Introduction: Electron Transport Chain
Among the extensive biodiversity of life that we see around us, green plants are some stupendous group of organisms. With a distinguished ability to fix atmospheric carbon dioxide, these photosynthesizing organisms form the basis of biological existence on this planet. This distinguished ability of plants is not just limited to the carbon dioxide fixation and synthesis of food but also endows the Earth with the resource of atmospheric oxygen which is undoubtedly one of the necessities of animal life.
The electron transport chain forms the basis of photosynthesis. It constitutes the different components of light-dependent reactions. Several electron carriers and protein systems cumulatively give rise to this magnificent electron chain assembly that eventually ensures the establishment of a proton gradient. This proton gradient ultimately serves as the primary driver for the production of the energy molecule of life, i.e., ATP.
So, as we know this topic holds a lot of substance to biological life and hence becomes quite an important concept to deliver objectively to students. With so many details to be taken care of and a multitude of novel ideas, the electron transport chain (ETC) can become a headache for students.
Teachers often struggle to identify the real obstacles faced by students when learning this topic. So, for educators and teachers explaining this topic in their classes, this article can provide help as it highlights the major issues encountered by students and lists practical solutions to resolve them. By the end, we’ll share why a virtual lab simulation will prove useful not only for your students but also for you as an educator to deliver concepts more efficiently.
3 reasons why Electron Transport Chain can be tricky to teach or learn
There are 3 reasons why students are overwhelmed by the topic of Electron Transport Chain (ETC). Acknowledging these blocks is the first step toward making the topic more approachable.
1. Confusion between ETC of Photosynthesis and Respiration
Both photosynthesis and respiration are important metabolic processes. And both of them have their individual Electron Transport Chains (ETCs). Students tend to get confused between the 2 ETCs. Not knowing the basic nature of the “anabolic” photosynthesis process and the “catabolic” respiration process can be a confusing situation to be in for students. Many students also don’t understand ‘why’ and ‘how’ the electron flow is exploited in these processes. Most students also believe “photosynthesis is restricted to plants and respiration is restricted to animals”. But that is only partially true. Yes, photosynthesis is restricted to plants but respiration occurs in both plants and animals. This idea has been the most problematic thing for students to comprehend.
2. It is data-rich and full of complex terminologies
There are several novel terminologies, ideas and concepts in this topic for students to imbibe and memorize. Students often feel the heat when the names of different protein systems (photosystem I and photosystem II), electron carriers (plastoquinone, plastocyanin, ferredoxin), several other components like oxygen-evolving complex, cytochrome, Fe-S complex, ATP synthase, etc involved in electron transport chain are taught to students. Without knowing the roles of these different components and their positions in the chain reaction, it becomes quite a task for students to picture what’s going on at the molecular level.
3. It seems to have no practical applications
Another major issue faced by students while studying ETC is the sheer inability to connect the dots between this heap of information and the real world. Students are rarely aware of why they are being educated about electron transport chains. The importance of plant life on this planet and its indispensable role in the healthy functioning of the ecosystem are often undervalued and go unrecognized. This makes the topic look impractical and not worthy to invest one’s time in. While students understand that the process is wondrous, classroom teaching fails to exhibit any beneficial cause where theoretical knowledge gained from ETC can be practically applied.
5 ways to make Electron Transport Chain a more approachable topic to understand
To address the blocks encountered while teaching this topic, educators can engage the under-listed solutions in their classes. These can clarify many instrumental aspects of the Electron Transport Chain (ETC). Not only can they make teaching easier for educators like you but will also make lessons clearer and easier to assimilate for your students.
1. Build a story; short and simple
Clarify the difference between “Photosynthesis ETC” and “Respiration ETC”: Since this is a major confusion that perturbs most students, educators dealing with this subject should first clarify the difference between the 2 types of ETCs.
Start with the basic plant structure: We recommend teachers dealing with physiology and biochemistry to first clarify the structure of the plant body and how the presence of chloroplasts majorly in the plant’s leaf makes them the primary photosynthesizing organs. At this point, you can explain why chloroplasts are important for the electron transport chain. You can use the Photosynthesis: Electron Transport Chain simulation from Labster to further explain the idea.
Stress on the structure of chloroplasts: You can explain the structure of chloroplasts and the site of electron transport chain reactions. At this point, you can explain the distinction between thylakoids, thylakoid membranes, thylakoid lumen, stroma, lamella, etc.
Explain the sequence in which electrons move: Explain how PS-II, oxygen-evolving complex, plastoquinone, plastocyanin, ferredoxin cytochrome, PS-I, Fe-NADP reductase, and ATP synthase are organized in a chain called “electron transport chain”. Emphasize the importance of each of these membrane proteins and electron carriers. Take it very slowly; otherwise, this can be overwhelming for your students.
Figure: A snippet from Electron Transport Chain simulation from Labster when your students can learn about the molecular structure of a chloroplast and the location of ETC reactions. Full simulation is available for High School and University/College classes.
2. Plan live demonstrations in your class
Teaching sessions with experiments and lively demonstrations are always a treat for the learners, especially when a topic as complex as ETC is being explained. You can plan a classroom demonstration of Hill’s reaction.
Collect some dark-colored algae and use them for a fun-filled class activity.
Discuss the importance of different pigment molecules in green plants.
Contrast them with the probable pigment molecules in the dark-colored algae.
Once the idea of pigment molecules and their importance is delivered, put forth a question if these algae will use red and blue light like the other green plants and algae, or will it use green light.
Now, there could be two situations: (1) Dark-colored algae absorbs and uses the same wavelengths (red and blue light) of light as green plants and green algae, or (2) Dark-colored algae absorb and uses a different wavelength of light (green light).
Make your students analyze both situations and find the reasons for each of those speculations.
Move ahead and posit another question: ‘if the dark-colored algae use green light, is the measurement of electron flow possible using lab tools?’. Here, you can explain the idea of spectrophotometry in your class. You can use the Spectrophotometers simulation and Spectrophotometry technique simulation from Labster to explain the basics of this technique.
While you are demonstrating the measurement technique, you can also briefly discuss the historical work of Dr. Robert Hill. Dr. Hill designed an in vitro experiment for the measurement of electron flow in ETC. You can explain the importance of the redox dye (like DCPIP) that’s used in such a lab-based experiment. Ask them to look out for any changes in the color of the dye (which signifies a change in redox state, i.e. an electron movement in the ETC).
As you’ll notice, such a small demonstration can enable you to deliver insightful points about a range of topics that won’t have been possible in a theoretical teaching session.
Figure: A snippet from Electron Transport Chain simulation from Labster when your students can learn about the different components that constitute the ETC. Full simulation is available for High School and University/College classes.
3. Clarify the basic concepts
Several novel ideas are unknowingly introduced when explaining about electron transport chain. Educators should be cautious when using new terminologies. We recommend you cover the under-listed topics to avoid any confusion later on.
Different wavelengths of light and idea of PAR
Different pigment molecules and their specification for different wavelengths (You can use the Photosynthesis: Algae Pigment Analysis from Labster)
Absorption versus Action spectrum of different pigment molecules
Importance of natural NADPH and its replacement with artificial DCPIP in ‘in vitro experiments
Feasibility of using dark-colored algae for biofuel production (but under a different range of light, i.e. green light)
Importance of lab handling (use of ice buckets, micropipettes, spectrophotometer)
Importance of hypothesis design and testing (You can use The Scientific Method simulation from Labster)
Importance of experimental controls: positive and negative (You can use the Experimental Design simulation from Labster)
Figure: A snippet from Electron Transport Chain simulation from Labster when your students can engage in the spectrophotometric analysis. Full simulation is available for High School and University/College classes.
4. Show them the utility of these ideas in real life
Students often fail to understand the importance of basic science topics like the electron transport chain in real life. Educators can emphasize that the recent industrial shift from conventional sources of energy to sustainable sources is monumental in the history of mankind. You can explain how this is creating a “market for the alternative fuels/biofuels”.
If one understands the Basic Science behind photosynthesis, electron transport chain, pigments, etc, they can innovate and apply their knowledge that potentially can one day produce a “game-changing biofuel”. Such an optimized plant or algae would be able to serve as an exceptional biofuel that can replace conventional harmful fuels.
Quote similar examples to boost students to develop robust core concepts. This can ensure brilliance to perpetuate in the future STEM scientists!
5. Use virtual lab simulations
Many times educators struggle to organize live demonstrations due to the lack of resources or facilities. This is why we encourage modern-day educators to make the most of our Electron Transport Chain simulation.
In our virtual lab, students get the opportunity to help and learn from a group of engineers who are working on a mysterious dark alga. This is a quest to understand if this alga can photosynthesize using green light. If this alga can use green light, it can potentially be used in conjunction with other green plants or algae to maximize the utilization of sunlight. Such a system can serve as a ‘groundbreaking biofuel powerhouse’. With such a handy activity, you can educate your students about the instrumental role of ETC in photosynthesis.
Moreover, your students don’t have to struggle to imagine the different steps and structural components of ETC themselves as our interactive simulation along with gamification elements come to the rescue. By using this way of active and immersive teaching, our virtual learning platform takes an advent in the field of Science to make the upcoming scientists thorough with the “basics of their respective subjects”.
Figure: A snippet from Electron Transport Chain simulation from Labster when your students can actively use the lessons from this topic in the practical world. Full simulation is available for High School and University/College classes.