Tardigrade

    What do you think the world’s toughest animal is? Is it a bear? How about a lion? If you guessed any land animal, you’re wrong. The world’s toughest animal is actually an extremely small organism that cannot be seen from the naked eye called a tardigrade. Tardigrades are so small, that 90,000 of them can fit into one droplet of water! Usually tardigrades are filtered out when drinking bottled water, but if you have ever drank unfiltered water (from a river or stream or something of that sort), chances are, you probably have digested over three billion tardigrades! But don’t worry about it, tardigrades are completely harmless. Right now, you may be thinking: “how could this tiny animal possibly be the toughest animal in the world?” Well, I’m glad you asked.

    Tardigrades are much tougher than you and I. For starters, they can withstand temperatures as low as -200 degrees Celsius, and as high as 304 degrees Celsius! If you thought that was impressive, then you won’t believe this next fact. Tardigrades can survive without oxygen for up to ten years. They can also withstand pressure six times greater than a human can! You know that feeling your ears get when you go high up in the air or to the very bottom of a swimming pool? Imagine the feeling being one hundred times stronger. Tardigrades are also able to withstand pressures six times the amount of the deepest parts of the ocean, that much pressure could destroy a metal ship!

    Although tardigrades thrive in water, they can go without it for two years straight. They can also go two years without anything to drink, and three years without anything to eat! Tardigrades have adapted to environmental stress by undergoing a process called cryptobiosis. Cryptobiosis is a state in which metabolic activities come to a reversible standstill. It is truly a death-like state; most organisms die by a cessation of metabolism. Several types of cryptobiosis exist, the most common include:

• anhydrobiosis (lack of water);
• cryobiosis (low temperature);
• osmobiosis (increased solute concentration, such as salt water);
• anoxybiosis (lack of oxygen).

Tardigrades can survive dry periods by curling up into a little ball called a tun. Tun formation requires metabolism and synthesis of a protective sugar known as trehalose, which moves into the cells and replaces lost water. While in a tun, their metabolism can lower to less than 0.01% of normal. Revival typically takes a few hours, depending on how long the tardigrade has been in the cryptobiotic state. The longest known time that a tardigrade has spent in this tun is one hundred years!

Vocabulary:

Tardigrade: a minute animal of the phylum Tardigrada; a water bear.

Cryptobiosis: a physiological state in which metabolic activity is reduced to an undetectable level without disappearing altogether. It is known in certain plant and animal groups adapted to survive periods of extremely dry conditions.

Anhydrobiosis: of a usually aquatic organism :  life away from water

Cryobiosis: an ametabolic state of life entered by an organism in response to adverse environmental conditions such as desiccation, freezing, and oxygen deficiency. In the cryptobiotic state, all metabolic processes stop, preventing reproduction, development, and repair

Osmobiosis: a drastic increase of a solute in a concentration

Anoxybiosis: life in the absence of free or atmospheric oxygen

Tun: A cryptobiotic state where an organism remains in a coma-like status until it is removed or removes itself

Metabolism: the chemical processes that occur within a living organism in order to maintain life.

Synthesis: combination or composition, in particular.

Trehalose: a sugar of the disaccharide class produced by some fungi, yeasts, and similar organisms.

The Four States of Matter

Think of an ice cube. It’s extremely cold, right? That’s because it’s a solid, but not all solids are cold, however. Usually, when a liquid turns into a solid it’s because it froze. Then, it turns into a solid! A solid is one of the four fundamental states of matter. It is characterized by structural rigidity and resistance to change shape or volume. Unlike a liquid(which we will talk about later) a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a gas does. In a solid, the molecules have little to no movement.

Next, we move on to liquids. We talked about an ice cube, but what happens when it melts? Then, it becomes a liquid. A liquid can be any type of drink, Coke, Pepsi, Dr Pepper, Mountain Dew, or any other drink you can imagine! There is also a “bad” type of liquid. Agents (a scientific term for liquid) in a science lab typically are dangerous. If you drank those, you would probably need to go to the hospital! A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter, and is the only state with a definite volume but no fixed shape. In a liquid, molecules have a slow movement.

Now, let’s talk about gases. Oxygen, the air we breath, is a gas. So is Helium, that stuff that fills balloons and makes our voices sound funny, is another example of a gas. A lot of gases, like liquids, can be extremely dangerous. Gases are one of the four fundamental states of matter. A pure gas may be made up of individual atoms (ex. a noble gas like neon), elemental molecules made up from one type of atom (ex. oxygen), or compound molecules made from a variety of atoms (ex. Carbon dioxide). A gas mixture would contain a variety of pure gases much like air. In a gas, molecules have a fast movement.

Have you ever seen a bolt of lightning? Have you heard of the northern lights? Well, those are just two examples of what is called plasma. Plasma is an ionized (becoming ions) gas that consists of positive ions and free electrons in proportions, resulting in more or less no overall charge, typically at low pressures (as in the upper atmosphere and in fluorescent lamps) or at very high temperatures (as in stars and nuclear fusion reactors). Plasma can be created by heating up a gas or subjecting it to a strong electromagnetic field applied with a laser or microwave generator. Do you know those purple balls that make your hair stand up or shock you when you touch it? That’s made of plasma. Do you know what else is made up of plasma? Ninety-nine percent of matter in the known universe! Plasma isn’t like solids, liquids, or gases (the other three states of matter). It is so hot, that it could kill a human! Plasma is also known as the fourth state of matter. Plasma’s molecules move extremely fast.

Lastly, there is a way to get from one state of matter to another. That’s what we call phase changes.  Let’s start with a solid. Solids can either become liquids or become gases. Solids become liquids through a process called melting. The typical melting point is 32 degrees fahrenheit. Solids become gases through a process called sublimation. Next, we move on to liquids. Liquids can either become solids or gases. A liquid to a solid is called the freezing point. The typical freezing point is also 32 degrees fahrenheit. A liquid to a gas is called the boiling point. The typical boiling point is 99.97 degrees fahrenheit. Now, we move on to gases. Gases can become either a liquid, a solid, or plasma. Gases become liquids through condensation. The condensing point is typically the same as the boiling point, 99.97 degrees fahrenheit. Gases become solids by a process called deposition. Like sublimation, there is no specific temperature for it to occur. Lastly, gases become plasma through a process called ionization. Ionization does not have a specific temperature, but it is between 10,000 and 20,000 degrees fahrenheit. Yeah, pretty hot right? To conclude, plasma is too hot to become a solid or liquid, so it can only become a gas through a process called recombination. Recombination is when plasma’s molecules connect and don’t move around so fast.

Vocabulary

Solid: One of the four fundamental states of matter. It is characterized by structural rigidity and resistance to change shape or volume. Unlike a liquid(which we will talk about later) a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a gas does.

Four Fundamental States of Matter: Four states of matter are observable in everyday life; solid, liquid, gas and plasma.

Molecules: a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Liquid: a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter, and is the only state with a definite volume but no fixed shape

Agent: A scientific term used in a lab for liquid

Incompressible: not able to be compressed.

Gas: one of the four fundamental states of matter. A pure gas may be made up of individual atoms (ex. a noble gas like neon), elemental molecules made up from one type of atom (ex. oxygen), or compound molecules made from a variety of atoms (ex. Carbon dioxide).

Noble Gases: any of the gaseous elements helium, neon, argon, krypton, xenon, and radon, occupying Group 0 (18) of the periodic table. They were long believed to be totally unreactive but compounds of xenon, krypton, and radon are now known.

Plasma: Plasma is one of the four fundamental states of matter, the others being solid, liquid, and gas. A plasma has properties unlike those of  he other states. A plasma can be created by heating a gas or subjecting it to a strong electromagnetic field applied with a laser or microwave generator.

Ionized: convert (an atom, molecule, or substance) into an ion or ions, typically by removing one or more electrons, or to become converted into an ion or ions; undergo ionization.

Ion: an atom or molecule with a net electric charge due to the loss or gain of one or more electrons

Free Electron: an electron that is not bonded to an atom or molecule and so is free to move under external electric or magnetic fields

Electromagnetic: of or relating to the interrelation of electric currents or fields and magnetic fields.

Phase Changes: A phase change is a change in the state of matter of a sample. A phase change is an example of a physical change. Examples: An example of a phase change is water changing from a liquid to vapor.

Melting Point: the temperature at which a given solid will melt.

Sublimation: Changing directly into a vapor when heated, typically forming a solid deposit against on cooling

Freezing Point: the temperature at which a liquid turns into a solid when cooled.

Boiling Point: the temperature at which a liquid boils and turns to vapor.

Condensation:  1. water that collects as droplets on a cold surface when humid air is in contact with it. 2.the conversion of a vapor or gas to a liquid.

Ionization: the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions, often in conjunction with other chemical changes. Ionization can result from the loss of an electron after collisions with subatomic particles, collisions with other atoms, molecules and ions, or through the interaction with light.

Recombination: the process of recombining things.