Overview
The lecture provides a summary of key biology topics, including cell characteristics, movement of molecules, biological molecules, enzymes, and animal nutrition.
Chapter 1: Characteristics and Cells
- Living things share characteristics such as movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition.
- Cells are the basic units of life, with structures like the nucleus, cytoplasm, cell membrane, cell wall (plants), and chloroplasts (plants).
- Differences exist between plant and animal cells in structure and function.
Chapter 2: Movement of Molecules
- Diffusion is the passive movement of molecules from high to low concentration.
- Osmosis is the movement of water across a selectively permeable membrane from dilute to concentrated solutions.
- Active transport moves molecules against the concentration gradient using energy.
Chapter 3: Biological Molecules
- Carbohydrates, proteins, and lipids are the main types of biological molecules.
- Enzymes, antibodies, and some hormones are examples of proteins.
- Tests exist to identify each biological molecule, such as the Benedict's test for sugars.
Chapter 4: Enzymes
- Enzymes are biological catalysts that speed up chemical reactions without being consumed.
- Enzyme activity is affected by temperature and pH, with optimal conditions for each enzyme.
- Substrate specificity means enzymes only act on specific molecules.
Chapter 6: Animal Nutrition
- Nutrition involves ingestion, digestion, absorption, and assimilation of food.
- The digestive system includes organs such as the mouth, esophagus, stomach, intestines, and associated glands.
- Enzymes break down food into smaller molecules for absorption.
Key Terms & Definitions
- Diffusion — movement of molecules from an area of high concentration to low concentration.
- Osmosis — movement of water through a semipermeable membrane from low to high solute concentration.
- Active transport — movement of substances against a concentration gradient using energy.
- Enzyme — a protein that acts as a biological catalyst to speed up reactions.
- Cell — the basic structural and functional unit of living organisms.
Action Items / Next Steps
- Review each chapter's PDF for detailed diagrams and examples.
- Complete assigned reading and any homework or questions related to these chapters.