Cellulose

Plants use this to stay strong.

It is found in green plants and algae. It is also in wood and cotton.

This stuff is very common on Earth. It helps plants hold their shape. It works like a strong frame.

We use it to make paper. It can also make things like cellophane.

Some animals like cows can eat it. Tiny bugs in their bellies help them. It is a part of our world!

Cellulose is a very common material on Earth.

It is a part of many living things. It makes up the cell walls of green plants and algae. It is also in wood and cotton.

Cellulose is made of long, straight chains. These chains are built from many small pieces called glucose units. These units link together like a long string. Many strings sit side-by-side and stick together tightly. This makes the material very strong. In wood, it works like steel bars in concrete. It helps plants and trees stay stiff and hold their shape.

Humans use cellulose to make many things. Most paper and paperboard come from it. It can also make things like cellophane and rayon. Some scientists are even working to turn it into fuel.

Most animals cannot eat cellulose on their own. However, some animals like cows and termites can digest it. They have tiny living things in their guts. These small helpers break the cellulose down so the animals can use it. In our own bodies, cellulose is a type of fiber. It helps our bodies stay healthy during digestion.

Cellulose is a very important building material found in nature. It is the most abundant organic polymer on Earth.

This means it is a huge, natural substance made of repeating parts. You can find it in the cell walls of green plants and many types of algae. Some bacteria even make it to build films.

It is a key part of many things we see every day. Cotton is made of 90% cellulose. Wood contains between 40% and 50% cellulose. Dried hemp has about 57% cellulose.

This material works by building long, straight chains. These chains are made of many small units called D-glucose.

These units link together in a specific way called a β(1→4) bond. Unlike starch, which coils or branches, cellulose stays in a stiff, rod-like shape. These rods sit side-by-side and stick together using hydrogen bonds.

This creates strong bundles called microfibrils. In wood, these fibers work like steel bars in concrete. The lignin in the wood acts like the hard cement that holds the fibers in place.

People have been studying cellulose for a long time. A French chemist named Anselme Payen discovered it in 1838. He was able to pull it away from plant matter. Later, the Hyatt Manufacturing Company used it to make celluloid in 1870. This was the first successful thermoplastic polymer. In the 1890s, people began making rayon, which is like artificial silk. Cellophane was invented in 1912. In 1920, Hermann Staudinger figured out its polymer structure. Scientists Kobayashi and Shoda finally made it in a lab in 1992.

Cellulose has many different uses and facts. It has no taste and no smell.

It does not dissolve in water. Most paper and paperboard come from cellulose. It can also be turned into cellophane or rayon.

Some scientists are even working to turn energy crops into biofuels. These are fuels like cellulosic ethanol. Cellulose can also melt at a very high temperature of 467 °C.

Not all living things can use cellulose the same way. Most mammals cannot digest it. However, some animals like cows and termites can.

These animals have tiny living things in their guts to help them. For example, a protozoan called Trichonympha helps termites. In humans, cellulose is part of the fiber in our food. It is a hydrophilic bulking agent. This means it holds water and helps our bodies move waste through our digestive systems.

Cellulose is a vital organic compound found throughout the natural world. It is the most abundant organic polymer on Earth.

Chemically, it is a polysaccharide with the formula (C6H10O5)n. This formula tells us that cellulose is a long chain made of many repeating units. These units are known as D-glucose. Cellulose serves as a primary structural component for many organisms. It builds the cell walls of green plants, various algae, and oomycetes. Some bacteria even secrete it to create biofilms.

The structure of cellulose is what gives it such incredible strength. Each D-glucose unit connects to the next through a β(1→4)-glycosidic bond. This specific linkage creates a straight, unbranched chain. This is very different from starch, which coils or branches. Because of this, cellulose molecules take on a stiff, rod-like shape. These rods sit side-by-side and form hydrogen bonds with one another.

These bonds hold the chains together into bundles called microfibrils. In plant stems and wood, these microfibrils are meshed into a matrix. You can think of this like reinforcement bars in concrete. In this analogy, the cellulose fibers are the bars, and the lignin is the hardened cement holding them together.

Scientists have identified several distinct types of cellulose. These types are categorized by how the hydrogen bonds are arranged. Natural cellulose is known as cellulose I, which includes two structures called Iα and Iβ. Bacteria and algae often produce cellulose enriched in the Iα form. Higher plants mostly consist of the Iβ form. When cellulose is processed into fibers, it becomes cellulose II, also called regenerated cellulose. The change from cellulose I to cellulose II is irreversible. This suggests that cellulose I is metastable, while cellulose II is more stable.

The history of cellulose research spans nearly two centuries. In 1838, the French chemist Anselme Payen isolated it from plants. He was the first to determine its chemical formula. In 1870, the Hyatt Manufacturing Company used it to create celluloid. This was the first successful thermoplastic polymer. The late 1800s and early 1900s saw many more inventions. Rayon production began in the 1890s, and cellophane was invented in 1912. In 1920, Hermann Staudinger discovered the actual polymer structure. Finally, in 1992, Kobayashi and Shoda achieved the first chemical synthesis of cellulose without using biological enzymes.

Cellulose is found in massive quantities in many common materials. Cotton fiber is composed of 90% cellulose. Wood contains between 40% and 50% cellulose. Dried hemp contains approximately 57% cellulose. These high concentrations make cellulose a primary source for industrial products. Most paper and paperboard are produced from cellulose. It is also used to make cellophane and rayon. Today, researchers are even developing ways to turn energy crops into biofuels, such as cellulosic ethanol.

In living organisms, cellulose is built through a complex biological process. In plants, this happens at the plasma membrane using rosette terminal complexes, or RTCs. These are protein structures about 25 nm in diameter. They contain enzymes called cellulose synthases that "spin" microfibrils into the cell wall. These enzymes use UDP-glucose to build the chains.

While most mammals cannot digest cellulose, some animals can. Ruminants like cows and sheep have symbiotic microorganisms in their guts. These microbes produce enzymes called cellulases to break the cellulose down. Termites also use similar methods with protozoa or bacteria in their digestive tracts.

Cellulose also reacts to extreme heat through a process called thermolysis. When heated above 350 °C, it decomposes into char, vapors, and gases like carbon dioxide. If heated to 500 °C, it produces a maximum yield of vapors that condense into a liquid called bio-oil. During this process, the cellulose goes through a very fast transition from solid to liquid to vapor. This chemical breakdown is known as hydrolysis. In the human body, cellulose acts as an insoluble dietary fiber. It is hydrophilic, meaning it attracts water. This helps it act as a bulking agent to aid in digestion.