Nutrition Concepts !!Class Notes : October 4, 2013 October 4, 2013 !Amino Acids and Proteins Amino Acids are the building blocks to proteins!What does it mean to be essential? Our body can not make them, so we have to get them from foods!Nonessential- our body can convert amino acids into nonessential amino acids unless we have a deficiency in that precursor or an inherent genetic disorder Peptide bonds (tri, poly, etc.) !Polypeptide chains linked by polypeptide bonds through amino acid Carbohydrates begin in the mouth, fats only barely in the mouth, protein is breaking down through introduction of saliva (but no digestion because no protease in the mouth) Enzyme Pepsin likes the acidic environment, which activates peptides to break down the protein into smaller polypeptides !Polypeptides then move to the small intestine, where the intestinal enzymes split polypeptides further (tripeptides, dipeptides, amino acids) for digestion All the proteins that make up a body are unique, which come from their amino acid sequences. It’s the sequencing that makes people different. Important to get adequate protein and amino acids so that we can get all the amino acids in the body and make proteins according to our code. !DNA is set at conception (when we all end up with the genetic code, which gives the messages to sequence the amino acids) Expression of our code may change, but our sequencing never does. DNA holding template to make messenger RNA, messenger RNA carries code to ribosome, where amino acids are made and linked to form all of the proteins. Two processes: transcription and translation !Transcription: DNA template to make mRNA, which then carries the code to ribosome where they make proteins!Translation: mRNA specifies sequence of amino acids, which makes tRNA? tRNA bring amino acids to the mRNA to make the amino acid sequences Sequencing errors can cause problems such as sickle cell anemia (which changes the shape of the protein) - fever, joint pains, etc. !Date October 4, 2013 Class Nutrition Concepts Page OneProtein Synthesis Process by which the gene makes the proteins by the amino acid code !Each cell contains all of the DNA and the code to make every cell in the body, but not every cell needs to make every type of protein, so make specific type of protein that they need. (Cells in pancreas express the code for insulin) Benefit for polyunsaturated fats, they have a different effect on the gene expression (elicit different response)!!Roles of Proteins Matrix of protein collagen for bones and teeth (the stakes and metal that are putting in to make a sidewalk before pouring the cement) Protein builds the mold/structure Replacement of dead or damaged cells (skin cells live 30 days, then build new skin cells) Enzymes!Some proteins are enzymes (digestive enzymes) Some have roles of being catabolic (drive processes that break things down) !Building up (anabolic) !Transform substance (amino acids into glucose for energy) !Enzymes like a marriage official (priest) can marry a bunch of people but not effect them Hormones!Some hormones are made of cholesterol, some about proteins!Hormones are messenger molecules !Insulin is a hormone, blood glucose rises, insulin from pancreas, uptake of glucose/insulin levels from the cells. feedback mechanism !They are transported in blood to target tissues !When blood glucose is too low, glucagon is released !Regulators of fluid balance,!Causes of edema may be protein losses from inflammation and illness, inadequate protein intake!Edema common in pregnant women Proteins help with transporting molecules across the concentration gradient (transport protein) Antibodies!They act as antibodies and defend the body against disease, protects the body through foreign invaders. Memory of the immune system so next time, work faster at destroying that foreign invade Acid Base Regulators!Proteins work as acid base regulators because attract hydrogen ions, to accept or release the hydrogens in response to the environment. Help to maintain PH balances in the environment. More hydrogen=more acidic environment. Buffer the hydrogens, lower the PH. Page 2Transporters!Lipoproteins (example) !Page
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