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FNDH 400 Exam 1 – 4 & Final Exam
FNDH 400 Exam 1
- Carbohydrates are made of: Carbon, hydrogen, oxygen
- Proteins are made of: Carbon, Hydrogen, oxygen, nitrogen
- Lipids include: fatty acids, triglycerides, phospholipids
- Lipids are made of: Carbon, hydrogen, oxygen
- Macronutrients definition: Nutrients needed in large amounts
- Micronutrients definition: Nutrients needed in smaller amounts but still important
- What are the macronutrients?: Carbs, Proteins, Lipids, Water
- What are the micronutrients?: Vitamins and minerals
- What is a vitamin: COMPOUNDS essential for normal physiological processes
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- What is a mineral: ELEMENTS essential for normal physiological processes
in the body - What is a calorie?: Energy needed to raise 1 g of water 1 degree C
- How are kcals determined: A food is put into a bomb calorimeter and the
energy output is determined by the heat produced - Kcal/g of the nutrients: Carbs: 4
Proteins: 4
Lipids: 9
Vitamins, Minerals, Water: 0
Alcohol: 7 (but not a nutrient) - Phytochemical definition: Compounds found in plants that are believed to
provide healthy benefits beyond the traditional nutrients - Phytochemical found in tomatoes that is thought to decrease cancer risk
(esp. prostate): Lycopene - Diets rich in and have been shown with a decreased rate in
chronic diseases.: fruits and vegetables - Zoochemicals: Compounds found in animals that are believed to provide
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healthy benefits beyond the traditional nutrients
- Compounds that are both phyto and zoochemicals: Lutein and Zeaxanthin
- yellow carotenoids found in kale, spinach, and corn. or found in egg yolk
- Functional food defintion: A food, or food ingredient, that may provide a
health benefit beyond the traditional nutrients it contains
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- 3 types of studies: Cross-sectional: Present
Case-control: Past
Prospective cohort: future - Cross-sectional study: Compare different populations at the same point in
time - Example of a cross-sectional study: French paradox. Despite consuming
same amount of cholesterol/saturated fat france had 5x lower death rate from
coronary heart disease. Led to research into resveratol (red wine) - Ecologic fallacy: Believing that members of the group have characteristcs,
which as individuals they do not - Case control study: Look at a group of cases vs controls
Retrospective
Often uses food frequency questionnaires - Prospective Cohort study: Initial information on a group collected (food frequency questionnaire) and then group is followed over time to quantify health
- Scientific method:
get pdf at ;https://learnexams.com/search/study?query=
Phenylalanine, tyrosine, phenylalanine, tyrosine
In individuals with PKU, can’t be converted to because of the mutation in _ hydroxylase. So is conditionally essential
If consuming a no carbohydrate diet, what would the brain use as its primary energy source? Where would these come from? Why does it use these and not fatty acids?
The brain would have to use ketone bodies as its primary energy source since it is unable to use carbohydrates and also unable to go through beta oxidation and utilize fatty acids. The ketone bodies would come from the liver.
Your friend rarely drinks alcohol, but at a social event is drinking heavily. How would he/she be metabolizing the alcohol? What would it be metabolized to and at what intermediate does it join macronutrient metabolism products?
First my friend would be metabolizing the alcohol consumed by ADH, once its capacity was exceeded the MEOS system would be metabolizing it. They metabolize it to acetaldehyde and then ALDH metabolizes it to acetyl-CoA which is the metabolite that is a central point of macronutrient metabolism.
Why does the liver secrete glucose, but the muscle does not?
Because the liver has glucose-6-phosphatase while the muscle does not. This enzymes cleaves the phosphate group off of glucose-6-phosphate so that glucose can be secreted
DIAAS V PCDAAS
PDCAAS uses total digestibility, a single reference pattern, and is truncated
DIAAS uses ideal digestibility, multiple ref. patterns, & is not truncated
AAS V PDCAAS
PDCAAS takes into account protein digestibility along with the amino acid score
sucrose v high fructose corn syrup
The fructose in sucrose is bonded to glucose, so it will result in the same free fructose available for uptake as HFCS where fructose is free already.
linoleic acid v. alpha-linoleic acid
Eicosanoid production from linoleic acid (omega 6) elongated fatty acids are more inflammatory than those produced from alpha-linoleic acid (omega3) elongated fatty acids
good, not fermented, decreasing
Sugar alcohols are a _ option for chewing gum because they are by bacteria in the mouth, __ acid production and thus decreasing cavity formation.
Bile
Bile is synthesized by the liver and concentrated in the gallbladder and helps emulsify lipids.
alpha 1-6 bonds, oligosaccharides, decreasing
Beano contains an enzyme that cleaves the in thereby __ the fermentation by the microbiota in the colon decreasing gas production that can lead to flatulence
6 fructoses and 1 glucose
This compound is selectively fermented by beneficial colon bacteria and is both an oligosaccharide and a prebiotic.
Galactose, beta, glucose, lactose
_ is seldom found in nature alone, and is -bonded to in .
Name the only macronutrient that is digested to any great extent in the mouth and the enzyme responsible for this action
Carbohydrates – salivary amylase
Which type of fiber survives digestion and is excreted as a part of feces?
nonfermentable, non viscous fiber
Name the components of pancreatic juice
Bicarbonate, and Digestive enzymes
Gastric juice improperly moving back up into the esophagus results in what condition?
Heartburn and/or gastroesophageal reflux disease
Name the 2 alternative sweeteners that are derived from natural sources (not artificial or synthesized)
Stevia and Luo Han Guo (monkfruit) extract
Complete proteins
provide adequate amounts of all 9 essential amino acids. animal sources are good sources of complete proteins
Complementary proteins
both must have a different limiting amino acids.
Alternative sweetener that is a concern for those with PKU
Aspartame – Aspartame is broken down into phenylalanine, which is an amino acid that those with PKU should limit. They cannot metabolize it. Can lead to adverse effects if consumed at too high levels.
Differences between glycogen, oligosaccharides, and cellulose (main type of fiber)
Glycogen chains are alpha 1-4 bonds with alpha 1-6 bond branch points.
Oligosaccharides contain alpha 1-6 bonds.
Cellulose contains beta bonds.
Digestion process in the stomach and which macronutrients are not digested to any great extent.
Gastrin stimulates the release of pepsinogen, gastric lipase, and HCl.
HCl activates pepsinogen to pepsin, which digests protein.
Gastric lipase cleaves triglycerides.
Mucus is secreted to protect the stomach itself from the acidic environment and the digestive enzymes.
Carbohydrates are not digested to any great extent in the stomach.
Partial hydrogenation of unsaturated fatty acids results in the formation of what type of fatty acids? What are the pros and cons of these fatty acids?
Trans Fatty Acids (along with some saturated fatty acids). The pros are that trans fatty acids increase the melting point of the oil, generally making it solid at room temperature and thus easier to handle.
Cons: consuming trans fatty acids increases LDL and decreases HDL.
Significant increase / decrease
Significant increase above 1
Significant decrease below 1 NO OVERLAP
Statistically significant
pvalue = 0.001 to 0.049
Omega nomenclature
18:2 n-6
18=number of points starting from omega end
2= the number of double bonds
n-6 = where the double bond occurs
polyunsaturated bc 2 double bonds
double bond= unsaturated
no double bonds = saturated
Carbohydrate uptake active in small intestine
Enzymes: pancreatic amylase, disaccharides
End products: Monosaccharides
Triglycerides uptake active in small intestine
Enzymes: Pancreatic Lipase
End products: 2 monoglyceride, free fatty acids
Protein uptake active in small intestine
Enzymes: proteases, peptidases
End products: amino acids, di and tri peptides.
Rank of type of studies
- Systematic review
- Clinical trial/human intervention
- Prospective cohort
- Case-control
- Cross-sectional
Following consumption of a meal containing long chain fatty acids:
Chylomicrons, small intestine, lacteal
_ will be released from the _ into the_ and travel through general circulation.
Ornish diet post consumption
lipoprotein lipase will be active to cleave fatty acids from lipoproteins like VLDL
LDL v IDL
LDL is smaller, more dense, and more cholesterol-rich than IDL from having triglycerides cleaved during its formation
Foam Cells
Foam cells, macrophages that take up a lot of LDL / oxidized LDL, when they die they form a fatty streak in arteries that contribute to atherosclerosis.
Threonine
Threonine is metabolized to pyruvate and succinyl-CoA (citric acid cycle intermediate), it is thus classified as a glucogenic amino acid.
type 2 diabetes
insulin, insulin receptor, 4
Insulin resistance is common in type 2 diabetes, because _ binds to the but GLUT _ does not move to the cell surface to allow glucose uptake.
Diverticulosis / diverticulitis
Consuming a low fiber diet increases the risk of developing these.
Celiac Disease
Individuals with Celiac disease cannot consume the protein gluten, which is found in wheat products. because their body generates an autoimmune response that damages the vili in the intestine which impairs absorption
Statins
When a person’s cardiovascular disease risk warrants it based on an online calculator, he/she should take a stain, which improves people’s LDL levels by decreasing cholesterol synthesis.
Beta-Oxidation
Beta-Oxidation breaks down fatty acids into Acetyl-CoA.
Glycogenolysis / glycogenesis
Glycogenolysis is the catabolic breakdown of glycogen too glucose.
Glycogenesis is the anabolic synthesis of glycogen from glucose. in liver & muscle
Gluconeogenesis, glucose, liver
, the synthesis of from a noncarbohydrate source, is a anabolic pathway that is performed in the .
Transamination
Transamination is the transfer of an amine group from an amino acid to a keto acid forming another amino acid. This process is why not all amino acids are essential
Which indicates the highest glycemic response?
The food with the highest glycemic load. Since glycemic load takes into account serving size, it is a better indicator of glycemic response
Name the tissue, organ, or cells that do not perform the transition reaction
Red blood cells
What metabolic capability do red blood cells have?
They can perform glycolysis and lactate synthesis.
Name the tissues, organs, and/or cells that you learned about that do not perform beta oxidation at all or to any great extent
Red Blood Cells
Brain
Adipose
What is carnitine’s function related to macronutrient metabolism?
What is needed to transport long-chain fatty acids into the mitochondria?
Carnitine helps transport long chain fatty acids into the mitochondria.
Carnitine and CPT enzymes
Why are not all compounds that are taken up into enterocytes eventually absorbed?
enterocytes can be sloughed off with compounds that have been taken up within them. So, not everything that is taken up reaches circulation to be absorbed
Following the digestion of starch, protein, and triglycerides, what components are ready for uptake into the enterocyte?
Glucose
Di ad Tri glycerides
Amino acids
2-monoglycerides
Fatty Acids
During a fast, what would the adipose be secreting?
What hormone is stimulating this action?
Fatty Acids
Glucagon
**adipose only secretes during fast state
**only catabolic diet state
100% protein diet
uptake
Adipose:
Liver:
Muscle:
FA- minimal
Lactate, AA
Glucose, FA, AA- minimal
100% protein diet
secretion
Liver:
Muscle:
Urea, Ketone bodies, Glucose, (minim. VLDL)
Lactate
100% protein diet
hormone secreted
glucagon
100% Carb diet
uptake
Adipose:
Liver:
Muscle:
Glucose, FA
Glucose, AA
Glucose, FA
100% Carb diet
secretion
Liver:
Muscle:
Hormone:
VLDL
AA
insulin
100% Triglyceride diet
uptake
Adipose:
Liver:
Muscle:
FA
Lactate, FA, AA
FA, minimal glucose
100% Triglyceride diet
secretion
Liver:
Muscle:
Ketone Bodies, VLDL, minimal glucose
Lactate, AA
glucagon secreted when:
insulin secreted when:
No carbs in diet
IS carbs in diet
Cori Cycle
The Cori Cycle operates when glucose is limited, meaning that the Cori Cycle would be operating to spare glucose by not completely oxidizing it (maintains carbons).
Cori Cycle:
muscle – glycolysis – pyruvate – lactate synthesis – lactate
liver – lactate – gluconeogenesis – glucose
statins
Statins reduce LDL levels by decreasing HMG CoA reductase, which decreases cholesterol absorption.
(no carbs) What would the brain and muscles be using to generate ATP? Why aren’t they using the same substance?
Brain: ketone bodies
Muscle: fatty acids
They don’t use the same substrate because the brain’s beta-oxidation enzyme capability is limited, thus it cannot use fatty acids like the muscle does.
(no carbs) how would ethanol (from alcohol) be metabolized, including enzymes, in the liver. If this is in a positive energy balance, how would the “energy” from it be stored?
In the liver, Ethanol – (enzymes: AOH, MEOS) – Acetaldehyde – (enzymes: ALDH) – Acetyl CoA – FA- TG
Then going to the liver =
TG goes in through VLDL
FA – TG (look at pic)
(No fat, vegetarian)
Would the liver be secreting a significant amount of urea in this condition?
no. There is not a need to be readily deaminating amino acids to produce ammonia, which is what urea is produced to help safely excrete.
(no fat, vegetarian)
What would the liver be secreting?
VLDL
Glucose – Pyruvate – Acetyl CoA – FA – TG – VLDL
(no fat, vegetarian)
What would the adipose be taking up? What would it do with what is being taken up (metabolic processes, how stored)
Glucose, FA
Glucose – Pyruvate – Acetyl CoA – FA – TG
Selenium Deficiency
Selenium deficiency leads to decreased antioxidant selenoenzymes, the resulting increased oxidative stress causing the coxsackie virus to mutate and become more virulent causing the heart pathology typically seen in Kesha disease.
Consuming high amounts of white rice
Consuming large amounts of white rice can lead to pitting edema, a symptom of wet beriberi from deficient thiamin intake.
Nicotinic Acid
Binding of nicotinic acid to its receptor mediates niacin flush, improvement in lipid profile, and has a lack of effect on cardiovascular disease risk.
Cofactor PLP
Vitamin B6 / Pyridoxine, etc; is used for the cofactor PLP
Pyridoxine deficiency
Pyridoxine deficiency can result in microcytic, hypo chromic anemia because it is not available for heme synthesis.
Agouti Mice
In agouti mice, the agouti gene is unmethylated, which leads to the agouti gene being expressed, resulting in a yellow, obese mouse at higher risk of chronic disease.
Consuming large amounts of raw egg whites
Consuming large amounts of raw egg whites could be problematic for Biotin because the avidin found in it binds to it and prevent its absorption.
ORAC
ORAC is an in vitro antioxidant assay, which one of its limitations is that it doesn’t take into account bioavailability of the compound/substance
Theorized Antioxidant Network
In the theorized antioxidant network, alpha-tocopherol is oxidized to alpha-tocopherol radical in donating an electron to free radical / reactive oxygen species and then reduced by ascorbic acid.
Ascorbate recycling
Ascorbate recycling uses facilitated diffusion with the concentration gradient through GLUT transporters to accumulate large amounts of ascorbate.
Structure difference between gamma-tocopherol and alpha-tocopherol
The difference in structure between gamma-tocopherol and alpha-tocopherol is the methyl groups on their rings.
Cretinism
Cretinism is an iodine deficiency disorder that can result in growth, sexual maturation, and cognitive impairments.
Selenoenzymes
Selenoenzymes are a subset of selenoproteins that contain selenocysteine as an amino acid in them.
What is the structural difference between alpha-tocopherol and alpha-tocotrienol?
Alpha-tocopherol has a saturated tail, while alpha-tocotrienol has an unsaturated tail.
Name the primary dietary source of iodine that has greatly decreased the incidence of iodine deficiency
Iodized salt
What were factors A and B in early nutrition? Why are there so many B vitamins and why aren’t the numbers in sequential order?
Factor A was the early precursor to Vitamin A, Factor B was the early precursor of the B vitamins. They found that factor B consisted of multiple compounds that lead to the expansion of a number of B vitamins. Some B vitamins were discovered and then abandoned, which is why they aren’t in sequential order.
Name the two micronutrients that are important for thyroid hormone and briefly describe why each is important
- Iodine is important because it is incorporated into thyroid hormone.
- Selenium is important because the deiodinases that metabolize thyroid hormone are selenoenzymes.
What is the structural difference between the different thyroid hormones?
T4 has 4 iodines.
T3 has 3 iodines.
Consuming almost nothing but corn simply boiled in water may increase your risk of developing which micronutrient deficiency? Why is this type of diet particularly problematic for this micronutrient?
Pellagra. Because NIACIN is tightly bound in corn, if it is not treated with base, bioavailability is poor and can lead to niacin deficiency (pellagra).
RDA and EAR
In order to set an RDA, an EAR needs to be set, and to do that there needs to be research to do so. If there is no research available, then an adequate intake (AI) is set off the intake of an apparently healthy population. Since RDA’s are set using research and meant to meet the needs of 97.5% of the population, I am more confident in them than the AI.
2S-stereoisomers
2S-Steroisomers are those that have the 2 position chiral center in the S confirmation. This chiral center (R or S) is important for binding to alpha-tocopherol transfer protein in the liver. 2R forms are those that bind well to alpha-tocopherol transfer protein and thus are incorporated in to VLDL and lead to higher circulating alpha-tocopherol levels. 2S-Stereoisomers do not bind well, and thus are not included in meeting the Vitamin E requirements.
Is soybean oil a good food source to meet the vitamin E RDA? why or why not?
No it is not. Since the unit for the RDA is mg of alpha-tocopherol (and only 2R alpha-tocopherol counts towards it) and soybean oil is primarily gamma-tocopherol, it is not a good food source to meet this RDA.
Niacin equivalents
Niacin equivalents are needed because niacin can be synthesized from tryptophan.
Ranking the following forms of Vitamin E consumed in equal amounts from highest to lowest amounts in circulation.
d-alpha tocopherol, RSS alpha-tocopherol, SRR-alpha-tocopherol, dl-alpha-tocopherol, RRR-alpha-tocopherol, all-rac-alpha-tocopherol
d-alpha-tocopherol = RRR-alpha-tocopherol = RSS-alpha-tocopherol > all-rac-alpha-tocopherol = dl-alpha-tocopherol > SRR-alpha-tocopherol
Describe in detail why vitamin C deficiency results in weak collagen production that leads to the symptoms seen in scurvy
Fe2+ is a cofactor for prolyl and lysyl hydroxylases. In the course of the enzymes performing their function they oxidized Fe2+ to Fe3+. Ascorbic acid reduces Fe3+ back to Fe2+ so that the enzymes can continue to use Fe2+ as a cofactor for hydroxylating. These enzymes hydroxylate the amino acids proline and lysine within collagen allowing the formation of crosslinks between collagen strands to form the stronger tropocollagen. Without enough Vitamin C, this cross linking doesn’t occur and the tropocollagen is weak leading to the symptoms of scurvy like bleeding gums.
Fortifying cow’s milk
The choice to fortify cow’s milk with vitamin D is somewhat problematic because many individuals who are least efficient at synthesizing it from the sun because of more pigmented skin are lactose intolerant.
Iron storage
Iron is stored primarily by ferritin, and then if full, by hemosiderin.
Vitamin A storage
If you consumed a steak that contained Vitamin A, it would most likely be in the form of retinyl esters, and it would primarily be stored in stellate cells in the liver as retinyl esters.
Beta-Carotene v Alpha-Carotene
Beta-carotene in supplements would provide more RAE value than food beta-carotene and alpha-carotene in food.
Transferrin
Transferrin transports Fe3+ through circulation after it is transported through ferroportin and oxidized by hephaestin and ceruloplasmin.
Atrophic gastritis
Atrophic gastritis is a condition that results in inflammation of glands in the stomach thus decreasing the absorption Vitamin B12 by decreasing intrinsic factor.
Forms of Vitamin A
The active form of Vitamin A is all-trans retinoic acid, since this is the form that binds to the retinoic acid receptor and thus mediates many of its biological actions.
Iron levels
If circulating iron concentrations get high, this is sensed by the liver which will secrete the hormone hepcidin so that ferroportin is degraded to prevent iron absorption.
Dietary source of Phosphorus
Phytate is a common dietary source of phosphorus found in cereal/plant that is poorly absorbed because the we lack the enzyme phytase that efficiently cleaves it allowing it to inhibit the absorption of minerals such as calcium and iron.
Calcium’s role in teeth
In bones and teeth, calcium is found in hydroxyapatite which is responsible for its strength and when converted to fluorohydroxyapatite by adding fluoride, it increases teeth’s resistance to acid produced by bacteria in the mouth.
Forms of Vitamin D
Vitamin D3 has a saturated tail, is primarily produced by animals, and when consumed increases the circulating form of vitamin D (25(OH)D) concentrations, which is produced by the liver, more than vitamin D2.
Calcium concentrations
In response to too high calcium concentrations, calcitonin is released from the thyroid; and in response to too low calcium concentrations, PTH is released from the parathyroid.
Golden Rice
The major point of debate about whether to allow golden rice to be made available is about the safety and justification for genetically modified foods/crops.
Sensible Sun Exposure
Dermatologists are not supportive of sensible sun exposure to increase Vitamin D synthesis, because it is not consistent with their safe sun recommendations.
Iron deficiency indicators
An adequate blood hemoglobin can tell you that a person is not deficient in iron, but that iron stores are exhausted.
Folic Acid intake
High folic acid intake may mask a cobalamin deficiency by correcting the most easily recognizable symptom of it, but not the more serious neurological issues caused by it.
Menaquinone
Menaquinone is a form of Vitamin K produced by bacteria that has an unsaturated tail of varying lengths.
Folate
Folate is the natural, polyglutamate, less bioavailable form than folic acid which is the synthetic, mono glutamate form that provides more DFE value.
3 Micronutrients that lead to anemias that impact red blood cells.
- Vitamin B12 deficiency may lead to megaloblastic (macrocytic) anemia. Megaloblastic (macrocytic) anemia occurs because without enough cobalamin to convert 5-methyl-THF to THF, normal DNA synthesis cannot occur and RBC’s cannot properly divide.
- Folate deficiency may also lead to megaloblastic (macrocytic) anemia because folate is needed for DNA synthesis, and without it RBC’s cannot properly divide.
- Iron deficiency may lead to microcytic, hypochromic anemia because of decreased hemoglobin production.
Deiodinases
Deiodinases are selenoenzymes containing selenocysteinethat metabolize thyroid hormones, which contain iodine.
What are the circulating forms of Vitamin D and A and how are they transported through circulation?
Vitamin A: Retinol binds to retinol binding proteins (RBP)
Vitamin D: 25(OH)D binds to Vitamin D binding protein (DBP)
Is Vitamin D deficiency common?
No. Deficiency is a term for conditions that have specified symptoms that occur when intake/status is at a certain low level. In the case of Vitamin D, that is osteomalacia, or rickets. This is different than when intake/status is suboptimal or less than would be ideal over the long-term for chronic disease risk, like osteoporosis risk.
Which micronutrient has been fortified into the food supply and why?
Folic Acid. It is added to refined cereals and grains so that women of reproductive age get folate levels needed to reduce their risk of neural tube defects.
Which micronutrient is important to not supplement too much of while pregnant?
Vitamin A. Too high of supplemental levels can be teratogenic, meaning it can cause birth defects.
Which micronutrient is a newborn baby likely to receive after birth?
Vitamin K. All newborns receive an injection of it within 6 hours of birth because there is poor transfer across the placental barrier, their gastrointestinal tracts do not contain vitamin K producing bacteria, and breast milk is low in vitamin K.
Which two micronutrients are a concern for a child consuming a vegan diet?
- iron- because the child would only be consuming non-heme iron, which isn’t as bioavailable as heme iron. The DRI committee suggested that vegans might need to consume more iron as a result.
- Vitamin B12 – Because except for a few exceptions, it is only found in animal food products, which the child would not be consuming.
Why night blindness may occur in people without adequate amounts of a micronutrient.
11-cis-retinal, combines with opsin to form rhodopsin. Rhodopsin, when hit by light, is converted back to opsin and all-trans-retinal and causes a signal to be sent to the brain which leads to image formation. All-trans retinal is recycled back to 11-cis retinal, but this is not a 100% efficient process. Rhodopsin levels are increased under conditions of dim light, thus if there is not enough vitamin A available to make rhodopsin beyond what is recycled, night blindness can occur.
How the active form of Vitamin D increases calcium absorption
1,25(OH)2D moves into the nucleus of the enterocyte where it binds to the Vitamin D receptor (VDR), which is dimerized with RXR on the vitamin D response element of the calbindin gene, which increases transcription of mRNA. mRNA moves into the cytoplasm to synthesize calbindin protein, increasing calbindin protein levels. Calbindin is a calcium binding protein that facilitates uptake and transports of calcium, thereby increasing calcium absorption.
How Warfarin works as a blood thinner
Vitamin K is a cofactor for the enzyme gamma-glutamyl carboxylase which adds carboxyl groups to the amino acid glutamate. This allows it to then bind Ca2+ and they are activated. Proteins with these modified glutamates are referred to as Gla proteins. A number of these Gla proteins are within the blood clotting cascade, without adequate activation of them, blood clotting is decreased. When Vitamin K is used as a cofactor, it is converted to Vitamin K epoxide. Normally it is converted back to Vitamin K so it can continue to serve as a cofactor. Warfarin inhibits blood clotting (thins blood) by preventing vitamin K epoxide from being regenerated to form Vitamin K so that it can be used to form Gla proteins that are important in the blood clotting cascade.
Understand the importance of thionein/metallotheionein to zinc and copper
Thionein is the zinc storage protein. When zinc binds to thionein, metallothionein is formed. In the same way, copper binds to thionein forming metallothionein. Zinc is a better stimulator of thionein levels, copper is actually a more avid binder to this protein.
Metalloenzymes
Metalloenzymes are enzymes that use zinc as a cofactor.
Different forms of copper
Cupric (Cu2+) oxidized form of copper
Cuprous (Cu1+) reduced form of copper
Ceruloplasmin’s dual roles in the body
Ceruloplasmin serves two roles:
- Copper is transported through circulation in the body in the copper transport protein, ceruloplasmin, which binds 6 coppers/protein.
- Ceruloplasmin oxidizes Fe2+ to Fe3+ so it can bind to transferrin.
Why copper is important to iron absorption/transport
Two copper containing proteins, ceruloplasmin and hephaestin, oxidize Fe2+ to Fe3+. Fe3+ is the form that binds to transferrin. Therefore, copper is needed for these proteins to continue to serve their function so iron can be absorbed/transported to tissue cells.
Form of copper used in supplements that is essentially not absorbed at all
Cupric oxide is not absorbed at all
Why copper deficiency can result in hypochromic anemia
Copper deficiency can result in a secondary iron deficiency since Fe2+ cannot be oxidized to Fe3+ without the copper-containing proteins, ceruloplasmin and hephaestin, to bind to transferrin. This can cause hypo chromic anemia that occurs in iron deficiency.
What Kayser-Fleischer rings are and what they result from
Kayser-Fleischer rings are golden to greenish brown rings that form around the edge of the cornea. This results from copper toxicity. (golden rings)
How high zinc consumption can lead to deficiencies in copper and iron
High zing intake leads to increased thionein synthesis. Thionein will bind any copper that is taken up in the enterocyte. This prevents copper absorption, and instead the enterocytes are sloughed off. This leads to decreased ceruloplasmin in circulation and hephaestin on the membrane of the enterocyte. Without these copper-containing proteins, iron cannot be oxidized, so iron is trapped in the enterocyte because it cannot bind to transferrin. The enterocytes containing iron are then sloughed off and excreted in feces.
What electrolytes, cations, and anions are
Electrolytes: compounds that separate into ions (molecules with a charge) in water
Cations: ions with a positive charge
Anions: ions with a negative charge
How increased plasma sodium concentrations lead to increased blood pressure in salt-sensitive individuals
A decrease in plasma volume and blood pressure signals the kidney to release the enzyme renin. Renin activates the angiotensin that is converted to angiotensin ii. Angiotensin ii signals the adrenal gland to secret the hormone aldosterone. Aldosterone increases sodium reabsorption in the kidney, thus decreasing sodium excretions and increase the amount of sodium in circulation. The increase of plasma sodium concentrations is detected by the hypothalamus. The hypothalamus stimulates the pituitary gland to release antidiuretic hormone (ADH) that causes the kidney to reabsorb water which decreases water excretion. The result of this is an increase in blood volume and pressure.
Prevalance of salt-sensitivity, its relation to hypertension, and the impact on recommendations to reduce salt/sodium intake of all foods
27% of Americans have hypertension (high blood pressure) which increases their risk of developing cardiovascular disease. Salt is believed to be a major cause of developing hypertension, however, not everyone is salt-sensitive. Salt-sensitive means that a person’s blood pressure increases with increased intake of salt and decreases with a decrease of salt intake. 25% of people who are normotensive (normal blood pressure) and 50% of people with hypertension are salt-sensitive. In small portions of individuals, low salt intake can increase their blood pressure. There is not a clinical method that will readily determine whether a person is salt-sensitive.
Debate around whether public health policy should be trying to reduce the salt intake of everyone
Because a decrease of salt in all foods would only benefit some people, there is a debate whether we should lower all salt intake. This would help those who are salt-sensitive.