Psych 412 1st Edition Exam 1 Study Guide Lectures 1 6 Chapter 5 Lipids and Heart Disease Lipids Class of nutrients also known as fats Contain triglycerides phospholipids and sterols Fats are lipids that are solid at room temperature Oils are lipids that are liquid at room temperature Roles of lipids Provide 9 kcals gram of energy Insulate body against temperatures Protect against shock Provide bones and organs with a cushion Provide cell membranes with structural materials Helps with cell signaling pathways Fatty Acids Organic compounds composed of a carbon chain with hydrogen Fatty acids have a methyl group and an acid group at separate ends Fatty acids are different based off of the length of the carbon chain the number of double bonds and the number of single bonds they have Fatty acids can have up to 24 carbons in their carbon chains Long chain fatty acids have about 12 to 24 carbons 18 carbons in the chain are most abundant in food supply Long chains are usually in meats fish and vegetable oils Medium chains have about 6 10 carbons and short have less that n6 carbon in their carbon chains Saturated fatty acids have carbon atoms that all have four bonds Only single bonds are in saturated fats Monounsaturated fatty acids have one double bond in carbon chain These fatty acids are usually abundant in canola oil olive oil milk and beef nuts and peanuts Polyunsaturated fatty acids have two or more double bonds in carbon chain Oils nuts and animal fats are examples of polyunsaturated fatty acids Solid fats occur when there are no double or single bonds in a carbon chain Triglycerides Composed of a 3 carbon glycerol backbone with three fatty acids extending from each of the carbons of glycerol Found in all fat foods Forming triglyceride occurs from three fatty acids attaching to glycerol via a condensation reaction Polyunsaturated fatty acids are determined by position of their first double bond in relation to the methyl carbon end Omega 3 fatty acid has its first double bond between the third and fourth carbons from the methyl carbon Foods that contain Omega 3 are canola flaxseed wheat germ and soybean Contains linolenic acid Omega 6 fatty acid has its first double bond at the sixth carbon from the methyl carbon Foods that contain Omega 6 are vegetable oils leafy greens grains nuts and seeds Contains linoleic acid Linolenic and linoleic acids are precursors to fatty acids and eicosanoids They also are essential in membrane structure EPA and DHA are two long chain omega 3 fatty acids that are synthesized from linolenic acid Fatty fish breast milk and supplements contain large amounts of EPA and DHA Prostaglandins are an eicosanoid from EPA that decreases blood clotting inflammation and makes up part of membrane structure while also decreasing CHD risk Hydrogenation stabilizes polyunsaturated fats by adding hydrogen which converts them to saturated fats Partial hydrogenation produces C C bonds and moves hydrogen atom to the other side instead of being on the same side which results in a trans fat Examples would be solid vegetable oil products and snack foods Trans fats increase risk for heart disease Phospholipids similar in structure to triglycerides with the exception of its phosphorylated alcohol replacing a fatty acid chain Partially hydrophobic and partially hydrophilic Emulsions Cholesterol is a sterol that can be consumed and made in the liver Eggs meats fish shellfish and butter all consist high levels of cholesterol Plant sterols interfere with absorption of cholesterol which could result in lowering blood cholesterol levels Digestion and Absorption of Fats Triglycerides get hydrolyzed into monoglyceride and two fatty acids Bile emulsifies fat to produce small molecules called micelles in the small intestine Through the enterohepatic circulation of bile bile is reabsorbed and sent back to the liver to be reused Fatty acids and monoglycerides leave the micelles and absorb into the intestinal walls to be formed back into triglycerides and phospholipids Lipoproteins are lipids and proteins that transport lipids in the lymph and throughout the blood Chylomicrons are the least dense of lipoproteins but are also the largest Take lipids from small intestine and carry them through intestinal cell and into lymphatic system They then enter the bloodstream near the heart The liver packages lipids into lipoproteins VLDL and HDL HDL is considered good cholesterol and lowers risk of heart disease HDL is linked intakes of monounsaturated and omega 3 fatty acids LDL is considered bad cholesterol and increase risk of heart disease LDL is linked with intakes of saturated and trans fats above 35 of kcals g Cardiovascular disease All diseases of the heart and blood vessels Coronary heart disease is the most common type of Cardiovascular disease Atherosclerosis is a factor in cardiovascular disease Fibrous plaque builds up inside artery walls Results of atherosclerosis include angina heart attack transient ischemic attack or stroke Embolism or thrombosis is when unstable plaque breaks loose Chapter 6 Protein and Amino Acids Proteins Proteins are made up of carbon hydrogen and oxygen but also contain nitrogen The difference between lipids and protein is that protein contains nitrogen Amino acids The building blocks of proteins that contain an amino group acid group H atom and a unique side group The side group also known as the R group determines the folding of the amino acid chain to form functional 3 dimensional protein Conditionally essential amino acids are amino acids that are nonessential in normal circumstances but are necessary in a diet under special circumstances Special circumstance would be when diet fails to supply enough of an amino acid or is incapable of converting amino acid Chemistry of a Protein Disulfide bonds form across the side group as polypeptide folds Unique shapes of proteins allow them to perform different tasks in the body Four highly folded polypeptide chains form hemoglobin Denaturation of a protein is the change in its shape by mechanisms such as heating acid base or agitation This change in shape results in a loss of functioning of the protein Proteins in the Body Protein synthesis is DNA directing the amino acid sequencing of a protein Transfer RNA takes amino acids from cell fluid and to the messenger Sequence of amino acids determines the shape and function of a protein Roles of Proteins Collagen is the protein used for connective tissues and foundation of