NUTR 120 - Midterm 2

Contains C,H,O with O in the same proportions as water

Simple, Complex

Glucose, Galactose, Fructose

• maltose

• lactose

• sucrose

glucose + glucose

• maltase

Glucose+ Fructose

• sucrase

Glucose+ Galactose

• lactase

add water to break disaccharides

release water to form disaccharides (impossible in humans)

Mono and disaccharides

• prebiotics- growth of healthy gut microbes

• 3-12 monosaccharides linked together (not simple, not poly)

• legumes

• raffinose, stachyose, verbascose

-many monosaccharides linked

• 100-1000

starch, glycogen and fibre

CHO made of many glucose molecules linked together in a highly branched structure.

storage form of of CHO in animals

CHO made of many close molecules linked in straight or branched chains

storage form of CHO in plants

• very similar in structure and their function is the same ( store glucose)

• glycogen in animals, starch in plants

• digestible

• fibre

• bacterial (fermentation)

Carb: 45-65% calories

Fibre: 14g/ 1000 kcal

Meat and Alternative

• meat: not a source of CHO

• alternatives: legumes, nuts are rich in starch

Milk and Alternative

• Milk: has Lactose

• Alternatives: added sugars/starch like soy beverage

Grain Products- starch

• wheat

• rice

• barely

Vegetable- starch

• potatoes

• corn

• carrots

• peas

Fruit

• Simple sugars

1. mouth: salivary amylase breaks some starch into maltose

2. stomach: HCl inactivates salivary amylase and no digestion occurs

3. small intestine: starch broken down by pancreatic amylase to form disaccharides, disaccharides broken down by digestive enzymes (maltase, sucrase, lactase) to form monosaccharides

4. Mucosal cell: monosaccharides absorbed into mucosal cell

5. hepatic portal vein

6. liver

• remaining monosaccharides that aren’t already glucose (fructose and galactose) converted to glucose

• Glucose used in different ways:

  • Used by liver cells for Kcal

  • Liver glycogen (storage)

  • Nonessential amino acid synthesis

  • Conversion to fat } VLDL to adipose tissue

  • bloodstream

• Fuel for most body cells 4 Kcal/g

• Storage as glycogen in Muscle

Brain, red blood cells, kidney cortex, CNS

• increases blood glucose levels which activates pancrea

• facilitate uptake of glucose from blood into cells (kinda like an escort)

• stimulate the production of liver glycogen (turning glucose into storage)

• return of blood glucose levels to 'normal' ( baseline or basal value)

1. Insulin production decreases and glucagon increases (glucagon = hormone stimulates conversion glycogen to glucose)

2. Liver glycogen converted into Glucose which will be released into bloodstream

3. Blood glucose levels should return to basal levels, providing essential glucose as fuel to tissues

• pancreases cannot produce insulin

• Treatment: taking insulin

• Cause: genetic: in utero/infancy autoimmune reaction , viral infection destruction of beta cells

• body cells become 'resistant' to insulin (cell will not take up the insulin-glucose pair, so glucose remains in blood)

• Treatment: exercise, diet, medications (increase insulin sensitivity)

• Cause: genetic and environment, correlated to overweight/obesity

a measure of a persons ability to remove excess blood glucose following meals

1. higher basal glucose level

2. higher peak

3. delayed peak

4. levels stay higher longer

• 10 mili moles blood glucose concentration

• concentration where kidney transporters can absorb glucose out of blood stream

• over 10 mM all transporters in use so glucose in urine

• blood glucose response following eating certain foods

• some foods will give you quick response some will enter slowly ( white bread is higher index then whole grains and legumes)

• area under the curves are the same

• fruit sugar, honey

• less cariogenic (cavity causing) than sucrose

• high fructose corn syrup (HFCS) in pop, condiments

body uses fructose differently than other sugars

• does not stimulate insulin or leptin production (leptin tells you when you are full) HFCS makes you remain hungry … overeat

• stimulates liver fat synthesis = increase blood TG

• may promote high blood pressure increasing risk CHD

• table sugar

• isolated from sugar beet/ sugar cane

• sweetness value 1 ( low compared to aspartame 200)

dental caries

no

no

No, dependent on overall calories not just sugar

no, sugar does not cause hyper activity

dependent on overall calories, not just sugar

no

no

no

no

1. people replaced fat with low fat foods = replaced with more overall Kcal from sugar = increased Kcal = increased weight gain

2. Form of CHO affects satiety

   1. beverages are not detected in the same way as solid foods, so less filling

   2. simple sugars are less filling than complex CHO and fibre

3. Sugars have no nutrional values other than the k cal " empty calories"

5 features of Metabolic syndrome (disturbances that can lead to CHD)

1. abdominal obesity

2. increased fasting blood glucose

3. increase in TG

4. Decrease in HDL

5. High blood pressure

Having 3 features classifies as having metabolic syndrome, which can lead to CHD

• increased intake of sugars and refined CHO increase prevalence of features

• all infants and children possess enzymes lactase to break down lactose

• lactase deficiency is the drop in ability to make lactase enzyme (4-16 yrs)

• describes symptoms associated with being lactase deficient

• consequences of undigested lactose:

  • small intestine: attracts water = bloating, cramps

  • colon: diarrhea, bacterial fermentation = gas

• exaggerated immune response to protein

• milk protein broken into amino acids in small intestine, but amino acid gets into bloodstream which causes immune response, antibodies, anaphylaxis… impaired breathing

xylitol, sorbitol

• sugar free gum

• short chains of starch

• used for thickening

• non digestible

• oats

• barley

• cooled potatoes/rice

• oatbran, citrus, insides legumes, psyllium

• names: pectins, gums, carageenin

• 1/3 fibre intake

• slows digestion

• legumes skin, veggie and fruit skin, psyllium

• cellulose, lignan

• 2/3 fibre intake

• increases speed of movement of digestion through small intestine

• slows digestion, lots of fermentation = production of gases and short chain fatty acids

  • proprionate (3:0) absorbed, to liver → decreased cholesterol synthesis = decreased CHD

  • Butyrate (4:0) preferred energy source of colon cells = decreased colorectal cancer

• increased speed of movement, so less fermentation = increase elimination in stool and increased bowel movement regularity

• decreases diverticulosis - small bulging pouches develop in digestive tract

Wheat Bran

Bran- outer protective layer, insoluble fibre (concentrated source of dietary fibre) Allerome layer - Fe, B vitamins Endosperm-largest portion of the grain, starch and protein Germ- embryo or sprouting portion of the grain, B Vitamins, Fe, fat soluble vitamins E

·        production of butyric acid (4:0) - preferred energy source of colon cells

·        lowers PH (acidic) by decreasing amount of NH3 = good

·        stimulates growth of beneficial microbes

• because of bulking effect, dilutes colon content

• provides surface for adsorption (stick to) for NH3 by products

• decrease transit time (mouth to anus)

• altered bile acid metabolism (less secondary bile acids that are cancer promoters)

1. Binds Bild acids in small interline and physically prevents reabsorption/ recycling

2. propionic acid (3:0) reduced liver cholesterol synthesis

• Increases satiety

• delays gastric emptying

• takes longer to eat (beneficial because there is a delay between time we are full, and time it takes to feel full)

memorize: 14 g/1000kcal

• 2500 kcal x (14g/1000 kcal) = 35 g fibre/day

starch

Plants are able to synthesize disaccharides such as maltose in a condensation reaction, which releases water.

• glycogen

• starch

24 g pro x 4 kcal/g = 96 kcal protein

8 g fat x 9 kcal/g = 72 kcal fat

96 + 72 kcal = 168 kcal

252 kcal total – 168 kcal from pro and fat = 84 kcal carbohydrate

84kcal CHO/252 kcal total = 33% of kcal in this chili are from CHO

a) DRI recommendations for CHO: 45-65% total kcal \n b) 45% of 1800 kcal is: 45 x 1800/100 = 810 kcal \n c) 810 kal/4 kcal per g = 203 g CHO

glucagon

storage

c ) pancreas unable to synthesize insulin

• glucose intolerance

• type 2 diabetes

a. peeled, boiled potatoes

After cooking, allow them to cool – reheat for next meal: the process of cooling cooked potatoes converts some starch into ‘resistant starch’, which resembles soluble fibre physiologically and confers some of the same health benefits as soluble fibre.

• every AA contains nitrogen, proteins are about 16% N by weight

• Protein intake (g)= Nitrogen x 6.25

• Bond between 2 amino acids to form dipeptide

• Formed through condensation/dehydration reaction

-        2

-        linear order of AA in a string

• shapes within the protein

• alpha helix (spiral) & beta pleated sheets (stairs)

final 3-D shape of protein

• adding chemicals or heat denatures protein and it loses it’s final 3D shape

• protein’s shape critical to function so denaturation changes function

• occurs because of 1 AA change in hemoglobin

  • changes polypeptide shape -> hemoglobin shape -> causing long chains of molecules (instead of individual molecules) -> sickle shaped

• results: decrease O2 carrying capacity

• hormones: insulin

• enzymes: trypsin, pepsin

• neurotransmitters: serotonin

• muscle protein: collagen (structure), actin/ myosin (muscle contraction)

• normal “turnover” – breakdown and replacement of all body tissues and organs

antibodies

Hemoglobin- transports oxygen

Transferrin - transport iron

Stomach

• HCL denatures protein

• protein is converted to shorter peptides by pepsin

Pancreas

• Pancreas releases pancreatic pre-enzymes trypsinogen and chymotrysinogen

Small Intestine

• Produces intestinal enterokinase which converts trypsinogen into trypsin

  • Trypsin can activate various intestinal pre-peptidases -> Various peptidases (to active form)

  • Trypsin can convert chymotrypsinogen to active form chymotrypsin

  • Trypsin can cleave peptides into smaller peptide

• Peptidase, chymotrypsin, and trypsin breakdown proteins into di and tri peptides

• Di and tri peptides enter mucosal cell -> broken down into AA

• AA into bloodstream to portal vein to liver

AA from body tissue breakdown (endogenous) and AA from diet (exogenous) enters a liver cell and create an AA pool. Follows through to two processes:

1. Synthesis of body proteins: (enzymes, antibodies, lean body mass)

2. Breakdown of AA: (deamination)

   1. Amino group:

      1. Amino group NH2 is removed from carbon skeleton as free ammonia NH3+

      2. NH3+ is toxic to body so is converted to urea in liver

      3. Sent to kidney and excreted in urine

   2. Carbon skeleton

      1. Used directly by cells for Kcal (4 Kcal/g)

      2. Converted to glucose (gluconeogenesis)

      3. Converted to fat - stored in adipose (most likely pathway for people eating a lot)

low carb diet, starvation

• When energy is deficient, body proteins, such as enzymes and muscle proteins, are broken down into amino acids that can then be used to generate ATP or synthesize glucose.

• Excess protein converted to fat which can be used for energy

Enzyme activity is deactivated by HCl in the stomach

1. Absorption and Transport Issues:

   1. GI Tract: AAs share transporters, and they compete for absorption. If excess AA, transporters get overwhelmed with only 1 AA, preventing other AA from getting from GI to body. Causes an imbalance of absorption

   2. Brain: similar to GI tract, AA share Transporters in “Blood Brain Barrier”. Will take excess of one AA in, and lack of other AAs. AA imbalance can lead to changes in mood because AAs used to make brain chemical (ex. Tryptophan makes serotonin)

   3. Di and tri peptides absorb better than individual AA

2. N-retention:

   1. N retention better after eating protein, rather than one

   2. bottom line: get protein from food

1. Increased Kcal intake – contributor to overweight

2. High protein foods often high in fat and Kcal (meat, cheese, saturated fats)

3. Calcium loss in urine increases which might affect bone health?

   1. Animal proteins high in sulfur (methionine). Sulfur converted to acidic compound that body has to balance, so draws Ca+ out of bones.

4. Overworked liver and kidney? (work harder to extract extra urea, not a concern for healthy person)

5. Cancer? – diets high in red meat and processed meat linked to cancer

6. Gut microbiome (no idea the impact)

• digestibility of a protein

• types of amino acids

• proportion of amino acids (compared to ideal protein source which is a chicken egg)

animals 90-99% plants 70-90% soy +90%

• Complete: contain all 9 essential AAs. Usually animal origin

• Incomplete: low in at least 1 essential AA. Usually plant origin.

• Foods from plant origins

• Grains (Low in Lysine)

• Legumes (Low in methionine)

• Chicken

• Egg

• Dairy products

• The essential amino acid that is available in the lowest concentration relative to the body’s needs

• Lack of this amino acid limits the ability to make protein