FAT
How fat can be good...... Energy source Transporter for lipid soluble vitamin Cell membrane structure Precursor for Vit D and steroid hormoneÂ
Properties of Fat Water insoluble Can be solid or liquid at room temperature Energy dense (9 kcal/g) Triglyceride is the main form of fat in bodyÂ
Types of Fat Triglyceride Triglyceride = 3Fatty Acid + 1 glycerol Main form of fat in body
Phospholipid Phospholipid = 2Fatty Acid + 1 glycerol + Phosphorus compound Cell membrane Â
Cholesterol Found in animal source food Produced by the liver Produce hormone
Good Fat vs Bad Fat
Bad Fat
Good Fat
Essential Fatty Acid Omega-3
Vege Oil
Omega-6
Fat Digestion & Absorption Mouth
Mix with lingual lipase become lipid droplet
Stomach
Mix with gactric lipase. Trigleceride -> Diglyceride
Small Intestine
Mix with pancreatic lipase + bile. Tri/Diglyceride ->Â Free Fatty acid
Mouth
Esophagus
Stomach
Absorption (Chylomicron)
Large Intestine
Large Intestine
Fat Transport
High Density Lipoprotein (Good Cholesterol)
Low Density Lipoprotein (Bad Cholesterol)
Chylomicron
Fat Metabolism
FAT tRANSPORT Triglyceride = Fatty Acid + GlycerolÂ
Lipolysis
Carnitine
Glycerol Mitochondria
Lipase Enzyme Adipocyte
Free Fatty Acid
Cell
Glycerol Free Fatty Acid
+
Albumin
+
Beta-Oxidation Kreb Cycle ETC
Lipolysis Breakdown of fat stored in adipocyte Triglyceride -> Free fatty acid + Glycerol Produce ketone High ketone -> ketosis Ketone -> Glucose (Gluconeogenesis) Hormones that enhance lipolysis: Cortisol, Growth homone, Epinephrine, Norepinephrine Glycerol Lipase Enzyme Triglyceride Lipolysis
Free Fatty Acid
Beta-Oxidation Catabolic process Fatty acid are degraded by removal of 2-C unit Occurs in the mitochondria Produce Acetyl-CoA + NADH + FADH2 4 steps : Dehydrogenation, hydration, oxydation, thiolysis
ATP Production from BetaOxidation 7n - 6
n = number of carbon of fatty acid ATP C16:0 fatty acids = 7(16) – 6 = 112 – 6 = 106
Every double bond present must deduct 2 ATP. ATP C18:3 fatty acids = 7(18) – 6 – 2 – 2 – 2 = 114
Kreb Cycle Acetyl-CoA combines with oxaloacetate to form citrate Citrate is broken down to oxaloacetate again in 1 cycle Product :Â CO2, NADH, FADH, GTP (ATP) Occur in mitochondria
Electron Transport Chain (ETC) Primary site for ATP synthesis (aerobic) Contain of 3 protein complex and 2 electron carriers Convert NADH & FADH2 -> ATP Product : ATP, H2O Occur in mitochondria