Chemistry & Biology: Video Series

Diffusion, in general, is the net movement of particles from areas of high concentration to areas of low concentration. Learn about simple diffusion, channel diffusion and facilitated diffusion with help from a science teacher and field biologist in this free video on chemistry.

Scales are used to measure the mass or weight of a substance, and scales are usually separated into balances and spring scales. Find out how spring scales rely on the stretching or compressing of a spring with help from a science teacher and field biologist in this free video on scales and balances.

Buffer solutions are chemical mixes that resist changes in pH, and when strong acids or strong bases are introduced, they're able to react with it to absorb the solution. Learn about the rise or fall of pH levels in buffer solutions with help from a science teacher and field biologist in this free video on chemistry.

Density is a measurement, and it is found through the equation that states that density is equal to the mass over the volume. Discover methods for finding volume, such as liquid displacement, with help from a science teacher and field biologist in this free video on chemistry.

The nitrogen cycle is the process and movement of nitrogen through ecosystems, and humans affect the nitrogen cycle through the use of fertilizers and chemical additives in soil, as well as through the burning of fossil fuels. Find out how humans have caused a decrease in soil nutrients with help from a science teacher and field biologist in this free video on chemistry.

Natural selection is often referred to as the survival of the fittest, and it comes down to differential survival, the fact that survival is not all random and the inheritance of some variations. Discover why those who are best suited to their environment reproduce more with help from a science teacher and field biologist in this free video on biology.

People need nitrogen in order to build complex organic molecules, and nitrogen is most often found as a gas in the atmosphere. Find out why humans rely on plants to get nitrogen with help from a science teacher and field biologist in this free video on chemistry.

In order to help endangered species, it's important to understand the causes of their endangerment, such as habitat loss, exploitation, pollution, climate change, invasive species and diseases. Learn about community-based conservation with help from a science teacher and field biologist in this free video on biology.

Weather vanes are largely decorative, but they can tell somebody the direction that the wind is coming from by the individual looking at the arrow. Get an accurate reading of wind direction with help from a science teacher and field biologist in this free video on weather.

Distillation is the process of boiling and recollecting water so that the only remaining molecules are hydrogen and oxygen molecules, meaning that distilled water doesn't contain salt. Find out how to distill water with help from a science teacher and field biologist in this free video on chemistry.

Salt won't change the pH of water because it doesn't give any reactions when added to water. Find out if sodium or chlorine changes the pH of water with help from a science teacher and field biologist in this free video on chemistry.

Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required for a reaction to take place. Learn about the induced fit model, and how it's related to enzymes with help from a science teacher and field biologist in this free video on biology.

In order to make liquid oxygen, oxygen needs to be changed from its gaseous form into a liquid, and this occurs at -183 degrees Fahrenheit. Use several cycles of cooling and compression to turn oxygen into a liquid with help from a science teacher and field biologist in this free video on chemistry.

Titration is a common lab technique that is used in chemistry to figure out the concentration of a reactant or reagent. Discover what supplies are needed in a chemistry lab to perform a titration experiment with help from a science teacher and field biologist in this free video on chemistry.

Triglycerides are one of three types of lipids that are commonly referred to as fats, oils and waxes, and triglycerides are made up of a glycerol and a fatty acid. Learn about carbon chains used in the chemical structure of triglycerides with help from a science teacher and field biologist in this free video on chemistry.

CO2, or carbon dioxide, will freeze at -78 degrees Celsius at normal pressure. Find out how a change in pressure can change the freezing point of carbon dioxide with help from a science teacher and field biologist in this free video on chemistry.

Cellular respiration is important to all organisms because it generates energy in the form of ATP, which is used by cells to carry out chemical reactions or metabolism. Find out how 36 ATP result from every broken down glucose molecule with help from a science teacher and field biologist in this free video on biology.

When hot water is combined with salt, the main interaction is the breaking of different bonds that then results in weak bonds or interactions forming between individual molecules. Discover how heat changes the rate of a reaction, but doesn't change the amount of salt that is dissolved, with help from a science teacher and field biologist in this free video on chemistry.

An osmotically active substance is best understood by learning that osmosis is the movement of water from areas of high concentration to areas of low concentration. Find out how osmotically active substances cause osmosis to occur with help from a science teacher and field biologist in this free video on chemistry.

Bacteria are extremely common and abundant in every habitat, and it's estimated that their are 5 nonillion bacteria on Earth. Learn about the role of bacteria in nutrient cycles and as decomposers with help from a science teacher and field biologist in this free video on biology.

The function of the spinal cord is to send signals to and from the brain, and it is able to regulate some of its own reflexes, in addition to being a sort of neural transfer network. Get more information on the spinal cord, a thin bundle of neural fibers, with help from a science teacher and field biologist in this free video on spinal cords and the central nervous system.

Salt crystals are created through a simple process that involves boiling water, measuring out salt until it no longer dissolves in water, and suspending a paper clip or ring a couple of centimeters above the bottom of the container. Form small crystals in a day with help from a science teacher and field biologist in this free video on chemistry.

Squids are cephalopods, and they have an ink sack that contains melanin, which can be shot out through a propulsion system. Learn about the mucus membrane that surrounds a squid's ink sack with help from a science teacher and field biologist in this free video on biology.

Photosynthesis is the way that organisms capture energy from sunlight and translate it into potential work energy, and solar panels work on the similar theory that sunlight can excite electrons to create energy. Discover how humans mimic photosynthesis with help from a science teacher and field biologist in this free video on biology.

Weather vanes have arrows that point in the direction that wind is coming from, and this is achieved through differing surface areas on either side of the arrow. Discover how wind pushes the large surface area side of a weather vane around with help from a science teacher and field biologist in this free video on weather.