Proteins: what’s so special about them?

Today, we will talk about….

1. what are Proteins made of

2. what gives Proteins their characteristics

3. what are some of the major functions

of proteins

So, our first goal…

What are Proteins made of?

Proteins are polymers

•What does that mean?

• All proteins are made from a common set of 20 kinds of amino acids

• Amino Acids (AA) are the monomers of Proteins.

• They have weird names like….

• Methionine

• Isoluciene

• Histidine

• Threonine

• Glutamine

• Amino acids are bonded to other amino acids by peptide bonds

What are the monomers of Proteins?

• Three parts of an amino acid…

• 1. Carboxyl group

• 2. Amino group

• 3. Side group

• The side group is what makes amino acids different from each other!

• AA are bonded to other AA by dehydration synthesis, making “peptide bonds”

A bit about Amino Acids…

Copyright © 2009 Ekis, Inc., Tell Glenn to shand up Publishing

Dehydration Synthesis….

Copyright © 2009 Ekis, Inc., Bring me Macaroons Publishing

Peptide bond

Water is given off!

• We have the ability to make 12 of the 20 amino acids needed to build proteins• However, there are 8 that we must consume….

Phenylalanine, valine, threonine, tryptophan, isoleucine, methionine,

leucine, and lysine.

What is an “essential Amino Acid”?

The Amino Acids (AA) are arranged in a long chain, then the chain folds. This new shape enables it to function.

AAAA

AA

AA AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AAAA

AA

AA

AA

AA

AA

AA

Peptide Bonds!

This whole thing would be a Protein!! Sometimes known as a “Polypeptide”…

Important concept alert!!!Every protein can

only fold a specific way

, so if you need a specific type of fold (for a specific function or ability), you have to make a

specific type of protein!!

Now, our second goal…

What gives Proteins their characteristics?

In other words: what enables proteins to fold certain ways?

• Change The type of Amino Acids make the protein unique

• Change the number of Amino Acids make the protein unique

• Change the order of Amino Acids make the protein unique

These three things are what mainly determine a protein’s characteristics!

If YOU were to build a protein model (stick a bunch of AA together to create a protein), what could you do that would make your

protein unique compared to everyone else’s??

Example of how one small difference can cause HUGE changes…

Hemoglobin - an important protein used by red blood cells to transport Oxygen throughout the body.

It is 146 Amino Acids long!!

BUT, If you replace Glutamic acid (AA) with Valine (AA) at the sixth position, the hemoglobin cannot fold correctly.

This ultimately causes red blood cells to have a funky shape….

Sickle Cell Anemia

Normal

What do you think determines the order, number, and type of

amino acids used by the ribosome to build proteins???

•DNA!!

Big Question…

Now, our Third goal for today…

What are some of the major functions

of proteins?

• Also known as contractile proteins: actin

and myosin

• Create the structures in muscle cells that allow contraction

2. Structure• Collagen

• Most abundant protein in the body.

• Forms connective fibers like ligaments, tendons, cartilage, etc.

1. Movement

• Within body

• Hemoglobin

• Moves Oxygen (O2) throughout the body

• Red blood cells are FILLLED with hemoglobin!!

3. Transport

• Hormones!!

• Important in homeostasis

• Used to signal cell to cell

• Send messages throughout the body

• Produced by glands

• Insulin

• Regulates blood sugar level

• Diabetes

4. Regulation

• Antibodies

• Cover receptor sites on bacteria/viruses

• Prevents them from attaching to YOUR cells!

• Clumps them together so HUGE white blood cells can engulf and destroy them in large numbers

• Can you name this process of engulfing them in large numbers?????

Endocytosis - Phagocytosis!

5. Defense