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Speaker 1: Welcome to Brainstuff from house stuff works dot com where

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Speaker 1: smart happens. Hi. I'm Marshall Brain with today's question, what

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Speaker 1: exactly is jello made from? When you go to the

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Speaker 1: grocery store and you buy a box of jello, you're

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Speaker 1: buying three things. First, there's gelatin. Second, there's sugar or

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Speaker 1: some kind of artificial sweetener combined with artificial flavors, and

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Speaker 1: then third there's food coloring. When you get home, you

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Speaker 1: add a fourth ingredient, which is water. The gelatin and

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Speaker 1: jello is what lets you transform it into all sorts

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Speaker 1: of different shapes. What exactly is gelatin? Gelatine is just

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Speaker 1: a processed version of a structural protein called collagen that

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Speaker 1: is found in many animals, including humans. Collagen actually makes

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Speaker 1: up almost a third of all the protein in the

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Speaker 1: human body. It's a big fibrous molecule that makes skin, bones,

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Speaker 1: and tendons both strong and somewhat flexible. As you get older,

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Speaker 1: your body makes less collagen, and individual collagen fibers become

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Speaker 1: cross linked with each other. You might experience this as

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Speaker 1: stiff joints from less flexible tendons, or wrinkles from the

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Speaker 1: loss of skin elasticity. The gelatin you eat in jello

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Speaker 1: comes from the collagen in cow or pig bones, hoofs,

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Speaker 1: and connective tissues. To make gelatin, manufacturers grind up these

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Speaker 1: various parts and pre treat them with either a strong

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Speaker 1: acid or a strong base to break down the cellular

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Speaker 1: structures and release proteins like collagen. After pre treatment, the

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Speaker 1: resulting mixtures boiled. During this process, the large collagen protein

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Speaker 1: ends up being partially broken down, and the resulting product

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Speaker 1: is called gelatin. The gelatin is easily extracted because it

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Speaker 1: forms a layer on the surface of the boiling mixture.

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Speaker 1: Gelatin is a common ingredient and foods because it's really versatile.

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Speaker 1: It can be used as a jelling agent as in jello,

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Speaker 1: as a thickener, as an emulsifier, and as a stabilizer.

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Speaker 1: You'll find it in a variety of foods, from yogurt

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Speaker 1: to chewing gum. Here's some of the foods that commonly

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Speaker 1: contain gelatin. There's gummy bears, sour cream, cream, cheese, cake,

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Speaker 1: icing and frosting, marshmallows, soup, sauces and gravies, canned hams,

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Speaker 1: and chicken. The list goes on and on. Gelatine is

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Speaker 1: even used to make the coating for pills that makes

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Speaker 1: them easier to swallow. It's also in cosmetics, lozenges, and ointments.

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Speaker 1: When you buy a box of jello or another brand

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Speaker 1: of gelatine at the grocery store, you get a small

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Speaker 1: packet of powdered gelatin with artificial flavorings and colors. At

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Speaker 1: room temperature. The gelatin protein is in the form of

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Speaker 1: a triple helix. This is a fairly ordered structure, not

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Speaker 1: unlike that of d NA. With DNA, two chains of

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Speaker 1: nucleotides are twisted together in a spiral pattern. In a

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Speaker 1: gelatine protein, there are three separate chains of amino acids

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Speaker 1: also known as polypeptide chains, that have lined up and

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Speaker 1: twisted around each other, and the helix is held together

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Speaker 1: by weak bonds that form between the amino acids that

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Speaker 1: end up on the inside of that coiled structure. To

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Speaker 1: make a gelatine mold, you have to add boiling water

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Speaker 1: to the powdered gelatin. Then you stir the mixture for

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Speaker 1: about three minutes until the gelatine dissolves completely. What happens

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Speaker 1: to the gelatine when you add the boiling water the

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Speaker 1: energy of the heated water is enough to break up

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Speaker 1: the weak bonds holding the gelatin strands together. The helical

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Speaker 1: structure falls apart, and your left with free polypeptide chains

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Speaker 1: floating around in a water solution. The next step is

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Speaker 1: to add cold water and stick the dissolved gelatin in

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Speaker 1: the refrigerator to chill for several hours. When you cool

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Speaker 1: down the mixture, those polypeptide chains begin to reattach and

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Speaker 1: reform the tight triple helix structure. However, the chilling process

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Speaker 1: is slow and the individual strands have been widely dispersed

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Speaker 1: by mixing, so the helixes aren't perfectly formed this time.

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Speaker 1: In some places there are gaps in the helix, and

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Speaker 1: in others there's just a tangled web of polypeptide chains.

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Speaker 1: When the gelatine solution is chilled, water gets trapped inside

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Speaker 1: these gaps and pockets between the chains. The protein net

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Speaker 1: that's left after chilling gives the gelatine molded shape, and

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Speaker 1: the trapped water provides the characteristic jiggle that makes jello

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Speaker 1: a popular food for kids to eat. For more on

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Speaker 1: this and thousands of other topics, is that how stuff works.

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Speaker 1: Dot com and don't forget to check out the brain

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Speaker 1: Stuff blog on the house stuff works dot Com home page.

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