Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

GI > 21. Nutritional biochemistry > Flashcards

21. Nutritional biochemistry Flashcards

1
Q

What are the four proproteases secreted by the pancreas?

A

Tripsinogen
Chymotrypsin
Proelastase
Procarboxypeptidases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the active enzymes secreted by the pancreas?

A 
Alpha-amylase
Lipases
Colipase
Phospholipases
Cholesterol esters
RNAase
DNAase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the key ion secreted by the pancreas?

A

HCO3-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the three stages of pancreatic secretion?

A

Cephalic
Gastric
Intestinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What mediates pancreatic secretion in the cephalic phase?

A

Acetylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What mediates pancreatic secretion in the gastric phase?

A

Acetylcholine

Gastrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What mediates pancreatic secretion in the intestinal phase?

A

Cholecystokinin

Secretin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is HCO3- secretion by pancreatic duct cells controlled by?

A

Acetylcholine

Secretin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the three types of lipase?

A

Lingual
Gastric
Pancreatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Though lingual lipase and gastric lipase can act on their own, what does pancreatic lipase require for proper function?

A

Bile salts

Colipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the three types of enzymes responsible for the digestion of fat?

A

Lipase (lingual, gastric, pancreatic)
Phospholipases
Cholesterol esterases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What components of fat can be taken up directly into an enterocyte?

A

Glycerol
Short chain fatty acids
Medium chain fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What components of fat are taken up in a mixed micelle?

A

Cholesterol
Lysophospholipids
Long chain fatty acids
Monoacylglycerols

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the two main types of proteases?

A

Endopeptidases: cleaves in the center or proteins and peptides
Exopeptidates: cleaves from the N or C terminal ends of peptides and proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the endopeptidase in the stomach? What secretes it?

A

Pepsinogen–chief cells

**activated by acid and auto-activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What synthesizes and secretes the endopeptidases of the duodenum and jejunum?

A

Alpha cells of the pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is the endopeptidase trysinogen activated?

A

Activated by epithelial enteropeptidase/enterokinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is chymorypsinogen and proelastase activated by?

A

Typsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the two exopeptidases secreted into the duodenum?

A

Carboxypeptidases

Aminopeptidases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What synthesizes the exopeptidase carboxypeptidase vs aminopeptidase?

A

Carboxypeptidase: alpha cells of the pancreas
Aminopeptidase: intestinal epithelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the three types of protein transporters found in the duodenum and jejunum?

A

Amino acid class specific
Dipeptide
Tripeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the two kinds of epithelial cell peptidases?

A

Tripeptidase

Dipeptidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What enzyme digests carbs and is active in the oral cavity, early in the stomach?

A

Salivary alpha amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What enzyme disgests carbs and is acitve in the lumen of the duodenum?

A

Pancreatic alpha amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Where are the di and trisacchridases located?
Intestinal epithelial cell membranes (brush borders)
26
Where are carbohydrates absorbed?
Duodenum | Jejunum
27
What are the two transporters for the absorption of carbohydrates?
SGLT1 | GLUT5
28
What are the sx of lactase deficiency? Cause?
Bloating and diarrhea due to the bacterial degradation of lactose (upon delivery to the large intestine undigested)
29
What gets removed in a typical RNY bypass of the small intestine?
Stomach Duodenum Part of the jejunum
30
What do calorie requirements depend on?
Energy expendature: BMR, thermal effect of food, physical activity
31
What are the two essential fatty acids?
Linoleic acid: w 3 | Linolenic acid: w 6
32
What are the essential amino acids?
``` Arginine Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Valine ```
33
What has the highest calorie density of carbs, proteins, fat, alcohol
Fat 9kcal/gm Alcohol 7 kcal/gm Carbs 4kcal/gm Proteins 4kcal/gm
34
What % of diet should carbs, proteins, and fat compose?
Carbs 45-65% Proteins 10-35% Fat 20-35%
35
6 causes of malnutrition
``` Poverty Ignorance Chronic alcoholism Acute and chronic illness Self-imposed dietary restriction Other: GI disease, malabsorption syndrome, drugs, TPN ```
36
A malnourished child has a weight of less than __% normal
80%
37
What are the two protein storing compartments?
Somatic protein: skeletal muscle stores | Visceral protein: visceral organ stores
38
What is marasmus?
Severe reduction in caloric intake leading to >60% reduction in body weight
39
What protein compartment is depleted in marasmus?
Somatic protein compartment
40
What is the presentation of marasmus?
Growth retardation and loss of muscle mass Emaciated extremities Anemia and immunodeficiency
41
What protein stores are lost in Kwashiorkor?
Visceral protein stores
42
What causes Kwashiorkor?
Protein deprivation is greater than caloric deprivation Protein malabsorption Chronic protein loss: protein losing enteropathies, nephrotic syndrome, chronic diarrhea
43
Is albumin abnormal in Kwashiorkor or masasmus?
Kwashiorkor: hypoalbuminemia
44
What is the clinical presentation of Kwashiorkor?
Alternating hypo and hyperpigmented zones with desquamination Hair color and texture changes Fatty liver Immune deficiency, anemia
45
What are the patient populations that frequently show malnutrition?
Chronically ill Hospitalized Advanced cancer AIDS
46
Four complications of malnutrition:
Infection Impaired wound healing Sepsis Death after surgery
47
How is the BMI calculated
BMI = weight (kg) / height (m2)
48
What are the key limitations to using BMI?
High muscle mass High bone mass Ranges change for children and teens
49
Two measurements for the % body fat?
Skinfold | Impedance
50
What are the characteristics of metabolic syndrome?
``` Obesity Insulin resistance Hypertriglyceridemia Low HDL Hypertension ```
51
What are the characteristic of type II diabetes?
Elevated blood sugars Non-insulin dependent Insulin resistance
52
How is type II diabetes controlled?
Weight loss Exercise +/- medications
53
What are the key medical complications of obesity?
``` Metabolic syndrome Type II diabetes Cardiovascular morbidity Cholelithiasis Cancers PE/DVT Obstructive sleep apnea Hypoventilation syndrome Osteoarthritis Steatosis ```
54
What are the 4 Fs of cholelithiasis?
Femal Fertile Forty Fat
55
What are the estrogen dependent cancers that are associated with obesity?
Endometrial hyperplasia/carcinoma | Breast cancer
56
What are the estrogen independent cancers that are associated with obesity?
Colon cancer Kidney cancer Esophageal cancer
57
Why is PE/DVT associated with obesity?
Estrogen is a RF for thrombosis
58
What are the three hyperlipidemias that are associated with accelerated, premature atheroscleorosis of the coronary arteries
Familial hypercholesterolemia Hypertriglyceridemia Familial combined hyperlipidemia
59
What is the "Recommended Dietary Allowance" (RDA)?
Average daily level of intake sufficient to meet the nutrient requirements of nearly all (97-98%) of healthy individuals
60
What is the definition of adequate intake?
Established when evidence is insufficient to develop an RDA and is set as a level assumed to ensure nutritional adequacy
61
What is a tolerable upper intake level?
Maximum daily intake unlikely to cause adverse side effects
62
What are 'daily values' used for?
Food and dietary supplement labels to indicate the percent of the recommended daily amount of each nutrient that a serving provides
63
What are the two general types of water soluble vitamins
Non B-complex | B-complex
64
What is the non-B complex water soluble vitamin?
Ascorbate (Vitamin C)
65
What are the three types of B-complex, water soluble vitamins
Energy releasing Hematopoietic/1C metabolism Amino acid metabolism
66
What are the energy-releasing, B-complex, water soluble vitamins?
``` Thiamine (B1) Riboflavin (B2) Niacin (B3) Pantothenic acid (B5) Biotin (B7) ```
67
What are the hematopoietic/1C metabolism, B-complex, water soluble viatmins?
``` Folate (B9) Vitamin B12 (cobalamin) ```
68
What is the amino acid metabolism, B-complex, water soluble vitamin?
Vitamin B6 (pyridoxine, pyridoxamine)
69
What are the fat soluble vitamins?
``` Vitamin A (retinol, carotenes) Vitamin D (cholecalciferol) Vitamin E (tocopherols) Vitamin K (phylloquinones) ```
70
Where are most B vitamins absorbed? What is the exception?
Duodenum and jejunum | B12 absorbed in the ileum and mircobiota-produced biotin in the large intestine
71
What are the sources of most B-vitamins
``` Meats Milk Whole grains and fortified breads/cereals Legumes Nuts Green leaky vegetables ```
72
What are the sources of vitamin B12
``` Meat Shellfish Fish Eggs Milk, cheese, yogurt **not available in plant products ```
73
What vitamin is thiamine pyrophosphate dependent on?
Thiamine
74
What vitamin is flavin adenine dinucleotide dependent on?
Riboflavin
75
What vitamin is nicotinamide adenine dinucleotide dependent on?
Niacin
76
Where is thiamine (B1) absorbed?
Duodenum | Jejunum
77
How long does it take for thiamine (B1) storage to be depleted
14 days
78
What is the active from of thiamine (B1)?
Thiamine pyrophosphate
79
What are three key functions of thiamine (B1)?
1. Cofactor for pyruvate dehydrogenase (decarboxylation) 2. Cofactor in the pentose phosphate pathway 3. Maintains neural membranes and normal nerve conduction
80
What are dietary sources of thiamine (B1)
Pork Whole grains and fortified breads/cereals Legumes and nuts
81
Who commonly gets thiamine (B1) deficiency?
Alcoholics
82
What are the three clinical syndromes of thiamine (B1) deficiency
1. Polyneuropathy--dry beriberi 2. Dilated cardiomyopathy--wet beriberi 3. Wernicke-Korsakoff syndrome
83
What are two possible treatments for thiamine (B1) deficiency
``` Banana bag (IV Mg, K, thiamine, folate) Oral supplementation ```
84
What is Wernicke-Korsakoff Syndrome?
Reversible encephalopathy with opthalmoplegia, confusion and disorientation, nystagmus, and ataxia Cause: Thiamine (B1) deficiency
85
What is the chronic stage of Wernicke Korsakoff syndrome?
Korsakoff syndrome: irreversible memory disturbances and confabulation
86
What is seen in the brain with Wernicke-Korsakoff syndrome?
Periventricular and mammilary body hemorrhage and necrosis
87
Is thiamine (B1) toxic?
Non-toxic--excess excreted
88
What vitamin is panthothenic acid
B5
89
Where is panthothenic acid (B5) absorbed?
Duodenum
90
Storage of pantothenic acid
Excess excreted, very little stored
91
What is the active form of panthothenic acid (B5)
Coenzyme A
92
What is the function of pantothenic acid (B5)
Carbohydrate and fatty acid synthesis | **acyl carrier protein function
93
What are good sources of panthothenic acid?
Whole grains Meats Fish Poultry
94
Panthothenic acid deficiency ? Toxicity
Very rare | non-toxic
95
What vitamin is riboflavin
B2
96
Where is riboflavin (B2) absorbed?
Duodenum | Jejunum
97
What are the active forms of riboflavin
``` Flavin mononucleotide (FMN) Flavin adenine dinucleotide (FAD) ```
98
What is the function of riboflavin (B2)
Electron carrier: complex dehydrogenases, citric acid cycle to the electron transport chain
99
What are good sources of riboflavin?
``` Milk and milk products Eggs Meat Fish Whole grains and fortified breads/cereals Nuts and legumes ```
100
Who gets riboflavin (B2) deficiency?
Rare, except in alcoholics
101
What are the s/s of riboflavin (B2) deficiency?
Cheilosis: scaling and fissures at the mouth corners Angular stomatitis: inflammation at the corners of the mouth Glossitis: inflammation of the tongue Dermatitis
102
Toxicity of riboflavin (B2)
non-toxic, excreted
103
What vitamin is niacin?
B3
104
Where is niacin absorbed?
Duodenum | Jejunum
105
What are the active forms of niacin (B3)
NADPH/NADP+ | NADH/NAD+
106
When is NADH generated? Function?
Generated during degradation of carbs, fats, amino acids, nucleic acids Carried electrons from the TCA cycle to the electron transport chain
107
When is NADPH generated? Function?
Glucose-6-phosphate dehydrogenase in the pentose phosphate pathway Used in synthesis reactions for carbohydrates, fats, amino acids, and nucleic acids
108
What are good dietary sources of niacin (B3)
``` Meat Fish Milk Eggs Whole grains and fortified cereal/breads Nuts and legumes ```
109
What is the name fore niacin or tryptophan deficiency?
Pellagra
110
Who gets pellagra (niacin or tryptophan deficiency)?
Alcoholics | People living in poverty
111
What are the three key sx of pellagra?
Dermatitis (when exposed to the sun) Diarrhea Dementia
112
What is the toxicity of niacin (B3) when given at pharmacological levels for hypercholesterolemia?
Flushing Gastric irritation Rashes
113
What vitamin is biotin?
B7
114
Where is biotin (B7) absorbed?
Duodenum | Jejunum
115
What is the active form of biotin (B7)?
Biotin bound to carboxylase
116
WHat is the function of biotin (B7)?
Carboxylase cofactor: pyruvate carboxylase and acetyl CoA carboxylase
117
What are dietary sources of biotin (B7)
``` Liver Milk Eggs Fish Peanuts Chocolate Whole grains Legumes ```
118
Where in the body is biotin synthesized?
By intestinal bacteria
119
What can lead to biotin (B7) deficiency?
Rare, but more prevalent in the elderly | Can occur by binding of biotin to avidin in raw egg whites
120
What happens in a biotinidase deficiency?
Inability to convert dietary-derived biocytin to free biotin
121
What is the presentation of biotin deficiency in infants?
Poor growth | Neurological disorders
122
What is the presentation of biotin deficiency in infants and adults?
Dermatitis | Alopecia
123
Biotin toxicity?
None--excess is excreted
124
What vitamin is pyridoxine?
B6
125
Where is pyridoxine absorbed?
Jejunum and ileum
126
What is the active form of pyridoxine (B6)?
Pyridoxyl phosphate
127
What is the function of pyridoxyl phosphate?
Coenzyme involved in: 1. Amino acid degradation: aminotransferases, decarboxylases, serine hydroxymethyltransferase, aldolase 2. Glycogen degradation: glycogen phosphorylase 3. Porphyrin synthesis
128
Dietary sources of pyridoxine (B6)
``` Beans, nuts, leugmes Meats Eggs Fish Whole grains and fortified grains and cereals ```
129
Who gets pyridoxine (B6) deficiency?
Alcoholics People with kidney failure People on Isoniazid for tuberculosis
130
What are the sx of pyridoxine deficiency?
Cheilosis: scaling at the corners of the mouth Angular stomatitis: inflammation at mouth corners Glossitis: inflammation of the tongue Dematitis Peripheral neuropathy Microcytic hypochromic anemia Confusion and irritability
131
What is the toxicity of pyridoxine (B6)?
Peripheral sensory neuropathy
132
What are the two hematopoietic/1C metabolism vitamins?
Folate (B9) | Cobalamin(B12)
133
Where is folate (B9) absorbed?
Duodenum Jejunum ** Ileum
134
What is the active form of folate (B9)?
Tetrahydrofolate
135
What is the function of folate (B9)
Carrier of 1C units for: 1. Purine synthesis 2. dTMP synthesis 3. Conversion of homocysteine to methionine for S-adenocylmethionine synthesis
136
Dietary sources of folate?
``` Beans and legumes Citrus fruits Dark, leafy green vegetables Fortified grain and cereals Meat ```
137
What are the 2 main causes of folate deficiency?
``` Inadequate intake Antifolate treatment (methotrexate, 5-flurouracil) ```
138
What are the main sx of folate deficiency?
Megaloblastic anemia Leukopenia Fetal neural tube defects Glossitis
139
What are the sx of spina bifida occulta, a neural tube defect that can occur with inadequate maternal folate intake?
Pain Weakenss Numbness in the legs and back
140
What is anencephaly?
Missing parts of the brain
141
How much supplementation of folate does the USPHS recommend?
400 ug dose daily
142
How is vitamin B12 (cobalamin) absorbed?
IF-B12 complex in the ileum
143
Storage of cobalamin (B12)
Liver | Storage lasts around 2 years
144
What are the only 2 biochemical rxns that require B12?
Methionine synthase | Methyl malonyl-conenzyme A mutase
145
What are good sources of B12?
``` Meat Shellfish Fish Eggs Milk and yogurt and cheese **NOT PLANT PRODUCTS ```
146
What are some causes of vitamin B12 deficiency?
1. Impaired absorption: IF deficiency or ilieal resection 2. Increased requirement 3. Decreased intake (vegan) 4. Tapeworm (Diphyllobothrium)
147
What are the clinical s/s of B12 deficiency? (3)
1. Megaloblastic anemia (pernicious anemia) 2. Neural tube defects 3. Subacute combined neural degeneration: dorsal and lateral tract demyelination, parasthesias, spastic paraparesis, sensory ataxia
148
What are the three antioxidant vitamins?
Vitamin C Vitamin E Beta carotene (provitamin A)
149
What are the post-translational modificaiton vitamins?
Vitamin C | Vitamin K
150
Where is ascorbate absorbed?
Jejunum and ileum
151
What are the functions of ascorbate (vitamin C)
Antioxidant: reduces ROS Cofactor of enzymes that reduce metal ions Post-translational modification of proteins (collagens), lysyl and proyl hydroxylase Synthesis of neurotransmitters and hormones
152
What are sources of ascorbic acid?
Fruits and vegetables | Highest in citrus fruits, strawberries, green peppers, broccoli, green leafy vegetables, tomatoes, potatoes
153
What happens with vitamin C defiency?
SCURVY Impaired collagen formation: poor vessel support results in bleeding tendency, impaired wound healing, easy bruising, corkscrew hairs, and petechial hemorrhage
154
What are the fat-soluble vitamins?
``` Vitamin A (Retinol, Carotenes) Vitamin D (Cholecalciferol) Vitamin E (Tocopherols) Vitamin K (Phylloquinones) ```
155
Where are fat soluble vitamins absorbed?
Duodenum | Jejunum
156
Where is vitamin D absorbed?
Duodenum and jejunum | ALSO the ileum
157
Where is vitamin K produced in the body?
Produced by microbiota in the large intestine
158
What vitamin is tocopherol?
Vitamin E
159
What is the most active form of vitamin E?
alpha-tocopherol
160
How is tocopherol (vitE) absorbed?
From micelles in the duo and jej
161
How is vitE, or tocopherol distributed in the body?
Chylomicrons
162
Where is tocopherol (vitE) stored?
Adipose tissue Liver Muscle
163
What is the function of vitamin E/tocopherol?
Antioxidant--scavengers free radicals
164
What are dietary sources of vitaminE/tocopherol?
Vegetable oils Liver Eggs
165
Incidence of vitamin E / tocopherol deficiency?
Uncommon, except for with malabsorption syndromes, TPN, and premature infants
166
What are the sx of tocopherol/vit E deficiency
Irritability Edema Hemolytic anemia
167
What is a pharmacological use of tocopherol/vitamin E
Alzheimer's disease progression inhibitor
168
What vitamin is phylloquinones?
Vitamin K
169
How is vitamin K absorbed?
From micelles into the duo, jej, ileum
170
How is vitamin K distributed in the body?
Chylomicrons
171
Where is vitamin K stored?
Liver
172
What is the active form of vitamin K?
Vitamin K1
173
What are the functions of vitamin K?
- Cofactor for vit K dependent gamma carboxylase (needed for factors II, VII, IX, X, S, C) - -> modified Gla residue binds Ca and localizes coagulation proteins on activated platelets
174
What are the dietary sources of vitamin K?
Green vegetables, spinach, kale Peas Cauliflower and cabbage Synthesized by bacteria in the intestine
175
Though vitamin K deficiency is rare, what can cause it?
``` Warfarin tx Malabsorption syndromes Broad spectrum antibiotics (kills flora) Lack of gut flora in neonates Chronic liver disease ```
176
What are the sx of vitamin K deficiency?
Bleeding--defective clotting - >Easy bruising and hematomas - >Hemorrhagic disease of the newborn
177
What is seen in vitamin K toxicity?
Shortened bleeding time | **no toxicity with food as a source of the vitK
178
What vitamin are cerotenes and retinoids?
Vitamin A
179
Where is vitamin A stored?
``` Liver stellate (ito) cells Retinyl esters ```
180
What is the function of beta carotene?
Antioxidant | Vitamin A precursor
181
What is the major transport form of vitamin A?
Retinol
182
What form of vitamin A is important for vision?
11-cis retinal (retinaldehyde)
183
What form of vitamin A is involved in the regulation of retinoid responsive gene expression--epithelilal cells function, mucous cell function, immunity, reproduction
Retinoic acid (all-trans, 9-cis)
184
How is 11-cis-retinal involved in vision?
Binds rhodopsin in rods and to cone pigments in cones: difference in binding to the three cone pigments results in absorption of different wavelengths of light Light converts 11-cis retinal to all-trans-retinal
185
What happens with the conversion of 11-cis to all-trans retinal by light?
- The GPCR transducin in the rod and cone membranes changes conformation and activates the G-protein, activating a phosphodiesterase - Cleavage of cGMP closes cGMP coupled ion channel, signal to brain
186
What are good sources of beta carotene?
Green leafy vegetables | Intensely colored vegetables like carrots, sweet potatoes, and red peppers
187
What are good sources of rentinyl esters?
Eggs Meat Dairy products
188
When is vitamin A deficiency seen in the US?
Poor intake with serious viral infections Malabsorption syndromes Liver cirrhosis
189
What is the clinical presentation of vitamin A deficiency?
Impaired vision--night blindness Squamous metaplasia--mucus and epithelial cells Renal, urinary calculi Predisposition to pulmonary infections, diarrhea
190
What are some of the consquences of squamous metaplasia with retinoic acid deficinecy?
Xerophthalmia, Xerosis Bitot's spots (keritin debris) Corneal ulceration, keratomalacia FOllicular hyperheratitis
191
Toxicity of beta carotene?
Non-toxic, but yellow skin due to fat deposition | **sclera not yellow
192
Toxicity of retinol
Toxic at high levels: blurred vision, abdominal pain, peeling of the skin, hair loss, headache, dizziness, vomiting, bone pain and deformities Death if levels are high enough
193
Toxicity of retinal?
Toxic at high levels, esp to the retina
194
Toxicity of retinoic acid
Toxic at levels used to treat acne: teratogenic and peeling of the skin
195
What vitamin is calciferol?
Vitamin D
196
What are the two dietary forms of vitamin D?
Animals: D3, cholecalciferol Plants: D2, ergocalciferol
197
What form of vitamin D can be synthesized in the skin
D2
198
What is the active form of vitamin D?
1,25 dihydrovitamin D (cholecalciferal)
199
Absorption of vitamin D?
Micelles to epithelial cells | Duodenum, jejunum, ileum
200
Where is vitamin D stored?
Liver
201
WHat is the function of vitamin D?
Controls the expression of vitamin D responsive genes Maintains normal calcium and phosphate levels Controls: cell cycle arrest, apoptosis, immune suppression, anti-inf, differentiation
202
What is the effect of vitamin D when calcium or phosphate is low
Increases absorption in the intestines Decreases excretion by the kidney Increases release by the bones
203
Sources of vitamin D/calciferols
``` Cheese Butter and margarine Fortified milk Fish Fortified cereals **sunlight ```
204
What causes vitamin D deficiency?
``` Inadequate sunlight/dietary deficiency Decreases absorption Metabolic errors End organ resistance Phosphate depletion ```
205
What is the result of vitamin D deficiency in children
Rickets: - bowed legs - frontal bossing - pigeon breast
206
What is the result of vitamin D deficiency in adults
Osteomalcia: - soft, painful, bendable - osteoporosis: loss of bone density, fragile bone - Dowager's humb
207
What are s/s of vitamin D toxicity?
``` Diarrhea Dermatitis Headache Nausea Anorexia Calcification of soft tissue Decalcificaiton of bones Kidney stones ```
208
Where are ions absorbed?
Stomach | Entire intestine
209
What form is iron absorbed in?
Fe2+
210
How is iron stored?
Ferritin and hemosiderin | In the liver, spleen, and bone marrow
211
Sources of iron
``` Meats Fish Shellfish Lentils Beans Seeds Tofu Spinach ```
212
Function of iron
In heme as part of hemoglobin or myoglobin Iron sulfer complexes in the TCA cycle, ETC Enzyme cofactor
213
What is the most common nutritional deficiency?
Iron deficiency
214
Causes of iron deficiency
Inadequate diet, milk fed infants Impaired absorption Blood loss--GI and menstrual
215
What are the sx of iron defiicency?
Hypochromic, microcytic anemia Impaired cognition and work capacity Immune deficiency
216
What is the toxicity of iron?
Hemochromatosis | Abnormal deposition in the liver, pancreas, heart, and skin
217
Where is zinc absorbed?
Jejunum
218
What are sources of zinc?
Oysters and other shellfish Meat Plants
219
What are the functions of zinc
Component of enzymes involved in metabolism (oxidases, metalloproteinases) Gene expression--Zn finger protein Spermatogenesis Skin maintenance and wound healing
220
Though incidence of zinc deficiency is rare, in what cases is it relatively common?
``` Diabetes mellitus Malabsorption syndromes and chronic diarrhea Renal disease and dialysis IV feeding Major burn patients Inborn error of zinc absorption ```
221
What are the sx of zinc deficiency?
Rash Anorexia Diarrhea Growth retardation Depressed wound healing and immune response Infertility due to inhibition of testosterone syn
222
What happens in zinc toxicity?
Inhibits copper absorption, leading to a copper deficiency
223
Where is iodine absorbed?
Stomach
224
What are sources of iodine?
Salt water fish and shellfish | Iodized NaCl
225
What is the main function of iodine?
Component of thyroid hormones
226
What are the sx of iodine deficiency?
Goiter Cretinism: children with dwarfism, retardation, bone deformation, subnormal BMR) Myxedema: adults with dry skin, swelling of the skin around nose and lips, mental deterioration, subnormal BMR
227
What ate sx of iodine tox?
Goiter | Thyrotoxicosis
228
Where is copper absorbed?
Stomach | Duodenum
229
What are the sources of copper?
``` Liver Shellfish Chocolate Nuts Seeds ```
230
Functions of copper
1. Oxidation rxns including e- transport: cyt C oxidase, tyrosinase 2. Neurotransmitter reg: dopamine beta oxidase 3. Antioxidants: superoxide dismutase 4. Collagen crosslinking enzymes: lysyl oxidase 5. Development of vascular and skeleton structures and the CNS
231
Though copper deficiency is rare, when do you see it?
Malnutrition Excess zinc intake Dialysis patients Genetic diseases like Menke's syndrome
232
What are the sx of copper def?
``` Microcytic hypochromic anemia Muscle weakness Neurologic defects Abnormal collagen crosslinks leading to bleeding Neutropenia ```
233
When do you get copper toxicity?
Genetic disease--WD
234
What are the sx of copper tox?
Neurological defects | Kaiser Fleischer rings
235
Where is fluoride absorbed?
Stomach
236
What are the sources of fluoride?
Water (natural or supplemented) | Toothpaste
237
Functions of fluoride
Required by teeth
238
What happens with fluoride deficiency?
Dental caries
239
When does fluorine tox occur?
Kids eating fluorinated toothpaste
240
What are the sx of fluoride tox?
Mottled tooth enamel
241
Where is selenium absorbed?
Duo
242
Sources of selenium
Plants grown in selenium containing soil | Fish and shellfish
243
What are the functions of selenium
Component of glutathione peroxidase Antioxidant with vitamin E Regulates thyroid hormone action
244
Effects of selenium def
Myopathy | Cardiomyopathy (kids)
245
Selenium tox
``` Hair and hail damage Tooth decay Neuropathy Liver cirrhosis Depression ```
246
Name the ion: 1. oxygen transport and e metabolism 2. wound healing, spermatogenesis 3. antiox, e transport, collagen x linking, devo 4. dental health 5. antiox, thyroid hormone function
1. iron 2. zinc 3. iodine 4. copper 5. fluoride 6. selenium

GI (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions