Biochemistry L.1 Flashcards
(21 cards)
At what trimester does the pregnancy move into catabolic state?
Third trimester
FYI:
Anabolic state -> 1st and 2nd trimester
Catabolic= breakdown
Anabolic= building
What is the best independent predictor of gestational weight gain?
Prepregnancy BMI
Explanation:
How much weight gained during pregnancy MOSTLY depends on BMI before pregnancy (so imp, possible MCQ)
What is the energy and calorie consumption of the mother on the first trimester
Not changed
How many extra calories are need per day for a pregnant mother on her 3rd trimester?
450kcal/day
FYI:
2nd trimester -> 350kcal/ day
When do most changes to the basal metabolic rate happen?
In the third trimester
Why is there 106/180 kcal increase per day to the Basal Energy Expenditure BEE of pregnant women?
1) increased metabolism of uterus and fetus
2) increased cardiac and lung output
What is the RDA of protein for a pregnant woman that’s 70 kg ?
81grams/day
0.8 grams of protein per kg
So if 70 kg then 70x0.8=56 g/day before getting pregnant
Then add 25 kg
56+25=81
FYI:
RDA= Recommended Daily Allowence
The first half of gestation is protein metabolism is anabolic where protein storage increases, in the second half of gestation protein metabolism is catabolic, but there is still positive nitrogen balance and less urinary N2 excretion. Why is that?
1) decreased hepatic aa deamination
2) less urea synthesis
amino acid pool is directed towards tissue protein
Endogenous production increases with gestational age , paralleling fetal and
maternal needs [up to 30% by the 3rd trimester]. What is this molecule?
Glucose
How is glucose transferred through the placenta?
Facilitated diffusion by GLUT1. Concentration dependent (positive maternal-glucose gradient)
How is the placental transfer of glucose maintained?
Rapid oxidation of glucose by the fetus
How does leptin affect the hypothalamus?
Suppress the NPY pathway of the appetite regulatory center
When do maternal leptin serum levels peak?
Late second or early third trimester
What is the most important function of leptin during pregnancy?
Stimulates placental angiogenesis
What leptin receptor isoform is the soluble form and reduces leptin clearance and degredation?
OB-RA
How does the leptin resistance develop in pregnancy?
Increase in OB-RE soluble leptin receptor isoform
Kw= “soluble”
Placentas exposed to GDM exhibit what epigenetic modifications?
DNA methylation at the leptin and adiponectin genes
How would GDM lead to increased blood flow in placenta?
Inc. glucose -> high metabolism -> inc. oxygen consumption -> hypoxia -> endothelial dysfunction -> elevation in RNS, ROS, prostaglandin and purine concentration in the feto-placental circulation -> hypervascularization in placenta -> inc. BF -> this high input of nutrients and elevated circulation will be responsible for macrosomia in GDM.
What are the main hormones which influence beta cell function in early pregnancy?
Estrogen and progesterone
What do estrogen and progesterone the main hormones of in late pregnancy?
Insulin resistance
What does an increase in leptin and TNF-alpha levels contribute to?
Insulin resistance in GDM and in the third trimester of pregnancy
