Tutor profile: Vinayika P.
Subject: Biomedical Science
Compare and contrast the structural, enzymatic, and functional features of the skeletal muscle (fast-glycolytic and slow oxidative fiber types).
We know that there are many differences when it comes to understanding the different skeletal muscle types. If we start by understanding an example of where and which type of person has an abundance of those certain muscle types. Let's take a look at a cross country runner vs a sprinter. If we were to analyze their muscles, we would see that a cross country runner would have an abundance of slow-twitch fibers, which are also called red muscle, and the sprinter would have more of the fast-twitch fibers, which are also called white muscle. You know when you watch the Olympics track games and see the sprinters go as fast as they can for 30 seconds before collapsing? Well, the reason they can do that and get worn out after 30-60 seconds is that they have an abundance of the white/fast-twitch muscle fibers. These sprinters' muscles are working so hard and so fast that they are not steadily supplied with oxygen. Their muscles instead utilize glycogen, the storage form of glucose and undergo the biochemical process of Glycolysis to rapidly break down that glucose and make a little bit of ATP (2 molecules) to supply to the muscles to keep on contracting. However, even though glycolysis supplies that energy fast, it is not efficient for long-term production and that's why muscles cannot support a 30-minute sprint vs a 30-second sprint. Now, let's talk about the slow-oxidative fibers. These muscle fibers are more abundant in cross country runners, who can sustain long distances and even hours of running. How is that possible? Well, they actually have a more steady rate of oxygen flow as they run and this oxygen is utilized for oxidative phosphorylation, a process that makes ATP (around 28-30 molecules) from one molecule of glucose. This is a tremendous amount to just using glycolysis in the fast-twitch muscles, and therefore the cross country runners can run for longer, although not as hard. The reason they are called red muscle is because of the increased amount of myoglobin, a protein found in RED BLOOD that supplies oxygen to these fibers and also due to mitochondria, the cell organelle where oxidative phosphorylation takes place. In addition, in order to help supply more oxygen to these muscles, there is actually an increased number of capillaries to these muscles, and the more you train for a marathon, the more capillaries form to help to keep up supplying that oxygen to help with oxidative phosphorylation. So to summarize: Fast glycolytic muscles have these characteristics: 1.) Use glycolysis (no oxygen) process to make ATP 2.) White muscle color (lack of myoglobin and mitochondria) 3.) The rapid speed of muscle contraction (allows for a rapid sprint) And, slow-oxidative muscles have these characteristics: 1.) Use oxidative phosphorylation (uses Oxygen) to make ATP 2.) Red muscle color (increase in myoglobin and mitochondria) 3.) Slower speed of muscle contraction (allows for duration and distance running)
Explain the concept of Genetic Drift.
We've all learned about evolution by natural selection, where simply put, the species deemed the most "fit" in terms of color or other characteristics were more suited for their environment and likely to survive and pass on their genes, leading to evolution over time. But how does genetic fit play into the evolution of species? Genetic drift is when there is a change in the allele frequencies due to chance events. It's all based on a game of luck! To give an example, let's say there was a man walking down the sidewalk on his phone, not paying attention to where he was stepping. In his path, there were two mounds of ants, one mound full of red ants, and one mound full of black ants. Let's say that this man squished the mound full of the red ants, but the black ant mound was left untouched. That red ant population is now wiped out and cannot reproduce to pass on that red color trait all due to this RANDOM chance event that the man accidentally stepped on and exterminated a mound of red ants. There are many random type events such as this, including natural disasters. Forest fires don't choose which plants to wipe out and in which part of the world, but the damage is done due to random chance, and that in turn reduces the passing off of alleles to the next generation, reducing that allele frequency.
Subject: English as a Second Language
What external methods can you utilize to make learning a new, necessary language both fun and affordable?
I've taught myself Spanish and am currently learning French through the internet. From my experiences of language learning, I find that the most engaging and valuable, yet free resources are watching TV, movies, and Youtube Vlogs with the subtitles in your target language. Studies show that watching with the subtitles of your language improves your language processing skills from % to %. In addition, you can change your social media to be in the desired target language, in order to obtain exposure to more current variations and even slang of the language! In addition, exploring songs in the target language and translating them with the help of google translate, a valuable resource. Once you have some basic vocab and grammar done, you should keep a journal and record yourself speaking about a topic. And, if you don't know a word, use google and now you will know it! Once you review yourself speaking, hearing yourself will help you catch mistakes in speaking, too! Language learning does not have to be only about grammar, which is very necessary, but it should also be a fun process. Make mistakes! The best way to learn is by actually speaking and letting native speakers help you. As someone who has been there by learning new languages, I want to help ESL students reach English proficiency and even fluency in a more creative way.
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