Proteins- In order to protect the glucose levels we have a level of glycogen helps to keep the flow up and protect brain function- During the period of time that we are moving- The front two drops in the proteins and fats actually used to regulate glucose but then as starvation continues we begin using fats as energy in the form of ketone bodies and fatty acids- Once we get to the end of the line (this is bad) we begin to break down structural proteins and then we head towards death - What are proteinso Elements found in proteins Nitrogen Hydrogen  Oxygen  Sulfur is added into someo We are really talking about nitrogen (what happens to it in the body)  We cant use nitrogen in the form that it is found in the environment Plants use nitrate and bacteria to make the protein - So without this animals wouldn’t be able to get the protein needed Nitrogen is our most expensive feedstuff so we want to limit the losses (fecal & urinary losses) Proteins promote body growth and body function - Nitrogen- importanceo Amino acids Proteins- building blocks to heart function, muscle, etc. Neurotransmitters- Phenylalanine dopamine, epinephrine, norepinephrine- Tryptophan serotonin, melatonin- Arginine nitric oxide Energy- but only in times of need (starvation)o Purine/pyrimidines DNA  RNAo Also used to maintain blood glucose levels (energy)  we would prefer not to use for energy  we want to use this for muscle (BALANCE IS IMPORTANT)- Excretory forms of waste nitrogen o Ammonia (NH3) Direct urinary excretion- ammonia buffering system (kidney)  Urea formation This is how we get rid of most nitrogen waste in the body (mammals)o Urea Urea cycle (liver)o Uric acid Waste product of purine metabolism Causes gout- acid crystals are deposited into the joints Seen in birds and reptiles mainly (some mammals)- Nitrogen- Balanceo Nitrogen balance N intake minus N loss (N in – N out)- Ideally you want everything to stay- 100% in digestion, absorption, etc N loss- Fecal- Urinary- Perspiration  Fecal loss- Exogenous- external to the body not something the body has produced- Endogenous something produced inside of the body that we then loseo Microbial loss- doesn’t have time to digesto Why is N-Balance important Health and production status- Most proficient production that we can- Healthy for the animal and healthy for the environment Environmental concerns - Water quality- Protein definition o Polypeptide chain made up of amino acids arranged in a specific sequenceprovided for in the genetic code. o Has four levels of structure Primary- chain of amino acids linked together through peptide bonds Secondary- will many times take the form of a helices (a coil) it is bonding with other amino acids- Form a specific structure Tertiary- taking the secondary structures and joining them and folding them back on each other (think glob)  Quaternary- is like hemoglobin, there are 4 protein subunits that are bound together to from a 4 dimensional structure- Amino acid definitionso Apolar amino acid R group contains no electron withdrawing groups  Lipid soluble Will just be carbon, and hydrogen o Polar amino acid R group contains an electron withdrawing group  Will have something like an OH group or a Nitrogen groupo Aliphatic amino acid R group contains only carbon and hydrogen  Pretty much apolar- just carbon and hydrogen o Heterocyclic Ring structure of amino acid contains within the ring an atom other than carbon- Histdine (has nitrogen)o Typically when looking at the first 3, we are talking about the difference in the alpha carbon and the nature of that group o Aromatic Amino acid contains a benzene ring structure- Phenylalanine, tyrosineo Acidic Amino acid has an extra ionized carboxyl group at physiological pHo Basic  Amino acid has an extra ionized amino group at physiological pH- R-NH3o Zwitterion Amino acid that is ionized but has no net charge- Has a positive and negative but overall is neutral - Protein quality o Nutritional value of a protein The closer we get to meeting an animal’s needs with the feedstuff the better it is it is all about that balance we are trying to meet.  i.e., ability of a protein to meet the essential amino acid requirements of the animal o Example factors affecting quality  Amino acid balance Digestibility  Absorption  Anti-quality factors  Health of the animal  Caloric intake - Amino acid availability related to all factors affecting amino acid utilization from the time of ingestion to the time of assimilation into the body. o Factors affecting availability External Factors Internal FactorsProtein type (is it easy to digest/ structure make-up?)Efficacy of digestive track (type of digestive tract as well)Processing effects Catabolic/anabolic hormone (physiological state the body is in)Amino acid balance of the diet Microbial digestion/synthesisOther nutrients in the diet Anti-quality factorso These are the ones that will be put to work and utilized - Amino acid- essentialityo Dietary vs. life (those that are required in our diets {essential or dietary essential} vs. those that our body produces) Dietary essential amino acids - Amino acids that can not be synthesized at all or fast enough to meet the animal’s requirements- Can get by without these for a short term- Balance the diet with these Life Essential- (Vinvent Du Vigneaud)- Those amino acids so essential to metabolic function and life that the body can afford to utilize the resources neededto store the information relating how to synthezixe the amino acids. o Ex) alanine o De novo synthesized- we can build them from the ground upo Salvage pathways - Essential Amino Acidso PVT TIM HALL- these are almost all (primary ones to remember that there are different ones for species) primary essential amino acids Phenylalanine Valine Tryptophan Threonine Isoleucine Methionine Histidine Arginine  Leucine Lysine - Amino Acid chemistry- enantiomerso Dextrorotatory (i.e., D-amino acids) Rotate polarized light clockwise These can be inhibitors in the cells in some caseso Levarotatory (i.e., L-amino acids) Rotate polarized light counterclockwise This is what we can utilize in our cells (mammals)o Importance: Most natural proteins are products of L-amino acids D-amino acids not readily metabolized- May