PHOSPHATE Flashcards
1
Q
Found everywhere in the living cell
A
2
Q
The body contains about [?] of phosphorus in the form of phosphate
A
20 mol (260 g)
3
Q
Intracellular phosphate can be either:
A
Organic: macromolecules (like carbohydrates, proteins, lipids, nucleic acids)
Inorganic: participates in high energy transfer reactions
4
Q
: macromolecules (like carbohydrates, proteins, lipids, nucleic acids)
A
Organic
5
Q
: participates in high energy transfer reactions
A
Inorganic
6
Q
Requiring [?]
Ex. Redox reaction
A
ATP (source for most biochem rx) and ADP
7
Q
In bone: inorganic form
The majority of the extracellular phosphate (?) is inorganic form and acts as part of the hydroxyapatite.
A
85%
8
Q
In blood: inorganic form
[?]: bound to protein (non-filtratable)
The rest are complexed & free forms (ultrafiltrable) – can pass through the glomerulus
A
15%
9
Q
Diabetic Ketoacidosis (DKA)
A
Hypophosphatemia
10
Q
Chronic Obstructive Pulmonary Disease (COPD)
A
Hypophosphatemia
11
Q
Malignancy
A
Hypophosphatemia
12
Q
Increased renal excretion:
- hyperparathyroidism
A
Hypophosphatemia
13
Q
Decreased intestinal absorption:
- Vit. D deficiency
- antacid use
A
Hypophosphatemia
14
Q
Acute or chronic renal failure – most common
A
Hyperphosphatemia
15
Q
Increased intake of PO4: among neonates w/ cow’s milk or laxatives
A
Hyperphosphatemia
16
Q
Increased release of cellular PO4
A
Hyperphosphatemia
17
Q
Severe infections
A
Hyperphosphatemia
18
Q
Intensive exercise
A
Hyperphosphatemia
19
Q
Neoplastic disorders
A
Hyperphosphatemia
20
Q
Intravascular hemolysis
A
Hyperphosphatemia
21
Q
Lymphoblastic leukemia
A
Hyperphosphatemia
22
Q
Neonate
A
1.45 - 2.91 MMOL/L
23
Q
Children, ≤ 15 yrs
A
- 07 - 1.74 MMOL/L
24
Q
Adult
A
0.78 - 1.42 MMOL/L
25
URINE (24-HOUR) --
13.0 - 42.0 MMOL/DAY
26
Reaction with ammonium molybdate
FISKE & SUBBAROW (UV)
27
FISKE & SUBBAROW (UV) Product:
phosphomolybdate complex (measured at 340 nm)
28
REDUCTION OF PHOSPHOMOLYBDATE TO MOLYBDENUM BLUE Measured at
600 - 700 nm
29
: important cpt of cell membranes
As phospholipid
30
: High-energy nucleotides (Ex. ATP)
Energy metabolism
31
: Nucleic acids (DNA and RNA)
Gene replication
32
Component of [?]
Hydroxyapatite
33
Required in [?]
glycogenolysis
34
breakdown of glycogen to form glucose
glycogenolysis
35
immediate source of energy
glycogenolysis
36
plays an important role during flight or fight response
glycogenolysis
37
in the muscle cells
glycogenolysis
38
glycogen is degrade to form an immediate source of glucose-6-phosphate for glycolysis
glycogenolysis
39
Production of 2,3-DPG from [?] in rbcs
glyceraldehyde-3-PO4
40
Happens in response to
anemia or hypoxia
41
Important determinant of
bone mineral turnover
42
Hormones that regulate calcium & phosphate
43
chief cells of PT glands: production & secretion of PTH
PARATHYROID HORMONE (PTH)
44
a polypeptide chain of 84 amino acids (MW 9500)
PARATHYROID HORMONE (PTH)
45
Important factor in the renal regulation of phosphate
PARATHYROID HORMONE (PTH)
46
Balances Ca in the blood
PARATHYROID HORMONE (PTH)
47
Function: regulation of the ECF Ca concentration
PARATHYROID HORMONE (PTH)
48
hypocalcemia: stimulates PTH secretion
hypercalcemia: suppresses PTH secretion
PARATHYROID HORMONE (PTH)
49
PTH activities:
1. Stimulates [?] by osteoclasts
2. Increases [?] of Ca
3. Induces [?]
4. Inhibits parathyroid reabsorption of [?]
5. Inhibits parathyroid reabsorption of [?]
6. Stimulates [?] of Vit. D
bone resorption
tubular reabsorption
intestinal Ca absorption
inorganic phosphate
HCO3, Na, C, H2O & amino acids
renal hydroxylation
50
Bones breakdown to release Ca to the ECF
bone resorption
51
May affect the kidneys
reabsorption of Ca
52
From the diet
intestinal Ca absorption
53
– chemical process in the body that makes Vit. D biologically active
Hydroxylation
54
Net effects of PTH
increase in plasma CAT (total Ca) and CAI (ionized Ca)
decrease in PI
increased urinary excretion of Ca++
55
produced by C cells of the Thyroid gland
CALCITONIN
56
consists of a 32-amino acid polypeptide chain (MW 3500)
CALCITONIN
57
promotes deposition of Ca++ & PI in bones
CALCITONIN
58
Lowers CAT (total Ca) and CAI (ionized Ca)
CALCITONIN
59
promotes deposition of Ca in the skeleton of the human fetus
CALCITONIN
60
opposite relationship to Ca compared to PTH
CALCITONIN
61
hypercalcemia: stimulates PTH secretion
hypocalcemia: suppresses PTH secretion
CALCITONIN
62
Decreased level in the blood (imbalance) = stimulates parathyroid glands to secrete PTH (regulator) to:
increase Ca uptake in [?]
increase Ca uptake in [?]
stimulates Ca release from [?]
Active vitamin D
intestines
kidneys
bones (bone resorption)
63
Homeostasis: normal blood Ca level (about[?])
10mg/100mL
64
Decreased level in the blood (imbalance) = stimulates thyroid glands to secrete Calcitonin (regulator):
Stimulate Ca deposition in
Reduces Ca uptake in
bones
kidneys
65
Natural form produced in the skin from the action of sunlight
VITAMIN D3 (CHOLECALCIFEROL)
66
Manufactured commercially from precursors of plant origin
VITAMIN D2 (ERGOCALCIFEROL)
67
: activation of Vit. D
Hydroxylation
68
To be physiologically active, (?) are required (by specific hydroxylases)
hydroxylations
69
1. In the liver:
Vit D is converted to [?] in the liver
Transported by [?] to the kidney
25 hydroxy Vit D
Vitamin Debinding Protein
70
2. In the kidney:
[?] is converted to [?]
[?] - disappears quickly from the plasma; usual plasma conc. is low
[?] - disappears more slowly; plasma conc. is greater
25 hydroxy Vit D; 1,25 hydroxy Vit D or 24,25 hydroxy Vit D
1,25 hydroxy Vit D
24,25 hydroxy Vit D
71
– most potent; to inc blood conc; it stimulates:
1,25 (OH)2 D
72
1,25 (OH)2 D
Ca absorption by the [?]
Intestinal absorption of [?]
Ca resorption from [?]
Ca reabsorption by the [?]
SI
PO4
bone
distal tubules
73
Net effect of Vit D
Increased plasma CAT (total Ca) and CAI (ionized Ca)
Increase in plasma PI
Increased urinary Ca++ excretion
74
In the liver (hydroxylation of inactivated forms):
[?]- sunlight
[?]- food
Cholecalciferol (Vitamin D3)
Ergocalciferol (Vitamin D3)
75
In the kidney:
Conversion to the active form, [?] to [?] (Active Vitamin D)
in the presence of hydroxylase enzyme
[?]
25(OH) Cholecalciferol (Calcidiol) ; 1,25(OH), Cholecalciferol (Calcitriol)
↑ PI and Ca
76
Chief cells of PT glands: production & secretion of PTH
Parathyroid Hormone
77
most important factor in the renal regulation of PO4, lowers blood concentration and increase renal excretion
Parathyroid Hormone
78
Regulation of the ECF Ca++ concentration
Parathyroid Hormone
79
Hypocalcemia: stimulates PTH secretion
Parathyroid Hormone
80
Hypercalcemia: suppresses secretion of PTH
Parathyroid Hormone
81
Produced by C cells of the thyroid gland
Calcitonin
82
Secreted when the concentration of Ca in blood increase
Calcitonin
83
Secretion is regulated by the level of Calcium in the circulation
Calcitonin
84
Hypercalcemia = stimulates CT release
Calcitonin
85
Hypocalcemia = suppresses CT secretion
Calcitonin
86
Natural form produced in the skin from the action of sunlight
Vitamin D3 (Cholecalciferol)
87
Manufactured commercially from precursors of plant origin
Vitamin D2 (Ergocalciferol)
88
To be physiologically active, (2) hydroxylations are required (by specific hydroxylases)
Vitamin D2 (Ergocalciferol)
89
1,25 (OH)2 D – most potent; it stimulates:
Ca++ absorption by the SI, intestinal absorption of PO4, Ca++ resorption from bone, Ca++ reabsorption by the distal tubule
Vitamin D2 (Ergocalciferol)
