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Flashcards in MCM Review Deck (78):
1

What is the only source of pluripotent stem cells?

Cells of the inner cell mass

2

What is the problem in methemoglobin?

Iron is in its ferric state (Fe3+) and will not bind oxygen

3

Differentiate direct vs indirect methemoglobin

Direct --> genetically linked
Indirect --> oxidation by other compounds

4

What kind of shift does methemoglobin cause?

Left shift of oxygen curve

5

What kind of shift does anemia induce?

Anemia causes a right shift of the oxygen curve (decreased affinity

6

A patient has a blood oxygen content of 17.25 mL/dL and a hemoglobin concentration of 15.1 g/dL. The patient's oxygen saturation is best described as which of the following?
A. Normal oxygen saturation (97-99%)
B. Decreased oxygen saturation (<97%)
C. Maximum oxygen saturation (100%)

B Decreased oxygen saturation (<97%)

1.34 mLO2/1gHb x 15.1g/dL

7

How many mL of oxygen are there per gram of hemoglobin?

1.34 mL O2/1 gHb

8

What clinical situations could indicate a left shift of oxygen to blood?

Polycythemia

Methemoglobemnia

9

What is primary polycythemia (Vera)

⬇️ EPO

Extra RBCs

⬆️ blood volume x2

⬆️ viscosity

normal CO

10

Why are silent mutations not harmful?

First two letters of codon often the same, but the third is able to be 3 separate codons so the same amino acid product is still possible

11

What mutations of DNA can be significantly detrimental?

Nonsense and frameshift mutations

12

What causes Sickle cell anemia?

Single base substitution of Glu for a Val (hydrophobic, neutral)

13

What common energy expenditure is constant for all three steps of mRNA translation?

All three steps utilize GTP

14

What are the prokaryotic elongation inhibitors?

Tetracycline --> binds 30S, blocks tRNA entry

Chloramphenicol --> inhibits peptidyl transferase

Clindamycin/erythromycin --> binds 50s, blocks ribosomal translocation

15

What are the eukaryotic elongation inhibitors?

Cycloheximide --> inhibits peptidyl transferase

Diptheria Toxin --> inactivates GTP-eEF2

Shiga Toxin/Ricin --> binds 60s, blocks tRNA entry

16

What is the role of puromycin?

A eukaryotic elongation inhibitor that shares a similar structure to tyrosyl-tRNA

Enters A site and causes premature stop

17

What do initiation factors attached to small ribosomal subunit do?

What do initiation factors attached to met-tRNA do?

Small ribosomal subunit --> promotes binding of codon and anticodon of tRNA

IF attached to met-tRNA --> hydrolyzes GTP to provide energy for formation of initiation complex

18

Where are proteins destined that are made in the cytoplasmic pathway?

Cytoplasm

Mitochondria

Nucleus

19

What is the nuclear translocation signal?

KKKRK (tryptophan rich signal)

20

What is the mitochondrial translocation signal

An N-terminal hydrophobic α- helix peptide

21

What residues does O-glycosylation target?

Ser and Threonine

22

What does N-guyscosylation target?

Asn and Gln

23

What residues does phosphorylation target?


Ser, Tyr, Asp, Thr, His

Hydroxyls (OH)

24

What residue does disulfide bonding target?

Cystine residues

25

What may happen if a diabetic has an over-abundance of glycosylation?

Cataract formation in the eye

26

What happens in Alzheimer's Disease?

A mutated gene that produces amyloid precursor protein (APP) formation of neurotic plaques

Supplementation with lys may

27

What happens in Mad Cow disease?

Introduction of prions (misfolded proteins) that induce the same formation in their counterparts

28

What happens in Huntington's Disease?

Protein aggregations in the brain CAG repeats = polyglutamine (polyQ) tract

The abnormal Huntington protein (mHTT) forms intramolecular hydrogen bonds and aggregates

29

What happens in Parkinson's disease?

Mutated α-synuclein results in aggregates that form Lewy bodies

Function form is an α-helix while the febrile form is β-sheet

Results in neuronal death of the midbrain and a lack of available dopamine

30

Describe endocrine signaling?

Long distance Signaling - hormone

31

Describe paracrine signaling?

Signal diffused to neighboring cell - NMJ

32

Describe autocrine signaling?

Signaling cell is the targeting cell

33

Where do hydrophobic signal target?

The nucleus

34

Where do small polar hydrophilic signals target?

An EC receptor that utilizes secondary messengers

35

What are some sensory input for GPCRs?

Photons, ions, amino acids

36

An active GPCR switches out ________ for ______ via ________

GDP, GTP, GEF

37

What is the role of Gαs?

Stimulates production of cAMP via adenylate cyclase ultimately activating PkA

38

What is the role of Gαi

Inactivates adenylate cyclase = no PKA

39

What is the role of Gαq

Activates PLC (phospholipase C) causing the cleavage of PIP2 --> IP3 & DAG (ca2+ also)

40

What is the role of G protein receptor kinases? What is the end goal?

End goal - to desensitize the G protein

GRK phosphorylates GPCRs to which Arrestin can bind (3rd IC loop) and inhibit

41

What's happening in cholera?

Gαs is constantly active. The resulting cAMP keeps Cl- channels constantly open

42

What's happening in Pertussis?

Gαi is inhibited, excessive cAMP produced via adenylate cyclase

Dried out airways

43

What pathways are activated by RTK signaling?

Ras - dependent

Ras - independent

44

What blotting technique allows for visualizing of protein?

Western blot

45

What blotting technique visualizes DNA?

Southern blotting

46

What blotting technique visualizes RNA?

Northern blot

47

What is the problem with the heat-stable DNA polymerase used in PCR?

It has no proofreading capability an is described as a "dirty" method

48

What is RFLP used for?

Forensics

49

What is VNTR (variable number of tandem repeats)

Diagnostics of disease (Huntington's)

50

What is one use of recombinant gene technology?

Insulin production (better than wild type)

51

What is the use of ELISA?

Practical use --> HIV ag

52

What's the difference between indirect and sandwich ELISA?

Indirect --> Target is Ag

Sandwich --> target is Ab

53

What is the only version of totipotency?

Zygote

54

What are the examples of pluripotency?

1.) ICM of a blastocyst

2.) iPS

55

What can be associated with embryonic stem cells?

Teratomas, cancer, unrestricted growth

56

What growth factors produce an adipocyte?

Retinoic acid + insulin + thyroid hormone

57

What growth factors produce a neuron?

Retinoic acid

58

What potency is cord blood?

Multipotent

59

What potency are fetal stem cells?

Multipotent

60

What potency are hematopoietic stems cells?

Multipotent

61

What change in potency does iPS induce?

Taking a somatic multipotent cell and changing into a pluripotent cell

62

What are 5 important growth factors needed to induce iPS?

Oct 3/4, Sox-2, Myc (n-Myc and c-Myc), Nanog, FoxD3

63

Does urobilinogen have color?

No, it's translucent

64

Discern PKU from Cystic Fibrosis

Multiple genotype, one phenotype - Cystic Fibrosis

One genotype, multiple phenotypes - PKU

65

What does chemotaxis use to change

Monomeric G protein --> pip3 --> Ras --> ARP --> Rho

66

What is the consequence of an intra-hepatic jaundice

Build-up in the blood of conjugated and unconjugated billirubin

Increase in ALT and AST

67

What's the consequence of post-hepatic jaundice

Elevated blood levels of conjugated billirubin

68

Break down of heme, what is the first enzyme to act on heme? (Rate-limiting step before the liver)

Heme oxygenase

69

What type of signaling is Talin and FAK?

Talin (in --> out)
FAK (out --> in)

70

What is a good thing to know about FAK?

It's a drug target

71

What happens in secondary polycythemia?

Abnormal CO

⬆️ EPO

⬆️ RBCS

72

What changes in Physiologic polycythemia?

Normal CO

⬆️ RBCs

⬆️ EPO

73

What does activation of the RAS-dependent pathway lead to?

Gene transcription (increased glucokinase transcription)

74

What does the activation of the RAS-independent pathway lead to?

Alteration of protein and enzyme activity - GLUT 4 sequestering activation of glycogen synthase

75

What are important growth factors found in pluripotent cells?

Cripto and GDF-3

76

What two diseases are related to intra-hepatic jaundice?

Criggler-Najjar syndrome

Gilbert syndrome

77

What are all the cyclin-Cdks and what phases do they operate in?

Cyclin - D | D | E | A | A | B
Cdks - 6 | 4 | 4 | 2 | 2 | 1
Phase -G1|G1| S | S |G2|G2

78

Discern Prader Willi Syndrome from Angelman Syndrome

Prader Willi - paternal chromosome deletion (maternal silenced)

Angelman Syndrome - maternal chromosome deletion (paternal silenced)