how do you read a nutrition label?. four organic compounds

How do you read a nutrition label?

Four Organic Compounds

There are four main groups of organic compounds in living things…

1. Carbohydrates2. Lipids3. Proteins4. Nucleic acids

What does “organic” mean?

• Organic refers to compounds that contain bonds between carbon atoms.

What does “organic” mean?

• Organic refers to compounds that contain bonds between carbon atoms. – Examples: carbohydrates, proteins, lipids (fats)

• Examples of Inorganic Molecules:– Water, salt, hydrogen peroxide

Why carbon?

• Carbon is a VERY versatile element – it has four electrons on it’s outer shell, which means that it can make bonds with up to four other atoms.

What’s a “macromolecule”?

• Macromolecules are very large molecules made from many smaller molecules– Monomers are the small building blocks of these

molecules– Monomers join together to form polymers– Polymers are formed by polymerization

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Carbs, Lipids, Proteins, & Nucleic Acids

CARBOHYDRATES…

• Carbohydrates are used by organisms as a main source of energy, and the breakdown of glucose supplies quick energy for our body.• Glucose is C6H12O6

CARBOHYDRATES…

• Carbohydrates are made of carbon, hydrogen, and oxygen in a 1:2:1 ratio. Ex: C1H2O1 OR 1 : 2 : 1Glucose is C6H12O6

CARBOHYDRATES…

• Small carbohydrate monomers are called monosaccharides. – These simple sugar molecules usually end in the

letters O - S - E:• Example: glucose, fructose, lactose

CARBOHYDRATES…

• Many monosaccharides combine to form polysaccharides. – Extra sugars are stored as starch. – In plants, large carbohydrates form cellulose (used

for structure in plant cell walls) – In animals, large carbohydrates are stored as

glycogen.

Testing for Sugars and Starches

• Starches: Lugol’s Reagant (Iodine Solution)• Sugars: Benedict’s Solution – Both turn blue/black

bbc.co.uk

Potato contains starch so it has a positive Lugols test.

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positive test

negative test

Color change (cloudy, yellowish) indicates that sugars are present

No color change (clear, light blue) is a negative test (no sugars present)

Benedict’s solution – Test for Sugars

Why are carbs important?

• Carbohydrates are our main source of energy.• Glucose supplies quick energy for our body.

Where do we get carbs in our diet?

Potatoes, bread, pasta, rice, fruit, some vegetables, honey, milk

LIPIDS…

• Lipids re used for storing energy and they make up biological membranes (like cell membranes). Lipids are composed mainly of carbon and hydrogen.

LIPIDS…

• Lipids are made up of monomers called fatty acids which are then joined to a glycerol molecule.

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TriglycerideFormed from a glycerol and three fatty acids.

When fats join, water is kicked out. This is why the process is called condensation (polymerization)

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Triglyceride

Where do we find lipids?

• Lipids are always found in the form of fats, oils, and waxes.

Testing for Lipids

BrownPaper

BagTest

Where do we find lipids?• Where do we get lipids from in our diet?

Cooking oils, butter, animal fat, lard

Saturated vs. Unsaturated Fats --- What’s the Difference?

• A saturated fatty acid chain has only single bonds between carbons while an unsaturated fatty acid chain has at least one double bond.

The more hydrogens there are, the more saturated a fat becomes.

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Saturated vs. Unsaturated Fats --- What’s the Difference?

• Unsaturated fats take more work to digest (it takes more energy to break the double bonds, which means unsaturated fats are better for your body than saturated fats.

PROTEINS…

• Proteins are made up of carbon, hydrogen, oxygen, and nitrogen.

• They are used for everything!

Proteins are used for everything!

• For example:– Control rate of cell processes (enzymes)– Help form bone and muscles– Transport substances within cells– Help fight disease– Aid in regulation (hormones)

• Examples: hemoglobin, insulin

PROTEINS…

• Proteins are made up of many monomers called amino acids that link together in chains.

• There are 20 amino acids that the human body needs to make proteins.

2OAMINO ACIDS

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Amino acids are cool! Any amino acid can be joined to any other amino acid and they can form any combination.

Side Note: Amino Acids

• There are so many combinations of amino acids, and each combination folds up in a different way – this is why we have so many different proteins.

Protein Shape and Function

• The shape of the protein affects its job inside the body, thus

***STRUCTURE*** DICTATES ***FUNCTION.***

As the protein chain is made, it begins to fold into a

three dimensional

structure.www.yellowtang.org

cnx.org

What happens when a protein doesn’t fold correctly?

• When protein isn’t folded correctly, it is said to denatured. That means it won’t work or function properly because it is deformed.

Ex: sickle cell disease

What happens when a protein doesn’t fold correctly?

• When proteins don’t fold up in the right way, bad things can happen to our cells and bodies – things don’t work the way that they should.

Ex: sickle cell disease

Biuret solution is a blue liquid that changes to purple when proteins are present

Positive result

glossary-chemistry.blogspot.com

Testing for Proteins

Where do proteins come from?

• Meat, eggs, cheese, nuts, soy

NUCLEIC ACIDS…

• Nucleic acids are used for storing and transmitting hereditary and genetic information.

• They are composed of carbon, hydrogen, oxygen, nitrogen, and phosphorous.

NUCLEIC ACIDS…

• Examples:– DNA– RNA

NUCLEIC ACIDS…

• NUCLEIC ACIDS are made of monomers called nucleotides.– There are five different nucleotides: cytosine,

guanine, adenine, thymine, and uracil.

What does a nucleotide look like?

• A nucleotide is made up of a five carbon sugar, a phosphate group, and a nitrogenous base

What does a nucleotide look like?

• A nucleotide is made up of a five carbon sugar, a phosphate group, and a nitrogenous base

What does a nucleotide look like?

• A nucleotide is made up of a five carbon sugar, a phosphate group, and a nitrogenous base

Indicator Testing

How do we test food to figure out which types of organic molecules they contain?

• Starches – Lugol’s solution (Iodine)• Sugars – Benedicts solution• Proteins – Biuret solution• Lipids – Brown Paper Bag Test

bbc.co.uk

Potato contains starch so it has a positive Lugols test.

webexhibits.org

positive test

negative test

Lugol’s (Iodine) solution – Test for Starches

Lipids cause the brown

paper to look shiny

and translucent

Testing for Lipids – Brown Paper Bag Test

Biuret solution is a blue liquid that changes to purple when proteins are present

Positive result

glossary-chemistry.blogspot.com

Testing for Proteins