BIOL-141 Final Exam Comprehensive Study Guide

Chapter 1: Evolution, the Themes of Biology, and Scientific Inquiry

Cell Theory

• Cell Theory: All living organisms are composed of cells, and all cells arise from pre-existing cells.

• Cells are the basic unit of structure and function in living things.

Prokaryotic vs. Eukaryotic Cells

• Prokaryotic cells: Lack a nucleus and membrane-bound organelles (e.g., bacteria, archaea).

• Eukaryotic cells: Have a nucleus and membrane-bound organelles (e.g., plants, animals, fungi, protists).

• Similarities: Both have plasma membranes, cytoplasm, ribosomes, and genetic material.

• Differences: Eukaryotes are generally larger, more complex, and compartmentalized.

Scientific Inquiry Process

• Observation: Gathering information about phenomena.

• Hypothesis: A testable explanation for an observation.

• Prediction: What you expect to happen if the hypothesis is correct.

• Testing: Conducting experiments or collecting data to evaluate the hypothesis.

Variables

• Independent variable: The factor manipulated by the experimenter.

• Dependent variable: The factor measured in response to changes in the independent variable.

Chapter 2: The Chemical Context of Life

Atomic Structure

• Atomic number: Number of protons in an atom.

• Mass number: Sum of protons and neutrons.

• Isotopes: Atoms of the same element with different numbers of neutrons.

Valence Shells and Electrons

• Valence shell: Outermost electron shell of an atom.

• Valence electrons: Electrons in the valence shell; determine chemical reactivity.

• Atoms gain, lose, or share electrons to complete their valence shell (usually 8 electrons for main group elements).

• Gaining electrons forms anions (negatively charged), losing electrons forms cations (positively charged).

Chemical Bonds

• Ionic bonds: Formed by transfer of electrons from one atom to another.

• Covalent bonds: Formed by sharing of electrons between atoms.

• Hydrogen bonds: Weak attractions between a hydrogen atom (covalently bonded to O or N) and another electronegative atom; important in water and biological molecules.

Chapter 3: Water and Life

Properties of Water

• Lower density as a solid: Ice floats because hydrogen bonds hold water molecules apart.

• High heat of vaporization: Requires a lot of energy to convert liquid water to gas.

• High specific heat: Water resists temperature changes.

• Solvent properties: Water dissolves hydrophilic (water-loving) substances.

• Cohesion and adhesion: Water molecules stick to each other (cohesion) and to other substances (adhesion).

Hydrophilic vs. Hydrophobic

• Hydrophilic: Substances that interact well with water (e.g., salts, sugars).

• Hydrophobic: Substances that do not interact well with water (e.g., oils, fats).

pH and Hydrogen Ion Concentration

• pH: Measures hydrogen ion concentration; $pH = -\log_{10}[H^+]$

• Acidic: pH < 7; higher [H+]

• Basic: pH > 7; lower [H+]

• Neutral: pH = 7

• Each pH unit represents a tenfold change in [H+].

Acids and Bases

• Acid: Increases [H+] in solution.

• Base: Decreases [H+] (or increases [OH-]) in solution.

• Look for H+ or OH- in dissociation products to identify acids or bases.

Chapter 4: Carbon and the Molecular Diversity of Life

Isomers

• Isomers: Molecules with the same molecular formula but different structures.

Functional Groups

• Hydroxyl (-OH)

• Amine (-NH2)

• Carboxyl (-COOH)

• Carbonyl (C=O)

• Methyl (-CH3)

• Phosphate (-PO4)

• Sulfhydryl (-SH)

Chapter 5: The Structure and Function of Large Biological Molecules

Monomers of Biological Molecules

• Carbohydrates: Monosaccharides

• Proteins: Amino acids

• Nucleic acids: Nucleotides

• Lipids: Fatty acids and glycerol (not true polymers)

Polysaccharides

Polysaccharide	Function	Organism
Starch	Energy storage	Plants
Cellulose	Structural support	Plants
Glycogen	Energy storage	Animals
Chitin	Structural support	Fungi, arthropods

Saturated vs. Unsaturated Fatty Acids

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

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

Protein Structure

• Primary: Sequence of amino acids.

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

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

• Quaternary: Multiple polypeptide chains.

Denaturation

• Denaturation: Loss of protein structure (and function) due to heat, pH, or chemicals.

DNA vs. RNA

• Similarities: Both are nucleic acids made of nucleotides.

• Differences: DNA is double-stranded, contains deoxyribose, and uses thymine; RNA is single-stranded, contains ribose, and uses uracil.

Nucleotide Components

• Phosphate group

• Pentose sugar (deoxyribose or ribose)

• Nitrogenous base

Chapter 6: A Tour of the Cell

Prokaryotic vs. Eukaryotic Cells

• See Chapter 1 for similarities and differences.

Plant vs. Animal Cells

• Plant cells: Have cell walls, chloroplasts, and large central vacuoles.

• Animal cells: Lack cell walls and chloroplasts, have small vacuoles, and contain lysosomes.

Organelle Functions

• Nucleus: Contains genetic material (DNA).

• Ribosomes: Protein synthesis; found free in cytoplasm or bound to rough ER.

• Chloroplast: Site of photosynthesis (plants and algae).

• Mitochondria: Site of cellular respiration (ATP production).

• Rough ER: Protein synthesis and modification.

• Smooth ER: Lipid synthesis and detoxification.

• Lysosome: Digestion of macromolecules and cellular debris.

Chapter 7: Membrane Structure and Function

Phospholipid Bilayer

• Phospholipids have hydrophilic heads (face outward) and hydrophobic tails (face inward), forming a bilayer.

Fluid Mosaic Model

• Cell membranes are dynamic, with proteins and lipids moving laterally within the layer.

Tonicity

• Hypertonic: Higher solute concentration outside; water leaves cell.

• Hypotonic: Lower solute concentration outside; water enters cell.

• Isotonic: Equal solute concentration; no net water movement.

• Plant and animal cells respond differently to tonicity due to cell walls.

Transport Mechanisms

• Passive diffusion: Movement down concentration gradient; no energy required.

• Active transport: Movement against concentration gradient; requires energy (ATP).

Chapter 8: An Introduction to Metabolism

Energy Types

• Kinetic energy: Energy of motion.

• Potential energy: Stored energy.

Exergonic vs. Endergonic Reactions

• Exergonic: Release energy; $\Delta G < 0$

• Endergonic: Require energy input; $\Delta G > 0$

• Catabolic: Break down molecules; release energy.

• Anabolic: Build molecules; require energy.

Enzymes

• Lower activation energy of reactions, increasing reaction rate.

ATP

• Main energy currency of the cell; phosphate bonds store energy.

• Hydrolysis of ATP releases energy for cellular work.

Chapter 9: Cellular Respiration and Fermentation

Purpose and Overview

• Converts glucose and oxygen into ATP, CO2, and H2O.

• Overall equation: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}$

• Glucose is oxidized; oxygen is reduced.

Oxygen Requirement

• Oxygen is the final electron acceptor in the electron transport chain.

• Glycolysis occurs without oxygen and outside mitochondria.

Anaerobic Respiration/Fermentation

• Produces less ATP; end products include lactate or ethanol and CO2.

Chapter 10: Photosynthesis

Relationship to Cellular Respiration

• Photosynthesis stores energy in glucose; respiration releases it.

Overall Equation

• $6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$

• CO2 is reduced; H2O is oxidized.

Light Reactions

• Convert light energy to chemical energy (ATP, NADPH); produce O2.

Calvin Cycle

• Uses ATP and NADPH to fix CO2 into sugars.

Leaf Color

• Chlorophyll reflects green light, making leaves appear green.

Chapter 12: The Cell Cycle

Mitosis vs. Meiosis

• Mitosis: Growth, repair, asexual reproduction; produces two genetically identical diploid cells.

• Meiosis: Produces gametes; results in four genetically unique haploid cells.

Chromosome Terms

• Sister chromatids: Identical copies of a chromosome, joined at the centromere.

• Homologous chromosomes: Chromosome pairs, one from each parent, similar but not identical.

Chapter 13: Meiosis and Sexual Life Cycles

Gametes vs. Somatic Cells

• Gametes: Sex cells (sperm, egg); haploid (n).

• Somatic cells: Body cells; diploid (2n).

Meiosis Events

• Homologous chromosomes separate in Meiosis I; sister chromatids separate in Meiosis II.

• Crossing over: Exchange of genetic material between homologous chromosomes (prophase I).

• Independent assortment: Random orientation of homologous pairs during metaphase I.

Meiosis Products (Humans)

• Four haploid sperm cells, each genetically unique, with 23 chromosomes.

Chapters 14/15: Mendel and the Gene Idea & Chromosomal Basis of Inheritance

Genetics Vocabulary

• Dominant: Expressed trait; masks recessive allele.

• Recessive: Trait only expressed if two copies are present.

• Homozygous dominant: Two dominant alleles (AA).

• Heterozygous: One dominant, one recessive allele (Aa).

• Homozygous recessive: Two recessive alleles (aa).

• Genotype: Genetic makeup (e.g., Aa).

• Phenotype: Observable trait (e.g., tall, short).

Inheritance Patterns

• Monohybrid cross: One gene, two alleles.

• Autosomal dominant/recessive: Trait on non-sex chromosome.

• Blood types: Determined by multiple alleles (A, B, O).

• Pedigree analysis: Identify inheritance pattern (autosomal dominant, autosomal recessive, X-linked recessive).

Chapter 16: The Molecular Basis of Inheritance

DNA Replication

• Semi-conservative: Each new DNA molecule has one old and one new strand.

• Purpose: To accurately copy genetic information for cell division.

• Complementary base pairing: A-T, G-C.

Chapter 17: Gene Expression: From Gene to Protein

Genes and Genome

• Gene: Sequence of DNA that codes for a protein.

• Genome: All genetic material in an organism.

Gene Expression Steps

• Transcription: DNA → RNA

• Translation: RNA → Protein

Codon Redundancy

• Multiple codons can code for the same amino acid.

Transcription

• Requires DNA template, RNA polymerase, nucleotides.

• Produces mRNA from DNA template.

Translation

• Requires mRNA, ribosomes, tRNA, amino acids.

• Produces polypeptide (protein) from mRNA sequence.

Mutations

• Changes in DNA sequence can alter protein structure and function.

• Transcription and translation of mutated DNA can be used to predict protein changes.

Additional info: This guide covers the foundational concepts and vocabulary for a college-level introductory biology course, focusing on cell biology, genetics, biochemistry, and molecular biology. For exam preparation, students should be able to apply these concepts to novel scenarios and solve basic problems involving inheritance, chemical structure, and cellular processes.