Fundamentals of Nutrition Part 2 Chapter 7 Flashcards
What is Protein and its Function?
Body is made up of thousands of protein substances
- Contains atoms called nitrogen
- Regulates and maintains body functions
– Eg. Enzymes, hormones
- Building blocks of body components, hormones and enzymes.
- Maintain fluid balance
– Edema - Contribute to acid/base balance
– Buffers - Immune function
- Gluconeogenesis: glucose synthesis from lipids or protein
- Energy yielding
What are Amino Acids?
*Building block of proteins
*Most basic unit of proteins
R group differentiates amino acids
What are the different protein bonds?
- Peptide bond = connection between amino acids
- Dipeptide = 2 connected (bonded) amino acids
- Tripeptide = 3 connected (bonded) amino acids
- Polypeptide ≥ 50 amino acids bonded together
What are the steps of the digestion of protein?
Digestion of Protein in the Stomach
- Proteins are denatured by cooking and acid in the
stomach - Gastrin stimulates the release of acid and pepsin
- Pepsin is activated and breaks down proteins to smaller amino acid chains
- Hydrolysis = breaking down of
peptide bonds by enzymes
Digestion of Protein in the Small Intestine
- Pancreas release the protein splitting enzymes: trypsin, chymotrypsin, and carboxypeptidase into the duodenum
- The enzymes will break peptide bonds forming smaller peptides and amino acids
- Peptides and amino acids are ready for absorption
Protein Absorption
- Absorbed across the intestinal walls into blood capillaries.
- Amino acids are sent to the liver via portal vein
What are the risks of a high protein diet?
- Low in plant foods (fiber), vitamins, phytochemicals
- High intake of animal protein increases risk for heart disease (high in saturated fat)
- Excessive intake of red meat is linked with colon cancer
- Burden on the kidney
- Increase calcium loss
What are the risks of Individual Amino Acid Supplements?
- Supplement may cause imbalances and toxicities
- Body is designed to handle whole proteins
- Supplement can overwhelm the absorptive mechanism
- Excess of one AA can hamper absorption of other AAs
What is Malnutrition?
- Protein-Energy Malnutrition
– Consuming insufficient amounts of protein & energy
– Hospitalization
– Diet
Name 2 diseases of Malnutrition?
- Marasmus
- Kwashiorkor
* Especially persons who already have a disease eg.
Infection
* Primarily in children
What is Kwashiorkor?
- Moderate energy deficit &
severe protein deficit - “Disease that the first child
gets”
- Signs and symptoms:
- Apathy
- listlessness
- failure to grow, poor weight gain
- change in hair color
- nutrient deficiency
- flaky skin
- fatty infiltration in the liver
- massive edema in the
abdomen and legs
What is Marasmus?
- Severe protein and energy deficit
- Starving to death
- “skin and bones” appearance
- Little or no subcutaneous fat
- Reduce brain growth
What is Plant Protein?
- Provide protein, minerals, and dietary fiber
- Contain no cholesterol
- Limited saturated fats
- Allow a few weeks for the GI tract to adjust to the higher fiber
What is the Denaturation of Proteins?
Heat/acid/alkaline/enzymes Results in alteration of the protein’s three dimensional structure
What is Protein Turnover?
- Protein undergo breakdown and synthesis
- Responds to change
- Protein balance = protein equilibrium
- Positive protein balance = dietary protein intake exceeds protein lost
- Negative protein balance = dietary protein intake is less than protein lost
What are the Complementary Proteins?
Combining different sources of Protein to get all essential amino acids.
- Beans (Legumes)
- Nuts / Seeds
- Vegetables
- Grains
What are Limiting Acids?
It is when the essential amino acid is at is lowest quantity.
