Notes on Organic and Inorganic Compounds – Page by Page

• Page 2 – Organic and Inorganic Compounds: Introduction and Basics

UNIT TITLE: CELL THE BASIS OF LIFE
TITLE OF THE LESSON: ORGANIC AND INORGANIC COMPOUNDS
DURATION: 3 hours

Introduction

• Organic compound: a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen.

• Major organic categories found in all living things: carbohydrates, lipids, proteins, and nucleic acids.

• Inorganic compounds: substances that do not contain both carbon and hydrogen. Many inorganic compounds contain hydrogen (e.g., H2O, HCl).

• Exceptions: Wohler showed exceptions to the simple organic vs inorganic split.

• Covalency of carbon leads to organic compounds typically not forming salts, while inorganic compounds readily form salts.

Objectives

1. Define organic and inorganic compounds.

2. Enumerate the organic and inorganic compounds.

3. Explain the importance of these compounds in the body.

Contents

• Organic compounds: carbohydrates, proteins, fats, nucleic acids, vitamins

• Inorganic compounds: water, minerals

Notes

• Organic vs inorganic classification is foundational but not absolute; some exceptions exist in real biology and chemistry.

Page 3 – Lesson 7: Organic and Inorganic Compounds: Carbohydrates and Proteins Intro

Organic Compounds

• Organic materials serve as an energy source inside cells and are crucial for building tissues and synthesizing hormones and enzymes.

A. Carbohydrates

• Carbohydrates contain carbon, hydrogen, and oxygen in the same ratio as water; general formula is $C<em>n(H</em>2O)_n.$ (Note: Some source texts show variations; the general concept is carbon plus water units in a repeating pattern.)

• Simple carbohydrates are sugars. Primary energy source for cellular activities; when they react with oxygen, energy is released for cellular work.

• They can be converted to other cellular molecules for various physiological functions (example: glycogen and fat as storage products).

• Classification by sugar units:

  • Monosaccharides:

  • Simplest sugars with one sugar unit; typically 3–7 carbon atoms.

  • Examples and formulas (as printed in source):

    • Triose (3C): glycerose, $C<em>3H</em>6O_3$

    • Tetrose (4C): threose, $C<em>4H</em>8O_4$

    • Pentose (5C): ribose, $C<em>5H</em>{10}O_5?$

    • Hexose (6C): glucose, fructose, galactose, mannose, $C<em>6H</em>{12}O_6$

    • Heptose (7C): mannoheptose, $C<em>7H</em>{14}O_7?$

  • The most physiologically important monosaccharides are hexoses: glucose, fructose, galactose. Glucose is the most physiologically significant as the primary sugar transported by blood cells; hence called blood sugar.

  • Fructose and galactose are converted to glucose before cellular use.

  • Disaccharides:

  • Composed of two monosaccharides.

  • Common examples:

    • Sucrose (glucose + fructose): common table sugar; derived from beets or sugar cane; high intake linked to diabetes and heart disease when consumed in excess.

    • Lactose (glucose + galactose): sugar found in milk; normally hydrolyzed in the digestive tract to monosaccharides; lactose intolerance can lead to undernutrition and severe diarrhea in some individuals.

    • Maltose (glucose + glucose): found in fruit juices and sprouting grains.

  • Polysaccharides:

  • Large polymers of monosaccharide units.

  • Examples: glycogen (storage form of glucose in animals), starch (storage form in plants), cellulose (structural plant fiber).

B. Proteins

• Elements: carbon, hydrogen, oxygen, nitrogen; some contain sulfur and phosphorus.

• Roles: structural components, regulate cellular chemical activity, act as enzymes (catalysts), support muscle contraction, repair damaged tissues, antibodies against diseases.

• Proteins are made of amino acids linked by peptide bonds (-CO-NH-).

• Amino acids types:

  • Non-essential amino acids: synthesized in the body (examples in source include alanine, serine, glycine, aspartic acid, glutamic acid, proline, hydroxyproline, citrulline, cysteine, tyrosine, norleucine, hydroxyglutamic acid).

  • Essential amino acids: must be supplied in the diet (examples: histidine, isoleucine, leucine, lysine, methionine, arginine, phenylalanine, threonine, valine, tryptophan).

• Most animal proteins are complete (contain all essential amino acids); plant proteins are generally incomplete.

• Protein structure: amino acids linked by peptide bonds (-CO-NH-).

• Protein turnover: about $3.5\%$ of total body protein is destroyed and resynthesized; dietary protein is essential to replace ongoing breakdown.

• Protein functions (types by function):
  1) Structural Protein – provides mechanical shape and support; examples: fibroin (silk), collagen, elastin, keratin, dentine.
  2) Storage Protein – stores amino acids; examples: ovalbumin (egg white), casein (milk), seed proteins in plants.
  3) Transport Protein – carries substances; examples: hemoglobin (binds and transports oxygen), serum albumin (transports fatty acids), membrane transport proteins.
  4) Receptor Protein – cell response to chemical stimuli (membrane receptors in nerve cells).
  5) Hormonal Proteins – coordinate activities, e.g., insulin and glucagon regulate blood glucose; prolactin stimulates milk production; growth hormone (GH) affects growth and metabolism.
  6) Contractile Protein – enable muscle movement (actin and myosin).
  7) Defensive Protein – antibodies protect against disease (immunoglobulins).
  8) Enzymatic Protein – catalyze chemical reactions (example: digestive enzymes like ptyalin for carbohydrates and trypsin for proteins).

C. Nucleic Acids (the non-protein portion of nucleoproteins)

• Macromolecules in cells; store, transmit, and translate genetic information.

Page 4 – Carbohydrates Continued and Nucleic Acids Intro

Carbohydrates continued

• Disaccharides and polysaccharides (continued from Page 3) are reiterated here for emphasis on digestion and energy storage roles.

Proteins (continued)

• Emphasis on the chemical nature: amino acids, peptide bonds, and the diversity of functions across structural, storage, transport, receptor, hormonal, contractile, defensive, and enzymatic roles.

Nucleic Acids: Introduction

• Nucleic acids are essential macromolecules involved in genetic information storage and expression.

Page 5 – Nucleic Acids and Protein Diversity

Nucleic Acids (the non-protein portion of nucleoproteins)

• Key properties (as listed):

  1. Insoluble in alcohol; soluble in cold water; readily dissolves in hot water; forms alkali salts with dilute alkalis.

  2. Precipitated by HCl and by excess acetic acid.

  3. High molecular weight range: $1{,}286$ to $3{,}000{,}000$.

  4. Two types: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).

  5. Element composition: carbon, hydrogen, oxygen, nitrogen (roughly $15-16\%$), phosphorus (roughly $9-10\%$).

  6. Hydrolysis yields nucleotides; further hydrolysis yields phosphoric acid and nucleosides (sugar with a nitrogenous base).

  • Base types: Purines: adenine (A) and guanine (G); Pyrimidines: cytosine (C), thymine (T), uracil (U).

DNA Strands

• DNA is the chromosomal material containing genetic information.

• Base sequences form a template or mold: A-T-G-C; complementary partner is T-A-C-G.

• DNA is a double helix (spiral, twisted ladder).

• Adenine pairs with thymine; guanine pairs with cytosine.

Page 6 – DNA Structure and RNA Overview

DNA Structure Details

• The sides of the ladder are sugar-phosphate backbones; rungs are nitrogen bases connected by hydrogen bonds.

• In addition to hydrogen bonds, hydrophobic interactions among purine and pyrimidine bases contribute to the stability of the double-stranded form.

• Denaturation factors include acids, alkalis, heat, low ionic strength, urea, and formamide.

Ribonucleic Acid (RNA)

• RNA is long strings of single-stranded ribonucleotides and is shorter than DNA but more abundant.

• RNA can be hydrolyzed by weak alkali to form an intermediate phosphate triester.

• Types of RNA:
  1) Messenger RNA (mRNA) – serves as template RNA for translating genetic information into protein sequences; used by ribosomes for translation.
  2) Transfer RNA (tRNA) – soluble RNA; ~70–90 ribonucleotides; 70–90 nucleotides with molecular weight ~$23{,}000-30{,}000$; carries activated amino acids to ribosomes; anticodon pairs with codon on mRNA.
  3) Ribosomal RNA (rRNA) – major component of ribosomes; ~65% of ribosome weight; stable; essential for ribosome structure and biosynthesis.

Lipids

• Lipids are carbon-containing compounds that do not dissolve readily in water; essential elements: C, H, O with less oxygen than carbohydrates; lipids are heterogeneous.

• Main groups: A. Fats – triglycerides of fatty acids and glycerol; can be saturated or unsaturated.

  • Saturated fats have no C=C bonds; typical of animal fats; excess linked to cholesterol and cardiovascular disease.

  • Unsaturated fats contain double bonds; typical of vegetable fats; generally healthier.
    B. Phospholipids – similar to fats but with a phosphate or nitrogen containing group attached to glycerol; essential components of cell membranes.
    C. Steroids – interconnected carbon rings; absorbed intact or with slight modification; examples: testosterone, estrogen.

Vitamins

• Vitamins are organic substances in small amounts essential for growth and metabolism; most come from diet; deficiency or excess can cause disease.

• Classification: A. Fat-soluble vitamins

  • Readily soluble in fats and oils.

  • Vitamin A: formed in liver from carotenoids; roles in bone/teeth growth, epithelial tissues, rhodopsin synthesis in retina.

  • Vitamin D: anti-ricketic; includes D2 (ergosterol irradiation) and D3 (calciferol); sources include cod liver oil; synthesized in skin via UV light; supports calcium/phosphorus absorption and bone development; deficiency linked to rickets in children.

  • Vitamin D also found in leafy greens, oils, unmilled cereals, corn, nuts, eggs; involved in growth and hormone/cholesterol interactions; deficiency linked to cystic fibrosis and premature aging.

  • Vitamin K: found in liver, spinach, cauliflower, cabbage; synthesized by gut bacteria; necessary for prothrombin synthesis; newborns may have hemorrhagic issues due to delayed gut flora.
    B. Water-soluble vitamins (B complex, plus C)

  • Water-soluble vitamins are listed here with their roles and deficiencies (without repeating the entire list verbatim): Thiamine (B1) – glucose and pyruvic acid metabolism; beriberi; Riboflavin (B2) – metabolism of all foods; glossitis, cheilosis, dermatitis; Niacin (B3) – coenzyme in energy release; Pellagra symptoms; Pyridoxine (B6) – RBC formation, nervous system; Cyanocobalamine (B12) – DNA synthesis, hematopoietic tissue; Ascorbic Acid (Vitamin C) – collagen and dentine formation, iron absorption; deficiency scurvy with bleeding gums and poor wound healing.

• Note: Some vitamin naming in source text contains historical mismatches (eg, Thiamine labeled as B2). Treat the section as presented in the source.

Page 7 – RNA Details and Lipids Continued

Ribonucleic Acid (RNA) – Recap

• RNA types include mRNA, tRNA, rRNA with roles as described on Page 6.

• RNA structure: single-stranded polymers, shorter and more abundant than DNA in cells.

DNA and RNA at a Glance

• DNA stores genetic information; RNA translates and expresses genes.

Lipids – Recap

• Lipids are nonpolar, not water-soluble, and include fats, phospholipids, and steroids.

Page 8 – Vitamins and Water Solubility; Fatty Acids

Fat-Soluble Vitamins (Recap)

• A, D, K (and sometimes E) are fat-soluble; absorption requires fats; storage can occur in body tissues.

Water-Soluble Vitamins (Recap)

• B vitamins and vitamin C are water-soluble; excess is typically excreted; toxicity less common than with fat-soluble vitamins but can occur.

Water and Mineral Essentials

• Minerals exist as salts or bound to proteins, carbohydrates, or lipids; ions play essential roles in bodily functions.

Page 9 – Vitamins Details and Pellagra

Vitamin Details

• Thiamine (B1) – role in carbohydrate metabolism; deficiency: beriberi (nervous system and heart involvement).

• Riboflavin (B2) – role in energy metabolism; deficiency: glossitis, cheilosis, dermatitis.

• Niacin (B3) – role in energy enzymes; Pellagra caused by niacin deficiency; symptoms include fatigue, dermatitis, diarrhea, dementia; sometimes summarized as the 3 D’s.

• Pyridoxine (B6) – role in nutrient utilization, RBC formation, nervous system; deficiency causes skin disorders, anemia, convulsions.

• Cyanocobalamin (B12) – essential for DNA synthesis; needed for rapidly dividing tissues like hematopoietic tissue; intrinsic factor may be deficient in pernicious anemia; injections of B12 can correct.

• Ascorbic Acid (Vitamin C) – necessary for collagen, dentine, cartilage, bone formation; enhances iron absorption; deficiency leads to infection susceptibility, poor wound healing, growth retardation; scurvy.

Page 10 – Water Solubility, Diseases, and Nutrient Roles

Water-Soluble Vitamin Summary

• Included are B complex vitamins and Vitamin C; roles in metabolism, RBC formation, nervous system function, and connective tissue health.

• Deficiency diseases discussed: beriberi (B1), pellagra (B3), scurvy (C), and pernicious anemia (B12).

Page 11 – Inorganic Compounds: Minerals and Table of Elements

Inorganic Compounds: Minerals and Water

• Inorganic compounds include mineral elements and water.

• Minerals exist as salts or bound to proteins, carbohydrates, or lipids; essential for proper bodily function.

Table of Elements that Make Up the Human Body (Selected Elements)

• Oxygen (O): 65%; function: required for cellular respiration; present in most organic compounds; component of water.

• Carbon (C): 18%; forms backbone of organic molecules; can form four bonds with other atoms.

• Hydrogen (H): 10%; present in most organic compounds; component of water.

• Nitrogen (N): 3%; components of all proteins and nucleic acids.

• Calcium (Ca): 1.5%; structural component of bones and teeth; important in muscle contraction, nerve conduction, blood clotting.

• Phosphorus (P): 1%; component of nucleic acids; structural component of bones; important in energy transfer.

• Potassium (K): 0.4%; principal intracellular cation; important in nerve function; affects muscle contraction.

• Sulfur (S): 0.3%; component of most proteins.

• Sodium (Na): 0.2%; principal extracellular cation; essential for fluid balance and nerve conduction.

• Magnesium (Mg): 0.1%; needed in blood and tissues; component of many enzyme systems.

• Chlorine (Cl): 0.1%; principal extracellular anion; important in fluid balance.

Iron (Fe): Trace; component of hemoglobin and myoglobin and certain enzymes.
Iodine (I): Trace; components of thyroid hormones.

Page 12 – Water as a Fundamental Molecule

Water

• Essential constituent of tissues and constitutes about $\frac{2}{3}$ of body weight; in tissues as well as cells.

• Water is the main vehicle for all physiological activities necessary for life.

• On land, life relies on water stored in organisms; typical body water content is $60-70\%$ of body weight.

• Solvent power: high ionizing power; many substances dissolve in water.

• High specific heat: substantial heat capacity; metabolism heat causes only small temperature changes in cells.

• High heat conduction: heat from the cell can transfer to body fluids and then to the skin with limited temperature rise.

• Latent heat of vaporization is high: evaporation of sweat removes large amounts of heat.

• Water has high surface tension; its surface tension can be lowered by various substances, allowing interactions between immiscible liquids.

Notes

• The transcript contains several typographical inconsistencies (example: mislabeling of vitamin B types). The key concepts and relationships are preserved for study purposes, but consult authoritative sources for precise chemical formulas where needed.