NUTR 470 1st EditionExam # 2 Study Guide -HDL— • Synthesized de novo in liver & small intestine.-Muscle—• Prefer FA but cannot always use it.-Liver & Heart—• Can use FA--> need more oxygen (2)-Brain— • Uses glucose & ketone bodies-RBC— • Cannot use FA-People should consume omega-6 fatty acid at an amount not more than ____ times of omega-3 fatty acids.• four (≤ 4:1)-Most Americans: over 9:1 (not good!)-There is less scientific consensus that eating ____ fat increases risk of cancer, diabetes, obesity, and liver dysfunction• trans-Fats are made up of various triglycerides (______ and _____).• fatty acids & glycerol-is the parent of omega 3 (n-3) fatty acid family• α-Linolenic acid-Essential fatty acids must be supplied in the diet. What are the two?• Linoleic acid• α -Linolenic acid-There is a need to increase intake of _____ fatty acids.• omega 3 (n-3)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.-Food Source of Unsaturated Fats?• Plants-Name 4 food sources of Omega-6 fatty acids?• Nuts, seeds, fish, seafood-There is an Acceptable Macronutrient; Distribution Range (AMDR) for total fat – _______%• 20% ~35%-There is an Acceptable Macronutrient Distribution Range (AMDR) for total fat –• Less then the low end?• Higher than the high end?• Both form what in the liver?-High CHO-High fat-TAG--Hydrolysis of triglyceride into _____ and ______• monoglyceride & fatty acids-Lipids are hydroph____ whereas enzymes for digesting lipids are hydroph___.• -obic• -ilic -_________ play critical role in lipid assimilation by promoting emulsification.• Bile acids-Bile acids promote ________.• emulsification-Hydrolysis of triglyceride into monoglyceride and free fatty acids is accomplished predominantly by ______.• pancreatic lipase-Fatty acids and monoglyceride enter the enterocytes by _______ across the plasma membrane.• simple diffusion-The formation of chylomicron: In __________ of the enterocyte, fatty acids and monoglyceride are used to synthesize triglycerides.• endoplasmic reticulum-Triglycerides are packaged with cholesterol, apoproteins and other lipids into particles called _____– First in ER, then in Golgi apparatus.• chylomicrons-________ are responsible for the transport of all dietary lipids into the circulation.• Chylomicrons-Dietary intake of both fats and carbohydrates, in excess of the needs, leads to their conversion into triglycerides in the liver.• These triglycerides are packaged into _____ and are released into the circulation for delivery to the various tissues.-very low density lipoproteins (VLDLs)-The 3 Fatty Acid Transporters of the FA transporter complex?• CD36; FATP: Fatty acid transport protein; FABP: Fatty acid binding protein-Triglycerides of CM or VLDL are hydrolyzed by ________, which produces free fatty acids and glycerol. Free Fatty acids are converted back to triglycerides and stored in fat tissue.• lipoprotein lipase-____________ found in adipocytes, hydrolyzes triglycerides, which in turn provides free fatty acids for the heart and skeletal muscle as fuel sources.• Hormone-sensitive lipase (HSL)-Very Low Density Lipoproteins• Apoprotein: apoB-100-Apoprotein: apoB-100 can be recognized by this receptor— Diets and hormones can modify this composition. • Low Density Lipoproteins (LDL)-Not associated with apoB-100• High Density Lipoproteins-Consumption of dietary trans FAs is associated with a deleterious ____ in small, dense LDLs. • increase-Smaller, denser LDL particles may be more ______.• atherogenic-The LDL Receptor • is a cell-surface receptor.• Can recognize apoB-100-Excessive glucose is converted into fatty acids, which are then used for the formation of ___.• VLDLs-High levels of ____ and low levels of ____ promote the synthesis of triglycerides and the secretion of VLDLs. • insulin• glucagon-Lipogenesis: De novo synthesis of fatty acids occurs in the _____. • cytosol-2 Substrates of Lipogenesis? • Acetyl-CoA• NADPH-________ catalyzes the generation of malonyl-CoA from acetyl-coA as the first step of lipogenesis. This is the most important enzyme in the regulation of lipogenesis.• Acetyl-CoA carboxylase (ACC)-________ is the most important regulator of fatty acid oxidation • Malonyl-CoA-__________ catalyzes seven steps in the fatty acid synthesis pathway, resulting in the synthesis of palmitate from malonyl-coA and acetyl-coA. • Fatty acid synthase (FAS)-____ and _____, through signaling, stimulates ACC and FAS gene expression.-Why?• Glucose; Insulin— Direct E source-____ activates AMP-activated protein kinase through cAMP-dependent protein kinase, which in turn phosphorylates and inactivates ACC, decreasing lipogenesis. -Glucagon-When glucose levels are high: Glucose, Insulin & Glucagon in relation to lipogenesis?• Glucose & Insulin increase, glucagon decreases = increase lipogenesis-Lipolysis-_______ is the breakdown of fat stored in fat cells. Hydrolysis of TAG-________ catalyzes hydrolysis triglycerides, diglycerides, and monoglyceride. In adipose tissue.• Hormone-sensitive lipase (HSL)-The 3 hormones that favor lipolysis? These hormones activate HSL. • Epinephrine and norepinephrine• Glucagon• Glucocorticoids-Insulin activates protein phosphatase 2A, which dephosphorylates HSL, thereby _____ its activity.• inhibiting-_________ also known as beta oxidation, is the process by which fatty acids are broken into acetyl-CoA.— Occurs in the mitochondria matrix• Fatty acid oxidation-Hydrolysis of triglycerides – in _______• adipose tissue-Under fasting conditions, free fatty acids, also known as non-esterified fatty acids (NEFA), are derived mainly from the hydrolysis of triglycerides by _________ in fat cells.• hormone-sensitive lipase (HSL)-FFA must be _____ to Acyl-CoA in the cytosol before being ____ in the mitochondria.• activated• oxidized-Transferring acyl-CoA into mitochondria is the rate determining step of beta oxidation.-Enzyme?• Carnitine palmitoyltransferase 1-_______ is present in the out mitochondrial membrance, converts long chain acyl-CoA to acylcarnitine.• CPT1-The β-oxidation of fatty acids occurs via four recurring steps. Name them in order.• Oxidation by FAD• Hydration• Oxidation by NAD+• Thiolysis-CPT1 is inhibited by ______, an intermediate of fatty acid