What are we made of? The unit of life

Last week I was chatting about the basic constituents of the body – quite literally what we’re made of, the elements and the working up of all the systems that join together. This week is a look at the controller of all that stuff – the thing that makes it all happen from our single fused-cell origins to the fully-formed trillions of cells we are today. Our deoxyribonucleic acid (DNA) sits protected in the nucleus of our cells and controls everything we are and everything the cell is and does. I’m sure describing DNA has been done a million times over, so I just want to make it a bit more understandable and tell you how amazing it actually is!

Below you’ll see what DNA actually looks like. It’s only when cells are ready to divide that it’s all coiled up tight into the chromosomes we’re used to seeing – it’s been twisted so much it’s called supercoiled.

dna structure 1

It’s made of things called nucleic acids, attached to a backbone of sugars and phosphates. The nucleic acids are the letters of the genetic code, called Adenine, Thymine, Cytosine and Guanine. In one strand of DNA, there are all these letters and they match the other strand since A only binds with T and C only binds to G, the bits just chemically match up and they seem to like each other!  See the image below, it shows you the chemistry of it all.

Chemical-structure-of-DNA

So great, there’s a big coiled bunch of chemicals held together in strands by this backbone. Crick and Watson theorized this shape it forms – the double helix. Now the fun comes with what all these letters do. When a bunch of letters together do something specific it’s called a gene; it “codes” for proteins. Basically, every three letters correspond to a specific building block – an amino acid. This means joining amino acids together in this specific order makes unique proteins. These fold up in unique ways too to eventually form proteins. It’s proteins that carry messages, give structure, virtually everything that makes cells and the body functional. Humans have about 20,000 genes that all encode proteins, which is a lot, but not really considering how many different functions cells have with all their unique components.

Cells can’t function properly if they don’t have DNA to make and control all the bits to keep it going. This is why there’s a security system in place to make sure that when it comes to making copies of itself, it’s only done if DNA is intact, without any changes being made to any of the letters – these are called mutations. So when the cycle comes round and it’s cell multiplying time, the DNA all condenses into the chromosomes we’re used to seeing. If there are any mutations it stops and will try repair it; if it can’t, it goes through a programmed cell death (apoptosis). If maverick cells ignore this, cells keep dividing until masses form – known as tumors, then certain criteria define it as cancerous.

So it’s pretty amazing stuff this DNA. It’s also true that we share most of it with our friends the chimpanzee. But there are a lot of “conserved sequences” which is why animal models are so useful in experimentation – if they make the same proteins as us, we can see the effects of its mutation or absence by following it around and seeing where it works and what it does. By tagging the proteins the sequence makes with something radioactive or fluorescent it can be tracked to see what’s going on. It’s been revolutionary in understanding countless mutations that can cause diseases and disorders.

Have a look below for the background of genetics and a summary of what DNA is and does. Meanwhile, since it’s summertime, go get some strawberries… and keep a few to extract some DNA for yourself! All you need is some salt, washing up liquid and ice cold rubbing alcohol/vodka. Look here for the instructions!

https://visual.ly/track.php?q=https://visual.ly/community/infographic/science/history-genetics&slug=communityinfographicsciencehistory-genetics From Visually.

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What are we made of? The Basics

I’m not very philosophical, so strictly scientifically – what are we?  It’s a complex thing the body, tiny but important parts all together making a pretty robust organism. There are a few different ways to look at this, it depends on how microscopic you want to go: systems, organs, tissues, cells, molecules, atoms.  You could go smaller but it’s too small for me – quantum mechanics governs that stuff.

You could get roughly 160 billion helium atoms side-by-side in a centimeter but there’s a relatively huge gap between the middle (nucleus) and the electrons whizzing round the outside of the atom.   If the Earth was an atom, the nucleus would be a football stadium. All the space adds up, so we are mostly empty space, but so is everything else!  The atoms that make us are a little bigger than helium, but not hugely…

periodic table

Oxygen ~65%     Part of water (H2O) that’s in every cell in the main fluid of the body.

Carbon ~18.5%     It’s in every carbohydrate, protein, fat, all the organic chemicals in the body.

Hydrogen ~9.5%     The other part of water, and in your organic chemicals too, not very big or heavy, but very important.

Nitrogen ~3.3%     It’s in all your proteins, the amino acids that make them have it and the nucleic acids your DNA is made of.

Calcium ~1.5%     Bones and teeth: we all know how important they are! Also used in signaling to make muscles contract.

Phosphorous ~1%     The major player in energy is something called ATP, the P being phosphorus, so very important! It’s in bones too.

There’s a lot more, like sodium, potassium, and magnesium that help electrical signals in the body, that’s those “electrolytes” you may have seen in sports drinks. There’s probably hundreds of elements inside you, including arsenic and uranium! But the top four make up over 95% of your body weight, so there aren’t much of the others but we need them!

Thinking bigger, we get cells. Cells are amazing: they’re the functional units that make us, the building blocks. We have trillions of them and they’re all specialized.

Cells of the same type grouping together give us tissues; like muscle, nerve and connective tissue.  For example, muscle cells are built to contract, nerve cells are built to pass along electrical charges.  A big tissue is epithelial, made from tightly packed cells forming sheets – barriers to separate bits.

Organs are when you’ve got tissues working together for something specific. The biggest is the skin. Skin is pretty amazing, it has plenty of functions with all the kind of sensors it has.  The liver is the biggest internal organ and it too is amazingly complex with hundreds of vital functions.

Systems of the body are made of a group of organs like the digestive system from mouth, stomach, with a lot of intestines. There’s the respiratory system, cardiovascular, endocrine, immune, skeletal, muscular, lymphatic, reproductive, urinary, nervous… it’s a complex thing the body. This is a good site to learn more about all the different systems and their bits!

The Human Body

There we have the basics of the body, taken down to the littlest bits. Not that you’d put a price on a life, and the body is hugely complex, but if you could sell all the elements – I thought it’d be maybe £100, but a few years ago, the Royal Society of Chemistry ran a competition to guess the value of Benedict Cumberbatch and he went for around £96,500. So who knows your value, you could be worth millions! But let’s just not sell our elements, I mean I’m quite happy with mine?

The science of gin

Time for a drink? Maybe today’s one of those rare occasions where it’s not raining, perhaps it’s actually warm and the yellow thing in the sky makes an appearance. If it’s a pleasant evening then gin is what you need to match it. Gin and tonic maybe? Gin has had a huge renaissance just in the past five years; in Scotland alone there’s been a few brands gaining huge support and many more being set up. One of the main reasons for its popularity for producers is its relative simplicity and speed in making; many whisky distillers have chosen to make gin whilst they’re waiting at least three years for their batch to be ready. If you’ve ever been to a gin distillery you’ll have heard the history of gin, and it is quite interesting; the word itself coming from the dutch “geniver”. Living in Edinburgh it has also been interesting to learn about the local history of gin.

 

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All the different gins across Scotland – there’s quite a few!

To start making your gin, you need some neutral grain spirit. It’s the basic, tasteless, odourless highly pure alcohol used for making spirits like vodka and gin. They come from grain crops that are fermented. Next, you’ll need some botanicals: legally you’ll need juniper berries. It’s the most important and defining ingredient. They grow wild in Scotland but are protected; they’re often imported from other countries like Greece and various places in Europe, southwest Asia, and North America. Juniper is part of the pine family and that’s what it tastes like. It’s been used for hundreds of years for medicinal properties: diuretic, antiseptic, stomachic, antimicrobial, anti-inflammatory, and antirheumatic. They all come from an oil inside; specifically there’s terpinen-4-ol that makes your kidneys filter more, which will make you need the toilet more often (diuretic); there’s amentoflavone that’s found in a few other plants and has a number of properties like antimalarial and anticancer, as well as inhibiting enzymes that metabolise some drugs (in the liver). If you get cold sores a lot, chemicals called desoxypodophyllotoxins might inhibit the virus that causes them (herpes simplex virus) – so drink up! Or just use a normal cream that definitely works… Other parts of the berry – the resins are tars – can be used for topical treatments for things like psoriasis. A really useful little berry then. Find out more about Juniper

Other botanicals add depth of flavour, bind flavours together and add special characteristics. Coriander, angelica, citrus peel and orris root are common ones used. There are a few different ways to infuse the botanical flavours into the gin, the infographic below describes them. You’ll probably add a bit water at some point soon to help everything mix properly. It’s heated and the first to be cooled, the “heads”, aren’t pure and aren’t collected. The product will be about 80% pure, once the product falls under about 60% again it’s not collected. After it all, there will just be the water and what’s left of your botanicals. The stuff that’s not collected for the final product can be scrubbed and the pure alcohol recovered to use again. Your final gin will be roughly 40% ABV (alcohol by volume) if you’re going for Navy Strength, closer to 60% ABV. There’s a bit more to it than that but that’s basically it.

 

The-Chemistry-of-Gin.png
The molecules important in all gins

A good tonic water will complement your gin nicely; the quinine gives a bitter taste and balances it all nicely. Then once you’ve got your bottling and PR sorted, you can go ahead and sell your gin! To get your “perfect serve” you’ll need to match whatever botanicals you have with the contents of good quality tonic, then a garnish of fruit or herb that will complement it too. It really makes all the difference. So you can say it’s for medical reasons, or just because it’s just really refreshing, either way, have a gin. If you want a proper review of any gins, head over to Juniper Daze – Steph’s even got a gin of the month going on!

Ginfographic-2016

The science of cider

Now that we’ve all experienced at least one day of sun so far, I think it’s fair to start planning some relaxing days in the garden just soaking in the warmth, vitamin D and drinking a nice cold beverage. Such a situation calls for cider. The cold, crisp, sweet and fizzy drink is the perfect refreshment. It really is unparalleled in its ability to quench and relax on those warm days. Sure there’s beer but I don’t like beer. There’s wine, but you need a lot of liquid to replenish and feel satisfied. Maybe a cocktail if you can be bothered with all the faff, or a long spirit based drink for a simple solution. But cider, oh cider. It has a complexity of flavour that makes you feel as though you’re drinking something special. You can just sit with a nice pint and feel like you’ve achieved in your life. In hindsight, this post should really have been sponsored by a cider brand… but ah well, I’m new at this.

Away from my self-indulgent delusions of being an eloquent advertiser, let’s get down to some definitions to get us started. Cider is basically fermented apple juice maybe some sugar; usually, there has to be a specific percentage of apple juice to call it cider. Fermentation involves yeast and sugar which provides alcohol (ethanol specifically) and carbon dioxide.

From the beginning then, you get some apples. Good start. It’s not usually your bog-standard apples though, it’ll have to be ones that would normally not be that pleasant to eat. Have you ever tried a crab apple? Different properties make apples more suitable for fermenting – if they are particularly acidic, sugary and high in compounds called tannins (bitter and astringent tasting compounds). Once you have your perfect apples and maybe some extra ones to add sweetness at the end, you need to get them pulped and pressed to get out the juice. If you filter it, it’ll be a clearer cider, or leave it for a cloudy one, depends on what your preference is. Next to ferment it. It would happen by itself by natural yeasts just in the air, but that not very predictable – who knows what kind of cider you’d get from that. Predictable fermentation would use a yeast like Saccharomyces bayanus which is the most common for wines and ciders, you can buy it pretty cheap, just like bread-making yeasts (Saccharomyces cerevisiae for bread, by the way). If you want a dry cider, leave the fermenting going until all the sugars have been used up, otherwise take out the yeast a bit early for a sweeter taste. This is done at pretty low temperatures, colder than room temperature, which is unusual since yeasts like things a bit cozier at maybe 30 degrees. But this low temperature makes things happen a bit slower which seems to benefit cider getting the best out of your apples. You’ll need to leave it a while to mature, all the flavours develop and you can add any extras like fresh apple juice if you want to mix things up a little. Bear in mind adding more sugar to make it sweeter would probably start the fermenting again so you could add artificial sweetener. I’d just keep it natural and see what happens. With all your carbon dioxide being produced it should have some fizz once you bottle your cider, then you can get it chilled and enjoy! Phew. It’s not that complex a process but a lot of tweaks to make to get the taste you’re looking for. See the infographic below for a nice summary of the process and all of the molecules involved in making a tasty fruity pint.

The-Chemistry-of-Cider
The main molecules involved in a pint of the good stuff
The UK is arguably the best place to get a good pint of cider. There’s a lot of big brands and the recent resurgence in popularity means there’s even more choice from loads of smaller brewers. We’re pretty lucky. Everyone’s got their preference, I’m not too keen on a dry cider but it’s got to have plenty flavour. Magners is probably what I’d aim for, the right balance I think. And as I’m sure all the purists will tell you: if it’s not apples, it’s not cider. If it’s pear it’s perry and if it’s any other fruit, alcoholic fruit wine?

THATCHERS_A4_APPLE_TABLE
Example of the variety of apples used in making cider
Unfortunately, if you’re going to drink alcohol and be diabetic, cider probably shouldn’t be your first choice. With all the sugar it’s not to treat you nicely. Up to five teaspoons of sugar are in a pint of cider and not much other nutritional value just calories. There are some antioxidants in cider, about the same as in red wine; I think antioxidants are overrated but they do have value and a genuine function in the body clearing up toxins. With all that sugar though there’s not really much benefit from it: it’s bad for drinking if you are diabetic and drink too much and it could make you diabetic. If you’re drinking responsibly though it’s not too bad. If you are gluten intolerant at least cider is a tasty drink.

sugar content
A few (albeit American) examples of the nutrition of cider compared to popular beers
Below you’ll see an informative wee graphic describing the effects of alcohol on the organs and how alcohol is processed. It’s well known how alcohol can affect the liver and this is because it’s the main site of alcohol metabolism. There are a few enzymes that deal with alcohol and it gets metabolized into something toxic in the first place, but then quickly into something that can be broken up to get rid off. Of course, these enzymes can only work so fast and the alcohol in the bloodstream starts to inhibit brain function, starting from the back. That’s why you get disorientated and stumble as the alcohol gets into the medulla, cerebellum then the big bit, the cerebrum as the alcohol starts affecting the senses, slowing down processing of information we get from the eyes, ears, and nose. Movement slows and responses slow as alcohol hits the motor cortex and then memories in areas like the hypothalamus until you eventually black out as basic processes shut down. The area of the cerebrum controlling behavioral inhibition is affected making most people more social… although some are just annoying. Alcohol affects a lot of processes in the brain, the chemistry of the brain can change dramatically in the presence of alcohol. When you’re taking benzodiazepines they work by increasing the effect of the inhibitory system of the brain – a chemical called GABA. It promotes sedation and relaxation. So when combined with alcohol it can relax you to a dangerous level when heart rate decreases a bit too low to do its job and pump blood enough. I think we all know how important pumping blood is…

http://visual.ly/how-alcohol-travels-through-body

So when you’re relaxing in the sun this summer, just think what that pint of cider is doing to your brain and how it was made. By this point, you’ll probably have lost your inhibition and will explain it all to your friend!

Disclaimer: please always drink sensibly – get some good info at Drinkaware