Ch5:

Question 1

What is brown adipose tissue?

Answer 1

It is metabolically active
Different than white fat
It is energy-burning, contributes to increasing energy expenditure
It has high vascularity, abundant mitochondria
Special mitochondria promote thermogenesis at expense of ATP
Have H+ pores in inner membranes formed of uncoupling protein)

Question 2

What does thermogenesis mean?

Answer 2

Heat production in the body

Question 3

What is brown fat thermogenesis triggered by?

Answer 3

Ingestion of food
Prolonged exposure to cold temperature
Exercise

Question 4

Review this diagram of the synthesis of triacylglycerols and phospholipids

Answer 4

Question 5

What is the ideal, healthy level of total cholesterol

Answer 5

<200 mg/dl

Question 6

What is the ideal, healthy level of LDL-cholesterol

Answer 6

<100 mg/dl

Question 7

What is the ideal, healthy level of HDL cholesterol

Answer 7

> 60 mg/dl
(or equal to)

Question 8

What is the ideal, healthy level of triglycerides

Answer 8

<150 mg/dl

Question 9

What are some characteristics of alcohol metabolism

Answer 9

It resembles a carbohydrate, but it is metabolized like a fatty acid
There are three ethanol oxidation systems:
- Alcohol dehydrogenase system (ADH)
- the microsomal ethanol oxidizing system (MEOS)
- Catalase System

Question 10

What is the alcohol dehydrogenase system (ADH)

Answer 10

This is how the majority of ethanol is oxidized
This occurs in the cytosol
ADH reduces Ethanol to Acetaldehyde with NADH
Reduced NADH is a byproduct of this reaction, so it accumulates when excessive ethanol is consumed

Question 11

What is the microsomal ethanol oxidizing system (MEOS)

Answer 11

It accounts for up to 20% of ethanol oxidation
It occurs in the ER
The CYP2E1 enzyme is a cytochrome P450 mixed function oxidase
NADPH is also oxidized in this reaction

Question 12

What is the catalase system

Answer 12

It occurs in the peroxisomes
It plays a minor role in the total ethanol oxidation
This reaction requires H2O2

Question 13

Here is the alcohol metabolism overview:

Answer 13

Question 14

What is the initial product of ethanol oxidation?

Answer 14

Acetaldehyde

Question 15

What happens to acetaldehyde

Answer 15

It is transported to the mitochondria and further oxidized to acetate by ALDH2

Question 16

What happens with NADH when excessive ethanol is consumed?

Answer 16

Reduced NADH accumulates in the mitochondria

Question 17

What is the final product of ethanol oxidation?

Answer 17

Acetate, which will be metabolized to acetyl-CoA and used for energy via the TCA cycle or for fatty acid synthesis

Question 18

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