Biochemistry - Nutrition and Metabolism 1 Flashcards
Vitamin A usage
promyelocytic leukemia
Acne
Measles “MAP”
thiamine function
Be APT In thiamine pyrophosphate (TPP), a cofactor for several dehydrogenase enzyme reactions:
- Branched-chain ketoacid dehydrogenase
- Alfa -ketoglutarate dehydrogenase (TCA cycle)
- Pyruvate dehydrogenase (links glycolysis to TCA cycle)
- Transketolase (HMP shunt)
B3 excess
Facial flushing (induced by prostaglandin, not histamine; can avoid by taking aspirin with niacin)
hyperglycemia
hyperuricemia
“Podagra=prostaglandin”
B5 function
An essential component of coenzyme A (CoA, a cofactor for acyl transfers) and fatty acid synthase.
CoA for FA synthesis
B6 function
cofactor used in:
transamination (eg, ALT and AST)
decarboxylation reactions
glycogen phosphorylase.
Synthesis of: cystathionine, heme, niacin, histamine, and neurotransmitters including serotonin, epinephrine, norepinephrine (NE), dopamine, and GABA (SEND G).
CNN-HH (CNN on the hours)
Vit C function
Antioxidant
Iron aBsorption
Collagen synthesis
Dopamine beta-hydroxylase
Vit C excess
Iron overload
Ca-oxalate stones
Vit D at higher levels…
bone resorption at higher levels.
give Vit D to______
Give oral vitamin D and K to breastfed infants. (give DicK)
Deficiency is exacerbated by pigmented skin, premature birth, breastfed.
Vit E excess
Risk of enterocolitis in infants.
High-dose supplementation may alter the metabolism of vitamin K - enhanced anticoagulant effects of warfarin.
Zinc deficiency
Taste,
smell
dec. adult hair
hypogonadism
immunity
wound healing
Associated with acrodermatitis enteropathica (defect in intestinal zinc absorption).
May predispose to alcoholic cirrhosis.
Ethanol metabolism inc NADH/ NAD+ ratio in the liver, causing:
FLOK:
F - Fatty liver (DHAP -> glycerol-3P, acetyl CoA -> FA, Both combine to make TG)
L - Lactic acidosis (pyruvate to lactate)
O - OAA -> malate (fasting hypoglycemia)
K - Ketoacidosis (acetyl Coa to ketone bodies)
ATP production in heart and liver
32 net ATP via malate-aspartate shuttle
ATP production in muscle
30 net ATP via glycerol-3-phosphate shuttle
NADPH is used in:
- Glutathione reductase
- Cytochrome P-450 system
- Anabolic processes
- Respiratory burst
“Powers the G-CAR”
anaerobic glycolysis - major pathway in…
C - cornea
a
T - testes
W - WBCs
a
L - lens
K - kidney medulla
e
R - RBCs
Electron transport inhibitors: complex one inhibitor
Rotenone
Electron transport inhibitors: complex 3
“An-3-mycin” (antimycin) A
Electron transport inhibitors: complex 4
Cyanide, carbon monoxide, azide (the -ides, 4 letters) inhibit complex IV.
ATP synthase inhibitors
Oligomycin.
Uncoupling agents
2,4-Dinitrophenol (used illicitly for weight loss)
aspirin (fevers often occur after the overdose)
thermogenin in brown fat (has more mitochondria than white fat).
Pyruvate carboxylase
Requires biotin, ATP.
Activated by acetyl-CoA
Phosphoenolpyruvate carboxykinase - Requires_____
Requires GTP.
Glucose-6- phosphatase location
In ER.
glucose-6-phosphate -> glucose.
Pentose phosphate pathway sites:
Sites of fatty acid or steroid synthesis - “the RALM”
R - RBCs
A - adrenal cortex
L - liver
M - mammary glands (lactating)
Pentose phosphate pathway Oxidative (irreversible) products:
(G6PD)
Products:
Ribulose-5-P
CO2
2 NADPH
Pentose phosphate pathway Nonoxidative (reversible)
(Phosphopentose isomerase and transketolases)
Products:
Ribose-5-P
glyceraldehyde-3-P
Fructose-6-P
Glucose-6-phosphate dehydrogenase deficiency leads to poor defense against oxidizing agents like…
F - fava beans
e
M - malaria Tx (primaquine/ chloroquine)
e
N - nitrofurantoin
I - Infection (most common cause)
S - sulfonamides
T - tuberculosis drugs
Dihydroxyacetone-P and Glyceraldehyde to Glyceraldehyde-3-P
Dihydroxyacetone-P: Triose phosphate isomerase
Glyceraldehyde: Triose kinase
Galactokinase deficiency Sx
galactose appears in the blood (galactosemia) and urine (galactosuria);
infantile cataracts.
May present as failure to track objects or to develop a social smile.
Classic galactosemia SX
failure to thrive
jaundice
hepatomegaly
infantile cataracts
intellectual disability
Can predispose to E coli sepsis in neonates.
Tissues with Aldose reductase and Sorbitol dehydrogenase
Liver, Ovaries, and Seminal vesicles have both enzymes
(they LOSe sorbitol).
Tissues with Aldose reductase only
L - Lens has primarily aldose reductase.
u
R - Retina
K - Kidneys
S - Schwann cells
Have only aldose reductase (LuRKS).
Urea cycle
ornithine can create and assemble Fn A Urea!
