This flipped case study is suited for general education undergraduate level biology. Students prepare ahead of time for class by viewing a video created by the authors that reviews the basics of nutrition and digestion; in class, students then engage in three activities to further explore aspects of the video's content using specific and concrete examples of diverse foods. During the first part of the case study, students learn information about balanced diets, nutrition and the digestive system. Students apply their knowledge on how food passes through the digestive tract, and how absorption and breakdown of nutrients occur by explaining and presenting the process based on assigned food items. Students are then asked to further apply their knowledge when presented with two scenarios ("mini-cases"), one involving gastric bypass surgery and the other the effects of cholera.
Across the planet, humans eat on average between 1 and 2.7 kilograms of food a day, and every last scrap makes its way through the digestive system. Comprised of ten organs covering nine meters, this is one of the most complicated systems in the body. Emma Bryce explains how the different parts of the digestive system work to transform your food into the nutrients and energy that keep you alive.
In our first animation of this series we learned how point mutations can edit genetic information. Here we see how duplication events can dramatically lengthen the genetic code of an individual. As point mutations add up in the duplicated region across generations, entirely new genes with new functions can evolve.
In the video we see three examples of gene duplications resulting in new traits for the creatures who inherit them: the evolution of a venom gene in snakes, the evolution of leaf digestion genes in monkeys, and the evolution of burrowing legs in hunting dogs.
This is the updated Amoeba Sisters human organ systems video, which provides a brief introduction to each of the 11 human organ systems including the circulatory, digestive, endocrine, excretory, integumentary, lymphatic/immune, muscular, nervous, reproductive, respiratory, and skeletal systems.
It's one of the big mysteries of cell biology. Why do mitochondria-the oval-shaped structures that power our cells-have their own DNA, and why have they kept it when the cell itself has plenty of its own genetic material? A new study may have found an answer.
Scientists think that mitochondria were once independent single-celled organisms until, more than a billion years ago, they were swallowed by larger cells. Instead of being digested, they settled down and developed a mutually beneficial relationship developed with their hosts that eventually enabled the rise of more complex life, like today's plants and animals.
All adult mammals but humans are lactose intolerant. Follow human geneticist Spencer Wells, director of the Genographic Project of the National Geographic Society, as he tracks down the genetic and societal changes associated with the ability to digest lactose as adults-or lactose tolerance.
ST. LOUIS, MISSOURI-Most of us think of Europe as the ancestral home of white people. But a new study shows that pale skin, as well as other traits such as tallness and the ability to digest milk as adults, arrived in most of the continent relatively recently. The work, presented here last week at the 84th annual meeting of the American Association of Physical Anthropologists, offers dramatic evidence of recent evolution in Europe and shows that most modern Europeans don't look much like those of 8000 years ago.
It is, when you think about it, sort of weird that nearly all mammals lose the ability to digest milk early in life. The Class Mammalia is, after all, defined by the gland that produces this life-giving fluid-supplier not only of necessary nutrients but also of water and molecules that protect against continual assaults from invading organisms.
Life on Earth is intimately connected to the natural cycles of light and dark that make up a 24-hour day. For plants, animals, and even bacteria, these circadian rhythms control many biological functions. Humans can overrule their body clocks, but at a price: People whose circadian rhythms are regularly disrupted-by frequent jet lag or shift work, for example-are more vulnerable to diabetes, obesity, cardiovascular disease, and cancer. There are various theories to explain these associations, and researchers now have a new player to consider: the bacteria that live in the digestive tract. According to a study in mice and a small group of human volunteers, the internal clocks of these gut microbes sync up with the clocks of their hosts. When our circadian rhythms get out of whack, so do those of our bacteria.
Some thyroid 101 background: Your thyroid gland is the butterfly-shaped gland at the base of your neck that secretes two all-important hormones that control major bodily functions (including how you use energy, regulate body temperature, and digest food) and organs (including the heart, brain, liver, kidneys and skin). But with hypothyroidism, your body can have normal to low thyroxine hormone levels and elevated thyroid stimulating hormone (TSH) levels. These high TSH levels are a result of an overworked pituitary gland that is trying to elevate the hormone levels in an inadequately responsive thyroid.
The agricultural revolution was one of the most profound events in human history, leading to the rise of modern civilization. Now, in the first study of its kind, an international team of scientists has found that after agriculture arrived in Europe 8,500 years ago, people's DNA underwent widespread changes, altering their height, digestion, immune system and skin color.
Researchers had found indirect clues of some of these alterations by studying the genomes of living Europeans. But the new study, they said, makes it possible to see the changes as they occurred over thousands of years.
This case study explores the topics of diffusion, osmosis, membrane transport, and the physiological significance of glucose and insulin in the human body. The story begins with a high school athlete, Timmy, who is incredibly efficient at metabolizing carbohydrates for energy; this is where the reader is introduced to normal carbohydrate digestion and metabolism for energy within skeletal muscle cells. As Timmy enters college, he withdraws from sports and physical activity but continues to consume massive amounts of highly soluble carbohydrates, resulting in insulin resistance and ultimately type II diabetes. Throughout the case students are prompted with conceptual questions and interactive figures that require the application and transfer of information they have been introduced to. Originally written for intermediate and advanced physiology courses that cover foundational and complex concepts in science, the case is also appropriate for courses in intermediate biology, nutritional sciences, animal sciences, and exercise sciences.
The bacteria in our guts can break down food the body can't digest, produce important nutrients, regulate the immune system, and protect against harmful germs. And while we can't control all the factors that go into maintaining a healthy gut microbiome, we can manipulate the balance of our microbes by paying attention to what we eat. Shilpa Ravella shares the best foods for a healthy gut.