Summary of "[중2 과학] 5단원 모든 개념 완벽 정리"
Summary of [중2 과학] 5단원 모든 개념 완벽 정리
Main Ideas and Concepts
1. Animal Body Composition and Organization
- The animal body is organized hierarchically: cells → tissues → organs → organ systems → individual organism.
- Cells are the basic units; examples include muscle cells and epithelial cells.
- Tissues are groups of similar cells; organs are formed by different tissues with specific shapes and functions (e.g., stomach stores and digests food).
- Organ systems consist of multiple organs working together (e.g., digestive system).
- Plants also have tissues and organs (stem, root) but do not have organ systems like animals.
- An individual organism is made up of multiple organ systems.
2. Nutrients and Their Roles
- Nutrients provide energy, build the body, and regulate functions.
- Three major nutrients:
- Carbohydrates: main energy source, 4 kcal/g; excess stored as fat.
- Proteins: build body, energy source (4 kcal/g), regulate body functions.
- Fats: energy source (9 kcal/g), build body.
- Inorganic salts (e.g., sodium, iron, calcium, potassium) form bones/blood and regulate functions.
- Vitamins regulate body functions in small amounts.
- Water (60-70% of body) transports substances and regulates temperature due to its high specific heat.
3. Detection of Nutrients in Foods
- Starch: Iodine potassium iodide solution turns blue-black.
- Glucose: Benedict’s solution turns yellow-red when heated.
- Protein: Biuret solution (sodium hydroxide + copper sulfate) turns purple.
- Fat: Sudan 3 solution stains fat red, distinguishing fat from water.
4. Digestion
- Digestion breaks down large nutrients into smaller molecules for absorption.
- Digestive enzymes are specific to certain nutrients and work best at body temperature and specific pH.
- Digestive system includes:
- Digestive tract (mouth, esophagus, stomach, small intestine, large intestine).
- Accessory organs (liver, gallbladder, pancreas) secrete digestive juices but food does not pass through them.
- Key Digestive enzymes:
- Amylase (mouth, pancreas): starch → glucose.
- Pepsin (stomach, with hydrochloric acid): protein → smaller peptides.
- Trypsin (pancreas): proteins → peptides.
- Lipase (pancreas): fats → fatty acids + monoglycerides.
- Bile (liver/gallbladder): emulsifies fats but contains no enzymes.
- Nutrients absorbed mainly in the small intestine, aided by villi and microvilli increasing surface area.
- Water-soluble nutrients absorbed into capillaries; fat-soluble nutrients absorbed into lacteals (lymph vessels).
5. Circulatory System
- Transports nutrients, oxygen, and wastes.
- Heart pumps blood via contractions (heartbeat).
- Heart structure:
- Right atrium receives deoxygenated blood from body via vena cava.
- Right ventricle pumps blood to lungs via pulmonary artery.
- Left atrium receives oxygenated blood from lungs via pulmonary vein.
- Left ventricle pumps oxygenated blood to body via aorta.
- Blood vessels:
- Arteries: thick, elastic walls, high pressure, carry blood away from heart.
- Capillaries: thin walls for exchange of gases, nutrients, and wastes.
- Veins: thinner walls, valves prevent backflow, carry blood to heart.
- Blood components:
- Plasma: yellow liquid, mostly water, transports substances.
- Red blood cells: carry oxygen via hemoglobin.
- White blood cells: immune defense via phagocytosis.
- Platelets: blood clotting.
- Blood circulation:
- Arterial blood: oxygen-rich.
- Venous blood: oxygen-poor, carbon dioxide-rich.
- Blood circulates from heart → body → heart → lungs → heart.
6. Respiratory System
- Function: absorb oxygen and expel carbon dioxide.
- Pathway: nose → trachea → bronchi → lungs (Alveoli).
- Nose filters, warms, and moistens air.
- Alveoli: tiny air sacs surrounded by capillaries; large surface area for gas exchange.
- Gas
Category
Educational
