Food Science & Nutrition/Supporting Sciences Flashcards
(104 cards)
1
Q
Which fruits are best stored at room temperature?
A
Dried fruit
Avocados
Bananas
Pears
Tomatoes
2
Q
What is the difference between climacteric and non-climacteric fruits? Give examples of each.
A
Climacteric fruits = ripen post-harvest
- peach, pear, banana, apple, tomato
Non-climacteric fruits = ripen before harvest
- grapes, melon, citrus
3
Q
How are chlorophyll, carotenoids, flavonoids and flavones affected by changes in pH?
A
Chlorophyll
- Insoluble in water
- Green + acid → olive green d/t pheophytin
- Green + alkaline → light green d/t chlorophyllin (mushy veggies)
Carotenoids (least affected by changes in pH)
- yellow/orange
- Insoluble in water
- Little effect in acid or alkaline solution
Flavonoids
- Soluble in water
- Anthocyanins (red/blue/purple)
- red/blue/purple + acid → pink/red
- red/blue/purple + alkaline → purple/blue
- Red cabbage in vinegar becomes bright red
- Lycopene is found in tomatoes, watermelons, and apricots (anything red). May reduce prostate cancer risk
Flavones (anthoxanthins)
- Soluble in water
- Colorless in acid (bleaching effect)
- Yellow in alkaline or when cooked in an aluminum pan (flavones chelate aluminum)
4
Q
What is the difference between a coulis and a compote?
A
Coulis: thin puree of fruit/veggie + sugar + water used as a sauce
Compote: fruit cooked (stewed) in syrup
5
Q
What happens to potatoes during storage?
A
Potatoes have phenolic compounds that cause color changes in raw, peeled or bruised potatoes.
Potato exposed to light during storage → green color under skin (d/t chlorophyll); may also have solanine, a natural toxicant
Starch changes to sugar during storage → old potatoes taste sweeter, cook to a darker brown (Maillard reaction), and are softer in texture
6
Q
What is the difference between Maillard Browning and Enzymatic Browning?
A
Maillard: chemical reaction between an AA and a reducing sugar, usually requiring the addition of heat.
- E.g. toasting bread until brown
Enzymatic Browning: polyphenol oxidase catalyzes the oxidation of phenols in the fruit forming quinones. The quinones can polymerize to form melanin, which causes brown pigments.
- E.g. browning of fruits/veggies
7
Q
What are the can sizes/net weight/measure etc. for fruits and veggies?
A
10: 6/case 6 lbs 9 oz. 13 cups 20-25 srvngs
#3: 12/case 46 oz. 5.75 cups 12-15 srvngs
#2.5: 24/case 1 lb 13 oz 3.5 cups. 6-8 srvngs
#2: 24/case 1 lb 4 oz. 2.5 cups 4-6 srvngs
#300: 24/case 14-16 oz. 1.75 cups 3-4 srvngs
8
Q
What is the difference between vacuum-packing meat and modified atmosphere packaging?
A
Vacuum-packing (anaerobic) aka sous vide:
- extends storage life
MAP:
- prolongs shelf life
- oxygen removed, replaced with nitrogen and CO2
- slows respiration –> prevents deterioration
9
Q
What are some examples of dry heat cooking?
A
BBQ, grilling, broiling, frying, searing, roasting, stir frying, baking
10
Q
What are some examples of moist heat cooking?
A
Braising, simmering, boiling, stewing, steaming, poaching
11
Q
Which 6 cuts of meat are best for braising?
A
chuck, brisket
bottom round
short ribs
flank steak
leg of lamb
12
Q
Which cuts of meat are best for stewing?
A
chuck roast
chuck shoulder
short ribs
round roast
shank
13
Q
What are the 3 types of fermented milks?
A
Cultured buttermilk
- lactic acid bacteria + skimmed/partly skim milk
- when replacing regular milk with buttermilk, increase the baking soda
Sweet acidophilus milk
- skim milk + lactobacillus acidophilus bacteria (reduces lactose)
Kefir
- fermented by lactobacillus kefir (reduces lactose)
14
Q
What is the difference between hydrolytic rancidity and oxidative rancidity?
A
Hydrolytic rancidity
- uptake of water –> flavor changes in butter (saturated fat)
Oxidative rancidity
- uptake of oxygen at a double bond –> changes in unsaturated fat
15
Q
What is the fat content of each of the 6 types of cream?
A
Heavy or thick: >36% fat
Medium: 30-36% fat
Whipped cream: 35% fat
Light or thin: 18-30% fat
Sour cream: >18% fat
Half and half: 10.5%+ fat
16
Q
List the wheat flours in order from most gluten and protein to least gluten and protein.
A
Durum flour (used for pasta)
Graham, whole wheat
Bread flour
All-purpose
Pastry
Cake flour
17
Q
What nutrients are wheat flours enriched with?
A
Fe, Folic acid, B1, B2, B3
18
Q
What is the difference between a shortened cake and a foam cake? Give examples of each.
A
Shortened cake: large amount of fat, uses chemical leavening
- layer cake = baking powder
- pound cake = air and steam
Foam cake: uses air as leavening
- angel cake = egg white foam, no dairy
- sponge cake = yolk foam and white foam
- chiffon cake = liquid yolks, egg white foam, baking powder, oil
19
Q
What is the reason a cake would come out yellow?
A
Too much baking soda
20
Q
Why would a cake come out hollow?
A
Too much sugar, fat and baking powder
Oven temp too low
21
Q
Why would a cake come out tough?
A
Too little sugar and fat
Too much mixing, flour and eggs
22
Q
Why would a cake come out coarse/dry?
A
Too much sugar and baking powder
Not enough mixing
Oven temp too low
23
Q
Why would a cake come out low in volume?
A
Improper levels of sugar and fat
Too little baking powder
24
Q
Why would a cake come out not leveled and unevenly shaped?
A
Fats not incorporated evenly
25
List the liquid:flour ratio for the four types of batters/doughs with examples of each.
Pour batter - 1:1 = waffles
Drop batter - 1:2 = muffins
Soft dough - 1:3 = bread
Stiff dough - 1:4 = pie crust
26
What happens when baking at high altitudes and how do you correct for it?
Decreased pressure --> gas expands faster --> steam forms earlier
May expand too much before oven heat has coagulated the protein and gelatinized starch to stabilize the structure
To correct: decrease baking powder, increase liquid
27
List starches in order from most thickening ability to least effective thickening ability.
Potato
waxy corn
waxy rice
waxy sorghum
tapioca
wheat
28
What is the difference between gelatinization and retrogradation?
Gelatinization: when heated starch swells, close to the boiling point
- E.g. sauces
Retrogradation: when chilled starch recrystallizes, becoming solid. Happens in starches with high amylose content (wheat, maize, rice, barley, potatoes)
- E.g. stale bread and old gravy
29
What are the 3 crystal inhibitors?
Acid: sugar + acid --> inversion (hydrolysis) of sucrose --> invert sugar (glucose and fructose)
Fat: chocolate, milk
Protein: milk, egg whites, gelatin
30
What is non-crystalline sugar and what are some examples?
amorphous, glasslike
- E.g. hard candies, brittles, chewy candy, gummy candies
Crystallization prevented by adding interfering substances OR by increasing sugar
Corn syrup retards crystallization → increasing viscosity, chewiness
31
What is crystalline sugar and what are some examples?
Large crystals = rock candy
Small crystals = fondant, fudge
32
What are some examples of emulsifiers and what foods are they used in?
Soy lecithin
Polysorbates
Egg yolks
Mono/diglycerides
Used in: salad dressings, PB, chocolate, margarine
33
What are some examples of anti-caking agents? What foods are they used in?
calcium silicate
iron ammonium citrate
silicon dioxide
Used in: salt, baking powder, confectioner's sugar
34
What are some examples of thickeners, stabilizers, binders and texturizers? What foods are they used in?
Gelatin
Pectin
guar gum
carrageenan
xanthan gum
whey
Used in: dairy products, cakes, pudding/gelatin mixes, jams/jellies/sauces
35
What are some examples of humectants? What foods are they used in?
glycerin, sorbitol
Used in: shredded coconut, marshmallows, soft candies, confections
36
What are examples of flavor enhancers? What foods are they used in?
monosodium glutamate (MSG)
hydrolyzed soy protein
autolyzed yeast extract
disodium guanylate or inosinate
Used in: many processed foods
37
What are some examples of preservatives? What foods are they used in?
ascorbic acid, citric acid
sodium benzoate, erythorbate, nitrate
calcium propionate, sorbate
potassium sorbate
BHA, BHT
tocopherols aka vitamin E
Used in: fruit sauces/jellies, beverages, cured meats, oils/margarines, snack foods, fruits/veggies, baked goods
38
What are the 3 types of qualitative (subjective) food sensory evaluations?
Analytical: difference/discrimination tests measure ability to recognize small differences between items
- Paired comparison test = which one is saltier?
- Triangle = Three samples presented, two are alike. Which two are identical?
Between new and old products
- Ranking or scaling = Rank in order of preference
Affective: untrained panelists
- Hedonic rating = scale; face hedonic = smiling faces
- Paired preference = compares two samples for a specific attribute
- Ranking test = paired preference with additional samples
Flavor profile method aka descriptive flavor analysis profile (DFAP)
- Trained panel analyzes/record aroma and flavor in detail
39
What are 4 objective (physical) measurements of food sensory evaluation?
Penetrometer = tenderness/firmness
Viscosimeter (viscometer) = measures flow on an incline plane or on a rotational basis
Line-spread test = measures viscosity of things that flow on a flat surface
Specific gravity = compares lightness of products; weight of a given sample volume/weight of same volume in water
40
Phytochemicals are compounds produced by plants (as a way to protect themselves from viral/bacterial/fungal infections) as well as being eaten by insects. What are some examples?
Indols (found in cruciferous veggies)
- may decrease the risk of breast cancer
- detoxify cancer causing agents
Isoflavones (found in soybeans)
- decrease elevated cholesterol levels
Lycopene (found in red foods like tomatoes)
- may reduce prostate cancer risk
41
What do low kcal, low fat, low sodium, gluten-free and organic mean on a food label?
Low calories: 40 calories or less per serving
Low fat: 3 g or less per serving
Low sodium: 140 mg or less per serving
Gluten-free: <20 ppm
Organic: at least 95% organic ingredients
42
What is the difference between a health claim, qualified health claim and a structure function claim?
Health Claim = based on authoritative statements from a scientific body of the US Gov or the National Academy of Sciences
- "a Ca rich diet may prevent osteoporosis"
Qualified Health Claim = emerging evidence of a relationship, but not conclusive. Requires a disclaimer.
- "scientific evidence suggests, but does not prove, that whole grains as part of a low saturated fat and low cholesterol diet, may reduce the risk of T2DM"
Structure Function Claim = describes the role of a nutrient on the structure or function of the human body without FDA approval
- "fiber maintains bowel regularity"
43
What is the difference between BMR and RMR?
BMR: measures oxygen consumed and CO2 produced
- Measured in the AM when at rest
- Measured by PBI aka protein bound iodine which measures activity of thyroid gland. Measures level of thyroxine produced
- When PBI is elevated, BMR is elevated
- Increased by exercise
RMR: resting metabolic rate; energy expenditure measured under similar conditions, after a short rest and controlled intake of caffeine, alcohol
- More frequently used than BMR
- Mifflin predicts within 10% of indirect calorimetry
44
What is the difference between direct and indirect calorimetry?
Direct = measures heat produced in respiration chamber (limited usefulness)
Indirect = measures oxygen consumed and CO2 excreted using a portable machine
- Practical way of measuring which nutrients are being used for energy and determining caloric needs)
- Useful for athletes, ill individuals, burned patients
- RQ (respiratory quotient): ratio of CO2 given off to that of oxygen consumed
Important in respiratory disease.
Depends on fuel mixture being metabolized
CHO: 1, Pro: 0.82, Fat: 0.7, Mixed: 0.85
If you have a pt with COPD, increase their fat and decrease their carbs (lower RQ).
Overfeeding → increased RQ and increases lipogenesis
45
What are the atomic elements that compose CHO, protein and fat?
CHO: carbon, hydrogen, oxygen
Protein: C, H, O, N (16%), sulfur (Cysteine and methionine)
Fat: Carbon, hydrogen, oxygen
46
What are the four types of CHO?
Monosaccharides (simple sugars)
- Glucose, fructose, galactose
Disaccharides
- Sucrose (glucose + fructose)
- Lactose (galactose + glucose)
- Maltose (glucose + glucose)
Polysaccharides (complex sugars)
- Starch (glucose chains)
- Cellulose = adds bulk, resistant to amylase
- Pectin = thickener; nondigestible
- Glycogen = animal starch, stored in muscle and liver
- Dextrin = intermediate product of starch breakdown
Sorbitol (alcohol from glucose)
- Absorbed more slowly than glucose via passive diffusion
- Converted into fructose
- Excess may cause diarrhea
47
List the CHO from most sweet to least sweet.
Fructose → invert sugar → sucrose → glucose → sorbitol → mannitol → galactose → maltose → lactose
48
What are the 3 functions of CHO?
Energy
Protein-sparing action = allows most of protein to be used for tissue synthesis
Regulation of Fat Metabolism = carb restriction → ketosis
49
What is the difference between essential AAs and conditionally essential AAs? List examples of each.
Essential = body can't make them (TV TILL MPH)
- tryptophan, valine, threonine, isoleucine, lysine, leucine, methionine, phenylalanine, histidine
Conditionally essential = essential during catabolic stress/illness (GGASP COT)
- glycine, glutamine, arginine, serine, proline, cysteine, ornathine, tyrosine
50
What is the difference between conjugated and derived proteins?
Conjugated
- Simple + non-protein substance e.g. Lipoprotein
Derived
- Fragments from simple & conjugated e.g. Peptide
51
What AAs are soybeans, legumes and gelatin low in/lack?
**Soybeans low in methionine, but equivalent in protein quality to animal protein.
**Legumes low in methionine, cystine & tryptophan
**Gelatin low in methionine, lysine and has NO tryptophan
52
What are the 3 functions of protein?
Tissue synthesis
Maintains growth
Regulates body processes
53
What is the most polyunsaturated fat? What is the most unsaturated fat?
Safflower - most polyuns; Canola - most unsatur.
54
omega 3 vs omega 6: function, deficiency symptoms, sources?
Omega 3
- Reduces TG, inflammation
- Deficiency → neuro changes, numbness, blurred vision
- Inhibits VLDL synthesis, little effect on total chol.
- Found in walnuts, chia seeds, herring, sardines, oysters, flax seeds, caviar, cod liver oil
Omega 6
- Builds fetal nervous system
- Deficiency → petechiae and eczema
- Omega 6:3 ratio is important
- Found in soybeans, corn, meat, fish, poultry, eggs, safflower and sunflower oils
55
What happens when:
omega 6 replaces CHO?
omega 6 replaces saturated fat?
omega 3 replaces high CHO?
LDL decrease, HDL increase
TC and HDL decrease
TG decrease, TC no change
56
What is the difference between compound and derived fat?
Compound
- Simple + other component e.g. Phospholipid
Derived
- Produced via hydrolysis or enzymatic breakdown e.g. FA, glycerol, steroid
57
What are the 3 functions of fat?
Energy
- Less oxygen, more carbon than CHO so provides more energy (more C atoms for oxidation)
Insulation and padding
Depresses gastric secretion so delays emptying
58
List fats in order from most saturated to least.
Coconut oil → palm kernel → cocoa butter → butter → palm oil → canola
59
List fats in order from most monounsaturated to least.
Olive oil → canola → peanut → sunflower → coconut (MCT source)
60
List fats in order from most polyunsaturated to least
Safflower → corn → soybean → cottonseed → palm kernel
61
What is a winterized oil? Give 3 examples.
Winterized oil = won’t crystallize when cold; clear (not cloudy)
Corn, soy, cottonseed oils are winterized
62
What health problems may be indicated when ECW increases in relation to ICW?
Acute Inflammation
- Body sends additional blood flow to the damaged area (temporary increase)
Renal Disease
- Kidney filters blood, removes toxins, regulates BP and blood pH, etc
- So when kidneys fail, their bodies have more Na than the kidneys can filter out → ECW increase (edema)
63
How much insensible water loss does the body incur per day?
0.8-1.2 L/day
64
What is the equation for mEq? What are the AW and valence numbers for Na, K and Ca?
mEq = (mg/atomic weight) x Valence
Na+: AW 23, Valence 1
K+: AW 39, Valence 1
Ca2+: AW 40, Valence 2
65
What are normal pH, HCO3, and pCO2 values?
pH = 7.4
HCO3 = 24-28
pCO2 = 35-45
66
Respiratory Acidosis: causes and compensation?
Causes
- CO2 retention by lungs
- Hypoventilation
- Emphysema
Compensation
- Kidneys increase absorption of base (bicarbonate)
67
Respiratory Alkalosis: causes and compensation?
Causes
- Loss of CO2 and H2O (low blood levels of CO2)
- Hyperventilation
- Anxiety, severe exercise
Compensation
- Kidneys increase excretion of base (bicarbonate)
68
Metabolic Acidosis: causes and compensation?
Causes
- Low HCO3 = Kidneys excrete excess base; uremia, diarrhea
- High H+ = Increase H production or retention by kidney; Uncontrolled diabetes; Starvation; High fat/low CHO diet
Compensation
- Increase respiration to excrete CO2
- Hyperventilation
69
Metabolic Alkalosis: causes and compensation?
Causes
- High HCO3 = Abnormal retention of base; Increased alkali diuretics; Vomiting/dehydration
- Low H+ = Loss of stomach acid; Diuretics; Loss of chloride
Compensation
- Decrease in respiration to retain CO2
- Hypoventilation
70
What are the four types of nonnutritive sweeteners?
Equal = Aspartame
Stevia in the Raw = Stevia Extract
Sweet n Low = Saccharin
Splenda = Sucralose
71
What are the nutrient needs for the elderly?
Kcal, protein, fluid, etc.
Kcal needs decrease, protein needs remain the same (1 g/kg)
Often lack calcium and iron (decreased absorption d/t decreased HCl)
Constipation d/t decreased gastric motility, decreased HCl secretion in stomach
Fluids = 25-30 ml/kg
Folate-rich foods, supplements of B6 and B12 may be needed
Diet high in antioxidants may delay cataracts
MOST VULNERABLE to vitamin A toxicity (increased liver storage, decreased clearance from blood)
72
Explain the summary of the digestion process including which enzymes act where.
SEE PIC IN GOOGLE DOC NOTES
73
Gastrin: site of synthesis and functions?
Site of synthesis:
- Produced by the stomach
- Released in the pyloric antrum of the stomach, duodenum & pancreas
Function: stimulates gastric secretions and motility
74
CCK (cholecystokinin): site of synthesis and functions?
site of synthesis:
- small intestine
- released from the duodenum when fat enters
Functions:
- contracts gallbladder, releasing bile
- stimulates pancreatic secretion
75
Secretin: site of synthesis and functions?
Site of synthesis:
- duodenum
Functions:
- Stimulates flow of pancreatic juice (bicarbonate) and water into the duodenum
- Inhibits gastric acid secretion (gastrin) and thus, GI motility
76
GLP-1 (glucagon-like peptide 1) & GIP (glucose-dependent insulinotropic polypeptide):
site of synthesis and functions?
Site of synthesis:
- small and large intestine
- released from intestine in presence of glucose and fat
Functions:
- stimulate insulin synthesis and release
77
Explain the different elements of mechanical digestions/muscular activity.
Mastication: produces bolus (mass of masticated food)
Rhythmic contractions of esophagus
- Force food to the stomach → mixed with gastric juice → reduced to chyme (acidic)
Gastric emptying
- Usually takes between 2-6 hrs
- Carb and protein empties at about the same rate from the stomach, high fat and complex carbs (soluble fibers) slow gastric emptying
Chyme → duodenum → mix with fluids and bicarbonate ions (from pancreas) that neutralize the acid
Peristalsis = rhythmic movements of small intestine
78
Explain bacterial digestion. Where does it take place?
Water, salts, and vitamins synthesized by bacteria absorbed in the large intestine → used by GI mucosal cells
Colonic salvage = anaerobic fermentation and absorption of end-products of CHO, fiber and AA breakdown
Malabsorbed CHO and fiber → gasses + SCFA (acetate, butyrate, propionate, lactate) → stimulate water and sodium absorption in the colon and provide substrate for energy production
79
Which AA is the most glucogenic?
Alanine
80
List 5 hormones that control BG level and how do they work?
Insulin
- stimulates uptake of glucose and AA into the cells
- stimulates the synthesis of glycogen by increasing glucose uptake in the liver
- promotes lipogenesis
- inhibits gluconeogenesis
Glucagon
- stimulates the release of FAs from TG
- stimulates glycogen breakdown
- stimulates gluconeogenesis
Glucocorticoids
- protein --> glucose
Epinephrine (adrenal medulla)
- Stimulates sympathetic NS
- Stimulates glycogenolysis (glycogen → glucose)
- Decreases release of insulin from pancreas during catabolic stress
Growth hormone ACTH (adrenocorticotropic)
- insulin antagonist
81
Explain the process of glycolysis and the TCA cycle.
SEE INMAN CHART
pg. IN 24
82
What is the main substrate for energy production within the Kreb's cycle?
Pyruvate
83
What happens if there is not enough oxaloacetate coming in from CHO for the TCA cycle?
FAs will be used and produce ketones as a byproduct
84
List 3 ketone bodies.
acetoacetic acid, acetone, beta-hydroxybutyric acid
85
How much ATP does full oxidation of 1 glucose molecule yield?
38 ATP
86
Where does gluconeogenesis occur?
In the liver
87
Where and when does glycogenesis occur?
in the liver and muscle during rest, following the Cori cycle. It will be activated by insulin in response to elevated glucose.
88
What is the formula for nitrogen balance? What does a positive and negative balance indicate?
(protein intake (g)/6.25) - (UUN + 4)
+ = net gain in body protein (infant, teenager, pregnancy, healing)
- = erosion of body protein (inadequate intake)
89
What is the difference between biologic value vs net protein utilization vs PDCAAS?
BV aka biologic value: uses N balance to determine fraction of absorbed N kept for growth and maintenance
- Eggs BV = 100, so 100% of N absorbed is retained
NPU aka net protein utilization: measures amount of protein actually used
- (N intake - N output)/N intake
Protein Digestibility Corrected Amino Acid Score (PDCAAS): estimates % of protein in each food category that’s actually digested
- Animal 97%, plant proteins 70-90%
90
Describe the protein catabolism process. What vitamin is involved?
See google doc.
Pyridoxine is involved
91
Which hormones are involved in protein anabolism and catabolism?
Pituitary growth hormone, thyroid hormone, insulin, testosterone → anabolism
Adrenal steroids (glucocorticoids): protein catabolism aka protein → glucose; stimulates gluconeogenesis
92
How are mono/diglycerides/LCFAs absorbed vs glycerol/SCFAs/MCFAs/some phospholipids?
Absorbed directly into portal blood: glycerol (water-soluble), SCFAs & MCFAs (<12 carbons), some phospholipids
Combined w/ bile salts to form micelles: Mono-, diglycerides, LCFAs
- Bound to protein to form lipoproteins (chylomicron) → intestinal mucosa → travel through lymph → thoracic duct → blood
93
What 2 places does lipogenesis occur?
Adipose (most active site): FA + glycerol →TG
Liver (synthesizes fat, but shouldn’t store it)
94
What hormones are involved in fat anabolism and catabolism?
Lipogenesis (anabolism): promoted by insulin
Lipolysis (catabolism): promoted by glucagon
- glucocorticoids, thyroxine, epinephrine, ACTH all increase fat mobilization rate
95
What is absorbed in the stomach?
Water
Alcohol
Minerals: I, Fl
96
What nutrients are absorbed in the duodenum?
Vitamins: B1,2,7,9
Minerals: Ca, Fe, Cu, Zn
97
What nutrients are absorbed in the jejunum?
Monosaccharides
AAs, small peptides
Lipids
Water
Vitamins: B1,2,5,6,7,9, C, ADEK
Minerals: Na, Ca, K, Mg, P, Fe, Zn, Cu, Molybdenum
98
What nutrients are absorbed in the ileum?
Bile salts/acids
Water
Vitamins: B12
Minerals: Ca, Mg, Na, K, Cl
99
What nutrients are absorbed in the colon?
Water
SCFAs
Vitamins: K, B1,2,3,5,7,9
Minerals: Na, K, Cl
100
Which mechanism of transport (active vs simple diffusion vs facilitated diffusion) do fructose, glucose, and galactose use?
Fructose = facilitated diffusion (passive)
Glucose & galactose = active transport with Na+
101
Which mechanism of transport (active vs simple diffusion vs facilitated diffusion) do AAs, di&tripeptides, and lipids use?
AAs, di&tripeptides = active transport
Lipids = simple diffusion via micelles
102
Which mechanism of transport (active transport vs simple diffusion vs facilitated diffusion) do fat-soluble and water-soluble vitamins use?
Fat soluble vitamins (A, D, E, K) - taken up by being incorporated into micelles (simple)
Water soluble vitamins (B and C) - taken up by simple diffusion
B12 and intrinsic factor - taken up by active transport and requires receptor-mediated endocytosis
103
Which mechanism of transport (active vs simple vs passive) do Na, Cl, I, Ca, Fe, K, and Mg use?
Na+ absorbed by active transport via Na/K ATPase pumps
Cl, I, and nitrate follow Na passively
Ca absorbed via active transport, regulated by Parathyroid and vitamin D
Fe, K, Mg absorbed via active transport
104
What are the factors that aid in the absorption of vitamin A, D, riboflavin, B12, iron and folate?
Vitamin A - bile salts, pancreatic lipase, fat
Vitamin D - hydroxylated in liver, then in kidney; needs bile salts, acidity of chime; accompanies Ca and P absorption
Riboflavin - Phosphorus
B12 - ileum, stomach secretions (HCl, intrinsic factor)
Iron - HCl, calcium (binds oxalates)
Folate - zinc dependent, cleaves polyglutamate to monoglutamate
- Folic acid in fortified foods = monoglutamate
