Lecture Exam 1 Study Guide: Foundations of Anatomy & Physiology

Chapter 1: Study of Body Function

Levels of Structural Organization

The human body is organized into hierarchical levels, each with increasing complexity and specialization.

• Chemical Level: Atoms and molecules essential for life.

• Cellular Level: Basic structural and functional units of life.

• Tissue Level: Groups of similar cells performing a common function.

• Organ Level: Structures composed of two or more tissue types.

• Organ System Level: Groups of organs working together for a common purpose.

• Organismal Level: The complete living being.

Homeostasis is the maintenance of a stable internal environment despite external changes. It is regulated by feedback mechanisms:

• Negative Feedback: Reduces the effect of the original stimulus (e.g., body temperature regulation).

• Positive Feedback: Enhances the original stimulus (e.g., blood clotting).

Example: Regulation of blood glucose by insulin and glucagon.

Chapter 2: Chemical Composition of the Body

Atoms, Ions, and Molecules

All matter is composed of atoms, which combine to form molecules essential for life.

• Major Elements: Carbon, hydrogen, oxygen, nitrogen.

• Ions: Atoms or molecules with a net electric charge due to loss or gain of electrons (e.g., Na+, Cl-).

• pH: A measure of hydrogen ion concentration; scale ranges from 0 (acidic) to 14 (basic).

Organic Molecules: Contain carbon and include carbohydrates, lipids, proteins, and nucleic acids.

• Carbohydrates: Main energy source (e.g., glucose).

• Lipids: Energy storage, insulation, and cell membrane structure.

• Proteins: Structural components, enzymes, and signaling molecules.

• Nucleic Acids: DNA and RNA, store and transmit genetic information.

Example: Water is the most abundant molecule in the body and is vital for chemical reactions.

Chapter 3: Cell Structure & Genetic Control

Cellular Components and Functions

Cells are the basic units of life, each with specialized structures (organelles) that perform distinct functions.

• Plasma Membrane: Selectively permeable barrier controlling entry and exit of substances.

• Nucleus: Contains genetic material (DNA) and controls cellular activities.

• Ribosomes: Sites of protein synthesis.

• Mitochondria: Powerhouse of the cell, site of ATP production.

• Endoplasmic Reticulum & Golgi Apparatus: Synthesis, modification, and transport of proteins and lipids.

Genetic Control: DNA is transcribed into RNA, which is translated into proteins. Genes regulate cell structure and function.

Chapter 4: Enzymes & Energy

Enzyme Function and Metabolic Pathways

Enzymes are biological catalysts that speed up chemical reactions by lowering activation energy.

• Enzyme Specificity: Each enzyme acts on a specific substrate.

• Factors Affecting Enzyme Activity: Temperature, pH, and substrate concentration.

• Metabolic Pathways: Series of enzyme-catalyzed reactions leading to the synthesis or breakdown of molecules.

Example: The breakdown of glucose during cellular respiration involves multiple enzymes.

Equation:

$\text{Enzyme} + \text{Substrate} \rightarrow \text{Enzyme-Substrate Complex} \rightarrow \text{Enzyme} + \text{Product}$

Chapter 5: Cell Respiration and Metabolism

Energy Production in Cells

Cells obtain energy through metabolic pathways, primarily cellular respiration, which converts glucose into ATP.

• Aerobic Respiration: Requires oxygen; includes glycolysis, Krebs cycle, and electron transport chain.

• Anaerobic Respiration: Occurs without oxygen; produces less ATP.

• ATP (Adenosine Triphosphate): Main energy currency of the cell.

Equation for Cellular Respiration:

$\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{ATP}$

Example: Muscle cells use ATP generated from glucose to contract.

Chapter 6: Interactions Between Cells and the Extracellular Environment

Cell Transport Mechanisms

Cells interact with their environment through various transport mechanisms across the plasma membrane.

• Passive Transport: Movement of substances down their concentration gradient (e.g., diffusion, osmosis).

• Active Transport: Requires energy to move substances against their concentration gradient (e.g., sodium-potassium pump).

• Facilitated Diffusion: Transport of substances via carrier proteins.

• Endocytosis & Exocytosis: Bulk transport of materials into and out of the cell.

Example: Glucose uptake by cells via facilitated diffusion and insulin regulation.

Transport Type	Energy Required?	Direction	Example
Simple Diffusion	No	High to Low	Oxygen into cells
Facilitated Diffusion	No	High to Low	Glucose uptake
Active Transport	Yes	Low to High	Sodium-potassium pump