Chapter 8 - Metabolism Flashcards
What is energy?
Energy is the capacity to perform work. Energy has many forms including chemical, mechanical, electrical, heat, solar, and nuclear energy.
What 4 entities can be used for energy?
- Carbs
- Lipids
- Proteins
- Alcohol
True or False
Cells cannot release energy from vitamins, minerals, and water.
True
What is catabolic?
Energy releasing
What is anabolic?
Energy requiring
Most of energy released by the breakdown of macronutrients is capture in chemical form as …
Adenosine Triphosphate
Glycolysis
An anaerobic process that results in the conversion of glucose to 2 pyruvate molecules & a net gain of ATP molecules.
Citric Acid Cycle
Is a complex series of chemical reactions that result in the release of CO2 hydrogen ions, and electrons from intermediates of citrate.
Electron Transport Chain
The coenzymes NADH & FADH2 carry hydrogen ions and their high-energy electrons from the citric acid cycle to a linked series of enzymes called electron transport chain.
True or False
The electron chain does not produce water & ATP during aerobic energy metabolism.
False
What does the human body need to store more energy in fat cells that is in glycogen stores?
Triglycerides
What are the phases for “Fat Catabolism”
- Hormone sensitive lipase facilitates the removal of 3 fatty acids from the glycerol “backbone” of triglyceride molecule.
- In the cell’s cytoplasm, a fatty acid bonds to coenzyme A, forming an activated fatty acid.
- Fatty acid catabolism occurs in the mitochondria via beta-oxidation
- The acetyl CoA molecules that form during beta-oxidation enters the citric acid cycle and undergo catabolism for ATP production.
- The final step, carriers transport electrons to the electron transport chain, and ATP synthesis occurs.
What is Ketogenesis?
Occurs when acetyl CoA molecules cannot be used efficiently in the citric cider cycle. This condition results when the glucose supply in cells is insufficient and cells must rely on fatty acids as a major fuel.
What is a Ketogenic Diet?
Supplies most of its energy from fat. Such low-carbohydrate diets are often popular with people who want to lose weight. Limiting carbohydrate intake to less than 50 g per day not only rapidly depletes glycogen stores, but it also results in ketosis. Ketosis usually causes loss of appetite, so people who are trying to lose weight may find this symptom desirable. The long-term health effects of mild ketosis are unknown.
What are the side effects of “Ketogenic diet”?
constipation, hypoglycemia, hunger, vomiting, lack of energy, elevated blood lipids, and kidney stones.
a serious complication of diabetes that occurs when the body produces high concentrations of the ketone bodies, which lower the blood’s pH and cause severe ketosis.
Diabetic ketoacidosis (DKA)
What tissue is the main site to store triglycerides?
Adipose Tissue
What happens if the diet provides an excess of amino acids and cells do not need energy?
the amino acids will be stripped of their nitrogen group and used to make either glucose or fat.
“Chemical Messengers”
Stimulates & regulates cellular activities
Key hormones that direct or regulate metabolic activities are:
Insulin
Glucagon
Cortisol
Epinephrine
Thyroid hormone
Anabolic Metabolism
Insulin directs liver and muscle cells to slow down their glycogenolysis rates and increase their rates of glycogenolysis. Such actions shift glucose molecules into storage as glycogen.
Insulin also increases the fatty acid uptake and triglyceride synthesis of adipocytes. Furthermore, insulin stimulates protein synthesis in cells. To summarize, insulin promotes energy storage.
Catabolic Metabolism
Glucagon, cortisol, and epinephrine are hormones that instruct cells to use catabolic rather than anabolic pathways. The cells that synthesize these catabolic hormones release higher amounts of them in response to intense exercise, extreme stress, or starvation.
The collective activity of these hormones is to increase fuel mobilization from storage, so sources of energy are available for all of the body’s cells.
Overnight Fasting
The metabolic responses to an overnight fast include the use of liver glycogen stores, as well as glycogenesis, to maintain adequate blood glucose levels. Glucagon stimulates these pathways.
Starvation
During starvation, multiple catabolic hormones, including glucagon and cortisol instruct cells to release all fuel sources into the bloodstream.
Starvation is a highly catabolic state, characterized by glycogenesis, lipolysis, proteolysis, and ketogenesis. Although these metabolic responses are necessary for survival, the starving person is in a very dangerous metabolic state and will likely die if the lack of access to nourishing foods continues.
The body gets its energy to perform work from the ______ energy that is stored in macronutrients and alcohol
Chemical
Metabolic reactions may be ______.
Anabolic and Catabolic
Which of the following vitamins is often present in the chemical structure of coenzymes?
Multiple choice question.
Vitamin A
Vitamin B
Vitamin C
Vitamin D
Vitamin B
The conversion of ATP to ADP results from ______.
the cleaving of the bond between the last two phosphate groups of ATP
Mitochondria are responsible for
transfer energy released to ATP.
catabolize macronutrients.
Human cells obtain energy by
releasing chemical energy from macronutrients.
ATP production during anaerobic metabolism is __________ during aerobic metabolism.
much less than
Metabolism is the sum of chemical reactions that occur in living cells including ______.
Metabolism is the sum of chemical reactions that occur in living cells including ______.
During anaerobic conditions, pyruvate is converted to ______.
Lactic acid
Which of the following statements best describes the relationship between enzymes and coenzymes?
Coenzymes will often help enzymes catalyze reactions.
When an ATP molecule loses its third phosphate group, it becomes ______.
adenosine diphosphate (ADP)
_______ are “powerhouse” organelles that synthesize most of the ATP that cells need to function
Mitochondria
Where is the primary site of glycogen degradation to provide tissues with energy?
Liver
During __________ metabolism, adequate oxygen is present allowing mitochondria to make lots of ATP.
Aerobic
A product of anaerobic metabolism of pyruvate?
lactic acid
lactate
Gluconeogenesis is the making of glucose from ______.
pyruvate
most amino acids
lactate and glycerol
Where does glucose go after it is degraded in the liver?
Bloodstream
Stages of glucose breakdown in order
- Glycolysis
- Pyruvate > Acetyl CoA
- Citric Acid Cycle
- Electron Transport Chain
When adequate oxygen is present in a cell, mitochondria can make lots of ATP through ______ metabolism.
Aerobic
during _____ conditions, each molecule of pyruvate converts to lactic acid.
Anaerobic
Define the word gluconeogenesis based upon the meaning of the following segements: “gluco” = ________, “neo” = __________, “genesis” = __________
Glucose
New
Formation
The human body stores more energy in _________ than in _________.
fat cells; glycogen stores
Steps of energy production from ATP in order.
- Enzyme cleaves bond btwn last 2 phosphate
- ATP molecule loses power
- ADP is formed
Beta-oxidation is the chemical pathway that breaks down ______.
Fatty acids
The nutrients provides the greatest energy density?
Triglycerides
Liver cells convert extra acetyl CoA molecules to ____________ which are known as ketone bodies.
acetoacetate
acetone
beta-hydroxybutyrate
Steps to explain how triglyceride is stored within the cell.
- Triglycerides are circulated in VLDL
- Lipoprotein lipase cleaves glycerol backbone from 3 fatty acids
- Triglyceride components enter the cells
- Three fatty acids attempt to glycerol molecule forming triglyceride molecules
During beta-oxidation, fatty acid molecules are separated into ______ carbon segments that are converted to ______.
2, acetyl CoA
The first priorities for amino acids derived from proteins are to ______.
synthesize hormones
synthesize enzymes
create structural molecules
Which vitamin deficiency would have a potentially limiting effect on protein metabolism?
B-6
The amount of ATP formed by catabolism of an amino acid depends on
Acetone
Factors may cause differences in the storage capacity of fat and glycogen between individuals?
dietary intake
physical fitness
body composition
______ ________ ________ is an enzyme that cleaves apart a triglyceride molecule leaving 3 fatty acids and a glycerol backbone.
Hormone Sensitive Lipase
Once the basic functions of amino acids have been met (e.g., synthesizing enzymes), the remaining amino acids can be used for energy or converted to ______.
Fatty acids
Glucose
After eating a combo meal from the local fast food joint, triglycerides get absorbed and
incorporated into VLDL.
flood into the liver.
What is required before an amino acid can be used for ATP production?
Pyridoxal phosphate must be available.
The nitrogen group must be removed.
The pathway by which glucose is stored as glycogen in the liver and muscle cells is .
Glycogenesis
Excess amino acids may be ______.
used to make glucose
oxidized in the citric acid cycle
Major storage site for energy within the body
Adipose cells
Muscle
Liver
How much of the triglycerides absorbed from a meal get incorporated into very-low-density-lipoprotein?
A considerable amount
Glucose is stored as ______ through a pathway called glycogenesis.
Glycogen
When excess protein is consumed, the amino acids are stripped of the _____ and used to make either glucose or fat.
Nitrogen group
The hormone that activates receptors on cell membranes of adipocytes and muscle cells and signals glucose transport proteins is
Insulin
Insulin, glucagon, cortisol, epinephrine, and thyroid hormone are key ______ that direct or regulate metabolic activities.
Hormones
Cortisol promotes which of the following actions?
increases use of amino acids for gluconeogenesis
increases protein catabolism
Liver glycogen becomes depleted in an approximate range of - hours.
12 to 24 hours
is a catabolic hormone that is produced in the adrenal cortex of the adrenal glands.
Cortisol
What transports glucose from the blood into the cell?
Glucose transport proteins
Insulin, glucagon, cortisol, epinephrine, and thyroid hormone are key ______ that direct or regulate metabolic activities.
Hormones
_________ is the degradation of proteins in order to release amino acids
Proteolysis
Oxaloacetate is produced during ________ metabolism.
Glucose
True or False
Insulin is released in the post-absorptive state
False - it’s glucose
A drink that contains 13 to 14g of alcohol is considered ______.
A standard drink
True or False
During starvation, the body will break down glycogen and adipose tissue while not degrading protein
False
Alcohol is absorbed in the _____ and _____.
Small intestine
Stomach
When a diabetic is suffering from ketosis, you know that glucose cannot be utilized as a fuel source and that the patient is breaking down _____ as an alternative fuel source.
Fatty acids
The effects of alcohol on the body.
Increases risk of esophageal, liver, stomach, pancreas, and colon cancers
Interferes with nutrient absorption
Increases fat deposits in abdominal region
You might be at risk for an alcohol use disorder if you
drink to relax, forget your worries, or improve your mood.
lose interest in food as a result of your drinking habits.
drink alone.
Choose the true statements about caffeinated alcoholic beverages.
caffeine may make the person feel more alert
caffeine does not changed the body’s ability to metabolize alcohol
Which of the following fuel sources would get metabolized first if ALL were present in the liver at the same time?
Alcohol
Which of the following fuel sources would get metabolized first if ALL were present in the liver at the same time?
may not meet the legal standard for a safe food additive
makes the person feel more alert
masks the effects of the alcohol and a person may drink more
