MCAT Basics (from MedSchoolCoach)

In this episode, we explore enzyme kinetics and inhibition, key concepts for the MCAT Bio/Biochem section. We’ll cover how enzymes accelerate biological reactions by lowering activation energy and introduce two models for enzyme-substrate interaction: the lock-and-key model and the induced fit model. You'll learn how to apply the Michaelis-Menten equation, focusing on factors like Km and Vmax to understand enzyme efficiency and substrate binding. We’ll also break down the different types of enzyme inhibition—competitive, non-competitive, and uncompetitive—and their effects on enzyme activity. Finally, we discuss the six major types of enzymes and their roles in biological processes, with examples like ligases, isomerases, and hydrolases. Visit MedSchoolCoach.com for more help with the MCAT. Jump into the conversation: (00:00) Introduction to enzyme kinetics and inhibition (01:58) Definition of enzymes and their role (03:50) Enzyme models: lock and key vs. induced fit (06:28) Michaelis-Menten Equation (10:53) Association and dissociation constants (12:34) Kcat and catalytic efficiency (14:43) Assumptions of Michaelis-Menten (18:23) Lineweaver-Burk Plot: linearized Michaelis-Menten Equation (21:09) Enzyme inhibition: reversible vs. irreversible (22:14) Competitive inhibition: Km and Vmax (24:46) Non-competitive inhibition: Effects on Km and Vmax (27:20) Irreversible inhibition (29:13) Allosteric inhibition (31:26) Homotropic and feedback inhibition (37:40) Common biological enzymes: dehydrogenase, synthetase, and kinase (43:44) MCAT Advice of the Day

Amino acids are the building blocks of life and an essential topic for the MCAT. In this episode, host Sam Smith takes us through the key concepts of amino acids, including their structures, naming conventions, and roles in protein formation. We’ll cover the differences between hydrophobic and hydrophilic amino acids, how to memorize single-letter abbreviations, and the importance of charged amino acids in physiological conditions. Additionally, Sam touches on mutations and how they can affect protein folding and enzyme function. Visit medschoolcoach.com for more help with the MCAT. Jump into the conversation: (00:00) Intro (01:47) Amino acids naming conventions and abbreviations (04:49) Hydrophobic vs. hydrophilic amino acids (05:39) Charged and uncharged amino acids (10:14) Explanation of mutation notation (11:53) Mutations affecting the substrate pocket of enzymes (13:15) Mutations impacting enzyme functionality (15:58) Role of amino acids in protein tertiary structure (17:15) Salt bridges and protein stability (20:47) Quiz

The electron transport chain is a fundamental pathway in biochemistry, critical for understanding the energy production that powers cellular function. In this episode, guest host Alex Starks breaks down the intricate process of the electron transport chain (ETC). Building on previous discussions of glucose metabolism, Alex walks through the components that play key roles in the movement of electrons through complexes within the inner mitochondrial membrane. We also cover the functions of coenzyme Q and cytochrome c, as well as oxygen’s critical role in completing the process. Visit medschoolcoach.com for more help with the MCAT. Jump into the conversation: (00:00) Intro (02:11) Recap of glycolysis, pyruvate, and the Krebs cycle (03:02) Location of the TCA cycle and ETC in the mitochondria (04:22) Overview of NADH and FADH2 production (05:38) Complex I: NADH dehydrogenase and coenzyme Q (08:00) Complex II: Succinate dehydrogenase and FADH2 (11:15) Complex III: Cytochrome c reductase and the role of proton pumping (14:32) Complex IV: Cytochrome c oxidase and oxygen (18:14) The role of ATP synthase (21:47) Total ATP yield from aerobic respiration (26:00) How the electron chain is disrupted (30:20) Uncouplers and their metabolic effects (35:16) Quiz

This MCAT podcast covers the respiratory system. First, I cover the anatomy of the respiratory system. Then, I dive into its main functions: Gas exchange (breathing mechanisms here too) Thermoregulation Particle filtration pH control Lastly I talk about how the respiratory system is controlled. Please email me if you have any comments or concerns: MCATpodcast@medschoolcoach.com To learn more about how MedSchoolCoach can help you along your medical school journey, visit us at Prospective Doctor. Thanks for listening!

One of the most fundamental biochemical processes is the Krebs cycle. This metabolic pathway plays a critical role in both the Chem Phys and Bio/Biochem sections of the MCAT, so understanding it is key. In this episode, our guest host, Alex Starks, walks us through the transformation of pyruvate into acetyl CoA via the Pyruvate Dehydrogenase Complex (PDC). We’ll explore how thioester bonds help transfer energy within the cycle, how acetyl CoA combines with oxaloacetate to form citrate, the difference between enzymes like synthetases and synthases, and how GTP is produced. We’ll also make connections to the electron transport chain and discuss how the TCA cycle influences blood pH through CO2 production. Visit medschoolcoach.com for more help with the MCAT. Jump into the conversation: (00:00) Intro (01:05) Recap of glycolysis and pyruvate (02:45) Pyruvate dehydrogenase complex (PDC) (03:40) Role of acetyl CoA in the Krebs cycle (05:37) How citrate is formed (07:17) How isocitrate is formed (10:00) How alpha-ketoglutarate is formed (13:42) How succinate and GTP are formed (16:28) How succinate, fumarate and oxaloacetate are formed (18:23) Fumarate converted to malate (21:53) Recap of the Krebs cycle and ATP yield (25:00) Regulation of the Krebs cycle (26:16) Quiz

In this episode, we dive into psychological disorders, a crucial topic for the Psych/Soc section of the MCAT. We’ll start by defining what a psychological disorder is, highlighting key concepts like significant stress and deviant behavior, and discussing how they’re classified using the DSM-5. You'll learn about various categories of disorders, including anxiety disorders, obsessive-compulsive disorders, trauma and stressor-related disorders, and more. We’ll explore the biopsychosocial and biomedical approaches to understanding these conditions, providing insight into the biological, psychological, and social factors that contribute to mental health issues. By the end of this episode, you'll have a comprehensive understanding of the different types of psychological disorders and how they are categorized and treated, helping you tackle related questions on the MCAT. Visit MedSchoolCoach.com for more help with the MCAT. Jump into the conversation: (00:00) Intro: Med School Coach promotion and podcast introduction (01:03) Overview of Psychological Disorders: Episode topics and structure (02:13) Defining Psychological Disorders: Significant stress and deviant behavior (05:29) Biopsychosocial vs. Biomedical Approaches: Holistic vs. traditional perspectives (09:18) DSM-5 Classification of Psychological Disorders: Overview of main categories (10:37) Anxiety Disorders: Fear and anxiety beyond normal levels (16:43) Obsessive-Compulsive Disorder: Obsessions and compulsions explained (18:20) Trauma and Stressor-Related Disorders: PTSD and related disorders (19:19) Somatic Symptom Disorders: Physical symptoms causing mental distress (22:01) Bipolar and Related Disorders: Mood swings and differentiating Bipolar I and II

In this episode, we cover the topic of work and energy. We’ll start off by talking about work, which includes the mathematical and conceptual definitions and the sign convention of work. We’ll also talk a little bit about mechanical advantage and also path dependency. Moving on to energy, we’ll talk about the general definition of energy, we’ll compare and contrast energy in work and the different types of energy that includes kinetic energy, potential energy, thermal energy, and total mechanical energy. Lastly, we’ll talk about energy transfer, specifically heat transfer, and the three types of convection, conduction, and radiation. Visit MedSchoolCoach.com for more help with the MCAT. Jump Into the Conversation: 00:00 Introduction 05:27 Summary: Limits of equation for work and force 08:39 Positive work: force and displacement in same direction 09:32 Comparison of mechanical and thermodynamic work sign conventions 12:50 Work changes kinetic energy of moving objects 16:32 Friction and energy 22:25 Pitching 27:10 Kinetic and potential energy relation 32:14 Sun and heat transfer

In this episode, we'll explore three crucial hormone axes: the hypothalamic-pituitary-adrenal (HPA) axis, the hypothalamic-pituitary-gonadal (HPG) axis, and the renin-angiotensin-aldosterone (RAAS) system. We'll decode the complex interplays among the hypothalamus, pituitary gland, and various peripheral organs, focusing on how these hormone systems regulate everything from stress responses and reproductive functions to blood pressure and fluid balance. We'll break down the HPA axis and its pivotal role in stress response, featuring hormones like corticotropin-releasing hormone (CRH) and cortisol. Next, we’ll navigate through the HPG axis to understand the hormonal orchestration behind testosterone, estrogen, and progesterone production. Lastly, we’ll zero in on the RAAS system, demystifying its essential function in blood pressure regulation and electrolyte balance. Visit MedSchoolCoach.com for more help with the MCAT. Jump into the conversation: [00:00] Introduction to the MCAT Basics Podcast with host, Sam Smith [03:11] Hypothalamus: brain section, regulates hormones, monkey bread. [08:57] Hypothalamus releases hormones to stimulate pituitary gland. [12:12] Cortisol is a crucial stress response hormone. [13:12] Steroid hormones need carrier proteins for transport. [17:05] Hypothalamic pituitary gonadal axis involves important structures. [21:01] Hypothalamus releases gonadotropin hormone for sex development. [27:14] Sex hormones regulate important body functions through feedback. [28:31] Juxtaglomerial cells respond to changes in blood pressure. [33:20] Angiotensin III and IV stimulate aldosterone release. [35:36] Renin angiotensin system increases sodium, blood pressure.

In this episode of MCAT Basics, we’ll cover Electrochemistry. We start with the role of salt bridges in electrochemical cells and cover the intricacies of cell notation. We’ll also discuss how ions maintain charge balance, the importance of reduction and oxidation potentials, and how these elements come together in galvanic and electrolytic cells. We’ll also take a closer look at concentration cells and the critical Nernst equation, which helps us understand cell potentials under non-standard conditions. Visit MedSchoolCoach.com for more help with the MCAT. Jump into the Conversation: [00:00] Introduction to MCAT Basics [01:09} Introduction to Electrochemistry [03:20] Concentration cell: same metal, different ion concentrations [13:05] Visualizing galvanic cells using royal analogy [22:19] Reduction potential, oxidation potential, cell potential explained [30:47] Electrochemical cells, Gibbs free energy, and Nernst equation [41:16] Electroplating and electric current to coat metals [45:40] Electrochemistry in Nanobiology: measuring oxidation of molecules

Understanding the kidneys' role in the body’s balance is essential for the MCAT and beyond. In this episode, host Sam Smith discusses renal physiology, covering everything from kidney anatomy to the nephron’s critical functions in filtration, reabsorption, secretion, and excretion. You’ll explore the roles of the renal cortex and medulla, learn about the loop of Henle, and uncover the importance of ions, plasma volume, and pH regulation in kidney function. Plus, we’ll examine hormones like ADH and aldosterone and their impact on fluid balance, as well as essential measurements like glomerular filtration rate (GFR) for assessing kidney health. Visit MedSchoolCoach.com for more help with the MCAT. Jump into the conversation: (00:00) Intro to renal physiology (02:43) Kidney anatomy overview (08:38) Nephron structure and function (09:50) Six key functions of the kidney (12:03) Nephron Processes: Filtration (17:32) Nephron Processes: Reabsorption and secretion (22:51) The Loop of Henle (26:05) Understanding osmolarity in the Loop of Henle (26:55) Ion transport in the ascending limb (32:04) The role of the collecting duct (37:18) Hormonal regulation of the nephron (46:50) Key measurements of renal function (50:15) MCAT Advice of the Day

Thermodynamics is fundamental to mastering chemistry concepts and understanding the energy dynamics within biological systems crucial for the MCAT. In this episode, host Sam Smith dives into the laws of thermodynamics, covering everything from the zeroth law to the third. You'll explore key concepts like enthalpy, entropy, and Gibbs Free Energy and learn how they apply to reaction spontaneity and equilibrium. Sam also gives practical examples, including how the equilibrium constant and reaction quotient (Q vs. K) affect reactions, and covers types of heat transfer—conduction, convection, and radiation—essential for the Chem/Phys section. Visit MedSchoolCoach.com for more help with the MCAT and use promo code PODCAST to receive a five percent discount on your first session. Jump into the conversation: (00:00) Intro (01:03) Introduction to thermodynamics (03:58) The four laws of thermodynamics (12:46) Thermodynamic variables: entropy, enthalpy, and Gibbs Free Energy (24:11) Phase changes in thermodynamics (25:30) Gibbs Free Energy and spontaneity of reactions (38:01) The three types of heat transfer: conduction, convection, and radiation