Chapter #5
negative nitrogen balance
Condition occurring when the body excretes more nitrogen than it takes in. Illiness or injury cause this
Define mutual supplementation and be able to recognize vegetarian meal plans that contain complementary proteins
Mutual Supplementation is the strategy of combining two incomplete protein sources so that the amino acids in each food make up for those lacking in the other food. The complementary proteins need not be eaten together, so long as the day's meals supply them all and the diet provides enough energy and total protein from a variety of sources (meals : oatmeal, rice & beans, pasta with vegetables & parm cheese)
Nitrogen equilibrium
N in = N out
Discuss reasons why consuming too much protein and amino acid supplements is not recommended
Protein supplements:-can place burden on kidneys to excrete extra nitrogen and adds extra unnecessary caloriesAmino acid supplements:-can induce sleepiness, nausea, and skin effects, digestive disturbances
State the health benefits and nutrient considerations of whole food, plant-based diets
-reduces saturated fat intakes, helps prevent obesity, high blood pressure, cancer, diabetes, osteoporosis, diverticular disease, and gallstones
Complementary proteins
when the amino acid of legumes and grains supply all the needed amino acidslegumes - isoleucine and lysinegrains- methionine and tryptophan
Describe the purpose and how to conduct a nitrogen BALANCE study
The purpose of a nitrogen balance study is to compare the nitrogen lost by excretion and with nitrogen in food. In healthy adults nitrogen in (consumed) must equal nitrogen out (excreted), Scientists measure the body's daily nitrogen losses in urine, feces, sweat and skin under controlled conditions and then estimate the amount of protein needed to replace these losses.
Protein quality
helps determine how well a diet supports the growth of children and the health of adults. Two factors influence this: a protein's digestibility and its amino acid composition
HCL
hydrochloric acid
protein synthesis
process of cells making proteins If any of the 9 essential amino acids are not present in sufficient amounts in your diet, protein synthesis will be stopped
Polypeptide
protein fragments of many amino acids bonded together
Tripeptides
protein fragments that are 3 amino acids long
dipeptide
protein fragments that are two amino acids long
positive nitrogen balance
state in which the body retains more nitrogen than it loses, normal in growing children and pregnant women
Edema
swelling of body tissue caused by leakage of fluid from the blood vessels; seen in protein deficiency (among other conditions)
electrolyte balance
the distribution of fluid an dissolved particles among body compartments, proteins help to maintain this
Describe protein digestion and absorption from the mouth to the colon
1. Stomach is where it starts and protein is partially digested by the enzyme pepsin and HCL 2. Pancreas: further protein digestion by enzymes released by the pancreas into the small intestine 3. Small Intestine: final digestion of protein to amino acids occurs in the small intestine 4. Liver: Amino acids are absorbed into the portal vein and transported to the liver. From there they enter the general bloodstream 5. Large Intestine: little dietary protein is present in feces
State the 7 roles of protein in the body
1. Supporting growth and maintenance of tissues 2. Building enzymes, hormones, and other compounds 3. Transport and recognition proteins (lipoproteins) 4. Building antibodies (fight infection) 5. Maintaining acid-base balance, help to keep bodily fluids within a normal pH level, not too acidic, not to basic 6. Proteins in the blood help to maintain fluid and electrolyte balance by attracting and retaining water 7. Energy (stored energy) as fat, glycogen
Enzyme
A type of protein that speeds up a chemical reaction in a living thing
State the different paths an amino acid can take once it is in a cell
Build protein Make another needed compound Make another type of amino acid Burned for energy Convert to glucose and burned as energy or stored as glycogen Conver to fat and burned for energy or stored in adipose tissue
State how many essential amino acids exist and why adequate amounts of all the essential amino acids are required for protein synthesis
There are 9 essential amino acids There are 20 amino acids in total Without these essential nutrients out body can not make proteins it needs to do work
Describe the general structure of proteins and the three components of amino acids
They contain a backbone which contains two groups 1. an amine group which contains nitrogen in addition to carbon, hydrogen, and oxygen atoms 2. sidechain (varies) Each amino acid has an amine group at one end, an acid group at the other, and a distinctive side chain Protein is the only macronutrient that contains nitrogen
Vegan
a person who does not eat food from any animal source
Vegetarian
a person who does not eat meat
Flexitarian
a person who has a primarily vegetarian diet but occasionally eats meat or fish.
conditionally esential amino acid
an amino acid that is normally nonessential but must be supplied by the diet in special circumstances when the need for it exceeds the body's ability to produce it
complete and incomplete proteins
contain all nine essential amino acids, whereas incomplete proteins are missing one or more.
High quality amino acid
dietary proteins containing all the essential amino acids in relatively the same amounts that human beings require. They may also contain nonessential amino acids