Hello biochemians! For my first youtube video review I decided to go with one based on glycolysis since that was a topic that gave me a bit of trouble. I thought this would be a great way of determining the quality of the information content and presentation of the video since if after watching it if I felt as though I understood glycolysis it would mean the video was of a high standard. I’m so relieved to say that the video I’m about to review is amazing! I am really impressed and have a much improved grasp on the topic of glycolysis.
Name of the video: Glycolysis made easy.
Claim of the video: To make glycolysis as easy as possible to understand.
Basic over view of the video:
The 1st molecule to enter the glycolysis pathway is glucose (6C molecule, hexagon shape) the reaction is facilitated by hexokinase which utilizes ATP which is Adenosine with 3 phosphates and in these phosphate bonds energy is stored. Kinase suggests that a phosphate group is either added or removed.ATP donates a phosphate group thus becoming ADP in donating a phosphate group it is donating energy as well. So a phosphate group is added at the sixth Carbon on glucose. This structure is therefore called Glucose-6-phosphate. This first reaction is rate limiting and requires energy (ATP).
The next step utilizes glucose-6-phosphate and the enzyme phosphoglucose isomerase (isomerase meaning the enzyme creates an isomer) which just changes the configuration of glucose-6-phosphate (not adding or subtracting any molecule). Glucose-6-phosphate gets transformed a pentagon structure, there are still 6 Carbon atoms which is called fructose-6-phosphate
Next important step goes from Fructose-6-phosphate to another energy required step. The enzyme phosphofructokinase.ATP comes in and donates a phosphate group to give ADP (as well as energy) and this phosphate group is added to the first Carbon. So the next structure has a phosphate group at the first carbon and at the 6th carbon and is called fructose-1,6-bisphosphate.
Fructose-1,6-bisphosphate is broken down into 2 3carbon structures by the enzyme Aldolase. IT can become either dihydroxyacetone phosphate or by the action of Triphosphate Isomerase it can become glyceraldehyde-3-phosphate. ( these two structures are isomers of one another). Utilizing this step the body regulates how much glycolysis occurs. If too much glycolysis occurs, this reversible reaction favors DHAP which acts like a “brake” on glycolysis. On the other hand if the body requires energy it will promote the formation of glyceraldehyde-3-phosphate.
Next step removes hydrogen ions using the enzyme glyceraldehyde dehydrogenase phosphate. NAD a hydrogen carrier and an inorganic phosphate group come into the reaction and the NAD picks up hydrogen while the phosphate is donated. 1, 3-bisphosphoglycerate (1, 3-bpg) is formed. (1, 3 BPG is a precursor to 2,3-BPG and 2,3-BPG regalutes haemoglobin’s affinity for oxygen in our red blood cells.)
1, 3-BPG is then acted on by phosphoglycerate kinase. This enzyme removes a phosphate from carbon1 so that ADP goes to ATP (bear in mind at this step 2 ATP s being produced since we are dealing with 2 3carbon structures, all these reactions are duplicated.) 3-phosphoglycerate is produced.
Phosphoglyceromutase changes around / mutates the molecule thereby changing 3-phosphoglycerate to 2-phosphoglycerate (takes the phosphate group from the 3rd carbon and attaches it to the 2nd carbon).
Next, Enolase converts 2-phosphoglycerate to phosphoenolpyruvate. In this step, water is released and the oxygen and the hydrogen come from the second and third carbon.
Pyruvate kinase acts on phosphoenolpyruvate, a phosphate group is removed so ADP turns into ATP (an energy producing step).Phosphoenolpyruvate is converted into pyruvate. Pyruvate then goes on to the Kreb’s cycle but if there is no oxygen present it goes on to form lactic acid.
1.Occurs in the cytosol
2.Starts with glucose
3. Ends with 2 pyruvate
4. functions in anerobic and aerobic conditions.
5. 2 ATP used, 4 ATP produced so there is a net gain of 2 ATP per glucose molecule. Also 2 NADH+ and H produced per glucose molecule and 2 H20 per glucose molecule.
Important to memorise:
1.Remember the rate limiting steps, that is, the ones that require ATP.
2. Remember that ATP and ADP regulate glycolysis. When the body needs energy it will promote glycolysis and ATP production and when the body has too much ATP it will down regulate glycolysis.
3.Remember where phosphates and hydrogen enters and leaves.
What I love about this video:
1. To begin the narrator of this video is actually a Doctor. This made me sure that the information was reliable. I felt comfortable knowing that I would be receiving accurate information from someone who is sure to understand glycolysis. The best teachers are those who are very knowledgeable in what they are teaching.
2. The video was very professional the use of already prepared slides of chemical structures and a voice over impressed me in comparison to many other glycolysis videos where by the information is presented using programs such as paint which can be at times difficult to understand the uploader’s hand writing.
3. The information was presented in steps and in order as how they would actually take place, this made it easier to understand.
4. I really love the way the names of the substances involved in glucose (example the enzymes) were broken down and translated so that it was possible to infer what its function was. This will really come in handy to someone like me who is not good at memorizing information and prefers to understand so in an exam . This way if I temporarily forget I can figure out the action of an enzyme for example just based on it’s name!
5. I like that he included a summary of the main points at the end. This could be useful when limited study time is available or If I just want a concise overview of the topic.
6.I especially like that he mentions what should be mentioned to earn extra marks in an exam question on glycolysis. This information is very useful to students because sometimes we are unsure of what or what not to include in our answers.
7. The duration of the video was perfect,not too short not too long. I am actually amazed at the amount of information he was able to provide in this amount of time while moving at a very manageable pace.
Imporvement suggestions: Sorry I have none! I am normally a very critical person and almost always have suggestions for improvement especially with educational youtube videos, but to be honest this video exceeded my expectations. It’s perfectly useful just the way it is, I don’t see any way in which it should be improved.
Conclusion: I was very skeptical about this video’s title and claim but honestly the claim was met. The doctor managed to make glycolysis as easy as possible to understand. If I were to rate this video I would honestly give it 5 out of 5 stars. I was so impressed that I not only liked the video but I also commented. Any student having trouble understanding glycolysis or any one who wants a simple refresher on the topic should check this video out 🙂