Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

► Med - Year 1 > Hematopoiesis Nutrition > Flashcards

Hematopoiesis Nutrition Flashcards

1
Q

Enzyme used in the rate limiting step converting dUMP to dTMP

A

Thimidylate synthase

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

Both of these nutrients are required for DNA synthesis

A

Folate and Vitamin B12

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

Cobalmin

A

Vitamin B12

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

Vitamin B9

A

Folate

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

What is the structural change when converting RNA dUMP to DNA dTMP

A

addition of one methyl grop

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

Source of methyl groups

A

Folate

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

Also involved in purine biosynthesis

A

Folate

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

Co-enzyme for recycling folate

A

Vitamin B12

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

After folate is taken in from diet, what are the two successive reduction steps?

A

Folate»DHF»THF

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

THF trap

A

If don’t have B12, can’t convert N5 methyl THF back to THF

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

The name of B12 or folate deficiency which results in fewer, but larger blood cells

A

Megaloblastic anemia

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

3 important consequences of B12 or folate deficiency

A
  1. DNA synthesis impaired
  2. Cell division impaired
  3. Cytoplasm matures faster than nucleus (cytoplasm can still undergo maturation so can make hemoglobin, gets larger, but won’t divide)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are visual signs of megaloblastic anemia?

A

Multilobed PMNs (normal are 3-4), macrocytic RBCs

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

Why are fortified foods with folic acid more stable?

A

Doesn’t contain/form a polygluconate conjugate

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

Why can hemolytic anemia cause an increased demand and use of folate?

A

Hemolytic anemia is due to RBC destruction, have to keep up with loss of RBCs, so requires a lot of cell division

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

Term for reduction of all types of blood cells (RBC, WBC, platelets)

A

Pancytopenia

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

Why is neural tube defect a symptom of folate deficiency?

A

Highest proliferation during embryogenesis, need high folate levels. Neural tube defect

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

Major component of VB12 structure

A

Corrin ring

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

Source of VB12

A

Made by bacteria, found in meats/animal biproducts

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

Two direct steps involving VB12 that are important in neuronal function

A

Homocysteine —*—->Methionine (—>SAM)

Methylmalonyl CoA —*—> Succinyl CoA

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

This breakdown product of methylmalonyl CoA will accumulate if B12 deficient

A

methylmalonic acid (MMA)

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

What produces haptocorrin?

A

Salivary glands in the mouth

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

2 other names for haptocorrin

A

Transcobalamin I, R factor

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

Vitamin B12 is not readily available because it is bound to proteins. Where does VB12 get digested and liberated from proteins?

A

Stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

After liberated from proteins, VB12 binds to this molecule to protect it from the hydrochloric acid found in stomach

A

Haptocorrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Instrinic Factor (IF) is made by?

A

Parietal cells (stomach epithelial cells)

27
Q

VB12 disassociation from haptocorrin occurs where? What chews up haptocorrin?

A

Duodenum, pancreatic enzymes

28
Q

When released from haptocorrin, VB12 binds to what? Where?

A

Intrinsic factor in the dudodenum

29
Q

Where is B12/IF absorbed?

A

Terminal Ileum by ileal cells

30
Q

Storage of B12

A

liver and muscle

31
Q

This glycoprotein binds and transport VB12 through the blood once it has been absorbed by terminal ileum

A

Transcobalamin II (TC-II)

32
Q

List 4 conditions that prevent VB12 absorption

A
  1. Loss of intrinsic factor (IF)
  2. Achlorhydria (not making enough HCL that maks up gastric acid)
  3. Pancreatic insufficiency
  4. Malabsorption in terminal ileum
33
Q

Gastric acid in the stomach favors binding to?

A

Haptocorrin

34
Q

How would pancreatic insufficiency affect VB12 absorption?

A

Need pancreatic enzymes to chew up haptocorrin and release B12

35
Q

How would gastritis, gastrectomy, or antibodies to parietal cell antigens affect VB12 absorption?

A

Loss of intrinsic factor= pernicious anemia

Pareital cells in stomach make intrinsic factor, haptocorrin hands off VB12 to IF in duodenum

36
Q

Blind loop, bacterial overgrowth, fish tape worm, and IBS all would affect

A

VB12 absorption in terminal ileum

37
Q

How does B12 deficiency specifically cause neurological impairment?

A

Affect myelination

38
Q

Where is folic acid absorbed?

A

Duodenum/jejunum (middle section of small intestine)

39
Q

Synthesis of heme and hemoglobin occur in these two cites

A

Mitochondria and cytoplasm (heme is made in mitochondria and joins with globin chains in the cytoplasm to make hemoglobin)

40
Q

What is the rate limiting step in heme synthesis? What enzyme?

A 
ALA synthetase (aminolevulinic acid)
converts succinyl CoA---> dALA
41
Q

Iron deficiency only affects

42
Q

size of RBCs when iron deficient

A

microcytic, small because not enough hemoglobin

43
Q

Iron deficiency shows these three signs

A
  1. microcytic
  2. hypochromic (less hemoglobin, expanded area, thinner hemoglobin, pale looking)
  3. Insufficient hemoglobin
44
Q

Why does iron cause insufficient hemoglobin?

A

Fe2+ gets incorporated into heme to make hemoglobin; incorporation is complex

45
Q

What is the most common cause of iron deficiency? Rare cause?

A

Bleeding bleeding bleeding. Rare cause is renal/pulmonary syndrome (kidney failure)

46
Q

Why might pulmonary syndrome cause iron deficiency?

A

Kidney responsible for EPO synthesis, so no reticulocyte response, and red blood cell survival decreases

47
Q

Eating, craving weird things; a symptom of iron deficiency

48
Q

Are platelets and WBCs affected by iron deficiency?

A

NO, ONLY RBCs

49
Q

4 iron parameters for deficiency diagnosis

A
  1. Serum Iron
  2. Transferrin saturation
  3. TIBC (total iron binding capacity)
  4. Ferritin
50
Q

Type of anemia in B12 and folate

A

Hypoproliferative

51
Q

Type of anemia in Iron

A

hypoproliferative (if don’t have enough heme, body sense that and slows down proliferation)

52
Q

Size of RBCs in B12 and folate deficiency

A

macrocytic (large, because not enough DNA synthesis but still can make hemoglobin)

53
Q

Size of RBCs in iron deficiency

A

microcytic (small, because not enough hemoglobin)

54
Q

Most common cause of deficiency in B12 and folate

A

Reduced absorption or intake

55
Q

2 key points about deficiency treatment

A
  1. should be rapid and complete

2. folate will partially correct the hematologic manifestations of B12 deficiency but NOT the neurologic

56
Q

This metal is involved in iron transport, heme synthesis, and RBC membrane

57
Q

This metal is involved in DNA synthesis, and in excess inhibits copper absorption

58
Q

This metal is the corrin core of cobalamin

59
Q

This metal blocks iron absoprtion and heme synthesis

60
Q

This vitamin is involved in iron absorption

A

Vitamin C (ascorbic acid)

61
Q

This vitamin is involved in heme synthesis

A

Vitamin B6, pyridoxine

62
Q

This vitamin is involved in iron absorption and mobilization

63
Q

Autoimmune version of VB12 deficiency

A

pernicious anemia

► Med - Year 1 (48 decks)

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