Unit 8 - 5 Biochemistry

Front 1

organic acids

Back 1

products of metabolism; they are weak acids (lactic acid, pyruvic acid, acetoacetic acid)

at physiologic pH weak acids are primarily dissociated

Front 2

low pKa regarding acid strength

Back 2

strong acid; more likely to be dissociated

Front 3

high pKa regarding acid strength

Back 3

weak acid; less likely to be dissociated

Front 4

High Ka

Back 4

dissociated very easily

Front 5

Low Ka

Back 5

not dissociated

Front 6

inorganic acid

Back 6

found predominantly in the dissociated state at physiological pH

H2S04 = sulfuric acid

Front 7

which amino acid in albumin is the buffering agent

Back 7

histidine;

bc pKa is the closest to physiological pH

Front 8

2 tissues that need glucose

Back 8

brain, rbc

Front 9

acetone

Back 9

metabolically useless ketone body; byproduct of acetoacetate formation; body just wants to get rid of it bc body cant use it for energy

Front 10

where are ketone bodies synthesized

Back 10

liver

Front 11

which tissues use ketone bodies

Back 11

used during starvation

ketone bodies used by brain

glucose used by rbc

Front 12

End product of B-oxidation

Back 12

Acetyl-CoA

can be oxidized in TCA cycle to NADH, FAD, or GTP

In liver they can be shuttled off to make ketone bodies

Front 13

what organelle is required to use ketone bodies

Back 13

mitochondria (thus rbc cant use them)

Front 14

three types of ketone bodies

Back 14

acetoacetate (2 acetyl-CoA's linked together), acetone, 3-hydroxybutyrate

acetoacetate + NADH -> 3-hydroxybutyrate


acetone is basicall acetoacetate w/ C02 (decarboxylation)

Front 15

which kind of ketone would aloholics generate

Back 15

3-Hydroybutyrate in order to recycle the excess NADH

Front 16

how can ketone bodies influence the pH of blood

Back 16

keton ebodies have a low pKa and are thus fond predominantly in the dissociated state at physiological pH. Liberated H+ decreases the pH of the blood if the buffering capacity is exceeded

Front 17

-ate suffix

Back 17

conjugate base

Front 18

which type of diabetes is most likely to have problem with ketoacidosis?

Back 18

Type 1

In Type 2 (insulin resistance) you're getting some glucose

Front 19

metabolic acidosis in alcoholics

Back 19

ketoacidosis caused by poor diet of alcoholics (increased FA breakdown) and hypoglycemia resulting from inhibited gluconeogenesis

Lactic acidosis caused by increased NADH from alcohol metabolism driving pyruvate -> lactate, thiamine deficiency also = low activity of pyruvate dehydrogenase which furhter promotes pyruvate -> lactate

Front 20

which coenzyme does pyruvate dehydrogenase need

Back 20

thiamine

Front 21

arsenate cofactor (arsenic poisoning)

Back 21

lipoid acid

Front 22

flavin FAD; (which vitamin)

Back 22

2

Front 23

niacin (NAD)

Back 23

3

Front 24

which compound can be used to synthesize niacin

Back 24

typtophan

Front 25

wernicke-korsakoff

Back 25

pyruvate dehydrogenase
alpha-ketoglutarate dehydrogenase
transketylase

Front 26

what other metabolic pathways also contribute to ketone body formation

Back 26

fatty acid oxidation
amino acid catabolism
glycolysis (except in diabetics bc they cant get glucose into the cell)

all these used to generate acetyl CoA

Front 27

2 ketogenic amino acids

Back 27

leucine, lysine

Front 28

why are leucine and lysine often used in tx of a pyriuvate dehydrogenase deficiency?

Back 28

feed into TCA cycle to form acetyl-CoA and thus bypass pyruvate dehydrogenase step

Front 29

why is isoleucine also considered gluconeogenic

Back 29

fed in as sucinyl CoA -> forms oxaloacetate which can then be used to make glucose

Front 30

treatment for someone with a PDH deficiency? (i.e. which amino acids can be used?)

Back 30

similar to someone with a thiamine deficiency; can't generate acetyl CoA from pyruvate

if they're given a diet supplemented with leucine and lyisne you can bypass pyruvaate -> acetyl CoA to just generate acetyl CoA

Front 31

mcc of lactic acidosis

Back 31

tissue hypoxia
drugs (ethanol, netanol, phenformin fructose, sorbitol)
congenital (G6PD, other inherited dz w defective gluconeogensis or pyruvate oxidation)

Front 32

Cori Cycle

Back 32

lactate metabolized by gluconeogensis in the liver

the lactate can be turned into gluconeogenesis (starved state)

Front 33

why do enzyme deficiencies leaidng to phosphate trapping commonly result in hyeruricemia

Back 33

a deficiency in glucose 6 phosphatase; only expressed in liver; hypoglycemia bc cant release glucose from hepatocytes; G6P must be dephosphorylated to be released into blood but cant do this w/o glucose 6 phosphatase

Front 34

function of PPP

Back 34

Synthesize NADPH for FA synthesis, glutathione reduction, nucleotides

if glucose-6-phosphate builds up, driven into PPP -> increased nuecleotide biosynthesis = increased breaking down of biosynthesis

ADP builds up/other purines = hyperuricemia (as seen in von gericks disease)

Front 35

glucokinase

Back 35

found in liver (glycogen/liver)

Front 36

2 most common enzyme deficiencies leading to increased orotic acid production

Back 36

deficient UMP synthesis (megaloblastic anemia)

OTC deficiency (

Front 37

tx of orotic aciduria w uridine

Back 37

allows you to synthesize the needed nucleotides; makes cytosine and thyomine; negatively feedbacks on carbamoyl phosphate synthetase which decreases orotic aciduria

Front 38

salicylate (aspirin) poisoning

Back 38

pKa is so low; lose protons which causes acidosis

also functions as an uncoupler of oxidative phosphorylation

grabs protein in intermembrane space, crosses membrane, then dumps it in the mitochondrial matrix

electron transport tries to restore gradient so it upregulates respiration trying to restore the proton gradient = respiratory alkalosis

increased respiration increased glycolyusis and roduction of pyruvate and lactate (metabolic acidosis)

Front 39

methanol poisoning

Back 39

increased levels of formic acid due to methanol metabolism; contributes to acidosis and inhibits electron transport chain (which ramps up metabolism)

(pt drinking methanol)

Front 40

ethylene glycol

Back 40

glycolic acid builds up

Front 41

Paramedics bring a patient to the emergency department because he was found unconscious in an alley by passers by. The man was unshaven and dishevelled and was found to have blood alcohol levels of 0.25% and blood glucose levels of 32 mg/dL. After glucose was administered and the patient regained consciousness, a thorough history was performed. The man admitted to being a chronic alcoholic and to having little to eat for approximately two weeks. Assuming that the patient’s liver is still functioning normally, why is the patient hypoglycemic?

Back 41

The high NADH/NAD+ ratio impaired gluconeogenesis

Front 42

Your patient, with a BMI of 36 and a waist circumference of 44 in., has a fasting blood glucose level of 145 mg/dL. He was diagnosed with diabetes after being found in a coma by his family three weeks prior. The patient has been reluctant to drug therapy or dietary changes and thus is continuing to experience problems related to his untreated diabetes. Which of the following is the primary energy source this individual is using to obtain energy (assuming inadequate treatment)?

Back 42

fatty acids

Front 43

A 3-month-old girl is brought to the pediatrician due to fussiness and lethargy. According to the parents, the baby was just fine until the mother needed to return to work, and the baby was being switched from breast milk to baby foods, formula, and fruit juices. Lab tests revealed both hyperuricemia and lactic acidemia. Which of the following enzymes is most likely deficient in this child?

Back 43

Aldolase B = fructose intolerance

Fructose-1-phosphate accumulates, causing a decrease in available phosphate, which results in inhibition of glycogenolysis and gluconeogenesis.

Tx by decreaseing intake of fructose and sucrose

Front 44

A newborn becomes lethargic and drowsy 24 hours after birth. Blood analysis shows hyperammonemia, coupled with orotic aciduria. This individual has an enzyme deficiency that leads to an inability to directly produce which of the following?

Back 44

Citrulline

Deficiency in ornithine transcarbamoylase -> carbamoyl phosphate accumulation -> shunts to form orotic acid and hyperammonia bc its ont being excreted

Front 45

A 6-month-old infant is seen by the pediatrician for developmental delays. Blood work shows megablastic anemia, although measurements of B12 and folate are in the high normal range. Urinalysis demonstrates, upon standing, the formation of a crystalline substance. Supplementation of the child’s diet with uridine reversed all of the clinical problems. Which of the following is this infant experiencing a deficiency of?

Back 45

Uracil, thymine, cytosine