NUTR400 Chapter 7: Proteins
lbs to kg
# lbs / 2.2 = # kg
What nutrients are major sources of fuel for cells?
Fats, Carbohydrates
Pepsin
a major stomach enzyme used for digesting proteins
Biological Value (BV)
a measure of how efficiently the absorbed food protein is converted into body tissue protein
Protein
a nutrient that plays a vital role in keeping the body healthy by forming important structures in the body, making up a key part of the blood, helping regulate many body functions, and fueling body cells
Where does protein synthesis takes place?
in the ribosomes which are located in the cytosol of the cell
A _______ amino acid cannot be synthesized by humans in sufficient amounts, or at all, and must be included in the diet
indispensable / essential
Transamination
involves the transfer of an amino group from 1 amino acid to a carbon skeleton to form a new amino acid
Protein deficiency is a rarely and isolated condition and usually accompanies.....
calorie deficiency and lack of nutrients
Transferrin
carries iron
Hemoglobin
carries oxygen
Retinol Binding protein
carries vitamin A
Food Intolerance
caused by an individuals inability to digest certain food components
Deamination
losing an amino group from an amino acid without transferring it to a carbon skeleton
vegetarian- Vegan
consumes animal products
vegetarian- Lacto
consumes milk
vegetarian- lacto ovo
consumes milk and eggs
foods with low PER
corn, bread
Calculating RDI
find weight in kg, then multiply weight in kg by 0.8 to find the person's RDI for protein
Which hormones stimulate positive protein balance?
growth hormone, insulin, and testosterone
Blood Proteins
help maintain body fluid balance; the presence of blood proteins in capillary beds attracts fluid from the extra-cellular space back into the blood
Almost all enzymes are _________
proteins
The body links amino acids with peptide bonds to form which nutrient?
proteins
Proteins
serve multiple functions in the body and is necessary for blood clotting, fluid balance, and cell repair
foods with high PER
tuna, chicken
What type of protein is an example of a plant-based protein that meets the essential amino acid needs?
Soy Protein
A diet rich in animal sources of protein may increase risk for cardiovascular disease because.... (2)
-foods of animal origin are often high in cholesterol -foods of animal origin are often high in saturated fat
If your carbohydrate intake is inadequate the liver is forced to make glucose from what macronutrient?
Amino Acids
A carbon skeleton is an amino acid without the....
Amino Group
The amino group is in what form in the urine?
Ammonia
Steps that can be taken to prevent the development of food- allergies...
Breast feed babies until they are at least 6 months old, delay feeding infants cow's milk until they are at least 1 year old, keep diets free of peanuts untli children are at least 3 years old
Food allergy
Causes an immune response
_____ protein diets can lead to kidney problems and are not recommended for people with (or at risk for) kidney disease
HIGH
What proteins function as transporters for other nutrients?
Hemoglobin, transferrin, lipoproteins
9 essential amino acids
Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Valine
How is the amino group from an amino acid excreted?
In the urine
North americans consume _______ protein from animal sources than those in other countries consume
More
Amino acids are unique among the energy-yielding nutrients because they contain....
Nitrogen
A ________ bond is a chemical bond formed between single amino acids in a protein
Peptide Bond
Functions of protein
Protein is necessary for fluid balance, supplies nitrogen in a form we can readily use, and is necessary for the visual process. Regulate and maintain essential body functions, play a role in enzyme and hormone production, and aid in blood clotting
which nutrients are vegans most likely to be low in?
Zinc, riboflavin, calcium, vitamin D, vitamin B-12
Lipoprotein
transports lipids
(3) components of an amino acid?
amino group, side group, acid group
Nonessential amino acids can also be referred to as...
dispensable amino acids
When would the RDA for protein be higher?
during recovery from an illness and in highly trained athletes
Animal proteins are a good source of all nine _____ amino acids
essential
Urea
nitrogenous waste product of protein metabolism and the major source of nitrogen in the urine
essential amino acids
ones the body cannot produce in sufficient amounts and needs must be met through the diet (9)
the liver and kidneys must work hard to use ______ to meet energy needs
protein
Incorrect mRNA production and incorrect polypeptide chain production both result from an error in what?
the DNA code
Limiting Amino Acid
the essential amino acid in lowest concentration in a food or diet relative to body needs
Denaturation
the process of altering the three-dimensional structure of a protein, useful during digestion
How does changing a protein's shape affect the protein?
the protein loses its biological activity and it destroys the protein's ability to function normally
Marasmus
the result of chronic PEM, caused by a nutrient deficiency. over time it results in a "skin and bones" appearane, with little or no subcutaneous fat
How do proteins contribute to acid-base balance of the blood?
they serve as buffers that resist changes in pH, and pump ions into and out of the cells
What individuals are at risk for PEM?
those suffering from anorexia nervosa, living in poverty, hospitalized patients