.45.
  • Homeostasis — Maintenance of stable internal body conditions.

Action Items / Next Steps

  • Review the importance of protein structure and enzyme specificity.
  • Memorize the optimal body temperature (98.6°F) and blood pH (7.35-7.45) for enzyme activity.
  • Read more about how temperature and pH affect protein function.