HES 2823 1st Edition Exam 2 Study Guide Lectures 9 15 Lecture 9 February 12 Introduction to Protein What is a protein It is an amino acid polymer What are the functions of proteins to catalyze chemical reactions that sustain life to regulate body processes often through hormones to transport such as lipoproteins to induce immune function antibodies to attack and prevent infection to provide strength and structure such as muscle and bone What is the structure of protein Proteins are formed with a central carbon and four bonded parts to it A carbon attached to the central carbon has further elements of double bonded oxygen and single bonded oxygen and hydrogen creating the carboxyl group A single hydrogen is also bonded to the central carbon A nitrogen and two hydrogen atoms are bonded to the central carbon to form the amine group A variable group represented by an R also branches from the central carbon What is the function of the R variable The R or variable group presents interchangeable options to form different kinds of proteins such as glycine or alanine and many more What is the amino acid pool and how does it function Single or free amino acids occur in the body and come from food intake and bodily protein Of the 20 amino acids important to human development 9 are essential and therefore must be consumed in one s diet because they cannot be made by the body unlike the other 11 nonessential amino acids which the body produces on its own The amino acid pool utilizes those free amino acids It completes protein synthesis through the amino acids and sustains fat energy and glucose levels while breaking down dietary protein and bodily protein How does starvation affect the amino acid pool When the body consumes muscular protein it breaks it down and adds it to the waning pool of amino acids These other proteins had an original use different from what it will soon become The body does not discriminate against the use of any particular type of protein so heart muscle can be consumed just like any other type Skeletal muscle is not prioritized either Lecture 10 February 17 Continuation of Protein Discussion How does overconsumption affect the amino acid pool Calories from protein can be stored as fat is over consumed What is the process of protein synthesis Genetic traits are determined by protein as instructed by DNA Within a cell the nucleaus houses DNA A strand of DNA will have many genes and each gene is a section of that DNA which codes for a sequence and instructs the construction of one protein The copied gene from within the nucleus forms messenger RNA mRNA which moves to the site of protein synthesis outside of the nucleus in the cytoplasm Transfer RNA tRNA finds the needed amino acids to create proteins and returns to the mRNA with each of the required amino acids from within the cell until all of them are positioned together at the site of protein synthesis to form a functioning protein This explains why certain amino acids are essential What is deamination its process and amino acids relevant to it Deamination is the removal of the amino group NH2 from a protein This process begins in the liver after the molecule has been released from the cell and becomes NH3 or ammonia which is toxic to the body The liver converts the NH3 into the nitrogen containing compound urea which then enter the blood stream from the liver The urea is filtered from the blood by the kidneys added to the urine and excreted from the body Amino acids used for fat glucose and energy participate in this process Only amino acids used strictly for protein synthesis avoid this Lecture 11 February 19 Discussion of Nitrogen Balance and Introduction to Protein Quality What is nitrogen balance and how does it function Nitrogen balance is the comparison of the amount of nitrogen that enters the body to the amount that leaves These values ought to be equal to one another in normal situations Nitrogen intake occurs through consumption of protein and nitrogen output happens mostly through urea in urine and also a small amount of undigested protein in feces What is the meaning of a greater nitrogen intake than nitrogen output and to whom does it apply A greater nitrogen intake signifies a net protein gain and a period of tissue growth Examples include humans under the age of 19 weight trainers and pregnant women What is preeclampsia Preeclampsia or toxemia of pregnancy can develop suddenly in pregnant women during which blood pressure spikes and often triggers a spontaneous miscarriage It is life threatening to the mother and the child and a result of inadequate protein intake Pregnant women require 75 more protein in addition to 20 more calories vitamins and minerals What is the meaning of a greater nitrogen output than intake and to whom does it apply A greater nitrogen output suggests net protein loss and degradation of muscle Examples include starvation as the body continues to break down body proteins to use as an energy source illness as infection causes fever to kill bacteria and body cell alike injury when damaged tissue dies low protein intake and poor quality nutrition What is the purpose of a nitrogen balance study Nitrogen balance studies measure the amount of urea present in urine What are characteristics of complete proteins and incomplete proteins and some examples of each Complete proteins provide adequate amounts of all essential amino acids and must come from the diet Examples include meat milk and eggs which are all animal protein similar to human proteins Incomplete proteins do no provide adequate amounts of all essential amino acids All plants which are dissimilar to human proteins constitute these proteins One exception is gelatin or collagen a substance boiled out of animal parts What is the function of complementary proteins Humans do not have to consume complete proteins to remain alive due to the availability of complementary proteins Two incomplete proteins provide adequate essential amino acids when combined thus combining different plant foods into group and then mixing the groups aids the process Combining any two foods from legumes and either grains or nuts and seeds displays a good example of complementary proteins and although it is recommended to consume complementary proteins at the same time it is not mandatory What is a limiting amino acid A limiting amino acid is the essential amino acid in an incomplete protein that is not adequately provided What are the three categories of