Unlocking Cellular Respiration: Virtual Learning in Action
Cellular respiration is one of the most essential biological processes, yet many students struggle to visualize how it works at the molecular level. To help bridge this gap, UniVirtual’s biology course contains high-quality, real-time, 3D animations that bring the whole process to life.
These animations not only illustrate each step of the cellular respiration, but they also prepare students for the activities and challenges that follow within our virtual learning platform. In this part of their studies, they don a shrinking suit, complete with Portable Absorption and Combination Kit (P.A.C.K.), and shrink down to explore the interior of an animal cell.
UniVirtual students gather around the shrinking suit, preparing to enter their cell resp lab
As part of the narrative, an inept lab researcher has accidentally left the shrunken students’ suits without energy! Within the cell, they must learn the steps of cellular respiration to power their suit and return to full size.
Below, we provide an in-depth look at both our animations and subsequent student activities.
“I loved using UniVirtual throughout my semester. It made learning biology more interactive and enjoyable. I hope [my university] continues using it, because it helps students understand the material on a deeper level.”
Glycolysis: Breaking Down Glucose for Energy
How it works
1. Energy Investment – Two ATP molecules are required to oxidize a six-carbon glucose molecule.
2. Splitting the Molecule – The molecule splits into two three-carbon molecules, called G3P.
3. Oxidation and ATP Generation – Each G3P is oxidized by reducing NAD+ to NADH. Two molecules of ADP join each G3P, producing two ATP molecules per G3P.
4. Final Products – Glycolysis yields 4 ATP, 2 NADH, and 2 pyruvate molecules, with a net gain of 2 ATP after the initial investment.
Following the animation, UniVirtual’s students must restore energy to their Portable Absorption and Combination Kit (P.A.C.K.) by completing cellular respiration. The first step is glycolysis, in which they gain the pyruvates needed for subsequent processes.
They begin by collecting glucose molecules using their laser tool and follow on-screen prompts to navigate the cell. Once gathered, they combine the molecules in their P.A.C.K., triggering the glycolysis reaction. The students then store the charged electron carriers in their P.A.C.K., ensuring they have the necessary energy to continue. They have also created pyruvate molecules, which are essential for the next phase of cellular respiration.
Pyruvate Oxidation and the Citric Acid Cycle
How it works: Pyruvate Oxidation
1. CO2 Release – In the presence of oxygen, each pyruvate molecule loses a carboxyl group, forming CO2 that diffuses out of the cell.
2. NADH Formation – NAD+ bonds with an H+ molecule, reducing to form NADH.
3. Formation of Acetyl-CoA and Citric Acid Cycle – The remaining carbon joins CoA to form Acetyl-CoA, which then enters the Citric Acid Cycle, also known as the Krebs Cycle.
How it works: Citric Acid Cycle
1. Formation of Citrate – Acetyl-CoA combines with a 4-carbon molecule (Oxaloacetate) to form a 6-carbon molecule, Citrate. CoA is released.
2. Carbon Removal and NADH Production – A carbon is removed, forming CO2, and NAD+ is reduced to NADH. This process happens twice, producing two CO2 and two NADH.
3. ATP Production – Through rearrangement of bonds, ADP is converted into ATP.
4. Electron Carrier Reduction – The remaining 4-carbon molecule is oxidized twice: first, reducing FAD to FADH2, then reducing NAD+ to NADH, regenerating Oxaloacetate for the next cycle.
5. Cycle Completion – Since two Acetyl-CoA molecules enter per glucose molecule, the Citric Acid Cycle produces a total of 6 NADH, 2 FADH2, 4 CO2, and 2 ATP per glucose.
Now deeper inside the cell, the UniVirtual student navigates to and enters the mitochondria, collecting the necessary molecules for Pyruvate Oxidation and the Citric Acid Cycle. They gather CoA and NAD+ to initiate the oxidation process and prepare for the next phase.
Managing inventory is key, as students must free up space and continue gathering components. Once enough materials are collected, they trigger further reactions, store the appropriate electron carriers, and prepare for the Electron Transport Chain.
The Electron Transport Chain: Powering ATP Synthesis
How it works
1. NADH & FADH2 Donate Electrons – NADH transfers electrons to Complex I, while FADH2 transfers electrons to Complex II.
2. Electron Transport & Shuttle Molecules – Ubiquinone and Cytochrome C move electrons between complexes.
3. Final Electron Acceptor – Oxygen bonds with H+ and electrons to form water.
4. ATP Synthesis – Hydrogen ions flow through ATP synthase, generating ATP through oxidative phosphorylation.
5. Continuous Process – This happens constantly, fueling energy production in the cell.
Inside the mitochondria, the student now needs to approach Complex I to initiate the ETC process, which results in the production of ATP. This ATP is then collected at the ATP Synthase to recharge their P.A.C.K. Once they have collected enough and the PACK is recharged, they are able to return to their normal size.
“This was an awesome way to learn the labs. A lot of the time I struggle to understand the processes in biology because I simply can’t imagine it. This method was a great way to resolve that problem.”
Bringing Science to Life in Virtual Classrooms
By integrating animations with interactive gameplay, UniVirtual provides dynamic experiential learning that helps students engage with complex biological processes in a more memorable and exciting way.
Whether you're an instructor looking for a classroom resource or a student seeking to master cellular respiration, UniVirtual offers a valuable tool to help deepen understanding.
Eager to add UniVirtual to your classroom? Visit our course page to learn more.