Micronutrients Flashcards Preview

CMBM 3 > Micronutrients > Flashcards

Flashcards in Micronutrients Deck (58)
1

How are micronutrients categorized?

Water and salts
minerals
vitamins

2

6 functions of Ca

regulation of intracellular enzymes
blood clotting
muscle contraction
growth of bones and teeth
calmodulin binding
messenger function; hormone-receptor

3

Absorption of Ca promoted by:

Vit D
Gastric acid
lactose
citrate, malate
protein, phosphorous
exercise

4

Absorption of Ca2+ prohibited by:

Oxalic acid
Phytic acid
Dietary fiber
Phosphate
Steatorrhea (soap) [fatty diarrhea]

5

Metal- phosphates are extremely (soluble/insoluble)

insoluble

6

What is seen in calcium deficiencies?

Rickets
osteomalacia (adult rickets)
osteoporosis

7

What prevents rickets?

Vitamin D

8

What is recommended consumption of Ca2+?

1000mg/day
women and adolescents need slightly more

9

What form of phosphorous is absorbed?

phosphate

10

Where is the vast majority of phosphate found?

85% bones and teeth

11

What is recommended intake of phosporous?

700-1250 mg/day

12

Excessive intake of phosphorous promotes excretion of what mineral?

Ca2+

13

What is the function of magnesium?

bone strength
ATP hydrolysis
enzyme cofactors
binds nucleic acids
muscle relaxation after contractions

14

What are the food sources of magnesium?

vegetables, nuts, legumes

15

What is the RDA of magnesium?

400 mg/day (male) 300 mg/day (female)

16

What symptoms are seen with deficiency of Mg? excess?

hypertension, vascular disease, preeclampsia

Alcoholics - DTs, tremors

Excess - anaesthetic effects, diarrhea

17

How is sulfur taken up by the body?

sulfate

18

What are some functions of sulfur?

source of electrons,
transfer groups Acetyl Coa
disulfide bonds, protein folding

19

Key metals involved in enzymatic activities and protein structure

Fe, Zn, Selenium, iodine Cu

20

What is the key role of Iron?

enzyme catalysis
electron transfer
oxygen transport

21

What is the role of Zinc?

catalysis
structure
protein interacting with DNA "Zinc fingers" (gene regulation)

22

Is Zinc redox active?

NO!!

23

What increases absorption of zinc? How is it bound?

binding of His, Cys (in various combinations) and nucleotides

24

What helps with Zn transfer into blood?

metallothioneins

25

Where is Zn stored?

muscle & bone

26

What are the Zn requirements?

M- 11 mg/day W 8mg/day

27

What are symptoms of Zn deficiency?

skin lesions, late onset of secondary sex characteristics, growth reduction, loss of appetite, genetic deficiiencies

28

What does Zn malabsorption lead to?

IBD

29

Too much Zn?

dizziness, nausea, gastric distress
can reduce Cu absorption
implicated in Alzheimer's
can lower HDLs

30

What are Cu RDA?

0.9 mg/day

31

What is Cu used for?

cytochrome oxidase

32

What other metal relies on Cu for uptake? ****

Fe

33

What impairs Cu uptake?

Excess Zn

34

What is seen with Cu deficiencies?

anemia, leukopenia, neutropenia, osteoporosis

35

What will excess Cu result in?

tremors, weakness, anorexia

36

What disease can impair absorption of nutrients?

Crohn's, CF

37

Describe Wilson's disease?

excess Cu and builds up leading to brain damage, involuntary movements

38

What is a sign of Wilson's

gold rings in corneas

39

What is iodine essential for?

thyroid hormones affecting development, growth, metabolism

40

What is RDA for iodine?

150 MICROgrams/day

41

Deficiency of iodine will stimulate what disease?

goiter - enlarged thyroid

42

What is RDA for selenium?

55 MICROgrams/day

43

Deficiency of selenium can lead to?

cardiac failure, liver disease, cancer, atherosclerosis, hair loss

44

An excess of selenium (>400 ug/day) can lead to?

peripheral neuropathy, nausea, diarrhea, dermatitis, hair loss, nail deformities

45

What is selenium used for?

enzyme cofactor for antioxidant defense
thyroid hormone and insulin function
regulation of cell growth
fertility

46

What are some other metals needed?

Manganese, molybedium, chromium, cobalt, nickel

47

Probably required metals?

boron
silicon,
arsenic,
tin,
rubidium,
germanium

48

possibly required metals?

Cd (Cadmium)
Pb (Lead)
Li (lithium)
Al (Aluminuam
Br (Bromine)
Rd, ? Rb - Rubidium
V - Vanadium
F - Fluorine

49

What are the major extracellular fluids (ECF) solutes?

Na+
Cl-
HCO3-

50

What are the major intracellular fluid solutes?

K+
organic phosphate esters (ATP, creatine phosphate, phospholipid)

51

What are miliequivalents?

milliequivalents = milliMolar when 1 ionizable group

mEQ = 2x mMolar is there are 2 charges

If 3+, more pH dependent

52

What are the main macrominerals?

sodium
potassium

53

What does excess sodium lead to?

hypertension
(ECF expansion)

54

The net activity of GI tract down to jejunum is secrection of water and electrolytes. If you vomit you?

lose solutes

55

The net activity from jejunum to colon in reabsorption so if you have diarrheas you can lose?

liters /water

56

What problems exist with excess or deficiency of water and potassium?

cardiac arrest
K:Na ration linked to hypertension
Deficiency: heart arrhythmia, muscle weakness, increased blood pH (alkalosis)

57

What are four other macro minerals besides water, Na, K?

Calcium
Phosphorous
Sulfur
Magnesium

58

What is the function of phophorous

structure of nucleic acids, phospholipids
activation of enzymes by phosphorylation
Energy (ATP)
acid-base balance