PROTEIN

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PROTEIN
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Protein Structure

• Polymer of amino acids
• amine group (N)
• acid group
• side chain

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Protein Structure

• Proteins are unique among energy nutrients
• They contain NITROGEN
• Composed of 20 different amino acids
• 9 amino acids are essential, other 11 are not
  essential
• Proteins are strands of amino acids
• linked by a peptide bond with next amino acid

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Glucose
Triglyceride
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Protein Structure

• Primary Structure
• Amino acid sequence or strand
• like a strand of pop-beads or pearls
• Secondary Structure
• coiling of the strand
• like a slinky positive and negative parts
  attract each other

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Protein Structure

• Tertiary or third level of structure
• Folding back of coil
• The slinky gets messed up
• Quaternary or fourth level of structure
• Subunits fit together
• Hemoglobin has four subunits to make the
  functional molecule

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Protein Structure

• SHAPE DETERMINES FUNCTION
• The shape of the protein molecule determines if
  the molecule is functional
• the shape of the lipase molecule determines if it
  will actually help breakdown a lipid

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Protein Structure

• Change of shape is called DENATURATION
• What causes change of shape?
• acid (like the stomach low pH) or base(high pH)
• alcohol
• mechanical agitation(beating an egg white)
• heat(heat an egg white) or heavy metals(mercury)

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Denaturation
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Cellular Protein Synthesis

• DNA in nucleus acts as a template for mRNA
• mRNA moves out of nucleus to cytoplasm
• Carries instruction for an amino acid sequence
  for a specific protein to a ribosome
• Ribosome reads the mRNA which dictates which
  amino acid is next
• tRNA carries the correct amino acid to the mRNA

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Cellular Protein Synthesis

• tRNAs line up one after the other with amino
  acids
• Amino acids form peptide bonds to make the
  primary sequence of the protein
• Protein then coils to form the secondary and
  tertiary structure
• SHAPE DETERMINES FUNCTION

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How Are Proteins Made?
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Heredity Factor

• Cystic fibrosis
• Hypercholesterolemia
• LDL-receptor
• Sickle cell anemia

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Sickle-cell hemoglobin
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Protein Digestion

• Stomach
• Denaturation
• Pepsin induced breakdown into shorter peptides
• Small Intestines
• duodenum peptidases or proteases enter from
  pancreas thru the common bile duct
• breakdown proteins to aas, dipeptides and
  tripeptides

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Protein Digestion

• Cells of small intestine
• complete digestion of proteins so that only amino
  acids remain
• cells of S.I. absorb amino acids and a few larger
  peptides and release them into the blood for
  circulation

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Protein Function

• Structure proteins
• Muscle fiber protein
• Connective proteins
• others

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Protein Function

• Supporting Growth and Maintenance
• body needs amino acids to grow new cells and
  replace cells that are worn out

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Protein Function

• Building Enzymes, Hormones, and other Compounds
• amino acids used to make enzymes (e.g.. lipases
  for digestion)
• amino acids used to make some hormones(e.g..
  insulin for glucose metabolism)

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Protein Function

• Building Antibodies
• antibodies are formed from amino acids to defend
  against foreign proteins and substances in the
  body
• Maintaining fluid and electrolyte balance
• Proteins act like magnets and hold water in the
  blood vessels and also electrolytes like sodium

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Transport Proteins

• Cellular content differ from the contents of the
  surrounding environment fluids and electrolytes
• Protein Membrane carriers provide a pump to
  maintain this difference
• Sodium-Potassium Pump
• Animation of the Sodium-Potassium Pump

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Protein Function

• Maintain acid-base balance
• proteins buffer the blood against big changes in
  pH so body remains pretty neutral
• .

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Protein Function

• Providing Energy
• When insufficient CHO and Fat are eaten, the body
  takes apart Protein for energy
• Nitrogen portion removed from A.A. and the rest
  is oxidized for energy. Nitrogen ends up in the
  urine as urea

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Amino Acid Possibilities

• Can be added to other A.A.s to make a protein
• Can have Nitrogen removed
• then it can be oxidized for energy or
• made into glucose (glucogenesis) or
• made into fat (lipogenesis)
• The diet needs to supply the 9 essential amino
  acids and 0.8 grams protein/kg wt.

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Protein Quality, Use and Need

• Protein Quality
• the amino acid assortment greatly influences a
  proteins usefulness to the body

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Protein Quality, Use and Need

• Measuring Protein Quality
• the amount of the essential amino acids present
  in the protein
• If all are well represented, the protein will
  support growth and maintenance COMPLETE PROTEIN
• If not, it wont support growth POOR QUALITY
  PROTEIN

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Protein quality

• Complete or good quality proteins
• soy beans, milk protein, animal flesh
• Poor quality proteins
• grains (missing lysine, an essential amino acid)
• many legumes(beans, missing methionine)
• Mutual Supplementation or complementing proteins
• mix grain and legume and get a good quality
  protein eg corn tortilla and refried beans

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Vegetarian Diets-Reasons
Health Religion Ethical Environmental Taste
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Types of Vegetarian Diets

• Non-red meat vegetarian
• poultry, fish, dairy, eggs O.K
• no special nutritional problems, may be high in
  fat, saturated fat
• Lacto-ovo vegetarian
• milk and eggs O.K.
• no special nutritional problems
• may be high in fat, saturated fat

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Vegetarian Diets Types

• Strict Vegetarian Vegan
• no animal products
• protein quality-complement
• calcium
• iron
• vitamin B 12
• Top Stories - The Olympian - Olympia, Washington

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Vegetarian vs Meat eaters

• Vegetarian
• reduced risk
• obesity
• diabetes
• hypertension
• heart disease
• digestive disorders
• cancer

• Meat eaters
• growth
• support during critical times.

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Protein RDA 0.8 grams/kg

• Nitrogen balance
• negative balance more out in urine than coming
  in from the diet
• protein is being broken down faster than it is
  replaced
• who is in this predicament? elderly, bedridden

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Protein RDA 0.8 grams/kg

• positive balancemore in the diet than going out
  in the urine
• protein is being made into tissue faster than it
  is taken apart

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Protein Rich Foods

• Animal products
• also high in vitamin B12, iron, and zinc
• lacking in vitamins C and folate
• often high in fat
• Legumes
• soy protein almost complete
• high in fiber, many B vitamins, iron, calcium
• low in vitamins A, C and B12

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Protein Intake (Fat Intake)

• 1 cup Frosted Mini Wheats 3 g(
• 1 cup Skim milk 8 g(0 g)
• 1 banana 1 g(1 g)
• 1 Arbys Turkey Sand Delux 20 g(6 g)
• 1 cup Skim milk 8 g(0 g)
• 1 cup lentil chili 19 g(3 g)
• green salad/dressing 1g (6 g)
• garlic bread 4g (10)
• 64 grams Protein(27 grams Fat

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Protein Intake (Fat Intake)

• 0.5 cup Granola 7g (10g)
• 1 cup 2 milk 8 g (5g)
• Arbys Roast Beef Dlx 25g (22g)
• 1 vanilla milk shake 11g (12g)
• 6 oz steak 45.5g(17g)
• baked potato/marg/sour 6g (16.5g)
• 0.5 cup green beans 1 g (0)
• 103 grams Protein (83 grams fat)

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Protein Needs

• 154 (70 kg)
• RDA 70 x .8g/kg 56 grams
• Athlete 1 to 1.5 g/kg (ADA)
• 70 to 105 grams Protein/day

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Allergies vs Intolerance

• Protein Allergy
• protein gets across from digestive system to
  blood without being digested to its amino acids
• this causes a sensitization and an allergic
  reaction
• whole body reaction itching, swelling, etc

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Allergy vs intolerance

• Lactose intolerance
• lack the enzyme to break down lactose
• causes digestive track upset
• gas production, bloating, diarrhea

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Too little Protein

• Kwashiorkor Protein deficiency
• true definition what happens to the first child
  when the second child is born
• symptoms edema, ascites(swollen belly)
• immune system failure so many infections
• loss of pigmentation
• Phenylalanine to Tyrosine to Melanin is blocked
• Fatty Liver
• no lipoproteins to carry fats and accumulate in
  liver

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Protein Problem

• Determine your RDA (0.8 gram/kg)
• (wt in lb/2.2 lb per kg)x0.8RDA for PRO
• From BMR activity, determine total energy
  expenditure from protein
• males (1 x kg x 24) x activity factor total
• females(.9xkgx24) x activity factor total CAL
  per day

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Protein Problem

• American Heart Association
• less than 30 from fat
• 55 to 60 from CHO
• 10-15 from Protein
• Total Cal x .15 _______ 15 Cal from PRO
• Pro Cal/4 Cal per gram Grams of PRO
• How does this compare to your RDA for PRO?

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Too Much Protein

• Dehydration
• 100 Cal of extra protein takes 350 grams(12 oz)
  of water to clear( this is how many grams of
  protein?)
• 100 Cal of extra CHO or Fat only takes 50 grams
  of water to clear
• Coupled with heavy workouts may result in
  dehydration

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Protein needs of Athletes

• May be up to 1.7 for power athletes
• May be up to 1.4 grams/kg for endurance athletes
• Tour de France, marathoners, triathletes
• They may need every available source of energy
  they can get their hands on