Why isn’t beetroot dye broken down by digestion?

Why isn’t beetroot dye broken down by digestion?

Well, in some people it is, but in some people it isn’t. The chemical that’s in beetroot that makes them red and makes some people wee red and also pass red faeces, which is what can happen if you eat a lot of beetroot, is a chemical called betacyanin. It’s actually an anti-oxidant that the beetroot makes and it can be used a colour change indicator too, but it doesn’t necessarily breakdown in the intestines of all people.

The things that seem to make it breakdown more are acidity, so if you have very strong stomach acid then it breaks down more. If you have weaker stomach acid, then more can get through into the small intestine, and there, pancreatic juice is alkaline. So that can encourage it to pass through into the colon which is actually where it’s absorbed.

People have done experiments on patients who have had things called ileostomies, which is where you take the ileum, the terminal bowel, and you bring it to the surface of the skin. And you take the contents away into a bag, for example. If you feed these patients with the betacyanins in beetroot they don’t ever get beeturia, in other words, the red dye getting into their urine. That shows that the absorption must take place in the large intestine.

The other things that seem to affect the absorption is a chemical called oxalate, oxalic acid, which you get from rhubarb and rhubarb leaves. That actually gets broken down by bacteria in the small intestine and in the large bowel. So it’s possible that there’s a combined effect whereby some people have a certain genetic makeup that makes them break this stuff down more than others because they have more acidity. It’s also possible that they have certain bacteria living in the intestine that breaks this stuff down more than others, and so that affects whether or not you see it appearing in the bloodstream.

But in people who do get beeturia, what seems to happen is that the pigment comes through the wall of the bowel, doesn’t get broken down, goes around in the bloodstream, and then it gets filtered out by the kidneys and goes into urine, and makes urine go red. But what’s really interesting is that on its way to the kidneys, of course, it has to go through the blood. And I was rooting around on the Internet, and I found this wonderful paper. It was published in the Christmas BMJ 2005 by two doctors, Julia Handysides and Stuart Handysides, who work in Essex... What they did was to - well, they’ve written this paper. I’ll read you this because it’s hilarious.

“One Sunday evening in 2004, our 11-year old son went to bed after various delaying tactics, arguments about friends staying up later, forgetting to brush his teeth, forgetting to come down for a drink of water, and so on. But shortly afterwards, the dining door room opens, and in he comes, cupping a bleeding nose in one hand and gripping the bridge of his nose with the other. We led him to the kitchen sink and helped him to clean up and stem the bleeding, but oddly, the blood on his hands would not wash off. And it also looked brighter than usual. The poor child was interrogated. Is this some kind of ruse or lark to stay up later?

The bleeding stopped, his hands, although stained pink, were now clean and dry. Upstairs, we found crimson stains on the bathroom carpet which proved impossible to shift and remain there over one year later. Our garden’s harvest of beetroot was very good in 2004, and we had eaten some the day before the nosebleed. It dawned on us that on its way to staining urine, the pigment in beetroot might also stain blood as well.”

So that means potentially, all of your internal organs are getting stained bright red by beetroot, and if you bleed, the stuff can come out and stain your skin

Does too much calcium make your bones brittle?

Does too much calcium make your bones brittle?

The answer is, yes it does, surprisingly. Calcium links up with phosphates to make the chemical "apatite" (calcium phosphate), one of the hardest chemicals we know, which is what makes bones hard and stony, and tough.

But if you have too much calcium, that can be as bad as having too little, as in condition osteoporosis where the bones actually begin to lose their calcification and the matrix of the bone, which makes them weak and more likely to break. There’s also another disease called "osteomalacia" where you have too little just of the calcium and that also makes bones weak.

But some people actually lay down too much calcium in bone, a condition called "osteopetrosis" from "petros" as in stony. This is where people can have say, five times the amount of calcium in their bones that they should have. It’s a genetic condition. It’s very rare and I think it also goes by the name "Albers-Schonberg disease" or something like that, but it’s very rare.

In these individuals, the cells that break down bone, called "osteoclasts", don't work properly. This is because the way bone is normally formed involves an equilibrium between laying down new bone and breaking down old bone, and that’s how bones are continuously remodelled.

So if you shift that equilibrium on one direction or the other, you either lose or gain bone. And what scientists have found is that in people who have osteopetrosis, the osteoclasts that normally breakdown bone cannot work properly. They have a deficiency of an enzyme called "carbonic anhydrase" and you need that to break down the calcium phosphate, the apatite, in order to remodel the bone.

As a result, they just keep on making their bones get harder and harder, and harder. Eventually they go beyond the point of this being beneficial and the bones become less flexible and more likely to break, so they get very brittle.

How do mosquitoes lay their eggs? We never see them doing so...

How do mosquitoes lay their eggs? We never see them doing so...

Mosquitoes depend on water for their life cycle. Different mosquitoes live in different environments and as a result they depend on different types of water - stagnant water, big ponds of water, dumped car tyres with a bit of water and so on. You can actually tell which species of mosquito you're dealing with depending upon where they're laying eggs.

The bottom line is the mosquito goes down to the water once it’s mated and different species of mosquito lay eggs in different ways. But they all lay their eggs into water.

Certain species lay them as individual eggs which drift off; others lay big rafts of eggs. The eggs mature and hatch into little larvae, which then have an aquatic phase; they grow in the water and eat algae and things, growing into large mosquito larvae. These then mature into full blown mosquito flies that then take off and come and bite you.

You just have to keep an eye on a patch of water and you’ll see the mosquitoes coming down to lay their eggs!

How are seedless grapes grown?

How are seedless grapes grown?

The correct answer is that the plants that grow them are actually clones. So instead of growing them from seeds, they're grown from cuttings, so from existing plants. So obviously the first seedless grapes were a plant that arose through mutation, that means that they don't have seeds. And some growers must have noticed this. And you can basically take a little shoot or a stem off the plant, dip it in rooting powder, put it in the ground, and a new tree will grow. This is how a lot of plants are cultivated now, and also a lot of seedless varieties. It's causing problems now with bananas though. Because they're all clones, they're getting struck down by funguses and things. If a population is genetically identical, it can very easily be wiped out because it has the same resistance to different pathogens.

Why can you see the moon during the day?

Why can you see the moon during the day?

Why shouldn’t you be able to see the moon during the day? The moon is orbiting around the Earth. It takes the moon about 28 days to go right away around the Earth, come back to where it started. The Earth turns. Obviously, it does a complete evolution in one day, 24 hours, since so you would expect to see the moon go across the sky every day, pretty much. At some point so it might not be visible on some occasions so much but it should be there. So that’s not so unusual

Why does cutting hair make it stronger?

Why does cutting hair make it stronger?

Actually, this is a myth. There is no evidence that cutting hair, shaving, doing anything like that actually makes hair grow more or adjust its strength or its length. Hair goes through three phases and its lifetime. The hair follicle has an anagen phase, when actually grows and makes hair and depending upon what sort of hair, where on the body surface you’re looking, that phase last different lengths of time.

On the head, for example, it lasts for several years, whereas on the face, it might last for weeks and an eyelash, for example, only grows for about three weeks before it goes into the next phase which is called the catagen phase when the hair falls out. And that’s when the hair follicle stops for a while. Obviously, you can imagine if your eyelashes grew for three years that would be a bit disadvantageous because you’ll be looking out through under these curtains, won’t you? So, it’s good that doesn’t happen. Then the third phase is something called the telogen phase, when the follicle rests before it re-starts itself again.

People often say when a person dies, their hair carries on growing after they die. Or, when you cut the hair it comes back far bushier. Both of those things are down to, in the case of someone dying, the skin dries and shrinks a bit around the hair coming out through the skin surface and this makes the hair look artificially a lot longer; and, when you cut hair, instead of having this tapered thin end, it’s got a very abrupt, cut off, sharp end, so the hair looks thicker when it comes back.

So, it’s just sort of illusion; it’s not really any fatter.

Why is flu more prevalent in winter?

Why is flu more prevalent in winter?

we think flu spreads better in winter because of human behaviour because it does this reproducibly in every country in the world and in which it is winter time - it doesn’t mean it goes away completely in summer but it does come much more commonly in winter.

We think that’s because it spreads better in winter because of what humans do. We go indoors more in winter so there are more people together indoors with the windows closed. Also, unlike summer time, it’s less light and therefore there's less ultraviolet radiation to dry out the virus and kill it. So 'flu finds it easier to persist on surfaces spread by coughs and sneezes, and it hangs around for longer.

As a result you have a higher chance of passing it on so that’s what we think goes on. And then the big determinant, the disproportionate determinant, is the school year. The long summer school holiday powerfully knocks 'flu on the head because kids stop mixing and spreading the infection amongst themselves. What normally happens is that they become infected and then go home and give it to their parents and the parents then carry the infection to all of the other parts of the social and age strata, usually through their workplace.

How does 'flu actually infect our cells?

How does 'flu actually infect our cells?

The way flu gets hold of cells is down to proteins on the surface of the virus particle. Each virus particle is tiny, about 1/10,000th for the millimetre across. If you could zoom in on the surface, you’d see that it had these spikes on the surface. These spikes are a structure called haemagglutinin, which is a tiny protein resembling a molecular grappling hook. It’s viral Velcro. It gets hold of something called sialic acid, which is a chemical on the surface of the cells that line our nose and throat, and this enables the virus to grab hold of those cells and pull itself in very close.

Through this interaction the cell thinks the virus is something that it has to take inside the cell. So the cell then does something called receptor-mediated endocytosis, which basically means it pulls the virus inside the cell. Once inside the virus releases it’s genetic material and productively infects the cell.

It’s a bit like a Trojan horse actually because the Trojan horse was this juicy tidbit sitting outside the gate of Troy. The guys inside the city thought, “Wow! That looks fantastic. We’ll pull that inside because it looks good.” And it goes inside the city. And then of course, lurking inside are all these people who are then wreak havoc inside the city. And that’s basically what a flu virus does. It hijacks the cell, turns it into a virus factory and then it infects all of the cells around it and all the people around you!

Why do washing powders remove stains but not dyes?

Why do washing powders remove stains but not dyes?

one of the main and important ingredients used is surfactants and the surfactant molecule is clever in the way that on one side it has a hydrophobic component, that’s a water-hating molecular chain. And on the other side, a hydrophilic water-loving component. The hydrophobic chain finds itself sticking to the stains on your clothes and the hydrophilic heads have a stronger attraction to water. They’re able to surround the dirts and roll it up into a small globular-type ball and the end result is that they’re able to lift the stain from your cloth, into the wash water.

Some of our detergents contain enzymes which are naturally derived molecules. Generally, we use different enzymes such proteases which break down proteins and amylase which breaks down starch and then finally, another major ingredient that we use, like most other detergent manufacturers is bleach. The bleach turns the stain into more soluble colourless particles that can be easily removed and carried away into the wash water. So, in actual fact, it can remove bleachable dye stains. So, to kind of answer the other part of the question, laundry detergents can remove certain dyes, as well as stains.

Most dyes are composed of molecules that these ingredients can’t target. Surfactants can't globuralize the dyes, nor can enzymes gobble them up, unless they're vegetable-based. But bleach can effect dyes and this is why, washing powders designed for colored clothes don’t contain any bleach.

Why is flu more prevalent in winter?

Why is flu more prevalent in winter?

we think flu spreads better in winter because of human behaviour because it does this reproducibly in every country in the world and in which it is winter time - it doesn’t mean it goes away completely in summer but it does come much more commonly in winter.

We think that’s because it spreads better in winter because of what humans do. We go indoors more in winter so there are more people together indoors with the windows closed. Also, unlike summer time, it’s less light and therefore there's less ultraviolet radiation to dry out the virus and kill it. So 'flu finds it easier to persist on surfaces spread by coughs and sneezes, and it hangs around for longer.

As a result you have a higher chance of passing it on so that’s what we think goes on. And then the big determinant, the disproportionate determinant, is the school year. The long summer school holiday powerfully knocks 'flu on the head because kids stop mixing and spreading the infection amongst themselves. What normally happens is that they become infected and then go home and give it to their parents and the parents then carry the infection to all of the other parts of the social and age strata, usually through their workplace.