1. “Chapter 4: Proteins and Amino Acids”
What foods are rich in protein?

2. Do you ever… Wonder why you need protein?
Find it curious that heating an egg changes it from a liquid to a solid?
Take amino acid supplements?
Fear that your diet will lack protein unless you eat some meat?

3. What do proteins do for us?
From Greek word proteios, meaning of prime importance.
They are “the building blocks of our body”
Including organs, blood cells, hormones, and antibodies

4. “The Structure of Proteins”
Like any other molecule, structure is everything.
Does anyone remember what they’re made of?
“Made of smaller molecules called amino acids.”

5. A Little Refresher Course in Genetics
Genes are made of what?
DNA
A group of three DNA letters (a word) is called?
A codon.
Each codon tells the body how to put amino acids together to make proteins.

6. So DNA is the instruction manual that tells the body how to build itself.
“DNA tells us how to put 20 amino acids together in different combinations to make different proteins.”

7. Let’s take a look at an amino acid..
“All amino acids have the same backbone:”
“An amine group attached to an acid group.”
In this way, they are all identical.

8. “They differ by the side chain attached to the backbone.”
There are 20 different side chains; therefore there are 20 different amino acids.

9. Valine
Leucine
Tyrosine
can bond to form…
Single amino acids with different side chains…
a strand of amino acids, part of a protein.

10. Side chains make an amino acid different in
Size
Shape
Electrical charge (positive, negative, or neutral)
So where do we get these amino acids?

11. Essential Amino Acids “Body can make half of the aa’s for itself.”
The others cannot be made, or cannot be made fast enough.
“The essential aa’s cannot be made by the body.”
If we can’t make it, where do we get it?

13. Recycling Amino Acids
“The body can also break proteins apart to harvest aa’s.”
We can either use proteins that we’re done with,
Or we can break down food proteins to make others.

14. Can’t proteins also be used for energy?
Yes, but it’s better to use them for building.
“Aa’s contain nitrogen.”
“When aa’s are used for energy, nitrogen is released as waste, and the body must dispose of it.”

15. This creates a burden on the body.
When aa’s are used to make protein, this does not happen.
It is more efficient for the body to use cleaner sources of energy, and save aa’s for body building.

16. But in an emergency…
“The body will sacrifice blood and muscle proteins for energy in an emergency.”
The body saves the organs, like heart and intestines, for a severe need.

17. “How do Amino Acids Build Proteins?”
“1. amino acids hook to others using a peptide bond.”

18. “2. Some aa’s are attracted to each other; this causes the chain to coil.”

19. “3. Other parts repel each other; this forms a tangle.”

20. “4. Multiple proteins join to form larger ones (like hemoglobin)”
Hemoglobin is the protein in blood that carries iron.

21. Next: The variety of proteins…hemoglobin, collagen, enzymes, and insulin