Random other info Flashcards Preview

Biochem Test 2 > Random other info > Flashcards

Flashcards in Random other info Deck (72)
Loading flashcards...
1
Q

glycogen supplements contain

A
  • macro glycogenic nutrients
  • micro intracellular ergogenic substrates
  • most body can use to restore: 0.7 g/kg
  • ‘recommended’ - 76 g
2
Q

glycogen phosphorylase converts from

A

n residues –> n-1 residues + glucose-1-phosphate

3
Q

phosphorylation of GP causes

A
  • the amino terminus of the protein (res 10-22) to swing through 120 degrees, moving into the subunit interface and moving Ser-14 by more than 3.6 nm (CONFORMATIONAL CHANGE)
  • 9 ser residues on GP are phosphorylated
4
Q

for glycogen synthesis, how many residues are phosphorylated?

A

5 Ser residues on GS are phosphorylated

5
Q

normal liver size for adult and 10 yo

A

adult liver: 2.2 kg (4.8 lbs)

10 yo liver: 1.2 kg (2.5 lbs) — becomes up to 7 lbs (10% bpdy weight in Von Gierke’s)

6
Q

molecular defects in Glucose-6-phosphatase deficiency (and location)

A

(Von Gierkes)
Type 1a: absence of activity of catalytic subunit of glucose-6-Pase enzyme complex
Type 1b: glucose-6-Pase transport
Type 1c: microsomal phosphate or pyrophosphate transport
Type 1d: microsomal glucose transport

Syria and Lebanon- serious form of disease
Saudi Arabia- mild

7
Q

Glucose-6-P can go to

A
  • PPP –> synthesis of NADPH and 5-C sugars
  • Fructose-6-P –> the rest of glycolysis
  • Glucose-1-P –> Glycogen (energy storage in liver/muscle) or Glucuronate
8
Q

The side products of PPP go to

A

the 2 NADPH go to reductive anabolic pathways (fatty acid synthesis)

9
Q

how is NAD+ converted to NADP+?

A

via NAD+ kinase

only difference between NAD+ and NADP+ structurally is a PO4- added where one of the OH’s used to be

10
Q

XK in PPP

A

may play an important role in metabolic disease, given that Xu5P is a key regulator of glucose metabolism and lipogenesis

D-xylulose –> xylulose-5-P via XK

11
Q

important products/purposes of PPP

A

oxidative phase: NADPH to fatty acid synthesis

non-oxidative: ribose-5-P to nucleic acid biosynthesis (DNA/RNA), Fructose-6-P and glyceraldehyde-5-P as glycolytic intermediates

12
Q

target for cancer therapy

A
  • NADK
  • Due to the essential role of NADPH in lipid and DNA biosynthesis and the hyper proliferative nature of most cancers, NADK is an attractive target for cancer therapy

Also:
- phosphatidic acid may act as a target model for novel anti-cancer drugs

  • Nucleotide synthesis pathways are good targets for anti-cancer/antibacterial strategies

Gln PRPP amidotransferase:

  • Site of action for Azaserine
  • Antibiotic and anti-tumor agent
13
Q

phosphatidylcholine

A

a complex membrane lipid

14
Q

size of glycogenin

A

37 kDA homodimer

15
Q

visceral fat linked to

A

metabolic disturbances and increased risk of CVD and T2D

  • in women, breast cancer, the need for gallbladder surgery
16
Q

excess fat stored in

A

lipocytes (which expand size until fat is used for fuel)

17
Q

values of energy per unit weight of different energy sources:

A

fat: 37 kJ
protein: 17 kJ
glycogen: 16 kJ
glucose: 16 kJ

18
Q

mass of different energy sources

A

fat: 15,000g (83%) of stored energy
protein: 6,000g
glycogen: 190g
glucose: 20g

19
Q

essential fat% for men and women

A

men: 2-4%
women: 10-12%

20
Q

acceptable fat % for women/men + obese fat%

A

acceptable:

  • 25-31% for women
  • 18-25% for men

obese:
- 32+% for women
- 25%+ for men

21
Q

what do pancreatic lipases do?

A

break triacylglycerols down into diacylglycerols and monoacylglycerols

22
Q

lipase enzymes

A

a diverse array of genetically-distinct lipase enzymes are found in nature and represent several types of protein folds and catalytic mechanisms
- most are built on an alpha/beta hydrolase fold and employ a mechanism using a catalytic triad consisting of a serine nucleophile, a histidine base, and an acid residue (usually Asp)

23
Q

mixed micelles are made up of

A

long-chain fatty acids + bile salts

24
Q

Knoop concluded that

A

phenyl products (phenyl acetate and benzoate) could only result from beta-oxidation if carbons were removed in pairs

25
Q

what are the important side products of beta-oxidation and when are they produced?

A

NADH (produced in step that uses hydroxyacyl-CoA DH)

FADH2 (produced in step that uses acyl-coA DH)

26
Q

reactions in beta-oxidation and where we’ve seen it before

A

oxidation -> hydration -> oxidation (first three)

(same as TCA)

note: fourth is reverse Claisen condensation that cleaves the beta-keto ester

27
Q

reaction 1 of beta oxidation

A

fatty acyl-CoA –> trans-delta enoyl-CoA

enzyme: Acyl-CoA dehydrogenase

produces FADH2 from FAD

28
Q

where does Acetyl-CoA come from (before entering Krebs)

A

breakdown of proteins, polysaccharides and FATS (to FAs)

29
Q

connection between ETS + beta oxidation

A

FADH2 enters flavoprotein 3 which goes to UQ/UQH2 pool

30
Q

ATP yield from beta oxidation for palmitic acid (C16)

A
  • 8 acetyl-CoAs
  • 7 NADH
  • 7 FADH2

(106 ATP)

31
Q

Beta-oxidation - oxidizing odd-carbon FA’s: the steps

A

propionyl coA -> D-Methylmalonyl-CoA –> L-Methylmalonyl-CoA –> Succinyl-CoA

Enzymes:

(1) Propionyl-CoA carboxylase
(2) Methylmalonyl-CoA epimerase (D-> L conversion)
(3) Methylmalonyl-CoA mutase (rearrangement)

32
Q

For beta-oxidation – oxidizing odd carbon FAs, what are two coenzymes involved and which enzymes are they involved with?

A

biotin + B12

Biotin: propionyl-CoA carboxylase is biotin-dependent (the first enzyme that converts propionyl-CoA)

B12: Methylmalonyl-CoA mutase (the enzyme that converts to succinyl-CoA)

33
Q

What is the enzyme number of Enoyl-CoA isomerase and what does it do?

A

EC 5.3.3.8

converts cis to trans-delta acyl CoA

34
Q

Path of beta-oxidation for unsaturated FAs

A

three cycles of beta oxidation
-> cis-delta-dodeconyl-CoA ——-(ECI)—–> trans-delta-dodecenoyl-CoA —>

(now normal beta-oxidation)

trans-delta-dodecenoyl-CoA -> beta-hydroxyacyl-CoA (via enoylCoA hydratase)…..

35
Q

Alcohol Dehydrogenase reactions

A

Ethanol (CH3CH2OH) —-> Acetaldehyde (CH3CHO) via ADH

Acetaldehyde —> Acetic acid (CH3COOH) via ALDH –> excreted

OR

Acetaldehyde –> GSH-adduct (via glutathione)

Acetaldehyde is TOXIC

36
Q

Acute Cerebellar Ataxia Symptoms:

A
  • impaired coordination in the torso or arms and legs
  • frequent stumbling
  • unsteady gait
  • uncontrolled or repetitive eye movements
  • trouble eating and performing fine motor tasks
  • slurred speech
  • vocal changes
  • headaches
37
Q

name one cis, one trans, and one saturated fat

A

oleic: cis
elaidic: trans
stearic: saturated

38
Q

reaction of beta-oxidation (for palmitic acid)

A

CH3(CH2)14CO-CoA + 108 Pi + 23 O2 –> 108 ATP + 16 CO2 + 130 H2) + CoA

39
Q

three ketone bodies

A

acetoacetate, acetone, beta-hydroxybutyrate

40
Q

ketogenesis pathway

A

acetyl-CoA ———-(beta-ketothiolase)——> acetoacetyl-CoA —–(HMG-CoA synthase)—–> HMG-CoA ——–(HMG-CoA lyase)——-> acetoacetate —–> acetone and beta-hydroxybutyrate (the second one is via b-hydroxybutyrate DH)

41
Q

HMG-CoA connection between paths

A

HMG-CoA is part of formation of ketone bodies from acetyl-CoA and also forms cholesterols via HMG-CoA reductase

42
Q

FA synthesis pattern and how it relates to other processes we’ve seen

A

reduction- dehydration-reduction (opposite of beta-oxidation)

43
Q

what coenzyme is involved in acetyl-CoA carboxylase reaction?

A

BIOTIN (because ACC uses bicarbonate, ATP)

44
Q

Animal ACC enzyme

A

one polypeptide with all three functions: biotin carboxyl carrier, biotin carboxylase, transcacrboxylase
(E. coli enzyme has three separate units)

45
Q

Bacteria/Plants: Domain 1 enzymes

A

Domain 1:

  • beta-ketoacyl-ACP synthase
  • malonyl transferase

enzymes are separate and in a complex

46
Q

FA Synthase in animals: what happens in each domain?

A

FA synthase is a multi enzyme complex

Domain 1: acyl and malonyl binding and condensation
Domain 2: reduction of domain 1 intermediate
Domain 3: liberation of palmitate product

47
Q

How does lipogenesis work?

A
  • Excess glucose from the blood enters adipocyte –> TAG
  • insulin
  • VLDL and chylomicrons enter adipocytes –> fatty acids –> TAG
48
Q

glucagon is associated with

A

low blood glucose

49
Q

biosynthesis of glycogen

A

extracellular glucose -> intracellular glucose -> glucose-6-P -> glucose-1-P -> UDP-glucose -> short chain of glucose polymer ——–> glycogen

50
Q

Lecithin/Sphingo (L/S) ratio for baby development

A

L:S ratio:

mature: >1.9 (PG present)
borderline: 1.5-1.9 (PG absent)
immature: <1.5 (PG absent)
mature (diabetic mothers): >3.4

51
Q

Spiders

A
  • Brown recluse venom, is cytotoxic/hemolytic.
  • It contains hyaluronidase, deoxyribonuclease, ribonuclease, alkaline phosphatase, and lipase and sphingomyelinase D.
  • Sphingomyelinase D responsible for most of the tissue destruction and hemolysis.
  • The intense inflammatory response mediated by arachidonic acid, prostaglandins, and chemotactic infiltration of neutrophils
52
Q

production of prostaglandins, thromboxjnes, prostacyclin

A

membrane phospholipids -> arachidonic acid

arachidonic acid –> prostaglandins, thromboxjnes (this is inhibited by NSAIDS)

arachidonic acid –> prostaglandins, prostacyclin (inhibited by NSAIDS, COX-2 inhibitors)

53
Q

tetrahedral intermediate is key for

A

HMG-CoA reductase (in cholesterol biosynthesis)

54
Q

pregnenolone is formed where? progesterone is formed where?

A

pregnenolone: formed in mitochondria
progesterone: formed in ERA

55
Q

diseases associated with estrogen

A
  • heart disease
  • cancer (1/8 women, 85% survival in 5 years)
  • stroke
  • more
56
Q

sources of omega 3, 6, 9

A

omega 3: essential FA

  • DHA, EPA: fish
  • ALA: flax seeds, chia seeds

omega 6: essential FA
- grape seed oil, sesame oil

omega 9: non-essential FA
- olive oil, canola oil

57
Q

ki for mevinolinic acid (related to statins)

A

ki = 0.6 nM

58
Q

side effects of colesevelam hydrochloride (cholestagel)

A
  • constipation
  • abdominal pain
  • bloating
  • vomiting
  • diarrhea
  • weight loss
  • flatulence
59
Q

lipoprotein density

A

highest density: HDL (also most protein compared to lipids)

lowers density: chylomicrons, VLDL

60
Q

molecular weight of apolipoproteins

A

Apo A-1: 29,000
Apo B-100: 513,000
Apo C-II: 8800
Apo E: 34,000

61
Q

LDL + LDL receptor interaction - key apoproteins

A

Apo B-100 and ApoE key in this interaction

- B-100 is embedded in surface of the LDL receptor

62
Q

transaminations (for purine synthesis) - dependent on what coenzyme

A

pyrudixal phosphate

63
Q

IMP Biosynthesis: Reaction 1

A

Enzyme: Ribose-5-P Pyrophosphokinase

- Ribose-5-P –> 5-Phosphoribosyl-pyrophosphate

64
Q

IMP Biosynthesis: Reaction 2

A

Enzyme: Glutamine PRPP amidotransferase

5-PRPP –> Phosphorybosyl-beta-amine

65
Q

Folic acid reduces risk of

A

cancer (colon, breast cancer), senility/Alzheimer’s

66
Q

What is unique about Alcohol Dehydrogenase?

A

its Zn site (structural stability role)

67
Q

name of the drug that inhibits ALDH

A

antabuse

68
Q

what’s a process NADH is used for

A

fatty acid synthesis

69
Q

what is inosine-5-P?

A

a purine nucleotide

70
Q

Importance of DPA, EPA, DHA

A
  • DPA is important factor for preventing CVD
  • EPA is a huge factor in fighting inflammation
  • DHA is an essential molecule for brain, nerve and eye tissues, and is a powerful factor for normalizing blood and tissue triglycerides
71
Q

What does LP lipase do and what is it activated by?

A

LP lipase is activated by apoC-11. LP lipase hydrolyzes TAGs

72
Q

Source of Nitrogen in plants and microorganisms

A
  • In these organisms, glutamate is the source of N, via transamination (aminotransferase) reactions