Nutrition Flashcards
Nutrition
The process of acquiring nutrients to support energy & cellular processes.
RD vs CDN vs Certified Nutritionists
RD is nationally board cert. by Comm. on Dietetic Reg.
CDN/LDN is state specific
CNS only by board for CNS
*Only RD/LD can prescribe meal plans
Micronutrients
Vitamins: organic
Minerals: inorganic, major & trace amt.
Phytonutrients: plant based
*Don’t provide energy but have important regulatory functions in the metabolic pathway
Protein
Synthesizes & repairs cells, tissues, and structures, such as collagen, elastin & muscle
Required for synthesis of hormones & transport of lipids & minerals
Amino acid (C-H-O-N) linked by peptide bonds in polypeptide chains. They are the building blocks that synth & repair protein.
9 essential, 20 non-essential
Protein turnover
The breakdown of internal proteins and recycling of the amino acids for synthesis of new proteins.
Name Essential Aminos & concept of Conditionally Essential
Histidine
Lysine
Leucine
Isoleucine
Theronine
Tryptophan
Phenylalanine
Methionine
Valine
Certain non-essentials may become conditionally essential under heavy workload or metabolic stress
Complete vs Incomplete Protein
Complete: Provides all EAA. Animal, Soy & Hemp (incl quinoa & buckwheat)
Incomplete: Lacks one or more EAA. Legumes, grains & Veg.
The 4 Protein Structures
Primary
Peptide chain: simple linear
Secondary: Helix shape
Tertiary: 3d Coil shape polypeptide chain
Quaternary: Assembled coils
Mutual supplementation
Combination of two incomplete protein sources, that will together provide all EAA.
Protein quality & Low Biological Value Proteins (LBV)
Quality: Contains all EAA & easily digestible
LBV: Lacking one or more EAA
Protein Assessment
Protein efficiency ratio (PER)
Biological Value (BV)
Protein-digestability-corrected AA score
(PDCAAS)
Net Protein Utilization (NPU)
PER: assessing value of protein based on weight gain divided by ingested protein
BV: a reference amt. measures digestibility & absorption of AA by a specific protein
PDCASS: compares AA in a food source to a standard AA profile & assesses
digestibility w/ top score 1.0
NPU: ratio of AA mass actually turned into proteins, compared w/ total AA mass consumed
Digestion steps of Protein
Saliva enzymes do little to digest proteins
Protein is consumed and enters the stomach where hydrochloric acid DENATURES it, meaning that the secondary & tertiary structures are unraveled to expose the primary structure (peptide chains)
Continuing in the stomach, digestive enzymes (Pepsin) clip the exposed peptide bonds, making di- or tri-peptides.
The small intestines continues the breakdown w/ protease enzymes reducing the now smaller remaining peptide chain into single AAs & di-peptides, which can be absorbed into the body.
Meanwhile, some AAs enter the intestinal wall & enterocyte (intestinal cell) ie-Glutamine
AAs are delivered into the liver through the portal vein & circulated into the bloodstream.
Using Protein for Energy: Deamination & Gluconeogenesis
Deamination: Occurs when excess protein is present. Nitrogen is removed and excreted in urea. Remaining Carb-Hydr-Oxyl are metabolized to meet energy demand.
Gluconeogenesis: Oxidation of AAs glutamine & alanine to synth glucose.
RDA of Protein
0.8g per kg to maintain nitrogen bal.
Accepted Macronutrient Distribution Range (AMDR)
National Academy of Medicine rec’d for 97-98% of population, associated w/ reduced risk of chronic disease.
