Week 2 Content - Fibrous Proteins, bioenergetics, nucleic acids, DNA packaging, DNA replication, DNA transcription, RNA processing, Enzymes Flashcards Preview

Medical Biochemistry > Week 2 Content - Fibrous Proteins, bioenergetics, nucleic acids, DNA packaging, DNA replication, DNA transcription, RNA processing, Enzymes > Flashcards

Flashcards in Week 2 Content - Fibrous Proteins, bioenergetics, nucleic acids, DNA packaging, DNA replication, DNA transcription, RNA processing, Enzymes Deck (77):
1

What enzyme degrades collagen? what cofactor do they need?

collagenases (MMP)
zinc!

2

what makes up the protein chains of collagen?

glycine, proline, lysine

3

what does hydroxylysine do?

residues can be glycosylated and can be used for linking of collagen

4

what is the catalyst for prolyl hydroxylase and lysyl hydroxylase?

Vitamin C

5

What does a glycine in each 3rd position do?

allows for very tight winding because of very small side chain

6

What does proline do?

makes kinks, disrupts the alpha helix which is good - allows close winding

7

what does hydroxyproline do? where it is?

on top of proline kink, many many hydrogen bonds (weak) but there are lots of them
they stablize the triple helix of 1 monomer

8

what does lysine do?

long positive side chains, binds more tropocollagen, cross linking

9

what does hydroxylysine do?

allows the addition of sugar (glucose, galatcose)

10

why does biosynthesis of collagen have to be with a soluble pro collagen?

because collgen is insoluble - it wouldn't be able to leave the cell if it was made insoluble

11

what is ehler danlos syndrome?

mutation of type III collagen (reticular) - hereditary defect related to one of the enzymes that are needed for correct collagen synthesis

12

what are the symptoms of ED syndrome?

hypermobility of joints, hyperextensiblity of skin, vessels can rupture

13

what is osteogenesis imperfect?

less collagen or abnormal (type I collagen)

14

what does lysyl oxidase need as a coenzyme?why?

copper
forms allysine residues which are needed for cross linking and desmosine formation (bend and stretch)

15

what makes up a demo sine?

3 allysine and 1 lysine (covalently linked)

16

what can be a result of copper defeicienty?

aneurism

17

what is marfan syndrome? what are the symptoms?

autosomal dominant defect in gene that encose fibrillin-1
long limbs, aortic root dilation

18

what packages DNA in eukaryotes/prokaryotes?

histones / HU

19

What is the DNa template strand called?

antisense strand

20

What is the DNA strand called that is not being used and is the same as RNA in terms of base sequences?

sende strand

21

what direction does RNA polymerase go?

3' to 5'
Synthesis in the 5' to 3'

22

what is TFIID do?

causes distortion = recruitment of other TF

23

what does TFIIB do?

start site recog - DNA polymerase interactions

24

what does TFIIH do?

helicase

25

what does TFIIE do?

positioning RNA polymerase

26

What is in RNA polymerase I in eurkaryotes?

rRNA...#S

27

What is in RNA polymerase II in eukaryotes?

mRNA, some snRNA and miRNA

28

what is in RNA polymerase III in eukaryotes?

tRNA, ssRNA, some snRNAs

29

SLE lupus whats the problem>

SLE antibodies react with U1 RNA on splicesoome = anormal splicing

30

What is beta thalassemia?

mutation of the beta globin gene that generates the addition spice sites within mRNA

31

what is limb girdle MD?

mutation in the calpain 3 gene that generates new splice sites witin the 16 exon (coding sequence) = shorter calpain 3 mRNA

32

What is magenizium a cofactor for?

DNA polymerase

33

GLUT-1-5 - name type of affinity and location

Glut 1 is high affinity found in brain and rbcs
Glut 2 is low affinity found in intestinal mucosa near portal vein
Glut 3 is high affinity found n neurons
Glut 4 is high affinity found in fat and muscle cells also they store inside the cell!
Glut 5 is low affinity found in intestinal lumen ...fructose

34

what does polycistronic mean?

This means that the mRNA contains more than one protein-coding region (ie. More than one protein will result from the translation of a polycistronic mRNA).

35

why is the 5' mRNA cap biologically important?

it is required for the efficient binding of the ribosome to the mRNA and the subsequent translation of the mRNA into protein.

36

what does poly-A-polymerase do?

add 200 A nucleotides to teh 3' end of mRNA produce by cleavage

37

what does poly A binding proteins do?

bind to poly a tail and assist in directing translation by the ribosome

38

what does the branch point sequence of the intron always have?

A nucleotide

39

what nucleotides are at teh 5' end and 3' end of the introns?

GU and AG

40

what is the lariet structure?

when the cut 5' G binds to the branch point A in the middle of the intron and forms a loop - simply a ring of intron segments

41

what is alternative splicing?

producing different forms of proteins from the same gene - smooth muscle mRNA, fibroblast mRNA, etc. use the same gene to make different mRNA

42

what happens in Beta thallasemia?

defects in mRNA splicing of the beta golbin gene! = enemia

43

at what level does RNA editing take place?

mRNA level - A-I editing and C-U editing (cytidine deaminase enzyme)

44

what is the purpose of alternative splicing?

increase diversity and increase expressed protein - use activators and repressors

45

what does the branch point sequence of the intron always have?

A nucleotide

46

what nucleotides are at teh 5' end and 3' end of the introns?

GU and AG

47

what is the lariet structure?

when the cut 5' G binds to the branch point A in the middle of the intron and forms a loop - simply a ring of intron segments

48

what is alternative splicing?

producing different forms of proteins from the same gene - smooth muscle mRNA, fibroblast mRNA, etc. use the same gene to make different mRNA

49

what happens in Beta thallasemia?

defects in mRNA splicing of the beta golbin gene! = enemia

50

at what level does RNA editing take place?

mRNA level - A-I editing and C-U editing (cytidine deaminase enzyme)

51

what is the purpose of alternative splicing?

increase diversity and increase expressed protein

52

what configuration are amino acids enzymes found in, what are carbs found in?

L and R

53

what does km describe?

the affinity for the substrate for the enzyme
low km = high affinity

54

what is alkaline phosphatase?

optimal pH is 9 - refflecting the basic pH env. oin bone - its involved in bone metabolism

55

what does the pH influence in terms of enzymes?

velocity

56

when do enzymes begint o denature?

40 degrees C in humans

57

when the substrate is oxidized...

the coenzyme is reduced ---"SOCR" = soccer

58

what do all oxidoreductases need?

a coenzyme

59

what are the coenzymes for oxidorectases?

NAD+ and FAD - get reduced

60

how can enzymatic reactions be measures?

NADH formation

61

what is teh michaelis menten equation?

v = Vmax[S]/Km + S

62

what type of curve do allosteric enzymes show?

sigmoidal

63

what happens to km and vmax with competitive inhibition?

km increases
v max does not change
ex. pravastatin

64

what happens to km and vmax with noncompetitive inhibition?

km is the same
vmax decreases

65

what is suicide inhibitor?

allopurinol - looks like comp. inhibitor but are used by the enzyme --> irreversible inhibitor (not reversible anymore) = purine degradation

66

what are irreversible inhibitors?

inhibitiors that bind covalently to the enzymes and inactivate it

67

what does DFP di-isopropyl fluorophosphate) do?

irreversible "suicide" inhibitor of acetylcholinesterase - binds covalently to the Serine in the active site !

68

what are isoenzymes ?

CK and LDH

69

what can you infer when ALP and GGT are elevated?

that ALP was released from the liver and NOT from bone

70

what does an increase in ALP-1 (liver) mean?

obstruction of bile ducts - liver
cirrhosis or bile duct obstruction.

71

what does increase in ALP-2 (bone) mean?

bone diseases = osteomalacia, Padget's disease

72

what do high levels of GGT and ALP indicate?

that the bile ducts are blocked/irritated

73

what will increase GGT alone?

drinking alcohol in LARGE amounts

74

a lipase/amylasse ratio greaters than 2 is what?

ethanol related pancreatitis

75

sALP is normal in who?

children and pregnant mothers

76

when is myoglobin increased?

general damage to muscle - nonspecific to heart but absolutely can be used in conjunction with the other markers!

76

when is myoglobin increased?

general damage to muscle - nonspecific to heart but absolutely can be used in conjunction with the other markers!