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Midterm - 3 November 2014 In class 50 minutes Start 12:55 sharp 55 multiple choice questions –1 point each 1 short answer-10 points from lecture 1a until end of lecture 6c .
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Midterm - 3 November 2014 • In class • 50 minutes • Start 12:55 sharp • 55 multiple choice questions –1 point each 1 short answer-10 points • from lecture 1a until end of lecture 6c
Re: 2104 class on 27 October- I may be delayed returning to CBU as I am returning from Winnipeg on 26 October and there are sometimes flight delays. If I am not here for class on 27 October then that class will be combined with the 29 October class. In the meantime, please assume that there will be a 2104 class on 27 October
Carbohydrate/lipid/protein/alcohol 4/9/4/7 kcal/gram 17/37/17/29 kJ/gram Note alcohol = ethanol
The new normal-Globe and Mail- 30 September 2012- parents do not recognise when they and/or others including kid(s) is/are overweight or obese Fat is the new normal
Lecture 5a 6 Oct. 2014 Lipids I 94/80
Overview of lecture 5a 1) Lipids defined 2) Functions of fats in foods 3) Structure, classification, presence in food and function of: a) fatty acids b) triglycerides c) phospholipids d) cholesterol 4) Ingestion, digestion, absorption, transport, metabolism and excretion 6) Functions of lipids-essential or not
Lipids defined p. 130 family of compounds that includes triglycerides, (TG), phospholipids (PL) and sterols other definition water insoluble organic compounds made up of C, H, and O like carbohydrates but less O and therefore 9 vs 4 kcal/gm
2)Functions of fats in foods • absorbing flavours and aromas of ingredients • providing flavour of its own • creamy and smooth mouth taste • tenderizing and adding moisture
a)Triglycerides-fatty acids-structure, classification, p.129-136 Organic acid Saturated 14:0 Monounsaturated 18:1 Polyunsaturated 18:2 n-6 18:3 n-6 (gamma-linolenic acid) 18:3 n-3 (alpha-linolenic acid)
REPLACE WITH FIG 5-2 ACETIC ACID Fig. 5-1, p. 140
a)Triglycerides-fatty acids-structure, classification, p.129-136 Glycerol + 3 fatty acids make a triglyceride Mixed triglycerides
Triglycerides continued Triglycerides infood Processed fat-fat manipulated mechanically or chemically -chemical manipulation-hydrogenation- -hydrogenation yields trans-fatty acids
A)- Triglycerides- in foods and function In foods-triglycerides are most of the fat in our foods (followed by sterols followed by phospholipids) Function in our bodies-triglycerides are an energy source and a major storage form of energy in our bodies
B) Phospholipids- structure, classification, in foods and function p. 136 Structure- 2 FATTY ACIDS (FA) and polar head group-generally but exceptions Classification Choline-containing phospholipids Ethanolamine-containing phospholipids Phosphatidylserine Phospatidylinositol Sphingomyelin
Phospholipids continued Foods- found naturally Function p. 140 Membranes Lipoproteins Cell signalling
C) Sterols- structure, classification, in foods and function p. 137 Structure-Ring structure Classification-Sterols
Sterols continued Foods- found naturally-cholesterol vs phytosterol Function Membranes Lipoproteins Bile acids Hormones Vitamin D
Fatty acids in foods regardless of free or esterified Function of fatty acids in food essential in diet- linoleic acid and alpha-linolenic acid-we cannot make these
Ingestion- mouth, tube or IV Digestion of lipids p. 137-138 fats start out separated from enzymes in gi (gastrointestinal tract)-why?\ goal of fat digestion mouth digestion of fat small intestine digestion of fat
Absorption of lipidsp. 140-141 small molecules short chain fatty acids medium chain fatty acids glycerol direct to blood larger molecules monoglycerides long chain fatty acids micelles formed in intestine micelles into intestinal wall cells chylomicrons formed and released into lymph E:\Media\Animations\chapter5\Absorption_of_Fat\0517.html
Transport of lipids p. 145-148 Lipoproteins-chylomicrons (CM) (POST-PRANDIAL ONLY) - very low density lipoprotein (VLDL) - low density lipoprotein (LDL) - high density lipoprotein (HDL) - albumin density change due to 2 factors
Lipoprotein metabolism Chylomicrons- made in small intestine – acted on by lipoprotein lipase in blood to give remnant particle which is taken up liver VLDL (very low density lipoprotein) made via liver VLDL acted on by lipoprotein lipase in blood to give remnant particle (intermediate density lipoprotein or IDL) which is taken up by liver- liver puts out low density lipoprotein (LDL) HDL ( high density lipoprotein) and albumin made by liver
Human lipid metabolism-in part only Fatty acids oxidised in mitochondria to give energy and water Glycerol metabolised (enters glycolytic path and then mitochondria) Can also synthesise fatty acids, triglycerides, phospholipids and sterols
Lipids excretion Faeces-undigested and/or unabsorbed fat Respiration (lipid metabolites -water and CO2) Urine-lipid metabolite (water) Sweat-lipid metabolite (water) Saliva?-intact fats and lipid metabolite (water)
Lipids essential or not ? p. 144-147 Yes-why ? healthy roles
Lipids- essential or not? yes- healthy roles 1)insulation- healthy roles protective layer in body to help keep heat losses down
Lipids-essential or not? yes Healthy roles 2)support and protection for internal organs and bones fat acts as support and cushioning for organs and cushioning for bones
Lipids- essential or not? yes Healthy roles 3)absorption of fat soluble vitamins fat soluble vitamins cannot be absorbed without fat in the diet- why?
Lipids- essential or not? yes Healthy roles 4)cell membranes cholesterol and phospholipids are important in maintaining the structure and hence function of cell membranes what is a cell membrane?