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Flashcards in Lipids 5 Deck (12):
1

What is the key physiological role of brown adipose tissue?

Maintenance of core body temperature

2

What is shivering thermogenesis?

Involuntary muscle contraction
Elevates heat production in cold climates
In adult humans it can reach intensities equivalent to 40% of maximum oxygen consumption and involve the oxidation of mainly lipids and carbohydrates

3

What is brown adipose tissue?

A thermogenic tissue

4

Where was BAT first discovered?

In mice

5

Main function of BAT?

Heat production when activated by cold exposure (cold exposure results in massive blood flow increases to rodent brown adipose tissue)

6

What is white adipose tissue like?

Stores energy
Low in mitochondria
Fat sits in lipid vesicles
Pro-inflammatory

7

What's brown adipose tissue like?

Dissipates energy
High mitochondria
Anti-obesity
Lots of little lipid vesicles
PRDM16

8

What is the proton circuit?

UCP1 causes a proton leak across the inner membrane of the mitochondria, thereby dissipating chemical energy in the form of heat

9

Brown fat adipocytes are energy inefficient for ATP production but energy efficient for...

Heat production

10

What carries protons across membranes like UCPI?

DNP; 2,4 dinitrophenol

11

What activates BAT?

1. Stimulation of B-adrenergic receptors by norepinephrine (increases levels of cAMP)
2. Stimulation of deiodinase enzyme (D2)- converts thyroid pro hormone (thyroxine T4)
3. T3 stimulates expression of UCP-1 (increases UCPI; uncoupling of mito-respiration, loss of energy as heat; activation leads to increased uptake of substrate)

12

What has a lot of brown adipose tissue?

Newborn babies (keep organs warm)
Warms blood in surrounding blood vessels before its distribution to the periphery