Chp 1 (1.1-1.4): Introduction to Anatomy & Physiology

1.1 Form (Anatomy) Determines Function (Physiology)

The relationship between structure and function is a foundational concept in anatomy and physiology. Understanding how the form of a biological structure enables its function helps explain the organization of living systems.

• Complementarity of Structure and Function: The concept that the structure of a body part or system is directly related to its function. For example, the thin walls of alveoli in the lungs facilitate gas exchange.

• Levels of Structural Organization: The human body is organized into levels: chemical, cellular, tissue, organ, organ system, and organismal.

• Example: The heart's muscular walls (structure) enable it to pump blood (function) throughout the body.

1.3 What are the Requirements for Life?

Living organisms share several essential requirements for survival and function. These requirements are met through the coordinated activity of organ systems.

• 11 Organ Systems: Examples include the circulatory, respiratory, digestive, and nervous systems.

• Feedback Systems: Organ systems interact through feedback mechanisms to maintain homeostasis.

• Example: The respiratory and circulatory systems work together to deliver oxygen to tissues and remove carbon dioxide.

1.4 Homeostasis is Maintained by Negative Feedback

Homeostasis refers to the body's ability to maintain a stable internal environment. Negative feedback mechanisms are the primary way the body achieves homeostasis.

• Definition: Homeostasis is the maintenance of a relatively constant internal environment.

• Dynamic Equilibrium: Homeostasis is dynamic, meaning conditions fluctuate within a narrow range.

• Negative Feedback: A process in which a change in a variable triggers a response that counteracts the initial change, returning the variable to its set point.

• Components of Feedback Loops: Stimulus, receptor, control center, effector, and response.

• Example: Regulation of body temperature: If body temperature rises, mechanisms such as sweating are activated to cool the body.

Chp 2 (2.1, 2.4, 2.8-2.11): Chemistry of Life

2.1 Matter is the Stuff of the Universe and Energy Moves Matter

Matter and energy are fundamental to all biological processes. Understanding their forms and how they interact is essential in physiology.

• Forms of Energy: Potential energy (stored) and kinetic energy (in motion).

• ATP: Adenosine triphosphate is the main energy currency of the cell.

• Thermoregulation: The process by which organisms maintain their body temperature.

• Example: Energy from food is converted to ATP, which powers cellular activities.

2.4 The Three Types of Chemical Bonds

Chemical bonds are the forces that hold atoms together in molecules. The type of bond affects the properties of the molecule.

• Ionic Bonds: Formed when electrons are transferred from one atom to another, creating charged ions (e.g., NaCl).

• Covalent Bonds: Formed when atoms share electrons (e.g., H2O).

• Hydrogen Bonds: Weak attractions between polar molecules, important in the structure of DNA and proteins.

• Example: When NaCl is placed in water, it dissociates into Na+ and Cl- ions.

Macromolecules

Macromolecules are large, complex molecules essential for life. They include carbohydrates, lipids, proteins, and nucleic acids.

• Carbohydrates: Provide energy and structural support.

• Lipids: Store energy, form cell membranes, and act as signaling molecules.

• Proteins: Serve as enzymes, structural components, and signaling molecules.

• Nucleic Acids: Store and transmit genetic information (DNA and RNA).

2.8 Carbohydrates

Carbohydrates are classified based on the number of sugar units they contain.

• Monosaccharides: Single sugar units (e.g., glucose).

• Disaccharides: Two sugar units (e.g., sucrose).

• Polysaccharides: Long chains of sugar units (e.g., glycogen, starch).

• Role: Main source of energy for cells.

2.9 Lipids

Lipids are diverse molecules that include fats, oils, and cholesterol. They play key roles in energy storage, membrane structure, and signaling.

• Triglycerides: Main form of stored energy in animals.

• Phospholipids: Major component of cell membranes.

• Steroids: Include cholesterol and hormones.

• HDL vs. LDL: High-density lipoprotein (HDL) is considered 'good' cholesterol; low-density lipoprotein (LDL) is 'bad' cholesterol.

2.10 Proteins (Including Enzymes)

Proteins are polymers of amino acids and perform a wide variety of functions in the body.

• Structure: Primary, secondary, tertiary, and quaternary levels.

• Enzymes: Biological catalysts that speed up chemical reactions.

• Denaturation: Loss of protein structure due to environmental changes (e.g., heat, pH).

• Activation Energy: The energy required to start a chemical reaction.

2.11 Nucleic Acids: DNA

Nucleic acids store and transmit genetic information. DNA and RNA are the two main types.

• DNA: Deoxyribonucleic acid, contains genetic instructions.

• Genes: Segments of DNA that code for proteins.

• ATP: Adenosine triphosphate, a nucleotide that stores energy.

Chp 3 (3.1-3.2, 3.4-3.5): The Cell

3.1 Cells are the Smallest Unit of Life

Cells are the basic structural and functional units of all living organisms. Each cell contains organelles that perform specific functions.

• Main Parts of a Cell: Plasma membrane, cytoplasm, nucleus.

• Plasma Membrane: Selectively permeable barrier that regulates what enters and leaves the cell.

• Importance: Selective permeability is crucial for maintaining cellular homeostasis.

3.2 Plasma Membrane: The Fluid Mosaic Model

The plasma membrane is composed of a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates. The fluid mosaic model describes its structure and function.

• Phospholipid Bilayer: Hydrophilic heads face outward; hydrophobic tails face inward.

• Membrane Proteins: Serve as channels, receptors, and enzymes.

• Carbohydrates: Involved in cell recognition.

3.4 Passive Membrane Transport vs. 3.5 Active Membrane Transport

Substances move across cell membranes by passive or active transport mechanisms.

• Passive Transport: Movement of substances down their concentration gradient without energy input (e.g., diffusion, osmosis, facilitated diffusion).

• Active Transport: Movement of substances against their concentration gradient, requiring energy (usually ATP).

• Example: Sodium-potassium pump uses ATP to move Na+ out and K+ into the cell.

3.4 Passive Membrane Transport: Diffusion

Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration.

• Simple Diffusion: Direct movement through the membrane (e.g., O2, CO2).

• Facilitated Diffusion: Movement via transport proteins (e.g., glucose transporters).

• Osmosis: Diffusion of water across a selectively permeable membrane.

• Example: Red blood cells in a hypotonic solution swell due to water influx.

3.5 Active Membrane Transport

Active transport requires energy to move substances against their concentration gradients.

• Primary Active Transport: Direct use of ATP (e.g., sodium-potassium pump).

• Secondary Active Transport: Uses energy from the movement of another substance down its gradient.

• Electrochemical Gradient: Combination of concentration and electrical gradients across the membrane.

Chp 24 (24.1, 24.3-24.7): Metabolism and Energy

24.1 Energy and Building Blocks

Cells require energy to perform work and build complex molecules. ATP is the primary energy carrier.

• ATP: Stores and releases energy for cellular processes.

• Catabolism: Breakdown of molecules to release energy.

• Anabolism: Synthesis of complex molecules from simpler ones.

24.4 Carbohydrate Metabolism

Carbohydrate metabolism involves the breakdown of glucose to produce ATP through cellular respiration.

• Cellular Respiration Equation:

• Glycolysis: Occurs in the cytoplasm; breaks down glucose into pyruvate, producing ATP and NADH.

• Krebs Cycle: Occurs in the mitochondria; processes pyruvate to produce ATP, NADH, and FADH2.

• Electron Transport Chain: Uses NADH and FADH2 to generate a large amount of ATP.

• Oxygen's Role: Final electron acceptor in the electron transport chain.

24.5 Lipid Metabolism

Lipids can be broken down to provide energy or converted to other molecules.

• Triglycerides: Broken down into glycerol and fatty acids.

• Beta-Oxidation: Fatty acids are converted to acetyl-CoA for entry into the Krebs cycle.

24.6 Amino Acids

Amino acids are used for protein synthesis or can be metabolized for energy.

• Transamination: Transfer of amino groups to form new amino acids.

• Deamination: Removal of amino groups, producing ammonia and urea.

24.7 Energy Storage and Use

The body stores energy in the absorptive state and mobilizes it in the postabsorptive state.

• Absorptive State: Nutrients are stored as glycogen, triglycerides, and proteins.

• Postabsorptive State: Stored nutrients are mobilized for energy.

• Example: After a meal, glucose is stored as glycogen in the liver and muscles.