Overview
This lecture introduces biochemistry by comparing living cells to factories, and explains how life's basic components and processes work together to sustain and reproduce life.
Life's Common Characteristics
- All life forms use similar rules, materials, and machinery to survive and reproduce.
- Each organism aims to perpetuate its existence.
- Life cycles start with single cells, such as eggs, acorns, or spores.
The Cell as a Factory Analogy
- The cell is compared to a factory with robots that maintain operations and replicate the factory.
- Cells need instructions, raw materials, energy, regulation, and currency for functioning.
- The factory's high-security office represents the nucleus, storing DNA blueprints.
Key Cellular Components and Functions
- Nucleus: Stores genetic information as DNA.
- RNA: Photocopies of DNA instructions used in protein synthesis.
- Proteins: Main machinery (robots) of the cell, built from amino acids.
- Vitamins and Minerals: Used as special tools by proteins.
- Lipids (Fats): Make up cell membranes and internal barriers.
- Sugars: Primary energy source; fats and proteins can also be used for energy in scarcity.
- Membrane Proteins: Form portals to control transport of materials and information.
Molecular Currency and Energy Transfer
- Chemical currencies like electrons, protons, oxygen, and phosphate enable protein activities.
- These currencies are stored safely in molecular carriers.
Biochemical Responses and Adaptations
- Excess fuel is stored as glycogen or fat; shortages trigger use of reserves.
- The immune system responds to invaders like viruses and bacteria.
- Nerve responses protect from harm.
- Shared designs across species allow biochemists to study diverse organisms together.
Key Terms & Definitions
- Biochemistry — Study of the chemical processes in living organisms.
- Nucleus — Organelle storing genetic information (DNA).
- DNA — Blueprint for all cellular functions and replication.
- RNA — Copy of genetic instructions for protein synthesis.
- Proteins — Workhorses (machinery) of the cell, built from amino acids.
- Lipids — Fats forming cell membranes and barriers.
- Glycogen — Storage form of excess sugars in the body.
Action Items / Next Steps
- Review the factory analogy and relate each cellular component to its real structure and function.
- Prepare for discussion on specific biochemical pathways and energy transfer in the next lecture.