Macromolecules

Life: Small Picture to Big Picture

Macromolecules

What are Macromolecules?

• Cells and their organelles are made up of smaller building blocks called macromolecules.

• There are 4 basic types of macromolecules. They are:– Lipids– Proteins– Carbohydrates– Nucleic Acids

Monomers & Polymers• Macromolecules are actually made up of

even smaller subunits. Each subunit of a macromolecule is called a monomer.

• The macromolecules themselves are called polymers, because they are made up of many of these subunits.

Monomer: one basic unit or subunit

Polymer: a chain of many basic units

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Macromolecules• Large organic molecules.• Also called POLYMERS.• Made up of smaller “building blocks”

called MONOMERS.• Monomers combine to form polymers

through a process called POLYMERIZATION

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How are Macromolecules Formed?: Dehydration Synthesis

• Also called “condensation reaction”

• Forms polymers by combining monomers by “removing water”.

HO H

HO HO HH

H2O

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How are Macromolecules Separated or Digested?

Hydrolysis• Separates monomers by

“adding water”

HO HO HH

HO H

H2O

What you need to know:• Names of the 4 macromolecules• Structure- monomers and polymers of

each• Function- what are they used for?• Food sources- what foods will you find

these in?• Indicator Tests- what tests do we use to

find out if a food contains them?

Lipids

Lipids: Structure• Lipids are made up of…

– Monomer (basic unit): fatty acids

– Polymer (chain of units): lipids• Specific examples: triglycerides, phospholipids

Lipids: Structure*

Properties of Lipids caused by:

• Saturated vs. Unsaturated fatty acids

• Polar head and nonpolar tail regions– Hydrophilic and

hydrophobic regions

Lipids: Function• Make up the cell membrane, providing cell

structure• Provide insulation (fat keeps body warm)• Long-term energy storage

Lipids: Food Sources

• As you might have guessed, fatty foods contain lipids.

• Lipids are found in meat and fish, oils, avacados, eggs & nuts.

Lipids: Indicator Test• Paper Bag Test:

– Smear substance onto paper bag– If see-thru, it contains lipids

Proteins

Proteins: Structure• Proteins are made up of…

– Monomer (basic unit): amino acids• 20 different kinds!*

– Polymer (chain of units): protein• More specifically- polypeptides

dipeptide

Amino acids linked by peptide bonds

Proteins: Structure*

20 Amino Acids:

Some of these are polar & hydrophilic,

others are non-polar and

hydrophobic. Proteins can contain both

kinds.

Proteins: Structure• Proteins have complex

structures. The shape of a protein determines its function!

• The levels of protein structure are:– Primary structure:

polypeptide chain– Secondary structure:

polypeptides in coils or sheets

– Tertiary structure: coils or sheets form a tangle

– Quaternary structure: more than one tangle combine to make a very complex protein!

Proteins: Function

• Build and repair muscle and tissues– “No pain, no gain!”

• Enzymes- proteins that speed up chemical reactions

Proteins: Food Sources• Proteins are found in meat, fish,

legumes, nuts, milk, eggs, grains and soy products.

• There are 6 amino acids that our bodies cannot make- we can only get these from food.

Proteins: Indicator Test

• Biuret’s Solution:– Turns from blue to purple if protein is present

Carbohydrates

Carbohydrates: Structure• Carbohydrates are made up of…

– Monomer (basic unit): simple sugars (or monosaccharides)• Ex.: glucose

– Polymer (chain of units): complex carbohydrates (or polysaccharides)• Ex.: starch, cellulose, chitin, glycogen

Disaccharide: 2 simple sugars bonded together

Carbohydrates: Function• Provide body with energy!

– What should you eat before playing the big game? Candy bar or pasta?

• Candy bar: contains simple sugars, provides a short burst of energy

• Pasta: contains starch which takes longer to break down, provides longer-lasting energy

– *We can’t digest cellulose- it is used as fiber, or roughage instead.

• Ex. : corn

Complex carb (ex. Starch)

Simple sugars (ex. Glucose)

Broken down to disaccharides

Broken down further

Carbohydrates: Food Sources• Simple carbs (simple

sugars) are found in most candy and sweet drinks, fruit, vegetables, and milk. They are quickly digested and give a short burst of energy.

• Complex carbs (like starches) are found in pasta, bread, potatoes, legumes & corn. They take longer to digest, and provide energy longer.

Carbohydrates: Indicator Tests

• Simple Sugars:– Benedict’s solution– Blue solution turns

orange/green/brown

• Complex Carbs:– Lugol’s

solution/Iodine– Turns from orange-

red-brown to black-purple

Nucleic Acids

Nucleic Acids: Structure• Nucleic Acids are made up of…

– Monomers (basic unit): nucleotides

– Polymers (chain of units): DNA or RNA

Nucleic Acids: Function

• Stores and carries genetic information

Nucleic Acids: Food Sources• We get nucleic acid components from

vitamins and minerals in our diet. These in turn, come from fruits, vegetables, grains, meats, & almost anything else you can think of with some nutritional value (no junk food!).

Nucleic Acids: Indicator Test• You will not be using an

indicator test for these but in case you’re wondering…

• Dische diphenylamine test– Turns from clear-light blue

to dark blue if nucleic acids

are present

Digestion & Reconstruction

• When macromolecules are eaten, they are digested and broken down into their subunits (monomers).– Analogy: taking apart an old brick building

• Inside the cells, these subunits are reconstructed into the macromolecules we need.– Analogy: using bricks to build a new building

Digestion ProductsMacromolecule eaten:

Broken down in stomach to:

Carbohydrates Simple sugars (i.e. glucose)

Lipids Fatty acids & glycerol (glycerol further broken down to glucose)

Proteins Amino acids

Nucleic Acids Nucleotides

HomeworkRead Chapter 2.3 (p. 44 - 48) and create flashcards for the following terms. Some terms may be found in the Elements and Macromolecules Coloring W.S. or this lecture’s PowerPoint.

1. Monomer 9. Nucleotide 17. Substrate

2. Polymer 10. Ribonucleic Acid (RNA) 18. Active Site

3. Carbohydrate 11. Hydrolysis 19. Catalyst

4. Monosaccharide 12. Protein 20. Peptide Bond

5. Disaccharide 13. Amino Acid 21. Enzymes

6. Polysaccharide 14. Macromolecule 22. Saturated Fats

7. Lipid 15. Lugol’s Solution (Iodine) 23. Unsaturated Fats

8. Benedict’s 16. Biuret’s Solution 24. Deoxyribonucleic Solution Acid (DNA)

25. Polymerization