Web Microbiology at ACM

Chapter 10, Episode 9In this episode, fermentation is introduced as a pathway that allows glycolysis to continue in the absence of oxygen by regenerating NAD⁺. Major fermentation types and their end products are discussed, along with their roles in food production, human physiology, and bacterial identification through lab tests.

Chapter 10, Episode 8In this episode, the electron transport chain and oxidative phosphorylation are explained, including how electron carriers create a proton gradient that drives ATP synthesis. The role of oxygen as the final electron acceptor and the reason ATP yield is an estimate are discussed, along with anaerobic respiration and nitrate reduction.

Chapter 10, Episode 7In this episode, glycolysis is introduced as the first step in glucose breakdown, producing pyruvate, ATP, and NADH. The possible fates of pyruvate are discussed, followed by an overview of the Krebs cycle and its role in generating electron carriers and small amounts of ATP.

Chapter 10, Episode 6In this episode, energy flow in the cell is explored through exergonic and endergonic reactions and how they are coupled. Redox reactions are introduced as the movement of electrons, with NAD⁺ and FAD acting as electron carriers. The three methods of ATP production, substrate-level, oxidative, and photophosphorylation, are also introduced.

Chapter 10, Episode 5In this episode, metabolism is introduced as the sum of all chemical reactions in the cell, including catabolism and anabolism. The role of ATP as the cell’s energy currency is explained, along with how enzymes function as catalysts and how they are regulated through gene control, feedback inhibition, and competitive and noncompetitive inhibition.

Chapter 7, Episode 4We wrap up chapter 7 by discussing how antiviral drugs target specific steps in viral replication and why treatment can be challenging. Then we explore prions, infectious proteins that break the traditional rules of biology and cause devastating neurodegenerative diseases.

Chapter 7, Episode 3This episode walks step-by-step through viral replication. From attachment to release, we examine how viruses enter cells, redirect cellular machinery, and produce new virions, including the unique strategies of RNA viruses and retroviruses.

Chapter 7, Episode 2We revisit the lytic and lysogenic cycles of bacteriophages and apply those concepts to human viral infections. Learn the difference between latent and chronic infections, how viruses can damage cells, and how some viruses even contribute to cancer.

Chapter 7, Episode 1Are viruses alive? In this episode, we explore what viruses are made of, how they’re structured, and why they must hijack host cells to survive. We break down capsids, envelopes, bacteriophages, and viral genetics to build the foundation for understanding how viruses work.

Chapter 8, Episode 16This episode focuses on how DNA manipulation is applied in real-world settings through biotechnology. Key topics include recombinant DNA technology, GMOs like Bt corn, gene therapy, CAR-T cancer treatment, and CRISPR gene editing. You’ll see how these tools are used to produce important products like insulin, improve agriculture, and treat disease, while also considering their benefits and limitations.

Chapter 8, Episode 15In this episode, we explore how scientists analyze and visualize DNA after it has been amplified or cut. Topics include gel electrophoresis, DNA profiling, sequencing, SNPs, and microarrays. You’ll learn how these techniques allow researchers to compare DNA samples, identify individuals, detect genetic variation, and study gene activity, with real-world applications in forensics, medicine, and research.

Chapter 8, Episode 14This episode introduces the foundational tools used to study and manipulate DNA, including restriction enzymes, PCR, and cloning vectors. You’ll learn how DNA can be cut at specific sequences, amplified into millions of copies, and transferred between organisms for genetic analysis and engineering. These techniques are essential for understanding how scientists work with genes in research, medicine, and biotechnology.

Chapter 6, Episode 13This episode explains how mutations alter DNA sequences, including point mutations, insertions, deletions, and frameshifts, and how these changes can affect protein function and phenotype. It also discusses mutagens, DNA repair mechanisms, and the biological significance of mutation in genetics, disease, and microbiology.

Chapter 6, Episode 12This episode discusses the unique ways bacteria evolve through DNA. They transfer genetic material horizontally, within the same generation, and the processes by which this is accomplished are discussed in the episode.

Chapter 6, Episode 11This episode introduces the operon, and discusses how bacterial cells control gene expression. The lac operon is discussed in detail as an example of the ways bacteria conserve energy and only make proteins when they are necessary for survival.

Chapter 6, Episode 10This episode is a continuation of the central dogma, focusing on the process of translation and how ribosomes create proteins from messenger RNA.

Chapter 6, Episode 9This episode introduces the central dogma and the genetic code. We'll discuss how cells create protein from genes, and point out the differences in the process of transcription between eukaryotic and prokaryotic cells.

Chapter 6, Episode 8In this episode we'll discuss the process of DNA replication and point out the subtle differences between linear chromosomes and circular chromosomes and how they are replicated. We'll also cover the important enzymes involved in this process, and how proofreading prevents mutations.

Chapter 6, Episode 7In this episode, we'll review the DNA molecule in detail, talk about how chromosomes are organized in prokaryotic and eukaryotic cells, and discuss how this organization sets cells up for replication.

Chapter 5, Episode 6In this episode we finish the chapter on eukaryotes by discussing algae, protozoa and helminths. We review the life cycle of Plasmodium, the protozoa that causes malaria, and cover the different classifications of helminths.

Chapter 5, Episode 5In this episode we explore the characteristics of microorganisms belonging to the kingdom of fungi. What makes them unique, what their morphologies are, the similarities between fungal cells and human cells, and the differences between fungal cells and bacteria. We also briefly touch on mycoses, the fungal pathogens, and end the episode with the benefits of fungi to humans and to our environment.

Chapter 5, Episode 4This episode introduces the Endosymbiotic Theory and explains how complex eukaryotic cells evolved from prokaryotic ancestors. We briefly review the major groups of microbial eukaryotes and highlight the structural features, including mitochondria, chloroplasts, and membrane-bound organelles, that distinguish them from bacteria and influence how we treat eukaryotic pathogens.

Chapter 4, Episode 3This episode examines the internal structures of bacteria, including chromosomes, plasmids, ribosomes, and the powerful survival strategy of endospore formation. We also compare bacteria to archaea and introduce Bergey’s Manual as a tool for microbial identification in clinical and lab settings.

Chapter 4, Episode 2We dive into the external structures that help bacteria move, attach, exchange genes, and survive. From flagella and chemotaxis to pili, capsules, and the Gram-positive vs. Gram-negative cell envelope, this episode connects structure to staining, antibiotic susceptibility, and disease severity. 

Chapter 4, Episode 1This episode explores the structure and “lifestyle” of bacterial cells, from shape and arrangement to biofilm formation and motility. Learn how features like capsules, flagella, and quorum sensing influence infection, antibiotic resistance, and clinical outcomes.

Chapter 25, Episode 16This episode focuses on applied microbiology, water safety, and the One Health concept connecting environmental, animal, and human health. Topics include biotechnology, fermentation, wastewater treatment, waterborne pathogens, and indicator organisms. The episode also discusses spillover events, climate change, vector-borne disease, and how environmental changes can influence infectious disease transmission. Exam 1 Content

Chapter 25, Episode 15This episode introduces microbial ecology and explains how microorganisms are essential for maintaining life on Earth. It focuses on microbial roles in the carbon and nitrogen cycles, decomposition, respiration, fermentation, methane production, nitrogen fixation, nitrification, and denitrification. The episode also highlights how microbes influence ecosystems, climate, and the interconnected concept of One Health.

Chapter 3, Episode 5This episode explains how clinical laboratories identify microbes using a stepwise, evidence-based approach, combining culture, staining, biochemical tests, and molecular methods. You’ll see how rapid, accurate identification guides treatment decisions and why no single test is sufficient on its own.

Chapter 3, Episode 4This episode covers how microscopes and stains allow microbiologists to visualize and interpret microorganisms, emphasizing magnification, resolution, and contrast. You’ll learn when light vs. electron microscopy is used and how staining techniques, especially the Gram stain, provide critical diagnostic information.

Chapter 3, Episode 3This episode focuses on isolation as a foundational microbiology skill, explaining why pure (axenic) cultures are essential for accurate identification. You’ll learn how streak plates, spread plates, and pour plates physically separate microbes and why contamination and mixed cultures complicate interpretation.

Chapter 3, Episode 2This episode explores culture media as diagnostic tools, explaining how media are classified by physical state, chemical composition, and function (general-purpose, enriched, selective, and differential). You’ll learn how microbiologists choose media to encourage growth, suppress competitors, and reveal metabolic traits critical for identification. 

Chapter 3, Episode 1This episode introduces the "Five I's;" Inoculation, Incubation, Isolation, Inspection, and Identification, and explains how they provide a logical framework for working with microorganisms in both teaching and clinical labs. You’ll learn how these steps guide everything from culturing microbes to making reliable identifications."The Five I's" created by Marjorie Cowan, 2024

Chapter 9, Episode 39This episode covers bacterial reproduction through binary fission, generation time and exponential growth, and the phases of the microbial growth curve. It also introduces methods for measuring population size, including turbidity measurements, direct cell counts, and viable plate counts (CFU).

Chapter 9, Episode 38This episode introduces symbiotic relationships, including mutualism, commensalism, parasitism, and antagonism. It also covers microbial interactions within communities, with emphasis on biofilms, polymicrobial environments, and quorum sensing as a mechanism for communication and coordinated behavior.

Chapter 9, Episode 37This episode focuses on environmental factors that influence microbial growth, including temperature classifications, oxygen requirements, and pH preferences. It also introduces reactive oxygen species and detoxifying enzymes, osmotic and pressure conditions, and the impact of these factors on microbial survival and distribution.

Chapter 9, Episode 36This episode covers how microbes are classified based on carbon sources (autotrophs vs. heterotrophs) and energy sources (phototrophs vs. chemotrophs). It introduces combined nutritional categories, growth factors, and the role of the cell membrane in nutrient uptake, including transport mechanisms such as diffusion, facilitated diffusion, active transport, and group translocation.

Chapter 9, Episode 35This episode introduces the chemical requirements for microbial growth, including essential nutrients (CHONPS) and the distinction between macronutrients and micronutrients. It also covers the composition of the cytoplasm as a solution, water movement through osmosis (hypotonic, isotonic, hypertonic conditions), and basic mechanisms cells use to maintain internal balance under osmotic stress.

Chapter 2, Episode 9This episode covers proteins, nucleic acids, and ATP as the core molecules of cellular function. You’ll explore protein structure and function, DNA and RNA as information molecules, and ATP as the cell’s energy currency.

Chapter 2, Episode 8This episode introduces carbohydrates and lipids, emphasizing their roles in energy storage, structure, and membranes. Topics include monosaccharides, polysaccharides, fatty acids, phospholipids, and how molecular structure explains function.

Chapter 2, Episode 7This episode focuses on carbon as the backbone of biological molecules and explains how functional groups determine chemical behavior. You’ll learn how hydroxyl, carboxyl, amino, phosphate, and methyl groups shape molecular structure and function

Chapter 2, Episode 6This episode explains why water is the chemical foundation of life and how its properties influence cellular function. Topics include polarity, solutions, concentration, acids and bases, the pH scale, buffers, and how pH affects enzymes and microbial growth.

Chapter 2, Episode 5This episode reviews the basic chemistry needed for microbiology, including atomic structure, elements essential for life, and the major types of chemical bonds. You’ll learn how polarity, electronegativity, and weak interactions like hydrogen bonds explain biological structure and function.  

Chapter 1, Episode 4This episode explains how microorganisms are classified and named using modern taxonomy. Major topics include the three domains of life, differences between prokaryotes and eukaryotes, binomial nomenclature, and why genetic data is essential for microbial classification and identification.

Chapter 1, Episode 3This episode explores the historical experiments that led scientists to reject spontaneous generation and accept germ theory. You’ll review key scientists, classic experiments, Koch’s postulates, and what a scientific theory really means in microbiology

Chapter 1, Episode 2This episode clarifies the relationship between microbes and disease, emphasizing that most microorganisms are harmless or beneficial. Topics include pathogens vs. microbes, communicable vs. noncommunicable diseases, emerging and reemerging diseases, and the role of host immunity and exposure.

Chapter 1, Episode 1An introduction to microbiology as the study of microscopic life, including cellular and acellular organisms, and why microbes matter beyond disease. Key topics include the seven major groups of microorganisms, pathogens vs. non-pathogens, and the concept of microbial ubiquity. 

Chapter 14, Episode 57Epidemiology studies disease patterns using measures like prevalence and incidence, along with data from diagnosis and reporting systems. It emphasizes how test accuracy (sensitivity vs. specificity) depends on context and highlights the importance of critically evaluating research, especially distinguishing correlation from causation.

Chapter 13, Episode 56Finish the infection cycle by learning how pathogens exit the body and spread to new hosts. This episode covers direct and indirect transmission, reservoirs, carriers, and vectors, as well as the stages of infection from incubation to recovery. It also introduces Koch’s postulates and how scientists determine the cause of disease.

Chapter 13, Episode 55Once inside the body, pathogens must attach, survive, and cause damage. This episode examines the tools microbes use to establish infection, including virulence factors like adhesins, enzymes, and toxins, and explains how infections can remain localized or spread systemically. It also introduces how symptoms develop and the role of the immune response in disease.

Chapter 13, Episode 54Explore how pathogens gain access to the body and what determines whether exposure leads to infection. This episode breaks down portals of entry, infectious dose, and the protective role of the microbiome, while also introducing key concepts like opportunistic, endogenous, and exogenous infections.