Biochemistry / Molecular Biology / Genetics

Front 1

What are the components of the pyruvate dehydrogenase complex?

Back 1

TPP: Thymine pyrophosphate
Lipoic acid
Coenzyme A
FAD (from riboflavin)
NAD+ (from niacin)

Front 2

What are the two ketogenic amino acids?

Back 2

Leucine
Lysine

Front 3

Describe the Cori cycle

Back 3

Lactate from RCB and skeletal muscle is sent to the liver to be converted into glucose. Then glucose is returned to the RBC and skeletal muscles.

Front 4

Pyruvate metabolism is under controlled of which 4 enzymes?

Back 4

Lactate dehydrogenase (Anaerobic tissue): Pyruvate <---> Lactate [NADH to NAD+].
Alanine aminotransferase (ALT, GPT, Muscle): Pyruvate <---> Alanine
Pyruvate Carboxylase: Pyruvate ---> Oxaloacetate ---> TCA or Gluconeogenesis
Pyruvate Dehydrogenase: Pyruvate--->Acetyl-Coa--->CO2+H2O (TCA) or Fatty Acid synth.

Front 5

What's the MoA of the treatment for cyanide poisoning?

Back 5

Nitrites to form methemoglobin which binds cyanide

Front 6

What's the rate-limiting step of the TCA cycle?

Back 6

Isocitrate dehydrogenase:
Isocitrate ---> alpha-Ketoglutarate + NADH + CO2

Front 7

What's the MoD of Leber Hereditary Optic Neuropathy (LHON)?

Back 7

Mutations of complex I and III of the ETC --->
Impairment of ATP production by oxidative phosphorylation --->
Accumulation of NADH inhibits pyruvate dehydrogenase --->
Lactic acidosis.

Front 8

What are the irriversible enzymes of glycolysis?

Back 8

1) Hexokinase/Glucokinase
2) Phosphofructokinase 1
3) Pyruvate Kinase

Front 9

The four key enzymes of gluconeogenesis

Back 9

1) Pyruvate Carboxylase: Pyruvate ---> Oxaloacetate
2) Phosphoenolpyruvate Carboxykinase: Oxaloacetate ---> Phophoenolpyruvate
3) Fructose-1,6-Bisphosphatase:
Fructose-1,6-Bisphosphate + H2O ---> Fructose-6-Phosphate + Pi
4) Glucose-6-Phosphatase:
Glucose-6-Phosphate + H2O ---> Glucose + Pi

Front 10

What are the precursors of gluconeogenesis?

Back 10

Lactate (cori cycle)
Alanine (transamination of pyruvate)
Glucogenic Amino Acids (all except lysine and leucine can be converted into TCA and glycolysis intermediates)
Odd-numbered fatty acids
Fructose
Galactose

Front 11

Glycogen storage diseases and their enzyme deficiencies

Back 11

Type I: von Gierke; Glucose-6-Phosphatase
Type II: Pompe; alpha-1,4-Glucosidase
Type III: Cori; Glycogen Branching
Type IV: Andersen (amylopectinosis); Branching enzyme
Type V: McArdle; Muscle glycogen phosphorylase
Type VI: Hers disease; Hepatic glycogen phosphorylase
Type VII: Muscle phosphofructokinase
Type VIII: Hepatic phosphorylase kinase

Front 12

What's the mechanism of treatment of hyperkalemia with insulin and glucose?

Back 12

Influx of K+ into the cell is coupled with the entry of insulin and glucose.

Front 13

Alanine cycle steps

Back 13

Muscle: glucose ---> pyruvate ---> alanine
Liver: Alanine ---> pyruvate (---> glucose) + NH2 ( + 4 ATP ---> Urea)

Front 14

What is the function of the hexose monophosphate shunt?

Back 14

An alternative route for the oxidation of glucose which supplies the cells with NADPH and pentoses.

Front 15

What are the functions of NADPH?

Back 15

1)Synthesis of fatty acids and steroids
2)Maintains the reduced form of glutathione which prevents hemolysis (Protects against ROS)
3) Bactericidal activity in PMNs and macrophages by generating superoxides.

Front 16

What's the MoD of chronic granulomatous disease?

Back 16

Neutrophils cannot produce superoxides due to a defect in the NADPH oxidase complex.

Front 17

Which enzyme mediates the rate limiting step of the HMP shunt?

Back 17

Glucose-6-Phosphate Dehydrogenase

Front 18

What's the MoD of glucose-6-dehydrogenase deficiency?

Back 18

In G6PD there is a decrease production of NADPH ---> decrease in the reduced form of glutathione ---> Increase in superoxide and hydrogen peroxide ---> Hemolysis

Front 19

Which drugs exarcerbate the hemolysis in G6PD?

Back 19

Aspirin, antimalarials, antituberculous, and sulfonamides

Front 20

What are the major classes of lipids?

Back 20

Fatty acids
Triacylglycerols
Ketone bodies
Cholesterol
Phospholipids
Sphingolipids

Front 21

Arachidonic acid is the major precursor of which compounds?

Back 21

Thromboxane
Prostaglandins
Leukotrienes

Front 22

Which lipid deficiency in the premature newborn gives rise to respiratory distress syndrome?

Back 22

Dipalmitoylphosphatidylcholine;
It is the active component of surfanctant which forms a film that lines the alveoli and reduces surface tension.

Front 23

Key enzymes of fatty acid synthesis

Back 23

Acetyl-CoA Carboxylase:
First step/Rate-limiting step
Acetyl-Coa + HCO3 + ATP ---> Malonyl-Coa + ADP + Pi

Fatty acid synthase:
Lengthens fatty acid chain by 2 carbons

Front 24

Location of fatty acid synthesis/fatty acid oxidation

Back 24

Fatty acid synthesis: Cytosol
Fatty acid oxidation: Mitochondria

Front 25

What enzyme is responsible of converting fatty acids to fatty acyl-CoA?

Back 25

Fatty acyl-CoA synthetase (thiolase)

Front 26

Which shuttle is responsible for bringing fatty acids into the mitochondria and what enzyme is responsible for the rate-limiting step?

Back 26

The carnitine shuttle uses carnitine-acyl transferase I

Front 27

Which vitamin is essential for carbohydrate metabolism?

Back 27

Thiamine (vitamin B1) is converted to thiamine pyrophosphate.

Front 28

Which vitamin is essential for amino acid metabolism?

Back 28

Vitamin B6, pyridoxal phosphate

Front 29

Biotin is important is the synthesis of?

Back 29

Fatty acid synthesis

Front 30

What are the 3 components of the PDH complex?

Back 30

1) Pyruvate dehydrogenase (decarboxylase)
2) Dihydrolipoamide transacetylase
3) Dihydrolipoamide dehydrogenase

Front 31

What metal is needed for the function of thiamine pyrophosphate?

Back 31

Magnesium

Front 32

What disease is associated with sphingomyelinase deficiency?

Back 32

Niemann-Pick disease

Front 33

What is the process of lyonization?

Back 33

Random inactivation of an x chromosome in each cell.

Front 34

What's manifesting heterozygote?

Back 34

When the active X chromosome is the one with the mutant gene.

Front 35

Why do autosomal domininant diseases manifest?

Back 35

1) More than 50% of the normal gene product is needed for a nondiseased state.
or
2)The defective protein has acquired a novel detrimental property.

Structural proteins and membrane receptors are usually affected

Front 36

What is southern blotting?

Back 36

Used to detect DNA

Front 37

What is northern blotting?

Back 37

Used to detect RNA

Front 38

What is western blotting used for?

Back 38

Used to detect protein

Front 39

What's allelic heterogeneity?

Back 39

Different mutation on the same allele

Front 40

What's compound heterogeneity?

Back 40

When the same exact locus is not mutated on each copy

Front 41

What's the equation used to describe the phenotypic distribution of a disorder and the genotypic distribution of an abnormal allele?

Back 41

Hardy-Weinberg
1 = p2 + 2pq + q2
1 = p + q

p2 = unaffected
2pq = carriers
q2 = affected
q = frequency of normal allele
q = frequency of abnormal allele (1 - p)

Front 42

Tay-Sachs

Back 42

Tay-Sachs:
1: Autosomal recessive
2: Lysosomal storage disorder
3: Hexosaminidase A deficiency
4: Accumulation of cerebral ganglioside (GM2, a sphingolipid)
5: Cherry red spot on macula

Front 43

Describe the Hurler and Hunter syndromes

Back 43

Coarse facial features, mental retardation
Hurler syndrome:
Alpha-1-iduronidase deficiency
Autosomal recessive

Hunter syndrome:
Iduronate sulfatase deficiency
X-Linked recessive

Front 44

Glucocerebrosidase deficiency
Hepatosplenomegaly

Back 44

Gaucher's disease

Front 45

Sphyngomyelinase deficiency
Neurological dysfunction

Back 45

Niemann-Pick disease

Front 46

2 year old
Choreoathetosis
Spasticity
Self mutilation
Orange "sand" in the diapers

Back 46

Lesch-Nyhan syndrome

Front 47

HPRT deficiency

Back 47

Lesch-Nyhan syndrome

Front 48

Which enzyme does allopurinol inhibit?

Back 48

Xanthine oxidase

Front 49

Which bonds are destroyed when DNA is denatured?

Back 49

Hydrogen bonds.
No covalent bonds are broken.

Front 50

Which methods are used to denature DNA?

Back 50

Heat
Alkaline pH
Chemicals (formamide, urea)

Front 51

What is the hyperchromic effect?

Back 51

The increase in absorbance of a DNA solution at a wavelength of 260nm in the DNA melting curve.

Front 52

What is the melting temperature (Tm) of denaturing DNA?

Back 52

It is the temperature at which the DNA is half denatured (half of the hydrogen bonds are broken)

Front 53

Which one G-C or T-A will have a higher Tm?

Back 53

G-C bonds because they have 3 hydrogen bonds

Front 54

DNA A protein function

Back 54

It recognizes origin of replication in bacterial DNA

Front 55

Helicase function

Back 55

Denatures DNA

Front 56

Single stranded DNA binding protein (SSB)

Back 56

Prevent the strands from reassociating and protects them from degradation by nucleases

Front 57

Primase

Back 57

Synthesizes a short RNA primer (5'--->3')

Front 58

DNA pol III

Back 58

Begins synthesizing DNA in the 5'--->3' direction beginning at the 3' end of each primer (leading strand)

Front 59

DNA pol I

Back 59

Fills the gaps and removes RNA primers

Front 60

DNA ligase

Back 60

Seals the nicks between Okazaki fragments (requires NAD/ATP)

Front 61

DNA pol delta

Back 61

Synthesizes the leading strand during replication

Front 62

DNA pol alpha

Back 62

Synthesizes the lagging strand during replication

Front 63

DNA pol beta and epsilon

Back 63

DNA repair/DNA pol e may substitute for DNA pol d

Front 64

Topoisomerase II

Back 64

Removal of positive supercoils ahead of advancing replication forks

Front 65

Telomerase

Back 65

Finishes 5' end

Front 66

Reverse transcriptase

Back 66

RNA-dependent DNA pol

Front 67

What are the essential amino acids?

Back 67

PriVaTe TIM HALL

Phe, Val, Thr, Trp, Ile, Met, His, Arg, Leu, Lys

Front 68

Glycogen storage: Anderson's (IV) vs. Cori's (III) enzyme defect

Back 68

defect ABCD: Anderson's=Branching enzyme Cori's=Debranching enzyme

Front 69

Pompe's disease

Back 69

"Police = Po + lys": Pompe's disease is a lysosomal storage disease (alpha 1,4 glucosidase).

Front 70

Metabolic acidosis (normal anion-gap) causes:
1) Hyperkalemia
2) Hypokalemia

Back 70

With Hyperkalemia:
RAISE K+:
RTA type 4
Aldosterone or mineralocorticord deficiency Iatrogenic: NH4Cl, HCl "Stenosis": obstructive uropathy
Early uremia
With hypokalemia:
ReDUCE K+:
Renal TA type 1 and 2
Diarrhoea
Urine diversion into gut Carbonate anhydrase inhibitor Ex-hyperventilation

Front 71

Enzyme kinetics:
competitive vs. non-competitive inhibition

Back 71

With Kompetitive inhibition: km increases; no change in Vmax. With Non-kompetitive inhibition: No change in km; Vmax decreases.

Front 72

Hemoglobin binding curve: causes of shift to right

Back 72

"CADET, face right!":
C = Increase in carbon dioxide, A = Acidosis (low ph),
D = Increase in 2,3 DPG aka 2,3 BPG,
E = Exercise,
T = increase in temperature

Front 73

Adrenaline mechanism

Back 73

"ABC of Adrenaline": Adrenaline--> activates Beta receptors--> increases Cyclic AMP

Front 74

Carbon monoxide poisoning electron transport chain target

Back 74

"CO blocks CO":
Carbon monoxide (CO) blocks Cytochrome Oxidase (CO)

Front 75

Glycolysis steps

Back 75

"Goodness Gracious, Father Franklin Did Go By Picking Pumpkins (to) Prepare Pies": Glucose Glucose-6-P Fructose-6-P Fructose-1,6-diP Dihydroxyacetone-P Glyceraldehyde-P 1,3-Biphosphoglycerate 3-Phosphoglycerate 2-Phosphoglycerate (to) Phosphoenolpyruvate [PEP] Pyruvate • 'Did', 'By' and 'Pies' tell you the first part of those three: di-, bi-, and py-. • 'PrEPare' tells location of PEP in the process.

Front 76

Glycolysis Enzymes Mnemonic

Back 76

“Hungry Peter Pan And The Growling Pink Panther Eat Pies.”
Hexokinase
Phosphohexo Isomerase
Phosphofructokinase-1 (6-phosphofructo-1 kinase)
Aldolase
Triose phosphate isomerase
Glyceraldehyde 3-phosphate dehydrogenase
Phosphoglycerate kinase
Phosphoglycerate mutase
Enolase
Pyruvate kinase

Front 77

Citric acid cycle compounds

Back 77

"Our City Is Kept Safe And Sound From Malice": Oxaloacetate, Citrate, Isocitrate, alpha-Ketoglutarate, Succinyl-CoA, Succinate, Fumarate, Malate

Front 78

Citrate Cycle Enzymes Mnemonic

Back 78

"Corrupt Anti Intelligence Agent Spoke Slander For Money." Citrate synthatase, aconitase, Isocitrate dehydrogenase, Alpha ketogluturate dehydrogenase, Succinyl CoA synthetase, Succinate dehydrogenase, Fumarase, Malate Dehydrogenase

Front 79

B vitamin names

Back 79

"The Rhythm Nearly Proved Contagious": • In increasing order: Thiamine (B1) Riboflavin (B2) Niacin (B3) Pyridoxine (B6) Cobalamin (B12)

Front 80

Electron transport chain: Rotenone's site of action

Back 80

Rotenone is a site specific inhibitor of complex one

Front 81

Golgi complex: functions

Back 81

"Golgi Distributes A SPAM": Distributes proteins and lipids from ER Add mannose onto specific lysosome proteins Sulfation of sugars and slected tyrosine Proteoglycan assembly Add O-oligosugars to serine and threnonine Modify N-ologosugars on asparagine

Front 82

Pyruvate: products of complete oxidation

Back 82

"4 Naked Fun 3 Coeds + 1 Guy": • Complete oxidation of pyruvate yields: 4 NADH FADH2 3 CO2 1 GTP

Front 83

Catabolism steps of branched chain amino acids

Back 83

"Truck hit the Ox to Death": Transamination Oxidative decarboxylation Dehydrogenation

Front 84

Niacin deficiency: signs and symptoms

Back 84

4 D's: Diarrhoea Dermatitis Dementia Death (if untreated)

Front 85

Enzymes: classification

Back 85

"Over The HILL": Oxidoreductases Transferases Hydrolases Isomerases Ligases Lyases • Enzymes get reaction over the hill.

Front 86

Phenylketonuria (PKU): which enzyme is deficient PHenylketonuria

Back 86

Phenylalanine Hydroxylase

Front 87

cDNA libraries

Back 87

complementary DNA libraries are made by reverse transcribing (making DNA from RNA) all of the mRNA in a cell. The DNA copies are replicas of mRNA without introns. These can be used as probes, primers, or many other uses.

Front 88

Transcription factors

Back 88

Bind to promoters, and help recruit RNA Polymerase II, which binds the TATA box and CAAT box, located upstream

Front 89

Enhancer regions

Back 89

Bind specific protein that aid in transcription of certain genes. These regions can be located upstream, within the gene, within introns, close, or far from the transcription start site.

Front 90

MoA of steroid hormones

Back 90

Steroid hormones cross membranes and travel directly to the nucleus of target cells. Bound to their respective receptors, steroid hormones act like transcription factors or enhancer binding proteins. They bind to hormone response elements near the genes they regulate and either enhance or inhibit transcription of those genes.

Front 91

What's the pKa of histidine?

Back 91

6 does not ionize at physiologic pH

Front 92

The role of SH2 domains

Back 92

They are normally found in proteins involved in signal transduction. By binding to phosphotyrosine, they allow signals to be passed from one molecule to another. For instance

Front 93

Inherited hyperlipidemias-- Type Increased lipoprotein

Back 93

I Chylomicrons Triglycerides
IIa LDL Cholesterol
IIb LDL and VLDL Cholesterol and triglycerides
III Remnants Triglycerides and cholesterol
IV VLDL Triglycerides
V VLDL and chylomicrons Triglycerides and cholesterol