Biochemistry and Human Body Orientation: Study Notes

Biochemistry: Organic and Inorganic Compounds

Introduction to Organic and Inorganic Compounds

Biochemistry is the study of the chemical substances and vital processes occurring in living organisms. Compounds in biology are broadly classified as organic (containing carbon and usually hydrogen) and inorganic (generally lacking carbon-hydrogen bonds).

• Organic Compounds: Molecules that contain carbon atoms bonded to hydrogen; typically found in living organisms.

• Inorganic Compounds: Molecules that do not contain carbon-hydrogen bonds; examples include water, salts, acids, and bases.

Key Difference: Organic compounds always contain carbon and hydrogen, while inorganic compounds generally do not.

Main Types of Organic Compounds

• Carbohydrates

  • Definition: Organic molecules made of carbon, hydrogen, and oxygen, typically in a 1:2:1 ratio.

  • Function: Main source of fuel/energy for cells; structural components in plants.

  • Example: Sugars (glucose, fructose), starch, cellulose.

  • General Formula: $C_nH_{2n}O_n$

  • Application: Glucose is used in cellular respiration to produce ATP.

• Lipids

  • Definition: Hydrophobic organic molecules, including fats, oils, and steroids.

  • Function: Long-term energy storage, insulation, cell membrane structure (phospholipids).

  • Example: Triglycerides, phospholipids, cholesterol.

  • Application: Phospholipids form the bilayer of cell membranes.

• Proteins

  • Definition: Complex molecules made of amino acids (contain carbon, hydrogen, oxygen, and nitrogen).

  • Function: Enzymes, structural support, transport, immune response.

  • Example: Hemoglobin, enzymes (amylase), antibodies.

  • Application: Enzymes catalyze biochemical reactions in the body.

• Nucleic Acids

  • Definition: Macromolecules composed of nucleotide chains; contain carbon, hydrogen, oxygen, nitrogen, and phosphorus.

  • Function: Store and transmit genetic information.

  • Example: DNA (deoxyribonucleic acid), RNA (ribonucleic acid).

  • Application: DNA encodes instructions for protein synthesis.

Unit 1: The Human Body: An Orientation

Introduction to Anatomy and Physiology

Anatomy is the study of the structure of body parts and their relationships to one another. Physiology is the study of the function of the body and its parts. Together, they provide a comprehensive understanding of the human body.

• Human Anatomy: Focuses on the form and organization of body structures.

• Human Physiology: Explains how those structures work and interact.

Anatomical Terminology

Precise terminology is essential for clear communication in anatomy and physiology. Anatomical terms describe the location of body parts, their positions relative to each other, and movements.

• Directional Terms: Used to explain where one body part is in relation to another.

• Examples:

  • Superior (cranial): Toward the head or upper part of a structure.

  • Inferior (caudal): Away from the head or toward the lower part of a structure.

  • Anterior (ventral): Toward the front of the body.

  • Posterior (dorsal): Toward the back of the body.

  • Medial: Toward the midline of the body.

  • Lateral: Away from the midline of the body.

  • Proximal: Closer to the origin of the body part or point of attachment.

  • Distal: Farther from the origin of the body part or point of attachment.

Table: Comparison of Organic Compound Types

Type	Elements Present	Main Function	Example
Carbohydrates	C, H, O	Energy source	Glucose, starch
Lipids	C, H, O (less O)	Energy storage, membranes	Triglycerides, phospholipids
Proteins	C, H, O, N	Structure, enzymes	Hemoglobin, enzymes
Nucleic Acids	C, H, O, N, P	Genetic information	DNA, RNA

Summary

• Biochemistry distinguishes between organic and inorganic compounds, with organic compounds being essential for life.

• The four main classes of organic compounds—carbohydrates, lipids, proteins, and nucleic acids—each have unique structures and functions vital to the human body.

• Understanding anatomical terminology is crucial for accurately describing locations and functions within the human body.