Foundations Week 2--Thursday - Sheet1

Question 1

What are the symptoms of a dietary deficiency in the vitamin precursor for the cofactor of transaminase enzymes?

Answer 1

anemia and seizures; transaminase enzymes include PLP (pyroxidylphosphate)

Question 2

What are the symptoms of a dietary deficiency in the vitamin precursor for the cofactor of decarboxylation enzymes?

Answer 2

Beriberi: headach, malaise. Wericke (confusion & ataxia). Thiamine (B1) deficiency.

Question 3

What are the symptoms of a dietary deficiency in the vitamin precursor for the cofactor of carboxylase enzymes?

Answer 3

dermititis, lethargy, alopoica (hair loss). Associated with Biotin deficiency.

Question 4

Cofactor for enzymes in amino acid metabolism: PLP

Answer 4

transamination, deaminations, carbon chain transfers

Question 5

Cofactor for enzymes in amino acid metabolism: FH4

Answer 5

one carbon transfers

Question 6

Cofactor for enzymes in amino acid metabolism: tetrahydrobiopterin (BH4)

Answer 6

ring hydroxylations: example phenylalanine hydroxylase

Question 7

M.V. Pitthall

Answer 7

essential dietary amino acids

Question 8

tyrosine synthesis requires

Answer 8

phenylalanine, via phenylalanine hydroxylase (ring hydroxylation)

Question 9

cystine synthesis requires

Answer 9

methionine

Question 10

amino acis can be derived from , and degrade into…

Answer 10

glycolysis, CAC, acetyl CoA, and acetoacetate

Question 11

amino acids derived from glycolytic intermediates

Answer 11

pyridine to alanine; 3-phosphoglycerate to serine

Question 12

alpha-ketoacids are good candidates for _________

Answer 12

transamination

Question 13

kidney stones

Answer 13

due to cysteine percipitates, and due to oxalate, which comes from glyoxylate and previously from glycolytic intermediates

Question 14

sulfuric acid and PAPS

Answer 14

sulfuric acid acidifies urine and can form PAPS, a

Question 15

Cystinuria

Answer 15

results from inherited mutations (autosomal recessive) in the amino acid carrier for cysteine and basic amino acids (lysine, arginine and ornithine).

Question 16

alanine aminotransferase

Answer 16

Alanine is the major gluconeogenic amino acid. It is transaminated by alanine aminotransferase (ALT) to pyruvate. ALT is normally expressed only in hepatocytes. ALT in the blood is an indicator of ***liver damage.

Question 17

What two amino acids can form from oxaloacetate:

Answer 17

**aspartate, **aparagine, these two can interconvert

Question 18

amino acid metabolism: glutamate dehydrogenase

Answer 18

can transfer ammonia to carbon

Question 19

amno acid metabolism: carbamoly phosphate synthetase

Answer 19

can transfer ammonia to carbon

Question 20

amino acid metabolism: glutamine synthetase

Answer 20

can transfer ammonia to carbon

Question 21

proline and its special role in protein structure

Answer 21

has special role in protein structure (ring structure=inflexability in secondary structure)

Question 22

All amino acids synthesized from TCA cycle intermediates can be degraded to TCA cycle intermediates.

Answer 22

read this again

Question 23

PDH carries out two reactions:

Answer 23

decarboxylation & oxidation/reduction

Question 24

Maple syrup urine disease (classic)

Answer 24

infant 1 week old, convlusions, vomitting, maple syrup odor in urine. this is fatal if untreated. d

Question 25

why is thiamine at very high doeses an effective treatment for intermittant and mild MSUD?

Answer 25

PDH E1 subunit. swamping a decarboxylation with its cofactor will help increase

Question 26

**In what condiation would PDH be inactive**

Answer 26

when it is phosphorylated by PDH kinase

Question 27

branched chain keto acid dehydrogenase kinase

Answer 27

similar to PDH, decarboxylation of a-keto acids has kinase, which when phosphorylated is inactivated

Question 28

branched chain keto acid dehydrogenase kinase deficiency would manifest itself with what levels in branched chain amino acids

Answer 28

low branch chain amino acid concentrations

Question 29

phenylalinine and tyrosine breakdown

Answer 29

produces fumarate (CAC inter) adn acetoacetate (ketone body)

Question 30

phenylketonuria (PKU)

Answer 30

a defect in phenylalanine hydroxylase prevents tyrosine biosynthesis. phyenylalanine accumulates in the brain and blood. tyrosine becomes essential aa. SYMP: seizures, cognitive delay, light complexion. DIAGNOSIS: all infants are screened. TREAT: phenylalanine reduced diet

Question 31

Tyrosinemia (type II)

Answer 31

(autosomal recessive) mutation of **tyrosine aminotransferase**. SYMP: plaques on hands and feet

Question 32

Alcaptonuria

Answer 32

(autosomal recessive) deficiency of homogentisate oxidase. SYMP: ochronosis, **homogentisic acid in urine**

Question 33

Tyrosinemia (type I)

Answer 33

succinylacetone in urine and blood. TREAT: **nitosinone

Question 34

transport accross mito membranes is faciliated by what two gradients

Answer 34

charge and proton gradient

Question 35

mitochondrial permeability transition pore (MPTP)

Answer 35

absolves gradients accross mito membranes---> programed cell death

Question 36

PDH deficiency are primarily neurological, affecting brain development. Why?

Answer 36

the brain can only use glucose (and ketone bodies) for energy. It cannot use FAs.

Question 37

X-linked Leigh's disease

Answer 37

(X-chromosome) (boys) PDH is active, but less active; girls--PDH deficiency is a range of activity (up to totally dead)

Question 38

one possible treatment for PDH deficiency is thiamine. Why?

Answer 38

Increasing [thiamine], a cofactor for dehydrogenase step (removes CO2) improves [holoenzyme]--operational PDH complex.

Question 39

KDEL  retrograde trasport from Golgi to ER

Answer 39

retrograde transport from Golgi to ER

Question 40

inner mito membrane is specialized in that it contains large amounts of the phospholipid ________

Answer 40

cardiolipin

Question 41

The nucleus is bound and protected by a ____________ called the nuclear envelope

Answer 41

double-membrane

Question 42

Rough endoplasmic reticulum

Answer 42

Site of synthesis of secretory (exported) proteins and of N-linked oligosaccharide addition to many proteins.

Question 43

nuclear matrix is a filamentous scaffolding made up of lamins and other less well-characterized proteins and RNA

Answer 43

helps organizes nuclear functions

Question 44

MARs regions

Answer 44

appear to be 'hot spots' for topoisomerase activity, and are important in relieving torsional stresses occurring during replication and transcription. A number of clinically important drugs (e.g., inhibitors of cancer cell proliferation) act as topoisomerase poisons. **higher level of gene expression here**

Question 45

Nucleolus

Answer 45

is formed of nucleolar organizing regions of DNA that produces ribosomal RNA (ribosomes).

Question 46

nucleoporins

Answer 46

Pores (nucleoporins) exhibit a semi-permeable nature: they are freely permeable to small molecules (5000 daltons or less), but proteins larger than about 60 kDa are not passively permeable at all. So 5000-6000 size range can have fast transport and slow. Transport of these molecules requires the activity of specific receptor proteins that ferry them across the pore

Question 47

B-oxidation occurs where

Answer 47

peroxisomes

Question 48

nucleolar organizing regions

Answer 48

regions of DNA that form the nucleolus: the place were rRNA is produced

Question 49

Microtubule

Answer 49

incorporated into flagella, cilia, mitotic spindles. Has two associated molucular motor proteins: dynein = retrograde motion (+ to -); kinesin = anterograde (- to +)

Question 50

myosin

Answer 50

in muscle. power stroke due to release of Pi from myosine head.

Question 51

Filaments formed from both _____ and _____ have a polarity – the ends are sterically different

Answer 51

actin and tubulin

Question 52

microfillaments contain ____

Answer 52

actin

Question 53

when actin polymerizes it is associated with ___

Answer 53

ATP (on positive end)

Question 54

when tubulin polymerizes it is associated with ___

Answer 54

GTP (on positive end)

Question 55

___________ filaments do NOT appear to have an inherent polarity

Answer 55

Intermediate

Question 56

Actin polymerization forming 3-D meshworks: ARPs

Answer 56

ARPs seed the growth of a new microfillament from an existing one. This can form mesh 3-D network

Question 57

The function of ____ dictates the function of the microfilament cytoskeleton

Answer 57

***ARPS*** seed the growth of a new microfillament from an existing one. This can form mesh 3-D network

Question 59

cytokeratin (intermediate fillament)

Answer 59

protein associated with intermediate fillaments, it can be used in an imunohistochemical stain to distinguish *epithelial cells.*

Question 60

Which two reactions are carried out by the pyruvate dehydrogenase complex?

Answer 60

Decarboxylation & oxidation / reduction

Question 61

When would pyruvate dehydrogenase be inactive?

Answer 61

When it is phosphorylated by PDH Kinase

Question 62

Chemical uncouplers:

Answer 62

Dinitrophenol (DNP), Salicylate

Question 63

Drugs that block complex I, NADH dehydrogenase:

Answer 63

Rotenone, Amytal

Question 64

Drugs that block complex III, cytochrom b-c1 complex:

Answer 64

Antimycin A

Question 65

Drugs that block complex IV, cytochrome c oxidase:

Answer 65

cyanide, carbon monoxide, Azide

Question 66

Drugs that block complex V, ATP synthase

Answer 66

Oligomycin