random

Question 1

other sugars

Answer 1

erythritol - artificial sweetner, 4 C, not much flatulence
xylitol - 5 C, natural sweetner, flatulence with lots of consumption
mannitol - used for hand injury, kidney issues, helps drugs pass BBB, helps with CF
sorbitol - found in gum, toothpaste, mouthwash, laxative, can cause catarcts or neuropathy in diabetics

Question 2

glutathione

Answer 2

antioxidant, found in cytosol

Question 3

3 membrane lipids

Answer 3

cholesterol, glycolipids, phospholipids

Question 4

3 glycerophospholipids

Answer 4

phosphatidylcholine, phosphatidylserine, phosphatidylinositol

Question 5

lipid rafts

Answer 5

made of cholesterol, important for cell signaling

Question 6

what do ligand gated ion channels have to do with alzheimer’s disease?

Answer 6

glutamate is excessively released in dying brain cells. glutamate receptor antagonist helps pts (Mimantine/Namenda)

Question 7

in P-type ATPases (one type of primary active transport) what aa residue gets phosphorylated?

Answer 7

aspartate

Question 8

Pb (lead) poisoning caused by what? treatment?

Answer 8

Pb inhibits ferrochelatase (coenzyme of hemoglobin), so heme can’t be made. Give pt Ca-EDTA bc Pb has higher affinity for EDTA. Pb-EDTA will be excreted in urine.

Question 9

allosteric effector, proenzymes, and isozymes?

Answer 9

allosteric effectors can change shape of enzyme to fit substrate (+) or make enzyme’s shape not fit substrate (-_.

proenzymes are zymogens, typically proteolytic. need peptide bond cleavage to become activated.

isozymes act on the same substrate as original enzymes but they have different kinetic properties (Km, Vmax, etc) and diff binding sites/aa sequences.

Question 10

what isozymes act as markers for MI by being elevated in the blood?

Answer 10

isozymes of lactate dehydrogenase, creatine kinase, and AST

Question 11

troponin subunits? what troponin subunit is elevated after MI?

Answer 11

Tn-T (tropomyosin), Tn-C (calcium), Tn-I (inhibitory). After MI, cTn-I increased (cardiac troponin). Troponin has overtaken isozymes to detect MI.

Question 12

Fanconi-Bickel syndrome

Answer 12

GLUT2 transporter mutation so can’t uptake glucose, galactose, and fructose

Question 13

clinical markers of hemolytic anemia

Answer 13

increased lactate dehydrogenase, bilirubin

Question 14

high fructose corn syrup + obesity link

Answer 14

since fructose bypasses PFK1, is unregulated, and joins in glycolysis as an intermediate, you end up with a lot of pyruvate that turns into a lot of acetyl coA. With too much acetyl coA, too much fat synthesis.

can lead to insulin resistance (diabetes 2) and fatty liver

Question 15

oxidative phase of PPP (non reversible phase)

Answer 15

making glucose 6 P into ribulose 5 P with glucose 6 P dehydrogenase. this step generated 2 NADPHs. When you have an infection, you need NADPH. so if there’s a problem with glucose 6 dehydrogenase, you can’t make NADPH. NADPH regenerates glutathione, which detoxifies H2O2. cancer prefers this pathway bc need ribose which comes from ribulose.

Question 16

non-oxidative phase (reversible)

Answer 16

end products (ribose, fructose, glyceraldehyde) go to nucelotide pathways, glycolytic pathways, and gluconeogetic pathways. Infections prefer this pathway bc they want NADPH. if you make frucose and glyceraldehyde, they can undergo nucleogenesis and make glucose 6 P for oxidative phase (which produces 2 NADPHs).

Question 17

hyperthyroidism is due to what

Answer 17

thyroidglobulin (thyroid makes this, it’s made from many Tyr resides, some which are ii and some i) makes T3 (Tyri + Tyrii) and T4 (Tyrii + Tyrii). Too much T3 and T4 leads to hyperthyroidism. Txt: take agents that block iodination of thyroidglobulin, hence decreasing amount ot T3 and T4.

Question 18

what two enzymes need PLP in what two rxns

Answer 18

1. CBS needs it to break down homocysteine

2. alanine amino transferase needs it to make pyruvate into alanine

Question 19

heart wants energy from what biomcules?

skeletal muscle wants energy from what biomcules?

Answer 19

heart - glucose, lactate, FA

skeletal muscle - glucose, FA, aas

Question 20

for metabolic syndrome you need one of? two of?

Answer 20

one of: insulin resistance, impaired glucose tolerance, impaired fasting glucose, diabetes

two of: BP over 140/90 or on BP meds, microalbuminuria, dyslipidemia (more LDL, less HDL), central obesity

Question 21

inborn errors of metabolism

Answer 21

x linked, mitochondrial inheritance, autosomal dominant/recessive

Question 22

orotic aciduria occurs if what?

Answer 22

UMP synthase doesn’t work

Question 23

in BCAA catabolism, what becomes what?

Answer 23

Val (glucogenic) and Ile (both) becomes succinyl coA. Leu (ketogenic) becomes acetyl coA.

Question 24

in the brain, what fixes ammonia?

Answer 24

glutamate dehydrogenase

Question 25

what does coenzyme A do?

Answer 25

activates acyl groups (like acetyl coA), forms high energy thioester linkages

Question 26

what does arsenite do?

Answer 26

modifies lipoic acid, so affects PDC. also affects a-ketoglutarate dehydrogenase, and a-keto acid dehydrogenase.

Question 27

if PDC doesn’t work, what happens?

Answer 27

you get pyruvate build up, and then lactic acidosis. avoid alanine, bc alanine can turn into pyruvate.

Question 28

how does rat poison work (fluoroacetate)?

Answer 28

fluoroacetate + acetyl coA becomes fluoroacetyl coA which becomes fluorocitrate (analog of citrate, inhibits aconitase). citrate builds up, negatively inhibiting citrate synthase. STOPS TCA CYCLE

Question 29

succinyl coA + glycine = ?

Answer 29

ALA (first step in heme synthesis)

Question 30

anapleurotic rxns in TCA cycle

anabolic rxns in TCA cycle

Answer 30

anapleurotic

fasting: proteins degrade to aas, which make OAA, fumarate, succinyl coA, and a-ketoglutarate
fed: carboxylation of pyruvate (make OAA) to make TCA cycle run

anabolic

1. OAA makes glucose via gluconeogenesis
2. citrate activates acetyl coA carboxylase (fatty acid synthesis)
3. OAA + a-ketoglutarate make aas.

Question 31

2-oxoglutaric acid aciduria

Answer 31

neural deficit, diagnosed with urine test

Question 32

fumarase deficiency

Answer 32

neural deficity, diagnosed with urine test, encephalopathy, speech delay, fatal

Question 33

succinyl coA synthetase (SCS) deficiency

Answer 33

mutations in 2/3 subunits that make up enzyme, direct genetic testing

Question 34

ferredoxin

Answer 34

small proteins that serve as electron carriers in mitochondrial/cytochrome systems

ferredoxin 1: biosynthesis of steroid hormones, metabolism of vitamin D and bile acids
ferredoxin 2: biosynthesis of heme, proteins