Bio 10: Intro to BiologyInstructor: Paul Nagami

Laney College

Sept. 6, 2013

Large Molecules and Living Things, Part 2

Agenda• Administrative Stuff• Review: Monomers and Polymers• Lactose Intolerance, Continued• Proteins• What Proteins Do (function)• What Proteins are Made of (structure)

• DNA• What DNA Does (function)• What DNA is Made of (structure)

• Wrap-up

Challenge Statement

“Human beings are made of acids.”

Agree or disagree?

Monomers and dimers• Macromolecules are often made of repeating pieces.

• Each piece is a monomer. Sticking two monomers together makes a dimer.

Monomerone + piece

Dimertwo + pieces

Glucose

Polymers

Dehydration builds polymers.

Hydrolysis breaks polymers.water + breaking

Test Your MemoryOn your index card, please name...

1) One example of a monomer, and where it can be found.

2) One example of a dimer, and where it can be found.

3) One example of a polymer, and where it can be found.

4) One example of a lipid, and where it can be found.

Discuss your guesses briefly with a neighbor.

Lactose Intolerance

Disaccharide

Monosaccharide

Lactase: A Protein

(Image Credit: chemicalconnection.org.uk)

Proteins are responsible for most chemical reactions in your body!

Proteins that drive chemical reactions are called enzymes.

Explain!When people with lactose intolerance drink normal milk, they can get flatulence and indigestion.

However, drinking lactase-treated milk does not usually result in these symptoms.

On your index card, please explain why this is the case, discussing your answer with your neighbor.

Proteins Do Almost Everything

Protein Structure

Strands of the protein keratin.

Let’s zoom in even closer... what are these helices (corkscrews) made out of? What holds them together?

Covalent and Hydrogen Bonds!

Monomers!

Proteins are polymers, like carbohydrates!

What Makes Proteins Different from Each Other?

Primary Structure: Proteins Are Amino Acid Polymers

(Chains)Imagine unfolding a protein chain…

You would be able to look at the individual monomers.

These monomers are amino acids.

One Amino Acid Can Make a Big Difference!

Let’s zoom in even more… what are amino acids made of?

Amino Acids

Amine functional group (has N)

Acidic functional group

Test yourself: Which part of the amino acid could come off in water to make an ion?

Amino Acids Can Release H+

Challenge Statement

“Human beings are made of acids.”

Agree or disagree?

Assembling Proteins

Peptide bond = bond between amino acids

Polypeptide = many amino acid monomers! (Polymer)Why don’t we call amino acids “monopeptides?” Because they don’t have a peptide bond.(You can have a dipeptide, though.)

Levels of Protein Structure

PrimarySecondary

Tertiary Quaternary

What Causes Lactose Intolerance?

DNA’s function: Instructions to make proteins, such as lactase!

Gene = Unit of Protein Coding

Nucleic Acids (DNA/RNA)

Monomer of nucleic acid = nucleotide

Adenine

The Double Helix

Whew!