jtotheizzoe:

Ever wondered how your body knows left from right? Why our bodies are asymmetrical on the inside, despite being so symmetrical on the outside? 

And why on Earth does singer Donny Osmond, like 1 in 20,000 people, have mirror-image inverted organs?

In this video, part 3 of my special series on how our bodies evolved to look the way that they do, find out the science of your asymmetry.

Watch below:


“The E. Coli Made Me Do It”

newyorker:

image

Can our microbiome affect the way we feel? James T. Rosenbaum explores how the organisms that live inside us may have implications for our brains and behavior: http://nyr.kr/1akXcCq

(via marqurite)



jtotheizzoe:

insteadofwatchingtv:

Myths and Misconceptions About Evolution

Great stuff from the TED-Ed folks! Evolution is much more nuanced and complex than usually presented, but it’s also that much more amazing.

(via marqurite)


insteadofwatchingtv:

7 Myths About the Brain You Thought Were True


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The Time Value of Money


jtotheizzoe:

When you think about it, consuming the milk of other animals is a freakin’ weird thing to do. Curdling, flavoring, and aging it in order to make cheese? That’s even weirder. But cheese is delicious, so whether it’s weird or not I have no intention of stopping. How exactly does milk magically morph from liquid to solid?
The origin of cheese, as the legend goes, can be traced to one (un)lucky Middle Eastern shepherd, maybe as far back as 8000 BCE. Journeying across the arid plains and lacking a container to carry his milk in, this shepherd fashioned a canteen out of the stomach of one of his sheep. Later, when he went to take a sip of milk, all he found was curds… the chunky precursor to cheese.

To this day, the cheesemaking process begins in pretty much the same way as it did in 8000 BCE, only instead of relying on offal accidents, we employ some nifty biochemistry. 
To begin its leap toward immortality, milk first has to make the leap out of a cow, sheep, goat, or other grazing animal. Compared to human milk, the milk of these domesticated ruminants is extremely high in protein. For reasons that will become clear shortly, the low protein content of human breast milk is why you can’t make it into cheese, should you be so inclined (although I sincerely hope you are not so inclined).
The reason that milk curdles in ruminant stomachs is because of baby ruminants. Behold the four-chambered ruminant stomach:

When a cow drinks water, or when grazing on hard-to-digest grasses, they engage all four stomachs, but the microbes that live in the top three chambers would create a dangerously unbelchable amount of gas if they were allowed to drink milk. When suckling, calves instead engage a valve that sends the milk directly to the last of their four stomachs, the abomasum.

It is there that the sugar-, fat-, and protein-laden milk curdles, which our friend the shepherd found out the hard way when he used the abomasum for a canteen. Curdling is good for the calf, because as any parent of a newborn will tell you, milk has a tendency to go right through a baby’s digestive system, if you catch my dirty-diaper-drift. Solid milk curds take longer to pass through the digestive system, so more nutrients can be extracted from the milk.
Milk’s main protein, making up more than 80% of the total, is called casein. One particular form of this protein, kappa-casein, is basically the reason that cheese exists at all. Thank you, K-casein, we owe you big-time. 
K-casein isn’t very happy floating around in the aqueous environment of milk, though. Like a shark-attack survivor, it’s a bit hydrophobic. In order to hide from H2O, casein molecules huddle together in globs called micelles, binding up fat and calcium along with it. 

You’ll notice that casein is more than just the globby bits, though. Its tail (a “casein point”?), coated with sugars and hydrophilic amino acids, juts out from those micelles, caging the protein in a water-loving coat and keeping your milk from becoming a curdled mess… that is, until rennet comes along. 
Rennet, the mixture of enzymes added to cheese cultures to start the curdling process, was originally extracted from the stomach linings of young calves, although today it’s manufactured by genetically engineered microbes. One of those enzymes, chymosin, is what does the curdling in both calf stomachs and cheese houses.

Chymosin acts like a molecular pair of scissors, snipping off the water-loving tail of K-casein at a very specific spot (between amino acid 105, a phenylalanine, and 106, a methionine, if you’re a sucker for detail). Without that cage to keep the micelles dissolved in milk’s watery environment, the micelles clump together in massive knots called curds.

What happens to those curds next is an adventure all its own, and every type of cheese has its own well-aged story.
Whether or not the legend of the shepherd is true or just a cheesy myth, one thing is for certain: When it comes to cheese, the stomach isn’t just where cheese ends its journey, it’s also where it begins.
This post accompanies this week’s episode of It’s Okay To Be Smart on YouTube: The Science of Cheese! Watch it here to learn more about cheese-ology:

jtotheizzoe:

When you think about it, consuming the milk of other animals is a freakin’ weird thing to do. Curdling, flavoring, and aging it in order to make cheese? That’s even weirder. But cheese is delicious, so whether it’s weird or not I have no intention of stopping. How exactly does milk magically morph from liquid to solid?

The origin of cheese, as the legend goes, can be traced to one (un)lucky Middle Eastern shepherd, maybe as far back as 8000 BCE. Journeying across the arid plains and lacking a container to carry his milk in, this shepherd fashioned a canteen out of the stomach of one of his sheep. Later, when he went to take a sip of milk, all he found was curds… the chunky precursor to cheese.

To this day, the cheesemaking process begins in pretty much the same way as it did in 8000 BCE, only instead of relying on offal accidents, we employ some nifty biochemistry. 

To begin its leap toward immortality, milk first has to make the leap out of a cow, sheep, goat, or other grazing animal. Compared to human milk, the milk of these domesticated ruminants is extremely high in protein. For reasons that will become clear shortly, the low protein content of human breast milk is why you can’t make it into cheese, should you be so inclined (although I sincerely hope you are not so inclined).

The reason that milk curdles in ruminant stomachs is because of baby ruminants. Behold the four-chambered ruminant stomach:

When a cow drinks water, or when grazing on hard-to-digest grasses, they engage all four stomachs, but the microbes that live in the top three chambers would create a dangerously unbelchable amount of gas if they were allowed to drink milk. When suckling, calves instead engage a valve that sends the milk directly to the last of their four stomachs, the abomasum.

It is there that the sugar-, fat-, and protein-laden milk curdles, which our friend the shepherd found out the hard way when he used the abomasum for a canteen. Curdling is good for the calf, because as any parent of a newborn will tell you, milk has a tendency to go right through a baby’s digestive system, if you catch my dirty-diaper-drift. Solid milk curds take longer to pass through the digestive system, so more nutrients can be extracted from the milk.

Milk’s main protein, making up more than 80% of the total, is called casein. One particular form of this protein, kappa-casein, is basically the reason that cheese exists at all. Thank you, K-casein, we owe you big-time. 

K-casein isn’t very happy floating around in the aqueous environment of milk, though. Like a shark-attack survivor, it’s a bit hydrophobic. In order to hide from H2O, casein molecules huddle together in globs called micelles, binding up fat and calcium along with it. 

You’ll notice that casein is more than just the globby bits, though. Its tail (a “casein point”?), coated with sugars and hydrophilic amino acids, juts out from those micelles, caging the protein in a water-loving coat and keeping your milk from becoming a curdled mess… that is, until rennet comes along. 

Rennet, the mixture of enzymes added to cheese cultures to start the curdling process, was originally extracted from the stomach linings of young calves, although today it’s manufactured by genetically engineered microbes. One of those enzymes, chymosin, is what does the curdling in both calf stomachs and cheese houses.

Chymosin acts like a molecular pair of scissors, snipping off the water-loving tail of K-casein at a very specific spot (between amino acid 105, a phenylalanine, and 106, a methionine, if you’re a sucker for detail). Without that cage to keep the micelles dissolved in milk’s watery environment, the micelles clump together in massive knots called curds.

What happens to those curds next is an adventure all its own, and every type of cheese has its own well-aged story.

Whether or not the legend of the shepherd is true or just a cheesy myth, one thing is for certain: When it comes to cheese, the stomach isn’t just where cheese ends its journey, it’s also where it begins.

This post accompanies this week’s episode of It’s Okay To Be Smart on YouTube: The Science of Cheese! Watch it here to learn more about cheese-ology:


insteadofwatchingtv:

How Does Soap Work?


jtotheizzoe:

This post is an explainer to go along with this week’s It’s Okay To Be Smart video, an animated ode to the cycles that oxygen and carbon take through the biosphere. Click here to watch it.
I’ve always been fascinated with the elegant cycle that oxygen takes through our bodies and through the biosphere. While equally elegant, the biological cycle of carbon is a lot more straightforward, so I’m not going to talk about it today. My apologies to Team Carbon :)
If you ask me, more than any other, your life depends on the following two chemical equations:


What isn’t immediately obvious when you look just at the equations is why these connections exist. Where exactly do the oxygen atoms that a plant exhales come from? Out of CO2, or water? And does the oxygen we breathe end up in CO2, or H2O? There is little elegance in an equation, only simplicity. 
A beautiful recycled chain of oxygen chemistry supports a vast majority of Earth’s living universe upon its back. While it is certainly poetic in its recursive harmony, we’re not here to view it only as art. It is because of decades of scientific research that we have unlocked the beautiful secrets of the living oxygen cycle.
Take a deep breath, and join me…

When we inhale oxygen gas, it diffuses into our blood via the alveoli of our lungs. Inside our red blood cells, that dissolved gas is caged by iron-containing hemoglobin proteins that shuttle it to hungry cells throughout your body. As oxygen-rich capillaries pass near oxygen-starved cells, the double-O’s diffuse across the cell membrane. 

Inside your cells, that oxygen makes its way to the mitochondria. In the early 1960’s, it was discovered that those cellular powerhouses use diatomic oxygen, the stuff you breathe, as an “electron acceptor" during the electron transport chain, the reactions that drive ATP production in our cells. Thanks to biochemistry, we know without a doubt that the oxygen you breathe ends up as water, and not CO2. You’d never learn that from the equation.
What happens to that water? You’ll be reminded next time you go to the bathroom.
Eventually, the H2O you “release” joins with rivers and rainclouds, which deliver it back to thirsty plants. Within their veins, water molecules (some containing oxygen atoms that were once breathed in by a living creature) are delivered to chloroplasts, where they begin the next phase of their cyclical journey.

We know that photosynthesis eats up light, water, and carbon dioxide in order to produce oxygen gas and sugars. But what are the fates of those atoms? Biologists had figured out the basics of photosynthesis by the early 1800’s, but argued for decades about the detailed atomic journeys within a leaf.
In 1941, at the age of just 27, a biologist named Sam Ruben wanted to find out once and for all if the oxygen that plants exhaled came from CO2, or from H2O. Again, the equation fails to tell the story. Ruben fed plants both water and carbon dioxide that contained a heavy isotope of oxygen. Only when the heavy oxygen began as water did he find it in oxygen gas, meaning the O you breathe comes from entirely from water!
That oxygen eventually makes its way back to us, along a long and frantic journey through the atmosphere, where some of it is now entering your lungs, ready to fuel the same curious brain that now understands the cycle of the breath that feeds it. Seems like we’re finding cycles within cycles now, eh?
The living world, at least according to the oxygen cycle, seems to be a very elaborate means to trade electrons between photosynthetic and respiratory branches of the Tree of Life. Richard Feynman once said that “all life is fermentation” … perhaps he should have said all life is electricity.
Breathe that in, and stay curious :)

jtotheizzoe:

This post is an explainer to go along with this week’s It’s Okay To Be Smart video, an animated ode to the cycles that oxygen and carbon take through the biosphere. Click here to watch it.

I’ve always been fascinated with the elegant cycle that oxygen takes through our bodies and through the biosphere. While equally elegant, the biological cycle of carbon is a lot more straightforward, so I’m not going to talk about it today. My apologies to Team Carbon :)

If you ask me, more than any other, your life depends on the following two chemical equations:

What isn’t immediately obvious when you look just at the equations is why these connections exist. Where exactly do the oxygen atoms that a plant exhales come from? Out of CO2, or water? And does the oxygen we breathe end up in CO2, or H2O? There is little elegance in an equation, only simplicity. 

A beautiful recycled chain of oxygen chemistry supports a vast majority of Earth’s living universe upon its back. While it is certainly poetic in its recursive harmony, we’re not here to view it only as art. It is because of decades of scientific research that we have unlocked the beautiful secrets of the living oxygen cycle.

Take a deep breath, and join me…

When we inhale oxygen gas, it diffuses into our blood via the alveoli of our lungs. Inside our red blood cells, that dissolved gas is caged by iron-containing hemoglobin proteins that shuttle it to hungry cells throughout your body. As oxygen-rich capillaries pass near oxygen-starved cells, the double-O’s diffuse across the cell membrane. 

Inside your cells, that oxygen makes its way to the mitochondria. In the early 1960’s, it was discovered that those cellular powerhouses use diatomic oxygen, the stuff you breathe, as an “electron acceptor" during the electron transport chain, the reactions that drive ATP production in our cells. Thanks to biochemistry, we know without a doubt that the oxygen you breathe ends up as water, and not CO2. You’d never learn that from the equation.

What happens to that water? You’ll be reminded next time you go to the bathroom.

Eventually, the H2O you “release” joins with rivers and rainclouds, which deliver it back to thirsty plants. Within their veins, water molecules (some containing oxygen atoms that were once breathed in by a living creature) are delivered to chloroplasts, where they begin the next phase of their cyclical journey.

We know that photosynthesis eats up light, water, and carbon dioxide in order to produce oxygen gas and sugars. But what are the fates of those atoms? Biologists had figured out the basics of photosynthesis by the early 1800’s, but argued for decades about the detailed atomic journeys within a leaf.

In 1941, at the age of just 27, a biologist named Sam Ruben wanted to find out once and for all if the oxygen that plants exhaled came from CO2, or from H2O. Again, the equation fails to tell the story. Ruben fed plants both water and carbon dioxide that contained a heavy isotope of oxygen. Only when the heavy oxygen began as water did he find it in oxygen gas, meaning the O you breathe comes from entirely from water!

That oxygen eventually makes its way back to us, along a long and frantic journey through the atmosphere, where some of it is now entering your lungs, ready to fuel the same curious brain that now understands the cycle of the breath that feeds it. Seems like we’re finding cycles within cycles now, eh?

The living world, at least according to the oxygen cycle, seems to be a very elaborate means to trade electrons between photosynthetic and respiratory branches of the Tree of Life. Richard Feynman once said that “all life is fermentation” … perhaps he should have said all life is electricity.

Breathe that in, and stay curious :)


insteadofwatchingtv:

Your Family Tree Explained