Olson Flashcards

This refers to the enzyme-catalyzed processes in the body that metabolize macronutrients (carbohydrates, fats, and proteins)

These are reactions that capture chemical energy in the form of ATP. They are typically oxidative and use NAD or FAD as a coenzyme factor.

Catabolic pathways are typically ________ and use ____ or _____ as a coenzyme factor

These combine small molecules to make complex molecules. These reactions require energy. They are generally reductive and use NADPH as an electron donor.

Anabolic pathways are generally ________ and use ______ as an electron donor.

This organ transports ions to maintain membrane potential; integrates inputs from the body and surroundings; and sends signals to other organs

This organ secretes insulin and glucagon in response to changes in blood glucose concentration

This organ processes fats, carbohydrates, and proteins from the diet; synthesizes and distributes lipids, ketone bodies, and glucose for other tissues; and converts excess nitrogen to urea

This organ carries nutrients from the intestine to the liver

This organ absorbs nutrients from the diet, moves them into blood or the lymphatic system

This organ uses ATP to do mechanical work

This organ synthesizes, stores, and mobilizes triacylglycerols

This organ carries lipids from the intestine to the liver

What are the macronutrients from the diet?

Within the Glycolysis Pathway, Glucose is converted to what three molecules? Where does this occur?

Within the Pyruvate Dehydrogenase Complex Pathway, Pyruvate is converted to what 3 molecules? Where does this occur?

Within the Beta-Oxidation Pathway, Fatty Acid is converted to what four molecules? Where does this occur?

The oxidation of Acetyl CoA results in reduced ______ and ______. These compounds carry the electrons derived from oxidizing Acetyl CoA to flow through the electron transport chain to drive the synthesis of ATP

Acetyl CoA is usually oxidized through what pathway?

Acetyl CoA is synthesized into other energy containing compounds for storage or distribution to other tissues. During the _____ state:
Acetyl CoA + Oxaloacetate are converted to Fatty Acids
This occurs in the Cytosol

Acetyl CoA is synthesized into other energy containing compounds for storage or distribution to other tissues. During the _____ state:
Acetyl CoA is converted to Ketones
This occurs in the Mitochondria

What two pathways produce free glucose?

Name the Pathway:
Amino Acids, Glycerol, or Lactate is converted to Glucose

Name the Pathway:
Glycogen is converted to Glucose

This cycle requires metabolic adaptations and changes in the specific functions of internal organs

The feeding cycle is under the control of _______, and the fasting cycle is under the control of _______ and ________. These hormones have antagonistic effects.

Does the hormone Insulin in the feeding cycle increase or decrease Glycogenesis, Gluconeogenesis, Ketogenesis, and Lipolysis?

Do the hormones Glucagon and Epinephrine in the fasting cycle increase or decrease Glycogenesis, Gluconeogenesis, Ketogenesis, and Lipolysis?

This is a polypeptide hormone that is synthesized as a preprohormone that is heavily processed prior to secretion.

This hormone is synthesized and secreted from a regulated exocytosis pathway in the beta-cells portion of the islets that make up the endocrine pancreas

After consuming a meal, glucose levels in the portal circulation increase or decrease?

Following a meal, blood levels of glucose (increase/decrease)? Insulin (increase/decrease)? Glucagon (increase/decrease)?

The insulin receptor is a ______ ______ enzyme that is activated when it binds to insulin. This sets off a cascade of intracellular phosphorylation events that change the function of the target cell.

The activated insulin receptor activates what four functions?

The activated insulin receptor inhibits what three pathways?

What are the counterregulatory hormones (2)? These are the hormones that oppose the actions of insulin, and function in the fasting state when insulin levels are low.

The specific cell surface receptors of glucagon and epinephrine are what type? Activation of these receptors increases intracellular levels of _______, a second messenger. This changes the function of the target cell.

Secretion of glucagon from ____ cells is stimulated by _________, and inhibited by _______ and _______.

Epinephrine is secreted from the ______ _______ in response to _________ under the action of the sympathetic nervous system.

Glucagon and epinephrine increase the biological actions of what 5 things? What does it decrease the biological actions of?

This state is the 2-4 hour period following ingestion of a meal. Nutrients are being digested in the intestines, and delivered to the body.

In the Absorptive or Fed State, is the metabolism anabolic or catabolic?

What is the dominant hormone that regulates the absorptive or fed state?

What is the function of the intestine during the absorptive or fed state?

What is the function of the liver during the absorptive or fed state?

In the fed state, the liver is a _______ organ

When Glucose enters the liver during the fed state, it can be shuttled into the hexosmono-phosphate shunt pathway (HMP). What does this pathway produce?

What is the function of adipose tissue during the absorptive or fed state?

How does Glucose enter the Adipocyte?

Insulin promotes storage of fat in what 3 ways?

What is the function of skeletal muscle during the absorptive or fed state?

What is the most important fuel for resting muscle in the fed state? What is a secondary energy substrate?

Muscle is able to remove what molecule from branched-chain amino acids?

What is de novo fatty acid synthesis, or de novo lipogenesis?

What hormone promotes lipogenesis through phosphorylation cascades and increasing the rates of synthesis of transcription factors that regulate lipogenic enzmes?

What two organs are responsible for lipogenesis?

What is the primary source for de novo fatty acid synthesis?

This organ synthesizes new fatty acids for esterification into triacylglycerol, and packaging as VLDL particles for distribution throughout the body. This process is driven by the availability of excess acetyl CoA and NADPH substrates required for the reaction

This organ synthesizes new fatty acids from glucose taken up after a meal. The triacylglycerol is stored in the adipose tissue awaiting mobilization during periods of fasting.

What is the primary source of glycerol phosphate backbones for esterification of new fatty acids into triacylglycerol

When does de novo fatty acid synthesis occur in the liver and adipose tissue?

Cytosolic acetyl CoA comes from acetyl CoA that is produced in the ____________ as a result of glycolysis. The acetyl CoA is converted to _______, which is able to either flux through the Krebs cycle, or cross the inner mitochondrial membrane to enter the cytosol.

Within the mitochondrial matrix,
Oxaloacetate + Acetyl CoA ---> Citrate

The citrate can then cross the inner mitochondrial membrane.
What enzyme catalyzes this reaction? What is given off as a by-product?

After crossing through the inner mitochondrial matrix,
Citrate + CoA --> Oxaloacetate + Acetyl CoA

This is how we get acetyl CoA into the cytosol, since there are no CoA carriers.
What enzyme catalyzes this reaction? What molecule is required for this reaction to take place?

What is the major pathway for getting NADPH into the cytosol? How many NADPH molecules are produced for every glucose that enters this pathway? What is the major source?

Why is it so important to get Acetyl CoA and NADPH into the cytosol?

What enzyme acts on Oxaloacetate that is produced as a result of citrate lyase in the cytosol? This is a minor source for generation of what?

What are the two uses of Malonyl CoA?

The first important regulated step in the synthesis of Malonyl CoA is the synthesis of Malonyl CoA from Acetyl CoA in the cytoplasm. What enyzme catalyzes this reaction? What are two methods by which this reaction is regulated?

The synthesis of Palmitate is a multi-step reaction that is catalyzed by what complex? This reaction begins with 1 molecule of Acetyl CoA as a primer and 1 molecule of Malonyl CoA to elongate the chain. A series of reactions are required to produce a reduced hydrocarbon chain. How many times is the cycle repreated to produce Palmitic Acid, a ___ C Saturated Fatty Acid?

What are the three important roles Glucose metabolism plays in Palmitate Synthesis?

To synthesize the newly synthesized fatty acids into triacylglycerol, ________ ________ backbones are required. What are the two sources of this in the liver? How is it generated by adipose tissue?

In order to synthesize triacylglycerol from new fatty acids, the fatty acids must be activated to ___________, and these are esterified to ____________ in a 4 step reaction.

In the synthesis of triacylglycerol from new fatty acids, step one in the reaction involves the conversion:
Glycerol Phosphate ---> Lysophosphatidic Acid

What enzyme catalyzes this reaction? What is required for this reaction to take place, and what is given off as a by-product?

In the synthesis of triacylglycerol from new fatty acids, step two in the reaction is:
Lysophosphatidic Acid --> Phosphatidic Acid (DAG phosphate)

What enzyme catalyzes this reaction? What is required for this reaction to take place, and what is given off as a by-product? What is Phosphatidic Acid a pre-cursor of?

In the synthesis of triacylglycerol from new fatty acids, step three in the reaction is:
Phosphatidic Acid (DAG phosphate --> Diacylglycerol

What enzyme catalyzes this reaction? What is required for this reaction to take place, and what is given off as a by-product?

In the synthesis of triacylglycerol from new fatty acids, step four in the reaction is:
Diacylglycerol ---> Triacylglycerol

What enzyme catalyzes this reaction? What is required for this reaction to take place, and what is given off as a by-product?

Fat stores are sufficient to meet energy needs for about ____ months

What do the hormones of fasting activate? What are the three hormones of fasting?

What hormone is secreted from the pancreas in response to lowering insulin levels? It activates a G-protein coupled receptor, and results in an increase in _______, the second messenger that is responsible for changing liver function to support fasting metabolism?

What hormone is secreted from adrenal glands and activates the adrenergic receptors on most tissues, including heart, skeletal muscle, adipose tissue, and liver? The adrenergic receptors are also G-protein coupled receptors, and results in the activation of ______.

What hormone is secreted from adrenal glands and activates the glucocorticoid receptor, which is a member of the Nuclear Steroid Receptor superfamily? The activated glucocorticoid receptor regulates the transcription of proteins and enzymes that regulate fasting metabolism. The secretion of this hormone is higher as "stress" is increased. It is secreted slowly, and induces longer term changes.

An activated ________ receptor regulates the transcription of proteins and enzymes that regulate fasting metabolism

During fasting metabolism, the liver becomes a ________ organ that secretes _______. It also oxidizes ______ _______ and produces _________. Both of these products secreted by the liver are used by other tissues for energy metabolism and synthesis of ATP.

During fasting metabolism, Glucose exits the liver through what receptor type?

During fasting metabolism, the amino acids, glycerol, and lactate that enter the liver enter into ___________, or energy metabolism.

During fasting metabolism, adipose tissue is under control of what hormone? This hormone activates the Hormone Sensitive Lipase, which cleaves triacylglycerol, allowing free fatty acids and glycerol to be secreted from adipose stores.

Hormone Sensitive Lipase, involved in adipose tissue during fasting metabolism, is activated by ___________ and deactivated by _________.

An increase in insulin levels during fasting metabolism can degrade ______ and activate phosphates that make ________ ________ ________ active.

Resting skeletal muscle and heart rely heavily on ______ ________ ________ during starvation.

The normal substrate for the brain is glucose. As fasting proceeds, the brain adapts to using ______, and will function quite well using this.

What is an important pathway for driving ATP synthesis in liver, skeletal muscle and heart under fasting conditions?

What are the two ways in which free fatty acids are delivered to the liver, skeletal muscle and heart under fasting conditions?

What is the rate-limiting step of beta-oxidation of fatty acids?

Beta-oxidation of fatty acids takes place in the inner mitochondrial matrix where the enzymes that mediate this process are located. The inner mitochondrial membrane is not permeable to CoA or derivatives of CoA. How is this transport problem solved?

Carnitine is obtained from the diet, or synthesized in the liver and transported to other tissues. _______ has the highest concentration of carnitine because it has the highest concentration of mitochondria and highest rate of beta-oxidation.

This is a congenital syndrome resulting from abnormal synthesis of carnitine or impaired cellular uptake of carnitine. The deficiency can be systemic or in muscle only. This deficiency occurs most often in people who consume a complete _____ diet. If this is systemic, it prevents synthesis of _______.

What molecule inhibits the Carnitine Shuttle? This prevents oxidation of fatty acids to take place under conditions when fatty acid synthesis is occuring

The beta-oxidation pathway is a multi-step pathway that sequentially reduces a 16-C fatty acid by ___ carbons at a time.

A carnitine-palmitoyl transferase-___ deficiency affects fatty acid oxidation in liver. This impairs gluconeogenesis during fasting.

A carnitine-palmitoyl transferase-___ deficiency occurs primarily in muscle and heart. This is accompanied by muscle weakness and intolerance to fasting.

This is the most common inborn error of metabolism. Beta-oxidation proceeds until the fatty acyl chain has been shortened to medium acyl chain length. The partial oxidation products are excreted in urine as carnitine esters. People with this deficiency are reliant on a high carbohydrate diet, and unable to tolerate long periods of fasting.

What is an alternative form of fuel that can be used by several tissues in the body? These are produced only in the liver, and can be used by most tissues, but cannot be used by the liver.

This is the formation of ketone bodies from acetyl CoA

What three molecules make up Ketone Bodies?

Ketone body synthesis occurs during _________ when the rate of beta-oxidation of fatty acids exceeds the capacity of the tricarboxylic acid cycle to fully oxidize acetyl CoA. Flux through the tricarboxylic acid cycle is diminished because _________ is being used for gluconeogenesis.

The purpose of ketogenesis is to regenerate a pool of free ______ _____.

This is the synthesis of compounds from Krebs cycle intermediates

When gluconeogenesis is high, the ________ pathways are reducing the number of Krebs cycle intermediates and reducing the ability of acetyl CoA to be oxidized through the Krebs cycle

In the fasted state, _________ is the major cataplerotic pathway.

In the fed state, _________ is the major cataplerotic pathway.

In the fasted state, amino acids feed into the Krebs cycle to produce ________, which can then be used for gluconeogenesis.

Where does synthesis of ketone bodies occur within the liver cell?

Why can't the liver use ketone bodies?

The adaptations that occur during the fasted state are driven by _____ levels of insulin, ______ glucagon, _____ epinephrine, and ______ cortisol levels as fasting proceeds.

When switching from glycolysis to beta-oxidation when converted to the fasting state, what cycle is responsible for shutting off fatty-acid synthesis? This causes glycolysis to be shut off by shutting off the flow of carbs into muscle.

The human body is only about ____% efficient in converting food into work.

What are the three main energy sources of working muscles?

In the phosphagen system (energy-rich phosphate compounds), ATP is the substrate for myosin. All ATP can be hydrolyzed in ___ to ___ seconds. The ATP pool can be regenerated from the _______ _______ pool in muscle. This can supply ATP for _____ to ______ seconds.

The second energy source for working muscles is anaerobic glycolysis from blood glucose and stored muscle glycogen. This supports vigorous activity from ___ seconds to ___ minutes. This pathway does not require oxygen, so ______ _____ will build up. Acidification of tissues will result in pain following the bout of activity.

Anaerobic exercise is typified by sprinting or weight lifting. This activity is dominated by the activity of the ______-_______ muscle fibers. These fibers are ________.

The third energy source for working muscles is oxidative metabolism, which is approximately 10x more efficient than the anaerobic glycolysis. However, it is limited by what?
The major fuels for this type of exercise are ______ _____ and ______, which are metabolized to completion (no lactate build-up). This can only occur during aerobic exercise.

Aerobic exercise is typified by long-distance running, swimming, etc. It involves prolonged activity that is carried out at a lower intensity, but long duration. This type of exercise involves what type of muscle fibers? They have an abundance of mitochondria, and appear red due to what?

Metabolism in exercise is under what type of control? The sympathetic nervous system regulates blood flow to increase perfusion of the working muscles

__________ is regulated by muscle contraction and catecholamines

_______ release precedes the exercise activity and prepares the muscle for activity by starting to activate the glycogenolysis cascade.

The nerve impulse resulting from muscle contraction signals the release of ________ from the sarcoplasmic reticulum, which activates ________ _________.

Fatty acid oxidation is important in endurance exercise. The fatty acids are derived from ______ ______. Lipolysis of triacylglycerol stores adrenergic stimulation by the sympathetic nervous system.

Fatty acid oxidation provides about ___% of the total energy required for high intensity endurance exercise. The remaining energy comes from where?

Why doesn't the liver provide significant glucose for exercise?

Is the Cori cycle active during exercise?

Intensity: work done/ unit of time. This is also referred to as power.

Light exercise is ____ W
Moderate exercise is _____ W
Heavy exercise is ______ W

Intensity of exercise can be judged by measurement of the rate of oxygen consumption (VO₂ max). Intense exercise is carried out at about _____% VO₂ max. Light exercise would be about ____% VO₂ max.

______ ______ is required for maintaining aerobic power during intense exercise. Light exercise will not mobilize these stores.

Substrate utilization of muscle can be measured by indirect calorimetry. This measuers CO₂ production/ O₂ consumed, also known as the Respiratory Quotient (RQ).

An RQ of ____ means that only carbohydrate is being used.
An RQ of _____ measn that only fat is being oxidized.

This type of fat distribution is characterized by a waist to hip ratio of >0.8 for women, and >1.0 for men. This is associated with increased visceral obesity and metabolic diseases.

This type of fat distribution is associated with lower body obesity largely due to increased subcutaneous fat. This is not as tightly linked with metabolic disease.

________ adipocytes are more metabolically active, and tend to mobilize fatty acids more rapidly than _________ adipose. The cytokines that are secreted from adipocytes enter the portal circulation more rapidly when they are secreted from _______ adipose.

What three cytokines are secreted from adipose tissue?

How does the size and number of adipocytes change as weight gain increases?

Body mass is based on energy balance (the difference between energy intake, and energy expenditure). We gain weight when we are in ________ energy balance (intake _____ than output) and we lose weight when in ________ energy balance (intake _____ than output)

What are the two genetic contributions (or evidence for them)?

This is an adipocyte-derived peptide hormone that crosses the blood-brain barrier. The hypothalamus has cell-surface receptors that bind it, and signal a cascade of events that lead to reduced food intake and increase in energy expenditure. This helps regulate body mass.

What is the effect of insulin during hyperinsulinemia?

Short-term signals from the intestinal tract control hunger and satiety, and are useful for signaling cessation of a specific meal. These factors are secreted by the gut or stomach and ultimately signal through hypothalamic neurons. What are they?

This is a constellation of metabolic abnormalities that include:
Glucose Intolerance
Insulin Resistance
Hyperinsulinemia
Dyslipidemia
Hypertension

What can it lead to?

What is the key to maintaining weight loss, and improving hypertension? This alone does not reduce body mass, however. This must be done in conjunction with a calorie-restricted diet. Together, this can prevent development of full-blown __________.

To lose one pound, you need an energy deficit of _______ calories.

A solid goal for weight loss is to achieve ____% loss over a ____ month period of time. This is more maintainable because it is a gradual loss

What are the three types of calorie-restricted diets utilized for weight loss?

How does a Ketogenic Diet work?

This is a chronic progressive disease resulting from chronic insulin resistance and relative deficiency of certain physiologic actions of insulin

What are the three factors that contribute to insulin resistance and Type II Diabetes?

Insulin resistance develops with obesity. When does it progress to full-blown diabetes?

To detect insulin resistant, what type of insulin levels should be measured?

Insulin resistance in the liver primarily affects __________. Insulin is not able to suppress it, so there is a high rate of glucose secretion.
On the other hand, insulin is able to activate de novo fatty acid synthesis and cholesterol synthesis, so there is a high level of _______ particle secretion that is loaded with cholesterol.

This is an autoimmune disease that results in destruction of the islet cells of the pancreas. These cells are the endocrine cells responsible for secreting insulin. The islet cells are made up of alpha, beta, and delta cells. It is the beta cells that produce and secrete insulin.

When is the clinical disease associated with Type I Diabetes manifested?

What are the symptoms associated with Type I Diabetes?

In Type I Diabetes, energy substrates are not properly metabolized and stored. There is no insulin-responsive ________ uptake into adipose tissue, heart, or skeletal muscle. In addition, when taken up into the liver, it is not converted into glycogen or new fatty acids.

In Type I Diabetes, energy substrates are not properly metabolized and stored. Fats are being mobilized from adipose tissue and also coming from the diet, so fatty acids are being taken up by the liver and resynthesized into _____ particles that do not contain much _________. The fatty acids are being oxidized in the liver, and converted to ketones at an excessive rate.

In Type I Diabetes, energy substrates are not properly metabolized and stored. Proteins that are broken down in muscle are sending ______ _______ back to the liver for gluconeogenesis

In Type I Diabetes, energy substrates are not properly metabolized and stored. _________ are slow to turnover because their cargo cannot be delivered to adipose tissue. Adipose tissue secretes a lipoprotein lipase when insulin levels are high. Without the lipoprotein lipase, the triacylglycerol content of __________ cannot be cleaved and taken up by adipose tissue.