Lecture #21 & 22 - Catabolism of Ethanol Flashcards
What enzymes convert ethanol into acetaldehyde?
Alcohol dehydrogenase (ADH) and microsomal ethanol oxidizing system (MEOS).
ADH and MEOS
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How toxic is acetaldehyde compared to ethanol?
Acetaldehyde can be as toxic or more toxic than ethanol.
What is the role of acetaldehyde dehydrogenase (ALDH)?
ALDH converts acetaldehyde into acetate in the liver mitochondria.
What type of molecule is acetate and what can it become in skeletal muscles?
Acetate is a short-chain fatty acid (SCFA) that can be converted into acetyl-CoA in skeletal muscles to produce energy via the Krebs cycle.
This process eliminates ethanol from circulation
How does the liver’s metabolism rate of alcohol affect blood alcohol concentration?
The liver can metabolize only one ounce of alcohol per hour; excess consumption results in increased blood alcohol concentration and possible intoxication.
What is the significance of the citrate that escapes the mitochondria in the context of alcohol intake?
When there is an abundance of alcohol intake, some of the citrate formed in the mitochondria escapes into the cytoplasm and is converted back into acetyl-CoA, which is a substrate for the DNL pathway (de novo lipid synthesis); allows the body to form fatty acids from scratch
What happens to fatty acids produced in the liver during excessive alcohol intake?
They can be converted into non-esterified fatty acids (NEFAs), VLDLs (a precursor to LDLs, leading to dyslipidemia), or esterified to form triglycerides, causing hepatic steatosis (fatty liver disease).
What potential health issues can arise from the accumulation of acetaldehyde?
It can form adducts, causing diseases such as cancer, and lead to insulin resistance and cell damage resulting in inflammation and further insulin resistance.
What potential health issues can arise from the accumulation of acetaldehyde on its own
On its own, it can also affect insulins ability to signal in the cell causing insulin resistance
What potential health issues can arise from the accumulation of acetaldehyde along with ethanol
Along with ethanol, it can cause damage to the cells leading to inflammation, which also leads to insulin resistance
