Water as a solvent. Polar solutes. Hydrophilic and hydrophobic substances.
- Subject:
- Biology
- Chemistry
- Life Science
- Physical Science
- Material Type:
- Lesson
- Provider:
- Khan Academy
- Provider Set:
- Khan Academy
- Author:
- Sal Khan
- Date Added:
- 07/01/2015
Water as a solvent. Polar solutes. Hydrophilic and hydrophobic substances.
Students are presented with the concepts of wetting and contact angle. They are also introduced to the distinction between hydrophobic and hydrophilic surfaces. Students observe how different surfaces are used to maintain visibility under different conditions.
This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:
"EnvironmentalDNA capture is helping researchers do the seemingly impossible: track the numerous plants and animals that call natural waters home. But fishing for so-called eDNA can be precarious work. Each step of the process, from water sampling to DNA detection, is a point of entry for contaminants or of loss for sample material. Now, a new standard could be in the making. Self-preserving and partially biodegradable, this new filtration system eliminates data-compromising steps from eDNA capture while ensuring long-term sample preservation and generating less plastic waste. In standard eDNA collection, a motorized or hand-powered pump is used to force a water sample through a DNA-capturing membrane. The filter housing is then opened and, using sterilized forceps, the membrane is carefully transferred to a vial. Finally, ethanol is added to preserve the captured eDNA while its transported to a lab for sequencing or PCR detection..."
The rest of the transcript, along with a link to the research itself, is available on the resource itself.