Study Notes
The topic of systems and cycles in science covers how living organisms store energy, how substances move within the body, and the roles of the circulatory and respiratory systems. Nutrients are essential for survival and include carbohydrates, proteins, fats, minerals, vitamins, fibre, and water. The digestive system breaks down large molecules into smaller ones, while the respiratory system facilitates gas exchange, and the circulatory system transports blood throughout the body. Homeostasis maintains balance in the body's internal environment.
Exam Tips
Key Definitions to Remember
- Carbohydrates — Macromolecules made of carbon, hydrogen, and oxygen, broken down into glucose.
- Proteins — Macromolecules made of amino acids, essential for cell repair and growth.
- Lipids (fats) — Macromolecules made of carbon, hydrogen, and oxygen, broken down into glycerol and fatty acids.
- Diffusion — Movement of substances from higher to lower concentration.
- Active Transport — Movement of substances from lower to higher concentration, requiring energy.
- Homeostasis — Maintenance of stable internal conditions in living organisms.
Common Confusions
- Confusing the roles of arteries and veins in systemic and pulmonary circulation.
- Misunderstanding the difference between diffusion and active transport.
Typical Exam Questions
- What is the role of the respiratory system? To get oxygen into the blood and remove carbon dioxide.
- How do enzymes aid digestion? They help break down large molecules into smaller ones.
- What is homeostasis? The balanced state of various conditions within living organisms.
What Examiners Usually Test
- Understanding of how nutrients are used by the body.
- The process of gas exchange in the alveoli.
- Differences between diffusion and active transport.