Ch 2: Chemistry Foundations for Anatomy & Physiology: Chapter 2 Study Guide

Chemistry Foundations for Anatomy & Physiology

Introduction

This study guide summarizes the essential chemistry concepts that underpin the study of Anatomy & Physiology. Understanding these topics is crucial for grasping the molecular and biochemical basis of human structure and function.

1. Basic Chemical Principles

1.1 Matter and Its Definition

Matter is anything that has mass and occupies space. All living and non-living things are composed of matter.

• States of matter: Solid, liquid, gas.

• Example: Water exists as ice (solid), liquid water, and steam (gas).

1.2 Subatomic Particles

Atoms are the smallest units of matter and are composed of subatomic particles:

• Protons: Positively charged, found in the nucleus.

• Neutrons: No charge, found in the nucleus.

• Electrons: Negatively charged, orbit the nucleus.

• Atomic number: Number of protons in an atom.

• Mass number: Sum of protons and neutrons.

1.3 Chemical Bonds

Atoms combine to form molecules via chemical bonds:

• Ionic bonds: Transfer of electrons between atoms, forming ions (e.g., NaCl).

• Covalent bonds: Sharing of electrons between atoms. Can be polar (unequal sharing, e.g., H2O) or non-polar (equal sharing, e.g., O2).

• Hydrogen bonds: Weak attractions between polar molecules, important in water and DNA structure.

2. Acids, Bases, and pH

2.1 Acids and Bases

• Acids: Substances that release hydrogen ions (H+) in solution.

• Bases: Substances that accept H+ or release hydroxide ions (OH-).

2.2 pH Scale

• pH: Measures the concentration of H+ ions in a solution.

• Scale: 0 (most acidic) to 14 (most basic); 7 is neutral.

• Formula: $\text{pH} = -\log_{10}[\text{H}^+]$

• Example: Blood pH is tightly regulated around 7.4.

3. Organic Chemistry Basics

3.1 Organic Molecules

• Organic chemistry: Study of carbon-containing compounds.

• Structural formulas: Show arrangement of atoms in a molecule.

• Molecular formulas: Show the number and type of atoms (e.g., C6H12O6).

3.2 Polymers and Monomers

• Monomers: Small, repeating units (e.g., glucose, amino acids).

• Polymers: Large molecules made by joining monomers (e.g., starch, proteins).

• Example: Proteins are polymers of amino acids.

4. Biomolecules Essential to Human Life

4.1 Four Major Classes of Biomolecules

• Carbohydrates: Provide energy and structural support.

• Lipids: Store energy, form cell membranes, act as hormones.

• Proteins: Catalyze reactions, provide structure, regulate processes.

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

4.2 Functions and Examples

• Glucose: Main energy source for cells.

• Triglycerides: Energy storage molecules.

• Enzymes: Proteins that speed up chemical reactions.

• DNA: Genetic blueprint for organisms.

5. Carbohydrates

5.1 Structure and Types

• Monosaccharides: Simple sugars (e.g., glucose, fructose).

• Disaccharides: Two monosaccharides joined (e.g., sucrose).

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

5.2 Functions

• Energy storage: Glycogen in animals, starch in plants.

• Structural: Cellulose in plants.

6. Lipids

6.1 Types and Functions

• Triglycerides: Composed of glycerol and three fatty acids.

• Phospholipids: Major component of cell membranes; amphipathic (hydrophilic head, hydrophobic tails).

• Steroids: Include hormones like cholesterol.

6.2 Saturation

• Saturated fatty acids: No double bonds; solid at room temperature.

• Unsaturated fatty acids: One or more double bonds; liquid at room temperature.

• Polyunsaturated: Multiple double bonds.

6.3 Amphipathic Molecules

• Phospholipids: Have both hydrophilic (water-loving) and hydrophobic (water-fearing) regions.

• Example: Cell membrane structure.

7. Proteins

7.1 Structure

• Amino acids: Building blocks of proteins.

• Levels of protein structure:

  1. Primary: Sequence of amino acids.

  2. Secondary: Alpha helices and beta sheets (hydrogen bonding).

  3. Tertiary: 3D folding due to side chain interactions.

  4. Quaternary: Multiple polypeptide chains.

7.2 Protein Functions

• Enzymes: Biological catalysts.

• Structural: Collagen, keratin.

• Transport: Hemoglobin.

8. Nucleic Acids

8.1 DNA and RNA

• Nucleotides: Composed of a sugar, phosphate group, and nitrogenous base.

• DNA: Double-stranded, stores genetic information.

• RNA: Single-stranded, involved in protein synthesis.

8.2 Complementary Base Pairing

• DNA bases: Adenine (A), Thymine (T), Cytosine (C), Guanine (G).

• RNA bases: Adenine (A), Uracil (U), Cytosine (C), Guanine (G).

• Pairing: A-T (DNA), A-U (RNA), C-G.

8.3 Replication, Transcription, and Translation

• Replication: Copying DNA before cell division.

• Transcription: Making RNA from DNA template.

• Translation: Making protein from RNA template.

9. Chemical Reactions in Biology

9.1 Dehydration Synthesis and Hydrolysis

• Dehydration synthesis: Joining monomers by removing water.

• Hydrolysis: Breaking polymers by adding water.

9.2 Enzymes

• Enzymes: Proteins that catalyze chemical reactions.

• Factors affecting enzyme activity: Temperature, pH.

• Example: Digestive enzymes in the stomach work best at low pH.

10. ATP and Energy in Cells

10.1 ATP (Adenosine Triphosphate)

• ATP: Main energy currency of the cell.

• Structure: Adenine, ribose, three phosphate groups.

• Function: Provides energy for cellular processes.

• Equation: $\text{ATP} \rightarrow \text{ADP} + \text{P}_i + \text{energy}$

11. Summary Table: Biomolecules

Biomolecule	Monomer	Polymer	Main Function	Example
Carbohydrate	Monosaccharide	Polysaccharide	Energy, structure	Glucose, starch
Lipid	Fatty acid, glycerol	Triglyceride, phospholipid	Energy storage, membranes	Triglyceride, cholesterol
Protein	Amino acid	Polypeptide	Catalysis, structure	Enzyme, collagen
Nucleic Acid	Nucleotide	DNA, RNA	Genetic information	DNA, mRNA

12. Additional Info

• Hydrophilic: Water-attracting; polar molecules.

• Hydrophobic: Water-repelling; non-polar molecules.

• Amphipathic: Molecules with both hydrophilic and hydrophobic regions (e.g., phospholipids).