Download Proteins: An In Depth Discussion

Proteins: An In Depth Discussion
Presented by:
Professor Steven Dion – Salem State College
Sport, Fitness & Leisure Studies Dept.
Proteins
Next to water it’s the most abundant
substance in body.
 It aids in the transport of iron and oxygen
to the body as well as:
 aiding in the growth, maintenance and
repair or all body tissues
 making of enzymes, hormones and
antibodies,
 helps fight infection.

Proteins - Pro. Dion
2
Classification of Proteins / Amino Acids
Peptides - link amino acids together to take on
different forms
 Dipeptide - 2 joined amino acids
 Tripeptide - 3 joined amino acids
 Polypeptide - up to 100 amino acids
 Protein - combining more that 100 amino acids
combined
A single cell can contain thousands of different
protein molecules. The body has over 50,000
different protein-containing compounds.

Proteins - Pro. Dion
3
Other Purposes:



Blood plasma, visceral tissue, and muscle = 3 major
sources of body protein.
There is not storage of unused protein - all the
protein in the body is being used for something - no
true “reservoir.”
Body protein makes up 12 - 15 % if body mass - but
the protein content of different cells varies. For
example:
 The brain cell consists of 10%, a white blood cell
and muscle cell have up to 20% protein.
 Skeletal muscle makes up about 65% of the
bodies protein - but can increase with lifting.
Proteins - Pro. Dion
4
Amino Acids






They are the building blocks for synthesizing tissues:
(approx. 20-22 amino acids)
AA’s: activate vitamins key role in metabolic and
physiologic functions.
Anabolism: tissue building process - accounts for 1/3
of bodies intake of protein per day during rapid growth
in infancy and childhood.
As we slow down growing - so does the amount of
protein the body sets aside for anabolism.
Once you have reached full growth - there is a continual
turnover of protein tissue.
AA’s / proteins make up the collagen which give
structure to our hair, teeth, nails, skin, bones, and
ligaments.
Proteins - Pro. Dion
5
Other Properties & Roles



Globular Proteins: - make up over 2000 enzymes
that speed up chemical reactions and regulate the
catabolism (break down) of fats, carbs, and
proteins for energy release.
Proteins assist in regulating acid-base quality of
the body fluids Buffering neutralizes excess acid metabolism
formed during vigorous exercise.
Proteins - Pro. Dion
6
Amino Acids
The body can not synthesize 8 amino acids
(nine in children and some older adults)
 Those 8/9 are called essential amino
acids: so you need to get them from
external nutrients.
 The 8 include: isoleucine, leucine, lysine,
methionine, phenylalanine, threonine,
tryptophan and valine.
 Infants can not synthesize histidine and have
difficulty with arginine.

Proteins - Pro. Dion
7
Amino Acids



The body manufactures the remaining 9
 Those 9 are called nonessential amino acids.
 Nonessential means our body synthesizes them
within the body, not that they are not important
The source of the amino acids doesn't matter - just
as long as the body gets the AA’s whether it’s from
plants or animals.
Ideally coming from a nutrient rich, healthy food
source.
Proteins - Pro. Dion
8
Proteins Major Categories
Complete proteins or higher quality
proteins - come from foods containing all of
the essential amino acids in the quantity and
correct ratio to maintain nitrogen balance and
allow for tissue growth and repair.
 Incomplete proteins or lower quality
proteins - lack ore or more of the essential
amino acid. Incomplete protein diets will
eventually lead to protein malnutrition.

Proteins - Pro. Dion
9
Protein Sources




Complete proteins sources include:
 eggs, milk, meat, fish, and poultry. (pg. 31 chart
– rating scale)
Eggs provide the optimal mixture of essential
AA’s.
Ideally choose egg whites and egg white protein
shakes over whey/Casine powder shake.
Complementary sources of incomplete / low
quality proteins to create a complete protein meal:
 You can combine incomplete proteins to create
a complete protein meal.
 For example: rice and beans, rice and lentils,
tortillas and beans, and rice and peas
Proteins - Pro. Dion
10
Recommended Dietary Intake:
An intake greater than 3 times the
recommended level does not enhance work
capacity during intensive training. (so 1215% of total cals)
 Excessive dietary protein becomes used for
energy or recycled as components of other
molecules including stored fat in
subcutaneous (adipose) deposits.

Proteins - Pro. Dion
11
In Addition

Consumption: Consume .83 – 1 gram per kg.
 For example: a 90 kg male should
consume approximately 75 grams of
protein per day.
 Infants and growing children should
consume 2 – 4 grams per kg.
 If you are pregnant: Increase by 20 grams
and if you are nursing increase by 10
grams.
Proteins - Pro. Dion
12
Protein Metabolism


In well nourished individuals - protein breakdown
contributes about 2-5% of the body’s total energy
requirements.
Catabolism: protein breakdown
 1. Body breaks nutrients into its amino acid
components.
 2. The amino acids go through the liver =
deanimation
 3. Deanimation causes AA’s to lose a nitrogen creating urea (urine)
 4. The new AA is free to produce carbs or fat or
metabolize directly for energy.
Proteins - Pro. Dion
13
Key Terms
Anabolism – tissue building process
 Catabolism – tissue breakdown process
 Deanimation – the removal of the amino
(nitrogen) from the amino acid – thus creating
urea.
 The remaining deaminated carbon
compound can be used to form carbs or fat
to produce energy.
 Excessive urea production requires
increased fluid loss – because urea must be
diluted.

Proteins - Pro. Dion
14
Key Terms Continued



Transamination – the passing of nitrogen of an
amino group form one compound to another
Positive nitrogen balance – nitrogen (protein)
intake exceeds nitrogen excretion. (children,
pregnancy & illness)
Negative nitrogen balance – greater nitrogen
output compared to intake. Energy has become a
fuel source.(heavy exercises, fasting, starvation
diets)
Proteins - Pro. Dion
15
Cautionary Note




When catabolization occurs, ammonia is a
byproduct of the process. This increases the amount
of urea produced.
High levels of urea production can lead to
dehydration and calcium loss since urea needs to
leave the body with water and it needs to be
matched with calcium to do so. (Osteo… what?)
There is no advantage of consuming more protein (except in times of growth and if you have poor /
malnourished diet)
These problems have been shown in individuals
taking 3 - 4 grams per body wt.
Proteins - Pro. Dion
16
Info to Consider
The type or amount of protein or proteins
needed depends on your type of activity
levels / exercises.
 A certain type of protein is made inside the
muscle nuclei depending on its use - either
aerobic or anaerobic protein synthesis.
 Athletes retain more protein and use more
protein for energy sources than non-athletes.
(pg. 337)

Proteins - Pro. Dion
17
Gender and Protein
Naturally men have a higher metabolism
than most women because of their larger
physical size, bone structure, muscle mass
& larger brain size.
 Women who have gone through
menopause, may need to pay attention to
protein intake and increase calcium to assist
in the prevention of osteoporosis 
Proteins - Pro. Dion
18
Vegetarianism
Vegan - no animal products
 Lacto-vegetarian - eats only dairy products avoid all flesh products
 Ovo-vegetarian – eats only eggs
 Ovolacto-vegetarian - eats eggs and dairy
 Pesco-vegetarian - eats fish, dairy, eggs, no
red meat, poultry & pork
 Semi-vegetarians - eat fish chicken, dairy,
and eggs, but no red meat & pork

Proteins - Pro. Dion
19
Benefits of the Vegetarian Diet
Lowers LDL cholesterol levels without
having an effect on HDL levels
 Typically less fat and healthier body
 Less possible toxins in food
 Reduced risk of colon, heart, breast cancer

Proteins - Pro. Dion
20
Drawbacks of a Vegetarian Diet






Difficult to have a lot of variety - more difficult to
prepare yummy foods dishes
Can be expensive
In the US less education on creative and healthy
cooking
Lack of knowledge can lead to deficiencies
Possible deficiencies in B2 (riboflavin) and B12, and
D. B2 is found in meats and eggs, dairy - but
broccoli, almonds, asparagus
B12 and D are found only in dairy products: but B12
is made by body and D can be synthesized with
sunlight, or soy milk.
Proteins - Pro. Dion
21