Fundamentals of Nutrition Part 2 Chapter 7 Flashcards
(17 cards)
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.
What are Conditionally Essential Amino Acid?
They are amino acids which are only essential in times of stress or injury. Otherwise, they are nonessential.
What are the 2 qualities of Protein?
- High-quality
– complete - Low-quality
– incomplete
