-protein catalysts

-specific (lock & key model)

ie: amylase-starch

-body can't absorb enzymes

Cells only use

GLUCOSE

Digestion of CHO:

Mouth

CHO digestion:

Stomach

CHO digestion:

small intestine

• pancreatic amylase
• enterocytes: disaccharides

CHO digestion:

small intestine- pancreatic amylase

-enters via pancreatic duct

-continues digestion of starch to dextrins to disaccharides

CHO digestion:

small intestine- enterocytes

-convert disaccharides to monosaccharides

-catabolic enzymes (maltase, sucrase, lactase)

CHO Digestion:

hepatic portal blood

oxidation to ATP

(if body needs E now)

stored as glycogen, fat

(if body needs E later)

-12 hours worth of E

-polymerized storage form of glucose (like starch in plants)

-liver, skeletal muscle

-30 days worth

-once glycogen stores full

-glucose to 2-C units routed to fat synthesis

E is captured as ATP (~50%)

excess released as heat (~50%)

-less O2

-small amount of ATP

-cytosol by glycolysis

-more O2

-large amount of ATP

-in mitochondria by oxidative phosphorylation

-glycogen stores in liver and muscle (~12 hr supply, when gone- exhaustion)

-protein in muscle liver and other tissues (protein to AA to glucose, weakens muscle, eventually- death)

-glycogen and protein by stimulating insulin release which blocks glycogen/protein breakdown

-provides E for CNS

which organ controls blood glucose?

• releases insulin (anabolic)

-inc. glucose uptake in most cells

-inc. glycogen synthesis by liver and muscle

• releases glucagon (catabolic)

-inc. glycogen breakdown to glucose

-endocrine portion

-releasing insulin in fed state

-releasing glucagon in fasted state

-insulin/glucagon activate enz.

-used for energy w/ glucose

-can't convert to glucose

-diet macronutrients block breakdown of body fat

CHO in foods

flesh and plant foods

CHO in flesh foods

-Dairy: milk, yogurt, cheese

(simple CHO)

-Meat, poultry, fish

(low CHO)

CHO in plant foods

-vegetables (mix of simple CHO+Starch+Fiber)

-Fruits (mix of simple CHO+Fiber)

-cereal grains: wheat, barley, rice (major source kcal (~50%), starch+fiber)

Simple CHO in foods sources of:

-dilute and concentrated sugars

-sucrose vs. 'healthful' sugars

sources of dilute sugars

vegetables

fruits

cereals

diluted sugars better nutrilyzation of concentrated sugars by:

-dilution= dec. E density= dec. kcal

-inc. nutrient density

(vitamins,minerals,phytomchemicals)

-inc. fiber content

-inc. complex CHO (whole grains), dec. simple CHO

sources of concentrated sugars

-all with low nutrient density

-whole foods

-partitioned foods

high fructose corn syrup

(HFCS)

-major sweetener in U.S. soft&fruit drinks, deserts, candies

-HFCS consumption is high

-elevates serum triglycerides

honey vs. sugar

-honey is not healthier

-mix of glucose+fructose=same as sucrose after digestion/absorption

-honey= more kcal/g due to air in sugar crystals

low blood sugar

-reactive(common, mild) and spontaneous (rare, serious)

-high blood sugar

-diabetes

-Type I (juvenile onset,rare,serious)

-Type II(common,less serious)

blood glucose AUC for test food w/ 50g CHO

blood glucose AUC for 50g glucose

-saturated (C-C single bonds)

-unsaturated (C-C) double bonds

-C-C double bonds

-monounsaturated= 1 double bond

-polyunsaturated >=2 double bonds

-linolenic acid (18:3 n-3,omega 3)

-linoleic acid (18:6 n-6,omega 6)

-fx: cell membraned fluidity

-95% of lipids

-glycerol + 3 FAs

-fats (solid at room temp.)

-Oils (liquid at room temp.)

-E repository

-3% of lipids

-glycerol + 2 FAs

-cell membrane bilipid layer

-lipid-cholesterol

-4 fused rings

-from flesh foods

-liver can synthesize

from glucose or FA

-membrane fluidity

-synthesis of sex hormones

-vit. D

-bile synthesis

-side product from production of partially hydrogenated oils

-banned in some U.S. cities

-E store for starvation

-E substrate for exercising muscle

-protective layer

-fat soluable nutrients

-source of fat soluable nutrients (EFA,fat soluable vit.)

-taste and smell good (especially in cooked foods)

-satisfy hunger (make us feel full)

-long chain polyunsaturated FAs

-many biological effects

-circulatory system ( bp via smooth muscle,clotting via platelets)

-GI tract (smooth muscle contrctin.)

-lungs(diltn/constrctn of airways)

-immune system(mechan clear)

-use omega 3/6=eicosanoids

-omega6=eicos.#1 (bv constrctn,platelet aggregation)

-omega3=eicos.#2(bv dilatn,platelet disaggrevation,lower risk ha)

-the body can synthesize inefficiently at ~10%

-PUFA to Omega3s which is linolenic acid which contains EPA & DHA

-blocks 2nd fatal heart attack

-blocks premeture delivery of fetus

-lowers blood triglycerides

-lowers pain from rheumatoid arthritis

-highest in cold water fish

-eggs from fish fed hens

(most practical)

-fish oil supplements

-flax oil (no EPA/DHA but FA to convert inefficiently)

-what is eaten is not same as what is in the blood

-most diet fat=tg

-primary factor for HD high blood cholesterol(NOT blood TGs)

-90% diet TGs drive blood chol.

(should limit diet TG intake)

-~10% diet TG and diet chol.

both affect blood chol.

(limit TG and chol. intake)