- C1 ✏︎ Molecules -
C1.1 - Enzymes & Metabolism (SL/HL)
LECTURE VIDEO
DESCRIPTION
They’re the over-caffeinated, tiny proteins that run your entire body 24/7. They’re biological Pac-Men, molecular matchmakers, and the reason you’re not a pile of unprocessed pizza. They are also the biggest divas in biochemistry.
This video dives into the frantic, microscopic world of enzymes. We’ll first break down how they work, but their activity can be influenced. This video turns up the heat (but not too much!) to explain:
- “Lock and Key” vs. “Induced Fit”: Are they rigid locks or do they give a squishy, enthusiastic handshake?
- Activation Energy: The bouncer at the club of every chemical reaction, and how enzymes fire the bouncer and let everyone in for free.
- Temperature Tantrums: Why a little heat speeds them up, but too much turns them into a permanently scrambled egg.
- The pH Panic: Discover why some enzymes are drama queens that only work in a specific acidity zone.
- Enzyme Concentration: What happens when the matchmakers outnumber the singles?
- Substrate Showdowns: We graph what happens when a party gets too crowded.
Forget boring textbooks. We’re diving into the frantic, microscopic factory inside you. Master the content, ace your exam, and finally understand why your teacher keeps drawing weird pac-men.
It’s time to catalyze your learning!
TIMESTAMPS
STUDY RESOURCES
00:00 – Intro To Enzymes
03:38 – Enzyme Mechanism
07:10 – Lock & Key V.S Induced Fit Model
11:33 – Enzyme Mechanism (Word Summary Diagram)
11:52 – Catabolism V.S Anabolism
14:13 – Real Life Example Of Enzyme
17:22 – Collision Theory
18:31 – Activation Energy
26:28 – Factors Affecting Enzymes [Temperature]
29:09 – Factors Affecting Enzymes [pH]
32:16 – Factors Affecting Enzymes [Substrate Concentration]
34:54 – Measuring Rate
35:56 – Questions & Answers
NOTES – All you need to know in one place!
QUESTIONS – Test your Big Brain!
C1.1 - Enzymes & Metabolism (HL)
LECTURE VIDEO
DESCRIPTION
Forget lone wolf enzymes. In reality, they’re organized into frantic assembly lines. The real plot twist? The final products can travel back to the start and fire their own bosses.
This video tracks the molecular supply chain:
- Intracellular vs. Extracellular: The in-house factory workers versus the reckless demolition crews sent into your gut.
- Linear vs. Cyclical Pathways: Simple step-by-step conveyor belts versus the elegant, recyclable carousel of the Krebs Cycle.
- Competitive & Non-Competitive Sabotage: The bullies who steal the spot versus the vandals who break the machine.
- Mechanism-Based (Suicide) Inhibition: The ultimate mole mission where a fake substrate permanently destroys the enzyme on its way out.
- Feedback Inhibition: The brilliant product that circles back to shut down the very first step of its own production line.
Witness the organized chaos of metabolism, where the product holds the master kill switch and spies work on a suicide mission.
TIMESTAMPS
STUDY RESOURCES
00:00 – Quick Enzyme Recap
01:13 – Intracellular & Extracellular Enzymes
05:37 – Linear & Cyclical Metabolic Pathways
10:53 – Competitive Inhibition
23:50 – Non-competitive Inhibition
29:38 – Competitive V.S Non-competitive CURVE
30:18 – Mechanism Based (Suicide) Inhibition
35:35 – Feedback Inhibition
43:52 – Cofactors Role
45:39 – Questions & Answers (& tchme.org)
NOTES – All you need to know in one place!
QUESTIONS – Test your Big Brain!
C1.2 - Cellular Respiration (SL/HL)
LECTURE VIDEO
DESCRIPTION
Forget “food is energy.” Your cells can’t power a single thought with a glucose molecule. They need a tiny, rechargeable battery called ATP (essential cell cash). Cellular respiration is the frantic, multi-step demolition derby that smashes your food to extract the cash.
This video cracks open the energy vault to explain:
- The Point of the Whole Show: The universal cell energy currenc that powers everything from blinking to thinking.
- Cellular Respiration: The Grand Strategy.The three-act play: Glycolysis, the Krebs Cycle, and the Electron Transport Chain (the grand finale where the real ATP cash is printed using oxygen).
- What Influences the Rate? Why your breathing changes. We’ll look at the effects of temperature, oxygen levels, and substrate availability. Why mitochondria work faster when you’re cold, during a sprint, or after a big meal.
Understand the fundamental, messy, and glorious process that funds your entire existence, one recharged ATP battery at a time.
TIMESTAMPS
STUDY RESOURCES
00:00 – Intro To Cellular Respiration
04:33 – ATP Structure & Function
12:15 – Cell Respiration Explained [Anaerobic]
18:37 – Cell Respiration Explained [Aerobic]
25:19 – Cell Respiration Summary
26:06 – Cell Respiration Equation
30:11 – Aerobic VS. Anaerobic Table Summary
32:06 – Factor Affecting Cell Respiration
35:47 – Questions & Answers
NOTES – All you need to know in one place!
QUESTIONS – Test your Big Brain!
C1.2 - Cellular Respiration (HL)
LECTURE VIDEO
DESCRIPTION
Think of your mitochondria like a tiny, high-tech power plant whose only job is to burn your pizza—very, very slowly—and turn it into usable cellular cash called ATP. It’s less “science” and more “organized food arson.”
Join the slow-motion snack demolition:
- Step 1: Glycolysis. Breaking glucose (originating from your food) into even smaller pieces (yes that is possible) in the cell’s general area (cytoplasm). A teeny tiny little bit of ATP is made, and some “high-energy coupons” (in the form of NADH) which can be traded in later for real cellular cash (ATP), are collected.
- Step 2: Krebs Cycle. Those broken down pieces get dismantled completely (crazy, I know) in the mitochondria. CO₂ is tossed out like trash, and even more coupons (including FADH₂ too!) are gathered.
- Step 3: Electron Transport Chain. All those coupons are traded in to pump protons and build up pressure—like inflating a biological battery. That pressure spins a tiny turbine (ATP synthase) that prints almost all your ATP.
- When the Oxygen Runs Out: No oxygen? The whole fancy system breaks. Your cell panics, recycles what it can, and makes lactic acid instead (hello, muscle burn). It’s messy, inefficient, and basically biochemical crying for help.
Finally understand how your food becomes fuel—without needing a biochemistry degree.
TIMESTAMPS
STUDY RESOURCES
00:00 – Introduction & Outline
00:55 – Cellular respiration Big Picture
03:14 – Oxidation & Reduction (REDOX)
06:01 – Cellular respiration equation
06:45 – Glycolysis
16:55 – Link Reaction
22:37 – Krebs Cycle (Citric acid cycle)
32:00 – Quiz yourself
32:34 – Electron Transport Chain & Chemiosmosis
44:47 – Summary
48:32 – Anaerobic respiration
52:21 – Other respiratory substrates
54:41 – Questions & Answers (tchme.org)
NOTES – All you need to know in one place!
QUESTIONS – Test your Big Brain!
C1.3 - Photosynthesis (SL/HL)
LECTURE VIDEO
DESCRIPTION
Forget complicated steps. At its core, photosynthesis is just plants using sunlight to turn air and water into food. But what makes them speed up or slow down? And how can we measure their snack-making rate?
This video strips photosynthesis down to its sunny essentials—no jargon, just the fun of how plants eat light and what happens when you change their environment:
- The Basic Idea: Sunlight + Water + CO₂ → Sugar + Oxygen. Plants are solar-powered chefs.
- The Rate Influencers: What turns the dials on plant productivity? We’ll test light intensity, CO₂ concentration, and temperature and see why too much of a good thing can be bad.
- Measuring the Snack-Making Rate: How scientists (and you in the lab) can track photosynthesis by measuring oxygen bubbles produced or CO₂ absorbed.
- The Light Spectrum Secrets: Why are plants green? We’ll decode the absorption spectrum (what light chlorophyll soaks up) vs. the action spectrum (what light actually powers photosynthesis). Spoiler: They match almost perfectly.
Get the clear, colourful, and practical lowdown on how plants make food from thin air—and how we can track their progress like tiny, green productivity managers.
TIMESTAMPS
STUDY RESOURCES
00:00 – Intro To Photosynthesis
01:48 – Photosynthesis EXPLAINED
08:00 – Cell Respiration Vs Photosynthesis
08:29 – Autotroph & Heterotroph
09:36 – LIGHT in Photosynthesis
12:14 – Photosynthetic Pigments
16:23 – Absorption & Action Spectrum
20:16 – Chromatography & Pigments
27:06 – Factors Affecting Photosynthesis
35:55 – Measuring Photosynthesis [BIOMASS]
37:58 – Measuring Photosynthesis [BUBBLES]
44:43 – Measuring Photosynthesis [pH]
47:52 – Summary
48:15 – MCQ & Answers
50:47 – Long Answers Question
NOTES – All you need to know in one place!
QUESTIONS – Test your Big Brain!
C1.3 - Photosynthesis (HL)
LECTURE VIDEO
DESCRIPTION
Forget “plants make food from light.” At the HL level, photosynthesis is a breathtaking, two-act biochemical ballet performed inside chloroplasts. It’s a story of photon-powered water-splitting, proton gradients, and a carbon-fixing cycle that literally builds life out of thin air.
This video is your detailed backstage pass to the stage—the chloroplast—and the precise, light-driven choreography that fuels the biosphere:
- Chloroplast Structure: The Stage Setup.Thylakoids as the light-capturing stacks, the stroma as the synthesis fluid, and why this compartmentalization is non-negotiable.
- Act I: The Light-Dependent Reactions.Photons hit Photosystem II, water gets split (hello, O₂!), electrons race down the Electron Transport Chain pumping protons into the thylakoid lumen, and chemiosmosis drives ATP synthase to make ATP. Photosystem I re-energizes electrons to reduce NADP+ to NADPH.
- Act II: The Calvin Cycle (Light-Independent Reactions).Using ATP and NADPH from Act I, the enzyme RuBisCOfixes CO₂ in the stroma. We’ll trace the 3-carbon sugar (G3P) production, and the regeneration of the starter molecule (RuBP) in this ingenious, recyclable carbon assembly line.
Master the elegant mechanics of how chloroplasts transform light energy into chemical energy and sugar—the detailed IB HL way.
TIMESTAMPS
STUDY RESOURCES
00:00 – Intro & Outline
02:15 – Chloroplast Structure
04:05 – Light DEPENDENT Reactions Explained
18:45 – Summary Page [Light DEPENDENT reactions]
19:59 – Photosystems Mechanism Explained
26:20 – Light INDEPENDENT Reactions (Calvin Cycle)
37:24 – Summary Page [Light INDEPENDENT reactions]
38:20 – SUMMARY of Photosynthesis
41:13 – Cyclic VS Non-cyclic photophosphorylation
45:30 – What about lipids, amino acids etc?
46:20 – Cell respiration VS Photosynthesis
47:36 – Questions & Answers
NOTES – All you need to know in one place!
QUESTIONS – Test your Big Brain!
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