Chapter 6

• Protein Turnover: existing proteins are degraded into AAs for new proteins
• Amino acid pool: AAs from food and cellular breakdown
• Essential amino acids: 9, obtains from food
• Nonessential: synthesized by body
• Transamination: transfer amine group from an essential amino acid to a different acid group
• Conditionally essential: non-essential becomes essential due to a condition or lakc of nutrients
• Limiting amino acid: missing in the small supply, slows or halts protein synthesis
• Incomplete protein (low quality): insufficient AAs, does not support growth or health
• Complete protein (high quality): sufficient amounts of all 9 essentials, derived from animal sources, soy beans, and quinoa
• Mutual supplementation: combine 2+ imcomplete protein sources to make a complete protein
• Complementary proteins: 2 or more foods that contain the complete AA profile
• RDA for Protein

  0.8g per kg of body weight

  during higher growth periods like developments theyre needed more
• Protein AMDR: 10-35%
• Most americans meet or exceed the RDA
• Protein-energy malnutrition: disorder caused by inadequate protein and energy intake
• Marasmus: inadequate energy, protein, and nutrient intake
• Kwashiorkor: low protein intake
• Vegetarianism: restricting diet to plant foods
• ProteinsL large complex molecules found in all living tissues, dictated by DNA
• What are proteins made of?

  20 amino acids
• Proteins are long amino acids chains, peptide bonds hold these together
• Gene expression: cells use genes to express proteins
• Transcription: mRNA copies genetic information from the DNA in the nucleus
• Translation: mRNA transcribed into an AA sequence at a ribosome
• Primary protein structure: The sequence of amino acids in a polypeptide chain
• Secondary protein structure: spiral shape or twisting of the AA chain
• Tertiary Protein Structure: three dimensional sjape from hydrogen bonds and disulfide bridges. determines it's function
• Quaternary protein structure: polypeptides bond to form larger proteins
• Proteins: can be globular or fibrous
• Protein denaturing: loose shape when exposed to heat, acid, base, heavy metals, or alcohol. Their function is lost forever.
• Protein function loss

  
• Nitrogen balance: determines proteins needs
• Positive nitrogen balance: consuming more nitrogen than is excreted (growth, pregnancy, recovery from illness)
• Negative nitrogen balance: excreting more nitrogen than taken. (starving, low-energy diet)
• Bone health: higher intakes of animal and soy show to protect bones in middle-aged or older women
• High protein intake may be beneficial in some populations
• High protein diets can increase calcium excretion, this does not degrade bone structure
• Kidney Disease: high protein diets can increase risk of kidney disease in diabetics. 2g of protein per kilo of body weight is safe for healthy people
• Intaking more water with protein intake is reccomended
• Elevated blood cholesterol increases risk of CVD, associated with protein diets. Recommended to limit sat. fats and replace with poly unsat. fats