Sam (13) asked “What are the building blocks of cells? And does it vary for each cell?”

Up-dated  24/10/2019

Thank you for your question Sam. As usual I put it to a member of my team. Lets see what they say and then, maybe, I can add to it.

Thank you for that team. Cells are obviously very, very important. We, and all, living things are all made up of them. But what about the cells themselves …what are they made of ? A little research shows that all cells contain  proteins, lipids, carbohydrates and nucleic acids. Let’s look at the role of each of these groups of compounds.

Proteins are all important (they are made of things called amino acids BUT enough of that). Proteins have important roles in cells. They provide the cell with energy, they fight infections they help move other components  around the cell.

Lipids are basically fats and therefore are a source of energy. The proteins will access the lipids to help them in their tasks and the Carbohydrates are another source of energy

Nucleic acids are better known as amino acids that make up  RNA and DNA structures. These are probably the most important, ………no I am wrong, the nucleic acid component of the cell needs all the other components to survive. They will not last long if left alone. The nucleic acids are the messengers of the cells. In simple terms they have, in their structure , the message that enables the construction of a living thing (animal, plant) from the activity of the rest of the cell. You could say they are the managers.

A little addition ……. what is an amino acid? Firstly as an acid it contains the -COOH group of atoms. CH3COOH is a familiar acid

Shown here in its structural form

known as acetic acid (vinegar).

Amino acids basically contain NH2 groups instead of CH3 . One of the simplest is glycine.

Proteins also (in some cases) act as catalysts (something that enables a reaction to occur. In these situations they are called enzymes.

I really hope this is helpful. Thanks for the question.

Taj (13) asks ” “What makes some metals more reactive than others?”

Many thanks for that introduction to Taj’s question. the images for the three metals show the electrons in ‘shells’ around the core metal atom.  Taj, you may be interested to know that the electron was discovered in 1897 by Thomson and the arrangement of electrons in shells around the nucleus by Neils Bohr in the 1920’s ….only 100 years ago.

Look at the ‘shells’ …the first one near the nucleus of all the metal atoms contains 2 electrons, the second shell  contains 8 electrons, the third shell contains 18 electrons , the fourth shell contains 32 electrons (which are subdivided into three levels).

It is the outermost shell that is the important one when it comes to chemical activity. If the shell is full (has its load of electrons) the atom is unreactive (noble gases). If the shell is not full …the atom is reactive and the reactivity seems to be linked to how empty the outermost shell is and how close the shell is to the atomic nucleus.

Think about these rules when you look again at the sodium, copper and gold atoms.

Thanks for the question.

 

Oliver (10) asks “Is it possible for any life form on Earth to survive the conditions of outer space?

Oliver, many thanks for the question.

I think it would be very difficult to survive the conditions of outer space. Think about it, no air, very cold temperatures, no water …………but. Think about it ….if anything was to survive in outer space ….. What size would it be, small  or large?  Would it have a thick or thin skin? Would it need lots of oxygen or very little to survive? Would it need lots of food or very little?

….meet the Tardigradum

It is less than 7mm long and has 8 legs

It can survive the pressure of living in deep water trenches and temperatures of over 150 degrees centigrade.

It has been known to survive without water for 30 years.

It has also been shown that it can survive, without protection in outer space.

Maya (10) asks “Neutrons, electrons and protons. What are they? Are they parts of an atom? Am I right?”

Maya, you are right. Neutrons, electrons and protons are all parts of an atom.
When do you think these were discovered? Let me show you the timescale

In 1808 a teacher and scientist called John Dalton discovered the atom.
In 1897 the electron was discovered by a scientist called J.J.Thomson
in 1911 the proton was discovered by a scientist called Rutherford
In 1932 Earnest Chadwick discovered the neutron

All this happened in 124 years! and the final bit ‘the electron’ was only discovered 87 years ago and you are now learning about it. I shall let my friends tell you a little bit about these particles.

 

Ella (10) asks “Was there ever any life form on Venus?”

Many thanks for the question Ella. At the present time there is no evidence that there has been any form of life on the planet Venus. Venus is quite close to the Sun, it is the second planet. Because of it’s closeness to the Sun it is a very hot planet.

It would be brilliant if we did find evidence of life on the other planets of our solar system. It would be evidence that at one time life on Earth was not alone in our Universe. If that was the case we could assume that life could exist on other planets in our Universe.

The planet that is closest to the Earth is Mars. At one stage during its existence Mars had a lot of water on its surface. As life on our Earth originated in it’s oceans any life on Mars might have started in its oceans.

I’ll let my friends continue the conversation.

There are plans to build a new Space Station that will allow humans to go to Mars. Meanwhile there are several mechanical ‘rover’ devices on the surface of Mars which at this very moment are looking for evidence wether life, did once, exist on Mars.

Freddy Benson (11) asked “Is it true that they teleported an atom to the Chinese space station?”

Freddy…first a little background. I asked my team if anybody knew about this , Peter replied…….

Thanks for that Peter.

The Chinese did have a Space Station (Tiangong-1) and some scientists  were trying to teleport a property of an atom to the space station.  It is thought that they managed to get an atom on Earth to share some information instantaneously with an atom on the space station. This has not yet been confirmed. The space station  involved crashed to the Earth  in 2018.

An artist’s concept of China’s Tiangong-1 space station prototype burning up in Earth’s atmosphere during its fiery fall back to Earth overnight on April 1-2, 2018.
(Image: © Alejandro Miranda/Alamy)

Rachitha (8) asked “Which of the following is not a pure substance A.common salt B.sugar C.rain water D.iron

Rachitha, below is a small animation about some pure substances and impure substances.

This animation initially suggests that Sugar, Water and Lemon Juice are pure substances.

The word Pure in science has a special meaning. Something is pure if it is only one substance, not a mixture of different substances …….so the sugar, water and lemon juice are considered pure. Lemonade is a mixture of these pure substances so it cannot be considered as pure.

However, it could be argued that the juice of a Lemon is not pure. It has a sharp taste which suggests that it is an acid. It does in fact consist of a MIXTURE of three acids so it is not pure.

A.  SALT is however pure it only contains a substance called Sodium Chloride.

B. SUGAR is pure if in only contains a substance called Sucrose

C. RAIN WATER is pure if it only contains a substance called H2O.

D. IRON is pure if it only contains Iron atoms. (if you add Carbon to the iron you get a mixture called Steel)

Like the juice of Lemons .. if any of the above (A,B,C or D) contain anything else they will not be pure.

“Will the world ever end?” asks Caroline (10)

Caroline. let us look at the possibilities that the team have suggested.

Yes we are destroying our world. Climate change will in the next hundreds of years will  probably make the Earth unlivable for humans. There might be some animals that will survive so life will survive even if we do not.

There are other things that could destroy our world. An asteroid strike killed the dinosaurs and if there is another strike it could kill humanity. It is reckoned that the Sun is about midway through it’s life. It will at some time begin to die BUT this will not happen for billions of years. When it does die the Earth (our planet) will also die.

Amasidda (?) asked “Give one reason to prove that light is form of energy”

 

Then Amasidda you might be able to answer the question yourself.  Think about what all forms of energy – electric (electricity), light, heat (thermal), movement (kinetic), nuclear, chemical, sound, gravitational, can do. Can they all in some way do work? Can they all be converted from one from one form of energy to another?

What do you think ‘work’ is? Let me know in the comment box below.

Jaydeep (7) asked “Why do sponges absorb more hot water than cold water?””

Thanks team. I agree with you I don’t have an answer to Jaydeeps question. I think the best I can do is try to carry out an experiment to test the observation that you have made.

I would need a sponge (natural or manufactured), a fixed amount of water and a way of drying the sponge. If we are going to do a fair test the sponge must be the same for both the hot water and the cold water test. It also must be in the same condition (preferably dry). I would also need to be aware that you should weigh the water, the weight of hot and cold water must be the same. As water is heated the volume gets bigger.

Jaydeep …maybe you could also try the experiment above and see whether a sponge does absorb more hot water than cold water. You could let me know the result by telling me your result in the comment box below.

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