This interrupted case study examines basic concepts of chemical bonding by telling the story of "Madison," a young girl eager to learn how her hair can transition from natural curls to straight, smooth tresses. The case can be used to teach or review the major categories of bonds (ionic, covalent and hydrogen), major macromolecules of life, and hydrolytic and dehydration reactions. It also explores how chemical relaxers and heat through blow drying and flat-ironing can change the nature of straight, wavy and curly hair through the disruption of protein shape. Students will thus learn what it means when a protein has become denatured and how various variables such as pH, heat and salts can lead to the unraveling of the three-dimensional shape of proteins. This case is suitable for an AP high school course, or for an introductory biology or chemistry course for majors or non-majors. This activity can also be used as a review of basic biology and chemistry for students in an upper-level biochemistry course.
Explore some properties of water with the Amoeba Sisters! It's all about those hydrogen bonds. Terms discussed include adhesion, cohesion, surface tension, specific heat - all made possible by those amazing hydrogen bonds.
A new study, published on Wednesday in Molecular Biology and Evolution, identifies gene variants in Inuit who live in Greenland, which may help them adapt to the cold by promoting heat-generating body fat. These variants possibly originated in the Denisovans, a group of archaic humans who, along with Neanderthals, diverged from modern humans about half a million years ago.
With a dozen or so 140-character dispatches (including three heat maps), Gilad suggested the results published in PNAS were an anomaly-a result of how the tissue samples were sequenced in different batches. If this "batch effect" was eliminated, he proposed, mouse and human tissues clustered in a tissue-specific manner, confirming previous results rather than supporting the conclusions reported by the Mouse ENCODE team.
To keep your kids from developing an allergy to peanuts, should you give them nuts at an early age or withhold them? For years the debate has generated more heat than light, but today a landmark study led by King's College London researchers offers some potent evidence that suggests giving peanuts to infants dramatically decreases the risk of developing an allergy to peanuts.
Squirrels are frequent and beloved residents of college campuses throughout the United States, but oftentimes less welcomed by campus maintenance officials who report squirrels nesting in buildings, interfering with airflow from heating and cooling units, and destroying gutters. In this laboratory case, students act as members of a fictitious "squirrel task force" appointed by their campus administrators to provide recommendations for how to manage their school's squirrel population. Students work in groups to assess the habitat suitability of their campus for squirrels by identifying and measuring trees that provide seasonal food for squirrels, and by identifying desirable hunting perches for common squirrel predators. Students conduct squirrel surveys in designated campus zones to calculate the number of squirrels per acre on their campus and compare it with mean squirrel densities reported in forested areas and at a rival institution. Students then compile and synthesize class data to provide management recommendations for university maintenance officials for either increasing or decreasing campus squirrel populations. Originally developed for an undergraduate wildlife biology course, the case could also be used in a lower-division biology or environmental studies course.
Managing manure to reduce emissions can be economically viable for larger enterprises or cooperative facilities that use the captured methane to generate heat and electricity. For small operators, the offset value alone is unlikely to warrant the large capital cost of infrastructure. This activity contributes to carbon farming.
Agriculture is responsible for 14% of Australia's greenhouse gas emissions and is the dominant source of methane and nitrous oxide, accounting for 56% and 73%, respectively, of Australia's emissions.