Human Biology Study Guide Exam 1 - Cellular Respiration

**Chapter 1: Human Biology, Science, and Society** **Key Definitions** - **Science**: The study of the natural world, including all matter and energy. - **Biology**: The study of living organisms and life processes. - **Human Biology**: The study of human anatomy (body parts) and p...

**Chapter 1: Human Biology, Science, and Society** **Key Definitions** - **Science**: The study of the natural world, including all matter and energy. - **Biology**: The study of living organisms and life processes. - **Human Biology**: The study of human anatomy (body parts) and physiology (function of body parts). **The 7 Characteristics of Life** 1. **Different Chemistry**: Living organisms contain unique biochemicals (proteins, carbohydrates, DNA, lipids). 2. **Energy Use**: Organisms take in food and convert it to ATP through cellular respiration. 3. **Cellular Composition**: All living organisms are made of one or more cells. - **Unicellular**: One-celled organisms (e.g., bacteria). - **Multicellular**: Organisms with multiple cells (e.g., humans, animals). 4. **Homeostasis**: Maintaining a stable internal environment (e.g., body temperature regulation). 5. **Response to Environment**: Organisms react to stimuli (e.g., nervous system response in humans). 6. **Growth, Development, and Reproduction**: DNA controls these processes. 7. **Evolution**: Populations evolve through natural selection. **Classification of Life** - **3 Domains of Life**: 1. **Archaea**: Primitive bacteria, prokaryotic (no nucleus). 2. **Bacteria**: Modern bacteria, prokaryotic. 3. **Eukarya**: Complex life forms with a nucleus (includes Plants, Fungi, Animals, and Protists). **Defining Features of Humans** - **Bipedalism** (Walking on two legs). - **Opposable Thumbs** (Fine motor control, ability to write). - **Large Brains** (Higher cognitive functions). - **Complex Language** (Communication and information sharing). **Scientific Process** 1. Observation of a problem. 2. Form a **hypothesis** (educated guess). 3. Conduct a **controlled experiment**. 4. Draw conclusions and publish results (**peer review** ensures validity). **Theories vs. Hypotheses** - **Hypothesis**: A testable explanation for a phenomenon. - **Theory**: A well-supported, tested explanation (e.g., Darwin's Theory of Evolution). **Chapter 2: Chemistry & Cells** **Basic Chemistry** - **Matter**: Anything with mass and volume. - **Element**: A pure substance composed of the same type of atoms. - **Atom**: The smallest unit of an element, composed of: - **Protons (+ charge)** - **Neutrons (neutral charge)** - **Electrons (- charge)** **Chemical Bonds** - **Ionic Bonds**: Transfer of electrons (e.g., NaCl - table salt). - **Covalent Bonds**: Sharing of electrons (e.g., H₂O - water). - **Hydrogen Bonds**: Weak bonds between polar molecules (e.g., in water molecules). **Water and pH** - Water is the universal **solvent**. - **Acids**: Release H+ ions (e.g., HCl). - **Bases**: Release OH- ions (e.g., NaOH). - **pH Scale**: - 0-6: Acidic - 7: Neutral (water) - 8-14: Basic (alkaline) - **Buffers**: Help maintain pH balance in the body (e.g., carbonic acid/bicarbonate system in blood). **Macromolecules** 1. **Carbohydrates**: Energy source (e.g., glucose, starch, fiber). 2. **Lipids**: Energy storage, insulation (e.g., fats, steroids, cholesterol). 3. **Proteins**: Made of amino acids; used for structure and function (e.g., enzymes, keratin). 4. **Nucleic Acids**: DNA & RNA, store genetic information. **ATP (Adenosine Triphosphate)** - The **energy currency** of the cell. - ATP stores energy between phosphate bonds. - When broken down, ATP releases energy for cellular functions. **Chapter 3: Structure and Function of Cells** **Cell Theory** 1. All living things are made of **cells**. 2. The cell is the **basic unit of life**. 3. All cells come from **pre-existing cells**. **Cell Types** - **Prokaryotic Cells**: No nucleus (e.g., bacteria, archaea). - **Eukaryotic Cells**: Have a nucleus (e.g., plant, animal cells). **Cell Organelles and Functions** - **Plasma Membrane**: Controls what enters/exits the cell. - **Nucleus**: Contains DNA, controls cell activities. - **Ribosomes**: Protein synthesis. - **Endoplasmic Reticulum (ER)**: - **Rough ER**: Has ribosomes, makes proteins. - **Smooth ER**: No ribosomes, makes lipids. - **Golgi Apparatus**: Modifies and packages proteins. - **Mitochondria**: Produces ATP via **cellular respiration**. - **Lysosomes**: Digests waste. - **Peroxisomes**: Detoxifies harmful substances. - **Cytoskeleton**: Provides cell shape and support. - **Cilia/Flagella**: Helps with movement. **Cell Transport Mechanisms** - **Passive Transport** (no energy required): - **Diffusion**: Movement of molecules from high to low concentration. - **Osmosis**: Movement of water from high to low concentration. - **Active Transport** (requires ATP): - Moves substances **against** concentration gradient. - Example: Sodium-Potassium Pump. **Tonicity (Cell and Solution Relationships)** - **Isotonic**: Equal solute concentration inside/outside the cell. - **Hypertonic**: More solute outside → Cell **shrinks**. - **Hypotonic**: More solute inside → Cell **swells/bursts**. **Cellular Respiration** **Aerobic Respiration (Requires Oxygen):** 1. **Glycolysis** (Cytoplasm) → Splits glucose into pyruvate (2 ATP). 2. **Preparatory Step** (Mitochondria) → Converts pyruvate into Acetyl-CoA. 3. **Citric Acid Cycle** (Mitochondria) → Produces ATP and electron carriers (NADH, FADH2). 4. **Electron Transport Chain** (Mitochondria) → Produces most ATP (32-34 ATP). **Total ATP Yield per Glucose: \~36 ATP** **Anaerobic Respiration (Without Oxygen)** - Only produces **2 ATP**. - Converts pyruvate into **lactic acid** (causes muscle burn). **Key Takeaways for the Exam** ✅ Understand the 7 characteristics of life. ✅ Know the 3 domains of life and key human traits. ✅ Review the scientific method and peer review process. ✅ Understand atoms, bonds, macromolecules, and water properties. ✅ Memorize organelle functions and transport mechanisms. ✅ Master cellular respiration and ATP production. ✅ Recognize tonicity and its effects on cells. ✅ Be familiar with pH, acids, bases, and buffers.