BIO 109 Study Guide: Introduction to Anatomy & Physiology, Chemistry of Life, and The Cell

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Introduction to Anatomy and Physiology

Anatomical Terminology

Understanding anatomical terminology is essential for accurately describing locations and relationships within the human body.

Directional Terms: Words such as superior (above), inferior (below), anterior (front), posterior (back), medial (toward the midline), and lateral (away from the midline) are used to describe positions.
Anatomical Position: The standard reference position for the body: standing upright, facing forward, arms at the sides, palms facing forward.
Example: The heart is medial to the lungs and superior to the liver.

Organ Systems

The human body is organized into several organ systems, each with specific functions and components.

Skeletal System: Provides support, protection, and enables movement.
Muscular System: Facilitates movement and maintains posture.
Endocrine System: Regulates body functions via hormones; includes glands such as the pancreas.
Respiratory System: Responsible for gas exchange (oxygen and carbon dioxide).
Pancreas: Functions in both the digestive system (producing digestive enzymes) and the endocrine system (secreting insulin and glucagon).

Body Cavities

Body cavities house and protect internal organs. They are classified as dorsal or ventral, with further subdivisions.

Dorsal Cavity: Includes the cranial cavity (brain) and vertebral cavity (spinal cord).
Ventral Cavity: Includes the thoracic cavity (heart, lungs) and abdominopelvic cavity (digestive organs, reproductive organs).
Example: The lungs are located in the thoracic cavity, which is part of the ventral cavity.

Homeostasis and Feedback Loops

Homeostasis is the maintenance of a stable internal environment. Feedback loops regulate physiological processes.

Negative Feedback: Counteracts changes; e.g., body temperature regulation.
Positive Feedback: Amplifies changes; e.g., blood clotting.
Example: When body temperature rises, sweat glands are activated to cool the body (negative feedback).

Gradients in Physiology

Gradients refer to differences in concentration, pressure, or electrical charge between two areas, driving physiological processes.

Concentration Gradient: Difference in solute concentration across a membrane.
Pressure Gradient: Drives blood flow and respiratory gas exchange.
Example: Oxygen moves from high concentration in the lungs to lower concentration in the blood.

Serous Membranes

Serous membranes line body cavities and cover organs, reducing friction.

Location: Found in thoracic and abdominopelvic cavities.
Types: Pleura (lungs), pericardium (heart), peritoneum (abdominal organs).
Function: Secrete serous fluid for lubrication.

The Chemistry of Life

Atomic Structure

Atoms are the basic units of matter, composed of protons, neutrons, and electrons.

Atomic Number: Number of protons in the nucleus; defines the element.
Example: Carbon has 6 protons; atomic number is 6.

Chemical Bonds

Chemical bonds hold atoms together in molecules.

Ionic Bonds: Formed by transfer of electrons; creates charged ions.
Covalent Bonds: Formed by sharing electrons between atoms.
Example: Sodium chloride (NaCl) is held together by ionic bonds.

Chemical Reactions

Chemical reactions involve the transformation of reactants into products.

Catabolic Reactions: Break down molecules; release energy.
Anabolic Reactions: Build molecules; consume energy.
General Equation:

Example: Cellular respiration is a catabolic reaction.

Factors Affecting Reactivity

Reaction rates are influenced by several factors.

Temperature: Higher temperature increases reaction rate.
Concentration: Higher concentration increases reaction rate.
Catalysts: Lower activation energy, speeding up reactions.

pH and Solutions

The pH scale measures hydrogen ion concentration in solutions.

pH Scale: Ranges from 0 (acidic) to 14 (basic); 7 is neutral.
Formula:

Example: Blood has a pH of about 7.4.

Biomolecules

Biological macromolecules are essential for life and include carbohydrates, lipids, proteins, and nucleic acids.

Carbohydrates: Energy source; building blocks are monosaccharides.
Lipids: Energy storage, membrane structure; building blocks are fatty acids and glycerol.
Proteins: Structure, enzymes; building blocks are amino acids.
Nucleic Acids: Genetic information; building blocks are nucleotides.
Dehydration Synthesis: Joins monomers by removing water.
Disaccharide Formation: Two monosaccharides join to form a disaccharide.

Lipids and Fatty Acids

Lipids are diverse molecules, and fatty acids vary in saturation.

Saturated Fatty Acids: No double bonds; solid at room temperature.
Unsaturated Fatty Acids: One or more double bonds; liquid at room temperature.
Example: Olive oil contains unsaturated fatty acids.

The Cell

Functions of the Plasma Membrane

The plasma membrane controls entry and exit of substances, communication, and structural support.

Isolation: Separates internal and external environments.
Communication: Contains receptors for signaling.
Support: Anchors cytoskeleton and extracellular matrix.

Cytosol and Intracellular Fluids

Cytosol is the fluid component inside cells, containing dissolved substances.

Cytosol: Site of many metabolic reactions.
Intracellular Fluid: Includes cytosol and organelle contents.

Structure of the Plasma Membrane

The plasma membrane is a phospholipid bilayer with embedded proteins and cholesterol.

Phospholipid Bilayer: Hydrophilic heads face outward; hydrophobic tails face inward.
Cholesterol: Stabilizes membrane fluidity.

Diffusion and Osmosis

Diffusion and osmosis are passive transport mechanisms across membranes.

Simple Diffusion: Movement of molecules from high to low concentration.
Facilitated Diffusion: Uses membrane proteins for transport.
Osmosis: Movement of water across a membrane toward higher solute concentration.

Cell Solutions

Cells respond differently to various solution concentrations.

Isotonic: Equal solute concentration; no net water movement.
Hypotonic: Lower solute outside; water enters cell, may swell.
Hypertonic: Higher solute outside; water leaves cell, may shrink.

Cellular Organelles

Organelles perform specialized functions within the cell.

Mitochondria: ATP production (cellular respiration).
Golgi Apparatus: Modifies, sorts, and packages proteins.
Endoplasmic Reticulum (ER): Rough ER synthesizes proteins; Smooth ER synthesizes lipids.
Peroxisomes: Detoxify harmful substances.
Ribosomes: Protein synthesis.

Endomembrane System

The endomembrane system includes organelles involved in synthesis, modification, and transport of cellular materials.

Components: Nuclear envelope, ER, Golgi apparatus, lysosomes, vesicles, plasma membrane.
Function: Coordinates production and transport of proteins and lipids.

Genetics: DNA Structure and Protein Synthesis

DNA contains genetic information; genes are sequences coding for proteins.

Triplet Code: Three DNA bases code for one amino acid.
Protein Synthesis: Involves transcription (DNA to mRNA) and translation (mRNA to protein).
mRNA: Carries genetic code from nucleus to ribosome.
tRNA: Brings amino acids to ribosome; anticodon pairs with mRNA codon.
Codon: Three-base sequence on mRNA.
Anticodon: Three-base sequence on tRNA.

Homologous Chromosomes

Humans have pairs of homologous chromosomes, important for inheritance.

Number: 23 pairs in human cells.
Significance: Each pair contains similar genes; one from each parent.

Study Strategies

Effective study techniques can enhance learning and retention.

Concept Mapping: Visualize relationships between concepts.
Practice Questions: Test understanding with sample questions.
Group Study: Collaborate and teach concepts to peers.
Flashcards: Memorize definitions and key terms.
Regular Review: Space out study sessions for better retention.
Utilize Resources: Supplement learning with textbooks, online materials, and videos.