Catalysts increase chemical reaction rates by providing a lower energy pathway

To use the various chemicals in crude oil, they must often be cracked—broken down into smaller molecules—to make their processing easier in everyday machines.

Metabolism, a collection of chemical reactions at the cellular level, processes food and converts it into energy to power the body.

Bath bombs can produce endothermic reactions that cool water

In bath bombs containing citric acid and sodium bicarbonate, water facilitates the reaction between the bicarbonate and acid, providing energy as the salt dissolves. The loss of energy in the water reduces the average speed of the water molecules, reducing the temperature of the bath.

Electricity is produced when the ends of a battery are connected by a conducting wire, triggering chemical reactions that release the energy stored in chemical bonds.

Nuclear fusion, where the nuclei of two atoms are combined, can produce near-limitless clean energy, but requires extreme conditions to kickstart because of the natural repulsion of atomic nuclei.

How artificial photosynthesis can help make plastics and fuels using sunlight

These systems link a molecular light absorber to a catalyst that can synthesize fuels—such as ethanol—and ethylene, a precursor to plastics, in a carbon-neutral manner. Because these byproducts have greater energy concentrations than the carbohydrates produced by photosynthetic organisms, research is ongoing to engineer the necessary catalysts.

Spontaneous combustion involves an object igniting on its own

Even without matches, sparks, or external flames, exothermic chemical or biological reactions can increase the internal temperature of objects to the point where they reach a threshold temperature that can cause them to catch fire. Running batteries and fermenting bacteria within compressed materials can build this heat and cause combustion.

Gradual chemical build-up reduces the effectiveness of rechargeable batteries

During charge cycles, small chemical deposits gradually form a film on the electrodes where they make contact with the electrolyte, trapping ions that would otherwise facilitate the flow of electricity. Mechanical degradation from electrode wear and electrical shorting from structural instability can also reduce battery capacity.

How greenhouse gases and climate change impact the efficiency of photosynthesis

A review in the Journal of Experimental Botany found that higher temperatures reduce the efficiency of enzymes involved in photosynthesis and impair a plant's ability to control water loss and regulate carbon dioxide uptake. While increased carbon dioxide levels are understood to accelerate plant growth by boosting photosynthesis, researchers suggest these effects more than offset the potential gain.

Laundry detergents designed for cold-water washes rely on proteins isolated from microorganisms native to cold climates, such as Iceland.

Breaking down the challenges of alkaline environments and how extremophiles survive them

These areas are far less acidic than the interiors of most organisms' cells, and this imbalance draws protons that are needed for various metabolic processes, including energy production, out of cells. To counter these effects, some alkaliphiles have developed stronger proton regulation across their cellular membranes and proteins that drive these processes with greater stability amid such acidity imbalances.

Batteries are likely to stop working sooner in cold temperatures

The electrolyte separating the cathode and anode of a battery can thicken, impeding ion flow. Lower temperatures also slow the rate of chemical reactions, further reducing battery capacity. Large draws of power, such as when using heaters, heated seats, etc., in a car during winter, exacerbate battery drain further.

View the industrial applications of extremozymes, from food safety to antibiotic production

Extremophiles possess unique enzymes and organic molecules that have enabled them to adapt to and thrive in otherwise lethal environments. Because these conditions resemble those found in various areas of manufacturing and production plants, these organisms and their macromolecules can optimize industrial processes where conventional catalysts would lose their ability to speed up reactions.

Nuclear-powered missiles replace chemical combustion with energy from nuclear fission

In these systems, energy is added to an airstream, which passes through a nozzle to generate thrust. Because the amount of energy released per unit mass of nuclear fuel is millions of times larger than that of chemical propellants, nuclear missiles can travel faster and farther with less fuel.

Cells modify their internal spacing to improve biochemical reaction efficiencies

Studies involving microscopy and genetic engineering tools in yeast and human cells show ribosomes act as crowding agents—much like packing peanuts—and their concentrations are actively tuned to alter the rate of cellular functions. However, these concentrations and cell crowding levels vary across different tissues and cell types.

While carbon capture and storage systems collect carbon dioxide at the source, such as power plants, direct air capture systems extract it from the atmosphere.

Particle accelerators propel matter toward small targets at high speed

Devices like cathode-ray tube televisions were once basic particle accelerators, but modern ones, such as the Large Hadron Collider, use massive magnetic fields and circular tunnels to achieve energies high enough to recreate the conditions just after the big bang.

Thermal runaway reactions can cause batteries to catch fire or explode

If a lithium-ion battery is heated, punctured, crushed, or short-circuits due to manufacturing flaws or degradation, the cathode and anode can make contact without the resistance provided by a circuit. The ensuing spike in chemical reactions increases the temperature and can release oxygen, initiating and intensifying burning of the battery's interior.

Atmospheric processes amplify the strength of storms by coalescing clouds

Research has shown that turbulent mixing of air at the edges of clouds and other small-scale thermal activity beneath them help clouds group together, intensifying short bursts of rainfall, especially in tropical regions. Simulations reveal this produces more powerful storms than predicted by older models, though they may occur less frequently.

Why bacterial bioremediation may help counter the negative effects of past chemical solutions

Molecules such as DDT, a synthetic insecticide, and PFAS—"forever" chemicals used to make products resistant to heat, water, and grease—have historically been used across various industries but are now known to be harmful. Microbes that can convert some of these substances into nontoxic products, such as water and carbon dioxide, have already been identified, with ongoing research to find others.

Heat pumps use an easily boilable chemical to regulate temperature

In air conditioners, warm air is pulled from a home to turn a refrigerant into a gas, which is then compressed, raising its temperature. The gas naturally releases this energy to the comparatively cooler environment when exposed, then expands and is reused in the system. Heaters run in reverse, with the refrigerant picking up energy from the comparatively warmer environment.

Internal-combustion engines convert fuel into motion using controlled explosions

Gasoline engines mix fuel and air, compressing it and igniting it to create thousands of tiny explosions that push pistons up and down. This movement spins the crankshaft, which moves a vehicle's wheels.

The depression paradox refers to a lack of energy to take action to help alleviate it

Activities like exercise, even at low levels, have been shown to alleviate some of depression's symptoms for some people. However, depression saps energy levels, making it particularly difficult to motivate oneself to take helpful action.

How sunlight helps chlorofluorocarbons destroy the ozone molecules that block solar radiation

CFCs, which are used in old refrigerants, air conditioners, and aerosol sprays, do not react with atmospheric molecules. Once they reach the stratosphere, ultraviolet radiation breaks chlorine atoms off of them, which can each break apart more than 100,000 ozone molecules, thinning Earth's protective layer against ultraviolet radiation.

Our bodies cool us down by sweating because water requires a significant amount of energy to change state from liquid to gas, making it an ideal medium for carrying thermal energy away from our bodies.

Complex molecular reactions in our tissues cause muscle contraction

When we want to move a muscle, a signal travels from the brain and into the muscle cells in question, sparking a chemical reaction that causes the muscle's smallest contractile units—sarcomeres—to shorten, forcing the muscle to contract.

Cathode-ray tube televisions are examples of electron accelerators

CRT TVs work by converting electricity into heat, which causes electrons to be emitted from the rear of the device in three beams responsible for the colors red, green, and blue. Electromagnets direct electrons to phosphor molecules on the screen, which emit light and illuminate the pixels.

Iron rusts in the presence of water and oxygen because these ingredients enable the metal atoms to release energy and enter a more stable state.

Stress activates the "fight-or-flight" response when we face threats, a reaction that can help keep us alive.

How does your body turn food into energy?

Cells get energy via a process known as cellular respiration, which involves turning glucose into ATP or adenosine triphosphate. Breaking the phosphate bonds of ATP results in usable energy being released into cells, which can then use that energy to power biological processes. This 10-minute video explains how glucose turns into ATP, giving the body the energy it needs to survive.

Fevers are an immune response to create hurdles for pathogens

Substances called pyrogens prompt the brain to raise the body temperature to levels where bacteria and viruses struggle to survive. The higher temps also support immune cells fighting off the invaders.

Too little stress can also harm our health because mild or moderate stress—followed by recovery—helps make us resilient.

The High Luminosity Large Hadron Collider will provide a tenfold increase in particle collisions compared with the initial LHC infrastructure by increasing the number of ions in collision bundles and by concentrating the ion beams.

Glow sticks feed energy released in chemical reactions to fluorescent dyes

When bent, the glass tube inside the stick breaks, releasing hydrogen peroxide into the surrounding solution. The ensuing reaction creates unstable molecules that decompose and release energy, which is then absorbed by molecular dyes that emit light when their excited electrons return to lower energy states.

Artificial photosynthesis turns CO₂ into sustainable fuel

Carbon conversion focuses on a central perplexing question: if carbon dioxide is a leading driver of climate change, and fossil fuels are made of carbon-based molecules, can we devise a way to convert CO₂ into useful alternatives efficiently? This video breaks down a potential pathway using artificial photosynthesis, which uses sunlight to convert CO₂ into fuel.

Comparing bioremediation with other treatment techniques, at three levels of complexity

Physical manipulation, such as collecting and moving contaminated material to a landfill, or chemical applications, which use strong, expensive substances and produce harmful byproducts, can be costly. While bioremediation leverages naturally occurring degradation processes that can be augmented without disrupting impacted ecosystems, these processes may be less effective in environments that bioremediation organisms are not adapted to.

Why the existence of extremophiles greatly improves the odds of life beyond Earth

The conditions for life have long been thought to include liquid water, an energy source, and the essential elements for organic molecules within environments on or near Earth's surface. However, because extremophiles thrive in far more inhospitable environments, astronomers now analyze exoplanets whose characteristics indicate environments that fall within a broader range of possibilities when searching for signs of extraterrestrial life.

Most plastics are not biodegradable because breaking their chemical bonds requires temperatures lethal to most microbes, and these organisms have not been exposed to plastic long enough to evolve the necessary enzymes.

Why the abundance of RuBisCO in photosynthetic cells may come from its inefficiency

Despite pulling about 115 billion tons of carbon dioxide from the atmosphere to build organic molecules each year, the enzyme instead binds oxygen at least one in five times, needlessly costing cells energy. To compensate for this and its processing of no more than 10 molecules per second—versus thousands processed by a typical enzyme—it's become the most abundant enzyme on Earth.

Why Earth would become a more deadly environment without the ozone layer

The ozone layer blocks almost all of the sun's harmful, including dangerous UVC rays that can damage cells by breaking chemical bonds. Without it, rates of skin cancer, crop failures, oceanic die-offs, and widespread ecosystem collapse would increase significantly, making Earth largely uninhabitable.

How scientists are improving on photosynthesis

Researchers increased yield in soy plants by making them better at photosynthesis, the process that powers life. The findings hold promise for feeding a warming world.

Some materials can absorb low-energy light and emit high-energy radiation

Through anti-Stokes cooling, incoming energy is combined with vibrations in a material's crystal lattice to produce a net reduction in its temperature. Using this effect, lasers can be directed at microchip hot spots to help keep data centers cool.

The cycling of carbon via tectonic activity may have facilitated life on Earth

Plates sinking into Earth’s mantle pull carbon from the surface, helping stabilize the atmosphere and climate by removing greenhouse gases from volcanic eruptions. At the same time, magma is a significant contributor of heavy metals and other crucial minerals for life to the surface.

If they could be built, antimatter drives, which run on energy released from the collision of matter and antimatter particles, would be the most efficient engines in existence.

Watch a demonstration of the greenhouse effect with carbon dioxide, where thermal energy is trapped by the gas within a container, causing the temperature to increase.

By absorbing 90% of the thermal energy trapped by greenhouse gases, oceans are providing increasingly more energy to power the rapid strengthening of hurricanes.

The importance of volatile aroma compounds in the flavor quality of food

Processes such as air movement and heating cause food to lose aroma molecules, which studies have shown play a major role in our sense of taste. While losing these molecules to the environment leaves fewer to be processed during consumption to intensify flavor, it can also produce previously nonexistent aroma compounds or release previously trapped ones, altering or enhancing the food's flavor.

Before 1932, when particle accelerators were first used for nuclear research, scientists relied on naturally radioactive substances to advance their understanding of the atomic nucleus.

Lasers can be used to reduce the motion of atoms because particles of light—photons—can collide with particles of matter, as billiard balls do, to slow them down.

Ozone protects against the sun's UV radiation and enhances the greenhouse effect

In the stratosphere, trioxygen molecules can absorb harmful ultraviolet radiation from the sun, preventing it from reaching Earth's surface, where it can harm organisms and raise surface temperatures. In the lower atmosphere, ozone acts as a greenhouse gas, trapping thermal radiation.