Nutrition-M Flashcards
Insoluble Fiber
Contents pass quickly
Cellulose
Some compounds are not absorbed
Soluble Fiber
Slow absorption for substances like glucose (low glycemic index)
Pectin
Artificial Sweeteners
Intensely sweet
Stevia is 30x sweeter than sucrose
Examples: sucralose (Splenda), aspartame (Equal), saccharin (Sweet’N Low), and stevia
Lactose Intolerance Etiology
Alpha 1,4 galactosidic bond between galactose and glucose can’t be broken
Nutritional Significance of CHO
Source of energy (glucose)
Spare proteins
Precursor to oxaloacetic acid
How many kcal/g does Glucose provide?
4 kcal/ g or if aqueous (IV) 3.4 kcal/g
Gluconeogenesis
Synthesis of glucose from non-CHO sources:
Amino acids (ala, ser)
Lactic acid
Glycerol
Where does gluconeogenesis occur?
Liver and small amount in kidney
Glycogenolysis
Breakdown of glycogen into glucose or glucose derivatives
Where does glycogenolysis happen?
Liver and muscles
Where does glycogenolysis product from the liver go?
Blood to regulate blood glucose levels
Where does the glycogenolysis product from muscles go?
Stay to provide a source of glucose for the muscle cells.
Exogenous sources of glucose
Plant-based foods
Essential amino acids
Thr, trp, Val, leu, lys, ile, met, phe, his
Conditionally essential amino acids
Cys and tyr
Protein quality
Complete and Incomplete proteins
Complete proteins
High-biologic value: contain all the essential aa and in correct proportions
Egg albumin
Soy and quinoa proteins
Incomplete proteins
Low-biologic value: lacking one or more essential aa
If sole source, not sufficient to support life and growth
Plant proteins
Nutritional significance of protein
Synthesize tissue proteins
Catabolized to meet E needs
Incorporated into E stores as glycogen or adipose
Synthesize other nitrogen containing compounds
Kcal/g from proteins
4 kcals/g
How to determine N-balance
Urea is used to measure protein output
RDA for adults for protein
0.8 G protein per kg healthy body weight
What is positive N-balance?
N-intake exceeds N-output
Lipids
Hydrophobic
Soluble in fat solvents
Utilizable in metabolic rxns
Nutritional significance of lipids
Insulate and protect body
Biologically important molec
Transporting fat-soluble vit
Flavor and satiety
Types of FA able to be esterified to glycerol
Saturated fatty acids
Monounsaturated FA
Polyunsaturated FA
Essential FA
Linoleic (omega-6 FA)
Linolenic (omega-3 FA)
Sterols
Sterane structures + lipids
Cholesterol
Vit D
Sex hormones
Trans fatty acids
Bad, act like saturated FA.
Increase LDL and decrease HDL
Lipoproteins
Transport lipids in aqueous environ
Chylomicrons
Formed in intestinal mucosal cell
Carry dietary fat
LDL
Bad cholesterol
Formed in liver and takes cholesterol to tissues
VLDL
Very low density cholesterol
HDL
Good cholesterol
Cholesterol from body back to liver to be removed
Dietary cholesterol
Foods from animals
Contributes very little to serum cholesterol
Stearic acid
Found in beef
No effect on serum cholesterol
Palmitic acid
Increases serum cholesterol
Elevated serum TG
More than 150 mg/dL
Risk factors for elevated serum TG
Overweight/obese Physical inactivity Smoking Excess ETOH Diet high in carbs (60% or more of calories)
Key omega-3 FA
EPA (eicosapentonoic acid)
DHA (docosahexanoic acid)
EtOH
Resembles carbs, metabolized like fat
Kcal/g from EtOH
7 kcal/g
What slows EtOH absorption?
Food: fat, protein, fiber
Increases EtOH absorption
Carbonated beverages
EtOH metabolism leads to
Increased NADH/NAD ratio
Inc pyruvate to lactate
Dec gluconeogenesis
Hypoglycemia
One drink = ?
12 oz beer
8 oz malt liquor
5 oz wine
1.5 oz liquor
