Cells translate genetic information into proteins using RNA messengers

Watch how proteins are created from DNA

When a DNA sequence—a gene—is activated, a copy of the activated portion is created in the form of RNA, a single-stranded version of DNA, in a process known as transcription. This RNA, called messenger RNA, leaves the nucleus and travels to a ribosome, a structure within a cell, which uses it to build a chain of organic compounds that fold into a protein.

Genes are the basic units of heredity

These segments of DNA—long molecules made of nucleotides that coil into chromosomes—code instructions for making specific proteins, which correspond to different traits. Approximately 98 to 99% of human DNA is non-coding, with functions beyond protein synthesis.

DNA's four-letter blueprint makes the variety of all living things possible

The proteins responsible for cellular functions and an organism's traits are built outside of a cell's nucleus from RNA—single-stranded molecules created by reading the information in DNA. DNA's double-stranded structure makes it more stable and allows RNA to be made from either of its complementary strands.

Recombinant DNA technology turns microorganisms into protein factories

Genes for molecules such as insulin can be inserted into loops of bacterial DNA called plasmids and reinserted into bacteria. Once placed in fermentation tanks, these bacteria use the gene to produce these molecules, which are then harvested and purified for eventual use.

Glowing chemicals allow scientists to read DNA like a barcode

The process of determining the order of nitrogenous bases in DNA involves first cutting the DNA into fragments, which are duplicated multiple times using bacteria. Fluorescently labeled terminator bases are added to fragments, which are sorted by length and read via laser to reconstruct the sequence.

Peptides may have predated ribosomes—the cell's protein factory

Some scientists have hypothesized that peptides and RNA molecules may have coevolved as a single, mixed "chimeric" molecule, fueling the beginning of protein production and predating a primitive version of the ribosome. All life today uses ribosomes to make peptides. (Some users may experience a paywall.)

Bacteria helped scientists realize that DNA was the hereditary molecule, not proteins

Until the mid-1900s, most scientists believed genes were made of proteins, which were known to act as enzymes, hormones, and other chemicals that mediated an organism's traits. The Avery-MacLeod-McCarty and that benign bacteria could be made lethal, where the inherited factor that caused bacterial transformation contained DNA.

Stacking nucleotide molecules like toy blocks helps build DNA's structure

Each nucleotide is made up of a sugar—deoxyribose—a phosphate group, and one of four bases that contain nitrogen. Like building a two-tone, spiral staircase from the ground up, nucleotides are linked one on top of another so that sugars and phosphates alternate. The twisted strands are held together by hydrogen bonds between base pairs.

Where do genes come from?

There are many more genes on Earth today than when microbial life first spawned on the planet about four billion years ago. Many of these newer genes grew from genetic mutations, misprints that slowly drift from the original blueprint via cellular division. If these mutations drift far enough, they can establish a new family of genes, though this process can take well over a million years.

How do you sequence a genome?

If the genome is made up of microscopic chromosomes, how do scientists actually sequence it? Here's a 5-minute video explaining one of the most common processes.

Gene therapy treats a disease by editing its DNA source

This modification is typically performed by viruses, which are naturally skilled at entering cells but have their disease-causing component removed before delivery. Once inside, cells can use the inserted genetic material to produce more helpful proteins, fewer harmful ones, or create new proteins.

Watch how DNA is packaged to a 10,000th of its original size in a cell

In humans, the 2-meter (6.56-foot) molecule wraps around spool-like proteins called histones, forming beads—nucleosomes—that fold up into fibers. These fibers—chromatin—form loops through folding that compress into larger fibers, which tightly coil together to form a chromosome.

What is a cell? A great quick overview.

YourGenome.org furnishes a collection of information on cells and how they work. Every body has trillions of cells, each serving a specific function: making proteins, processing chemicals, and creating energy. Every cell contains a genome, a set of instructions for the cell's function. Brush up on your cells for a better grasp on genetics.

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.

Neurons send signals through electrical impulses and chemical messengers

By converting electrical signals into chemical messages at synapses, neurons allow information to travel throughout the nervous system. With repeated use, synapses grow stronger, enhancing the associations between neurons.

Cells create more organelles and duplicate their genetic material before dividing

As part of the cell cycle, this ensures that after mitosis—the process of cell division—the two resulting daughter cells possess the tools necessary to complete the functions of their parent cell, including accumulating energy and making proteins. During meiosis, four egg or sperm cells are created, each with half the parent cell's DNA.

All publicly available DNA sequences are available at GenBank

The National Institutes of Health's database stores comprehensive, annotated DNA sequences as part of the International Nucleotide Sequence Database Collaboration. It encourages unrestricted data access within the scientific community while allowing submitters to retain intellectual property rights over their data.

Explore the differences between healthy and cancerous cells using a DNA microarray

In this simulation, you will learn how scientists use microarrays to experiment on thousands of genes at the same time. By determining which genes are on or off, users can identify those that contribute to cancer formation.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

The basics behind mRNA vaccines

In this video, Yale experts Saad Omer, MBBS, MPH, PhD; Onyema Ogbuagu, MBBCh; and Akiko Iwasaki, PhD, explain the science behind COVID-19 mRNA vaccines.

Epigenetic clock: DNA alterations on cells that predict biological age

Epigenetics refers to a biological process that controls whether certain genes are expressed or not. With a rising interest in the concept of biological age, researchers have discovered a cellular change known as DNA methylation that leaves a fingerprint on our genome as we age.

What sleep loss does to the brain

Proteins in the brain perform various critical functions, such as helping neurotransmitters function or enabling electrical activity in the organ. These proteins must fold in specific ways to perform their duties, similar to paper airplanes. Sleep deprivation contributes to the gathering of misfolded proteins that aren't shaped correctly for their roles and so accumulate in undesired spaces, such as in the gaps between neurons.

Plant hormones and growth regulators guide growth stages and responses in plants

Plants naturally produce hormones like auxin and gibberellins, while humans apply synthetic or extracted growth regulators to control plant development. These substances influence processes like flowering, root growth, dormancy, and ripening—even in very small doses.

Computer viruses' hijacking abilities led them to be named after biological viruses

Just as their counterparts infect cells and take control of cellular processes to replicate endlessly, computer viruses cannot replicate on their own and must copy their code into host software before duplicating when the program or file is opened. The term "virus" comes from the Latin word for "venom."

The promises and perils of using at-home genetic tests for your health

A primer on genetic testing, personalized medicine, and the promise of pharmacogenomics–the use of genetics to predict an individual's response to a drug.

Understanding how Claude Code and other AI coding agents function

Under human oversight, a supervising large language model interprets user tasks and delegates work to subordinate LLMs, which can generate code, fix bugs, and run tests, often most effectively for proofs of concept. Incremental backups and versioning are crucial when using such agents, which can lose details during their work as a result of compressing context history to work around memory limitations.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Ebola is a filovirus, meaning it resembles a thread under a microscope, though it sometimes twists and can resemble a bowl of spaghetti.

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

'Saturday Night Fever,' the 1977 film that introduced disco to the mainstream, was based on a fabricated magazine story.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

Children are now three times more likely to say they want to be a YouTuber when they grow up than an astronaut, with some even attending 'YouTube camps' that teach kids how to create content for the platform.

The Brothers Grimm were lawyers before they were storytellers, but became interested in fairy tales as they began investigating how rules and customs had been passed down through cultures.

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.

Hear 50 years of iconic hip-hop samples, the genre's foundational looped tracks

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

The term 'algorithm' originated from the Latinized name of al-Khwārizmī, a 9th-century mathematician whose works introduced Arabic numerals and the decimal-based numeral system to Europe and whose treatise 'Al-Jabr' gave algebra its name.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.