Chapter 6: Proteins Flashcards
what are amino acids?
- building blocks of proteins
what is the difference between plant and animal proteins in terms of building body proteins?
plant proteins are not used as efficiently as animal protein
what are attributes of animal proteins?
- high in vitamin B and minerals
- low in fibre
- high in saturated fat and cholesterol
what are attributes of plant proteins?
- low in iron, zinc, and calcium
- high in fibre, phytochemicals, and unsaturated fat
what is the structure of amino acids?
- carbon atom bound to a hydrogen atom
- amino group containing nitrogen
- acid group
- side chain
what is the function of nitrogen in amino acids?
- distinguishing factor from carbs and lipids
- inefficient for body to use for energy because it must to broken down
what are essential amino acids?
- “indispensable amino acids”
- can’t be made by the body in sufficient amounts
- must be consumed in the diet
- 9 essential amino acids
what are non-essential amino acids?
- amino acids that can be made in the body
- 11 non-essential amino acids
what are conditionally essential amino acids?
non-essential amino acids that can’t be made in sufficient amounts
what is phenylketonuria (KPU)?
- a genetic disease where phenylalanine can’t be metabolized properly causing build up in the blood
- can result in brain damage
what is a protein’s structure?
amino acids linked by peptide bonds which joins acid group to amino group
what are polypeptides?
chain of amino acids linked by peptide bonds
what is denaturation?
alteration of protein’s 3D structure
what are the 7 steps of protein digestion and absorption?
step 1: chewing begins mechanical breakdown of protein
step 2: in stomach, hydrochloric acids and pepsin begins chemical digestion of protein
step 3: in small intestines, pancreas secretes protein-digesting enzymes to break down polypeptides into amino acids, dipeptides, and tripeptides
step 4: transport proteins move amino acids, dipeptides, and tripeptides into mucosal cells
step 5: dipeptides, tripeptides enter mucosal cells, once inside are broken down into single amino acids
step 6: amino acids from mucosal cells > blood > liver > body
step 7: dietary protein excreted in feces
what is a negative affect of amino acid supplements?
amino acid supplements can clog transport system, reducing absorption of other amino acids that use the same transport system
what are amino acid pools?
amino acids in body tissue and fluids available for use by body
what are genes?
segments of DNA that contains information to synthesize a specific chain
what is transamination?
process in which an amino group is transferred to a carbon compound to form a new amino acid
what are limiting amino acids?
an essential amino acid available in the lowest concentration relative to body’s needs
where are structural proteins found?
skin, hair, ligaments, and tendons
what are the 6 functions of protein?
- provides structure to individual cells
- protects and defends body
- regulates fluid balance and prevents levels of acidity away from normal range
- enzymes can speed up biochemical reaction
- in blood can help material cross membrane and regulate processes throughout body
- contractile properties allow muscles to move body parts
what is protein-energy malnutrition?
- a condition characterized by loss of muscle and fat mass
- increases susceptibility to infection
- results from long term protein deficiency
what is kwashiorkor?
- protein-energy malnutrition when only protein is deficient
- typically in children
- means “the disease 1st child gets when 2nd is born”
what is marasmus?
- protein-energy malnutrition when energy and protein in deficient, causing severe body wasting
- caused by starvation
- means “to waste away”
what are negative effects of high protein diets?
- increases water loss, problematic for people with kidney disease > speeds the progression of renal failure
- calcium is lost in urine
- high in animal products which are high in saturated fat and cholesterol, increasing the risk of heart disease
what are kidney stones?
deposits of calcium and other substances in kidneys and urinary tract
what is diverticulosis?
associated with low fibre diets resulting in outpouching of colon and severe abdominal pain and fever
what is a food allergy?
immune response to a specific food protein
what is anaphylaxis?
compromised breathing and low blood pressure
what is food intolerance?
- “food sensitivities”
- reactions that don’t involve the production of antibodies by the immune system
what is monosodium glutamate (MSG)?
- flavour enhancer and meat tenderizer
- common in Chinese dishes
what is celiac disease?
- disorder that causes damage to intestines when gluten is consumed
- food intolerance, not an allergy, because the symptoms aren’t life threatening
where is gluten found?
wheat, rye, and barley
what is a nitrogen balance?
- amount of nitrogen consumed in the diet compared to the amount excreted
- when balanced, nitrogen intake = nitrogen excretion
what is a negative nitrogen balance?
when the body is losing body protein
what is a positive nitrogen balance?
when body protein is increasing
what is the RDA of proteins for adults?
0.8-2g/kg
what is the RDA of proteins for a pregnant woman?
25g higher than a non-pregnant woman
what is the AMDR for proteins?
10-35%
what is protein quality?
measure of how good protein in a food is at providing essential amino acids needed to make proteins
what is protein digestibility correct amino acid score?
method used to determine protein quality
what is the protein quality of animal and plant proteins?
- animal proteins have a higher score and are considered complete dietary proteins
- plant proteins have a lower score and are considered incomplete dietary proteins
what is protein complementation?
combining proteins from different sources for correct amino acid proportions to meet body needs
what are vegetarian diets?
diets that include plant-based foods and eliminate some/all animal products
what is a vegan diet?
plant-based diets that eliminate all animal products
what are the benefits of a vegetarian diet?
- healthy
- low cost
- decreases diseases
- more economical
what are the risks of a vegetarian diet?
- nutrient deficiency if poorly planned
- vitamin B12 deficiency, must take supplements
- iron deficiency
