How much protein is recommended for sedentary individuals?
8g protein/kg of body weight/day
What groups of people may require more protein than sedentary individuals?
a. Children
b. Adolescents
c. Pregnant or lactating
d. Athletes
e. Vegetarians
What do proteins contain that makes them distinct from carbohydrates and fats?
Amino Acids
What are amino acids?
Building blocks of proteins
How are amino acids attached to one another?
Peptide bonds
What is the difference between an essential and a nonessential amino acid?
a. Essential: 9 of 20; must consume in diet
b. Nonessential: can be made in our bodies
What are peptides? What are the different sizes of peptides?
a. 2 amino acids = dipeptide
b. 3 amino acids = tripeptide
c. 4-9 amino acids = oligopeptide
d. 10+ amino acids = polypeptide
Where do amino acids in the amino acid pool in the body come from?
Food
What is denaturation? What things can cause denaturation of proteins?
a. Proteins lose shape when subjected to heat, acids and bases, alcohol, heavy metals
b. Results in the irreversible loss in protein function
What is sickle cell anemia?
A single amino acid in the chain is changed and the entire cell is changed from circle to half-moon shaped
Painful condition
What are incomplete and complete proteins? What general food sources do each of these come from?
a. Complete proteins:
i. Contain sufficient amounts of all 9 essential amino acids
ii. Considered a high-quality protein
iii. Mostly found in animal proteins
b. Incomplete proteins:
i. Does not contain all 9 essential amino acids in sufficient quantities
What are plant sources of complete proteins?
Quinoa soy chia
What are complementary proteins?
Two incomplete protein sources that if you put together you would get all 9 essential Amino Acids
What are the general functions of proteins in the body?
a. Cell growth, repair and maintenance
b. Fluid and electrolyte balance
c. pH balance - proteins can raise pH levels and reduce acidity
d. Energy source (by deamination)
e. Transport and storage of nutrients
f. Compounds such as fibrin and collagen
Describe protein digestion.
1. Begins in stomach
--HCl and pepsin denatures the protein
2. Finishes in the small intestine (mostly)
--enzymes break protein apart
What types of proteins are considered high quality proteins and low quality proteins and why?
a. High quality: all 9 essential aminos (complete)
b. Low quality: not all 9 (incomplete)
Understand which types of foods (meat, dairy, grains, vegetables, etc) will provide the most protein per serving.
Dairy, Meats, supplements, nuts, beans
How much protein is associated with the maximum amount of protein synthesis after resistance exercise? What happens to protein consumed above this amount?
25 g. above, amino acids are used for energy,, and saturates the amino acid pool
Compare and contrast whey and casein proteins.
a. Whey protein isolate: Form of supplement, 90% protein, very little or no CHO or fat. Has all 9 essential AA's and high in BCAA's. Whey is fast acting.
b. Casein: has different AA's than whey, however still getting all 9 essential. High in glutamate. Sl
Body fluids are separated into what two compartments?
a. Water & electrolytes
b. Intracellular and Extracellular
How does body fluid content change with aging?
Declines
What are the primary extracellular and intracellular electrolytes?
a. Extracellular: tissue, fluid, plasma
b. Intracellular: inside of cells
i. Sodium & Chloride = outside cell
ii. Potassium & Phosphorus = in cell
Explain the functions of fluids in the body.
a. Maintain body temperature
b. Protective fluids (cerebrospinal, etc)
c. Blood volume
d. Dissolve and transport substances
What are the functions of electrolytes in the body?
a. Enable our nerves to respond to stimuli
b. Signal our muscles to contract
c. Normal cell function relies on fluid and electrolyte balance
When the body's fluid balance is disrupted, what can result?
a. Diarrhea and vomiting
b. Changes electrical impulses through the heart
i. Largely controlled by potassium
ii. Irregular heart rate ? death (over time)
Explain the principle of osmosis.
a. If you pour salt into one side of glass, other side of water will go to salted side
b. Controlled movement of fluids in and out of cells = osmosis
Describe the thirst mechanism (location in the brain, simuli, issue surrounding it)
a. Thirst mechanism is in the hypothalamus
i. Stimuli for thirst mechanism: concentration of salt or solutes in blood increase. Blood volume and pressure decrease. Dry mouth and or throat
b. It is not always sufficient
i. Turns on late and turns off early
What contributes to water loss and water gain in the body?
a. Gain: beverages, foods, metabolic reactions
b. Loss: urine, feces, sweating, evaporation, exhalation
Be able to identify foods that contain a high percentage of water. For example, would cucumbers or almonds contain a greater percentage of water?
a. Iceburg lettuce
b. Cucumbers
c. Peaches
d. Pineapple
e. Olives
In general, what can result if too much or too little water is consumed over time?
a. Too little: dehydration
b. Too much: water intoxication
What are the daily recommended intakes for water for males and females?
a. 3.7 L for males
b. 2.7 L for females
Describe what would happen in a case of water intoxication. (You can use the "Hold your Wee for a Wii" contest example.)
a. Dilution of sodium (hyponatremia)
b. Pulls salt outside of cell and floods the cells with water
c. Causes cells to burst and die
What are the functions of sodium in the body?
a. Fluid and electrolyte balance
b. Associate with blood pressure and blood pH in the body
c. Required for nerve transmission
d. Assists in the transport of certain nutrients into body cells
What are the risks associated with consuming too much sodium?
a. Hypertension
b. Hypernatremia
What are the risks associated with consuming too little sodium?
Hyponatremia
What are the functions of potassium in the body?
a. Fluid and electrolyte balance
b. pH balance
c. Important in muscle contractions and transmission of nerve impulses
d. High potassium intake helps to maintain lower blood pressure
Where is potassium found in the diet?
Fresh fruits, veggies, whole grains
What are the risks associated with consuming too much potassium?
Hyperkalemia
What are the risks associated with consuming too little potassium?
Hypokalemia
What are the functions of chloride in the body?
-assists with maintaining fluid balance
-component of HCl in the stomach
What is the main source of chloride in the diet?
salt
What are the functions of phosphorous in the body?
a. Required for fluid balance
b. Critical role in bone formation
What are common food sources of phosphorous?
a. Protein containing foods (meat milk eggs)
b. Animal sources better absorbed than plant\
What is a free radical?
A molecule with at least one unpaired electron
When are free radicals formed in the body?
When oxidation and reduction are not paired during metabolic reactions
How do free radicals act in the body?
a. Create "leaky" cells
b. Steal electrons from stable atoms which creates another
List the things in the body that free radicals typically damage? Which of these is most likely to be related to cancer development?
a. Cell membranes (phospholipids)
b. Proteins
c. LDL (more plaque)
d. DNA (mutated DNA) (Cancer related)
What nutrient in the diet can fight against free radicals?
Antioxidants