NSC 170C1 1st Edition Lecture 13Outline of Last Lecture I. Cardiovascular DiseaseOutline of Current OutlineI. What is protein?A. Amino Acids II. Protein FunctionsCurrent Lecture I. What is protein? A. The building blocks proteins are amino acidsB. Essential amino Acidsi. Amino acids are like digits in a phone number- they link together to create an unique sequence ii. Contain carbon, hydrogen, and nitrogeniii. A unique side chain gives the amino acid its distinguishing qualities iv. There are 20 amino acids II. Essential and nonessential amino acids A. There are nine essential amino acidsi. The body cannot create theseii. They must be obtained from foods iii. Found in foods such as milk and meatB. The remaining 11 nonessential amino acids i. They can be created in the body so they are not essential in our diet III. Building protein from amino acidsA. Amino acids are joined together by peptide bonds B. Dipeptide –two amino acidsC. Tripeptide - three amino acids D. Polypeptide- many E. Proteins typically consist of 100 to 1,000 amino acids in a specific sequence IV. Protein Function is altered by denaturationA. Denaturation- the alternation of a protein’s shape die to exposure to heat, acids, or saltsB. Does not alter the sequence of amino acids C. Alters its function, sometimes permanentlyi. I.E. frying eggs, marinating chicken, acidic stomach juicesV. What happens to protein you eat?A. Protein digestion begins in the stomach B. stomach acid denatures protein strandsC. In the small intestinei. polypeptides are broken down into tripeptides and dipeptides ii. these are absorbs by intestinal cells and broken down into single amino acids iii. Amino acids enter the body and travel to the liver iv. The liver uses the amino acids according to your body’s needs D. The diet provides essential and nonessential amino acids E. A limited amount of all these are stockpiled in amino acids pools in the blood and cells F. The body constantly degrades its proteins to replenish the amino acids pools and build the new proteins it needsVI. Protein TurnoverA. The process of continually degrading and synthesizing protein within the body i. 200 grams of protein are turned over dailyii. The intestines and liver account for as much as 50 percent of turnoverB. Protein and amino acids are lost daily through sloughed off skin, hair, nails, and intestinal cells C. Amino acids pools provide the building materials to synthesize replacement proteins and non-protein substances such as thyroid hormones and melaninD. Your body degrades and synthesizes proteins E. When amino acids are broken down, the components parts meet different fats-The nitrogen forms ammonia, which is converted to urea by theliver and excreted in urine via the kidneys i. The carbon-containing remnants are converted toglucose and used as energy or stored as fatF. Surplus amino acids from excess dietary protein can’t be stored as protein, so they are stored as fatVII. Proteins provide structural and mechanical supportA. Fibrous proteins in your bones, muscles, and other tissues help hold your bodyB. Collagen i. The most abundant protein in your body and is found in all your connective tissues C. Other proteins provide mechanical support by helping your muscles contractD. Eating extra protein won’t make muscles larger, but weight-bearing exercise will. VIII. Proteins help maintain body tissuesA. Daily wear and tear on the body causes breakdown of hundreds of grams of protein each day.B. Proteins help create a new layer of outer skin every 25 to 45 days.C. Your body has trillions of red blood cells with life spans of just 120 days.D. The cells lining the inner surface of your organs (such as lungs and intestines) are constantly sloughed off, excreted, and replaced.IX. Proteins Build Enzymes and HormonesA. Enzymes are substances that speed up reactions in the body.i. Many are proteinsii. Are not changed, damaged, or used up in the processiii. Many reactions also utilize a coenzyme, such as a vitamin, to initiate the reaction.B. Hormones are protein- or lipid-based chemical messengers that initiate ordirect a specific action.C. Released from tissues and organs and travel to target cells in another partof the body to direct an activity. Examples: glucagon and