1. By Jennifer Turley and Joan Thompson
Module 1.3
Proteins
By Jennifer Turley and Joan Thompson
© 2013 Cengage

2. Presentation Overview
Amino Acids in Protein
Amino Acid & Protein categories
Complementation
Functions
Dietary Recommendations

3. Amino Acids Amino acids are the “building blocks” of protein
Amino acids (and thus proteins) contain nitrogen, carbon, oxygen & hydrogen (a few contain sulfur)
Proteins are organic compounds
Each of the 20 amino acids has a different variable side chain

4. Amino Acids
Amino acids combine together to make a protein

5. Amino Acids There are 20 amino acids that make biological proteins
Categorized as Essential and Non-essential

6. Categories of Amino Acids
Essential: The body cannot make
Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine
Nonessential: The body can make from nitrogen & carbohydrate intermediates
Alanine
Arginine
Asparagine
Aspartic acid
Cysteine
Glycine
Glutamic acid
Glutamine
Proline
Serine
Tyrosine
See your textbook appendix for chemical structures

7. Categories of Proteins
Incomplete
Low Biological Value
Low Quality
Complete
High Biological Value
High Quality
*Categories are based on the proportions and amounts of essential amino acids in a protein

8. Categories of Proteins
High Quality Proteins: Contain all the essential amino acids, and are high biological value proteins or complete proteins
Complete Proteins come from animal sources such as milk, yogurt, meats, eggs, and cheese
Low Quality Proteins: Lack one or more essential amino acids, and are low biological value proteins or incomplete proteins
Incomplete Proteins come from plant sources such as vegetables, legumes (dried beans), nuts, seeds, tofu, and grains

9. Protein Complementation
Multiple low quality proteins can be combined in such a way that the essential amino acids lacking in one are supplied by another
Example: eating rice and beans instead of meat
In this way, the combined proteins can provide all of the essential amino acids of a high quality protein

10. Protein Complementation
Protein missing black and white amino acids
All the essential amino acids are present by the protein combination
Protein missing pink and purple amino acids + =

11. Protein Complementation

12. Protein Complementation
Grains
Legumes
Nuts & Seeds
Vegetables
Combine any 2 food groups for complementation

13. Functions Primarily used for tissue repair & maintenance
Secondarily used for energy (4 Calories/ gram)
 Not as efficiently used as carbs

14. Dietary Recommendations
Based on body weight
Adult daily recommended intake (DRI) is .8 grams of high quality protein per kilogram body weight per day
AMDR:
10-35% of Calories
from proteins

15. Summary
Protein is made of 20 amino acids categorized as essential & nonessential
Protein is also categorized as complete (high quality) and incomplete (low quality)
 Complete: from animal sources
 Incomplete: from plant sources
Combining plant proteins so that all the essential amino acids are present is complementation
References for this presentation are the same as those for this topic found in module 1 of the textbook

16. Summary The primary function of protein is tissue repair & maintenance
When used for energy, protein provides 4 Calories/ gram
Adults need 0.8 grams/ Kg body weight protein per day. Adults may consume 10-35% of Calories from protein.
References for this presentation are the same as those for this topic found in module 1 of the textbook