Metabolism and Alcohol Flashcards
metabolism
The balance in the body between the reactions that build things up, repair, or store things in the body (anabolism) and the reactions that break things down (catabolism)
anabolism
reactions that build things up, repair, or store things in the body
catabolism
reactions that break things down
ATP
A substance present in all living cells that provides energy for many metabolic processes and is involved in making RNA
enzymes
Facilitators of metabolic reactions
coenzymes
a nonprotein compound that is necessary for the functioning of an enzyme
pyruvate
output of the metabolism of glucose known as glycolysis
acetyl-coA
molecule that participates in many biochemical reactions in protein, carbohydrate and lipid metabolism
Oxaloacetate
intermediate of the citric acid cycle, where it reacts with acetyl-CoA to form citrate, catalyzed by citrate synthase
TCA cycle/The Citric Acid Cycle/Krebs Cycle
the three-stage process by which living cells break down organic fuel molecules in the presence of oxygen to harvest the energy they need to grow and divide
electron transport chain
A group of compounds that pass electron from one to another via redox reactions coupled with the transfer of proton across a membrane to create a proton gradient that drives ATP synthesis
glycolysis
the breakdown of glucose by enzymes, releasing energy and pyruvic acid
anaerobic
doesn’t need oxygen
aerobic
needs oxygen
mitochondria
membrane-bound cell organelles that generate most of the chemical energy needed to power the cell’s biochemical reactions
lactate
the process by which cells produce energy without oxygen around
Gluconeogenesis
process of making glucose from its own breakdown products or from the breakdown products of lipids (fats) or proteins
ketone bodies
Chemicals that the body makes when there is not enough insulin in the blood and it must break down fat instead of the sugar glucose for energy
keto acid
organic compounds that contain a carboxylic acid group and a ketone group
Acetaldehyde
an intermediate in alcohol metabolism that is responsible for many hangover effects
fibrosis
development of fibrous connective tissue as a reparative response to injury or damage
Microsomal ethanol-oxidizing system (MEOS)
a system of enzymes in the liver that oxidize not only alcohol, but several classes of drugs
Wernicke-Korsakoff Syndrome
a condition that is similar to dementia and is caused by drinking too much alcohol (lack of thiamin)
Alcohol dehydrogenase
the enzyme responsible for alcohol metabolism
What is the difference between anabolic and catabolic reactions? What are examples of both?
-anabolic: include the making of glycogen, triglycerides, and protein
~ synthesis of glycogen from glucose
-catabolic: include the breakdown of glycogen, triglycerides, and protein
~process of food digestion
The breakdown of glucose for energy results in which high energy compound? Why is this
important?
ATP
-It’s the only chemical in the body that can be directly used as energy
In which part of the cell does glycolysis happen? Which part of the cell does the TCA cycle
happen?
- cytoplasm
- mitochondrion
Diagram and describe the main steps of glycolysis. Start with glucose and end with pyruvate
hexokinase
-conversion of D-glucose into glucose-6-phosphate
Phosphoglucose Isomerase
-rearrangement of glucose 6-phosphate (G6P) into fructose 6-phosphate (F6P) by glucose phosphate isomerase
Phosphofructokinase
-Phosphofructokinase, with magnesium as a cofactor, changes fructose 6-phosphate into fructose 1,6-bisphosphate
Aldolase
-Aldolase splits fructose 1, 6-bisphosphate into two sugars that are isomers of each other.
Triosephosphate isomerase
-triosephosphate isomerase rapidly inter- converts the molecules dihydroxyacetone phosphate (DHAP) and glyceraldehyde 3-phosphate (GAP)
Glyceraldehyde-3-phosphate Dehydrogenase
-(GAPDH) dehydrogenates and adds an inorganic phosphate to glyceraldehyde 3-phosphate, producing 1,3-bisphosphoglycerate
Phosphoglycerate Kinase
-Phosphoglycerate kinase transfers a phosphate group from 1,3-bisphosphoglycerate to ADP to form ATP and 3-phosphoglycerate
Phosphoglycerate Mutase
-The enzyme phosphoglycero mutase relocates the P from 3- phosphoglycerate from the 3rd carbon to the 2nd carbon to form 2-phosphoglycerate
Enolase
-The enzyme enolase removes a molecule of water from 2-phosphoglycerate to form phosphoenolpyruvic acid (PEP)
Pyruvate Kinase
-The enzyme pyruvate kinase transfers a P from phosphoenolpyruvate (PEP) to ADP to form pyruvic acid and ATP
The fate of pyruvate can be anaerobic or aerobic.
How does this affect how we use pyruvate?
- aerobic: pyruvate is shuttled into the mitochondria and continues through the Citric Acid Cycle
- anaerobic: pyruvate goes through a reduction reaction that results in the production of Lactate
Describe the main steps of fatty
acid oxidation.
-dehydrogenation to create FADH2
and a fatty acyl group with a double bond in the trans configuration;
-hydration across the double bond to put a hydroxyl group on carbon 3 in the L configuration;
-oxidation of the hydroxyl group to make a ketone; and
-thiolytic cleavage to release acetyl-CoA and a fatty acid two carbons shorter than the starting one.
Diagram and describe the TCA cycle. What does the TCA cycle yield? What are the important
intermediates and by-products?
- metabolizes acetate derived from carbohydrates, proteins, and fats to form adenosine triphosphate (ATP)
- intermediates: oxaloacetate and citrate
- byproducts: Co2 and water
How does the electron transport chain function?
it pumps and creates a gradient
What happens to the storage of nutrients during the “feasting” state?
the body stores a small amount of glycogen and much larger quantities of fat
What does our body do to adapt during the “fasting” state?
making glucose, creating an alternative fuel, conserving energy
What makes up one alcoholic beverage?
.5 oz. of pure ethanol
What is the definition of moderation for females and males?
1 drink for females, 2 for males
What is the enzyme that breaks down alcohol?
alcohol dehydrogenase
Why are females more likely to have a higher blood alcohol content even if muscle mass,
height, weight, all other anthropometric variables are the same as a male?
they make less alcohol dehydrogenase
Why does alcohol intake lead to increased adipose tissue? (hint: describe the metabolism of
alcohol)
- alcohol dehydrogenase turns alcohol into acetaldehyde
- acetaldehyde dehydrogenase turns to acetaldehyde into acetate
- acetate is turned into acetyl CoA
- When excess acetyl CoA is produced that cannot be processed through the Krebs cycle, the acetyl CoA is converted into triglycerides and fatty acids to be stored in the liver and adipose tissue
Name the 3 stages of liver deterioration and briefly describe each stage.
○ 1st=fatty liver seen in heavy drinkers, interferes with nutrients and O2
§ Reversible
○ 2nd stage=fibrosis (alcoholic hepatitis)
§ Some liver cells can regenerate
§ Nutritional help and stop drinking
○ 3rd and final stage=cirrhosis
§ Damage is almost irreversible
Is alcohol a stimulant or depressant? What hormone does this impact in relation to
hydration status?
-depressant
-Depression of antidiuretic hormone
§ Loss of body water
§ Loss of important minerals
Explain how alcohol can lead to malnutrition.
Alcohol contributes to malnutrition by replacing foods needed for essential nutrients and by interfering with absorption, storage or metabolism of the essential nutrients
In which process is the cytoplasm involved?
glycolysis
The metabolic breakdown of glucose to pyruvate is known as
glycolysis
Which of the following is a feature of aerobic metabolism?
Energy is produced more slowly than in anaerobic metabolism
In the Cori cycle, lactate is converted to glucose in the
liver
Which of the following statements is not true of pyruvate?
The pathway of pyruvate to acetyl CoA is reversible
In energy metabolism, glycerol can convert to
glucose or pyruvate
Once acetyl CoA is formed, it has two main options: to generate ATP or to
make fats
Which of these statements about the electron transport chain is true?
It captures energy in the ATP bonds
Which of the following compounds can be synthesized by carbohydrate, protein, and fat?
acetyl CoA
