Flashcards in Lab 13 Deck (151):
A condition in which blood glucose levels are below normal
The metabolic processes involved in the building of larger biomolecules from smaller ones is?
What is diabetes mellitus?
A disease marked by chronic elevated blood glucose levels
This type of diabetes mellitus is a "lifestyle disease"
Chemical reactions in which larger biomolecules are broken down into smaller ones is
The movement of substances from the lumen of the gastrointestinal tract into the body's extracellular fluid is?
This term, often applied to diseases, means the rate of occurrence.
The sum of all of the chemical reactions in the body
This type of diabetes mellitus is an autoimmune disease.
What is hyperglycemia
A condition in which blood glucose levels are above normal
The monomer for lipids is?
The monomer for protein is?
The process of breaking down stored fat into its monomer is called?
The monomer for carbohydrates is?
The monomer for nucleic acids is?
The storage form of carbohydrate is?
What is glycogenolysis?
The process of breaking down stored carbohydrates
The storage form of fat is?
When fatty acids are broken down into fatty acids, the product enters this energy pathway.
Citric acid cycle
The energy pathway in which the carbohydrate monomer is broken down is?
Epinephrine is this type of hormone.
Insulin and glucagon are produced in this gland.
Hormones produced in the adrenal cortex are this type
Oxytocin and vasopressin are secreted from this gland.
This type of hormone can enter the cell and act as a transcription factor.
Glucagon is secreted by these cells.
Hormones produced in the pancreas are this type.
Insulin is secreted by these cells.
This hormone is produced in the skin.
In this test, the patient refrains from eating, drinking anything other than water, and exercise for 8 to 12 hours before the test.
Fasting blood glucose test
In this clinical test, a patient is fed a given amount of glucose and is then monitored to see how the body handles the glucose.
Glucose tolerance test
A fasting blood glucose test result of 117 mg/dL, would be classified as?
A major consequence of living with chronic hyperglycemia is?
The glucose molecules form bonds with proteins- where they normally do not belong
What is glycation?
Adding glucose to other molecules
There are some studies that suggest that someone with diabetes mellitus has a normal number of insulin receptors, but they do not respond correctly. This reduced functionality of the receptors is called?
Hemoglobin A1C test is?
This clinical test is used to evaluate long-term exposure to high blood glucose levels
A glucose tolerance test result that remains below 150 mg/dL and is 110 mg/dL after 2 hours would be classified as?
One possible cause of diabetes mellitus is a decreased number of receptors or glucose transporters. A decrease in the production of such proteins is called?
Physical activity leads to an increase in the number of glucose transporters in the trained skeletal muscle cells. Increase production of proteins like these transporters is called?
Feedback loop for increase in blood glucose
Stimulus: increase in blood glucose
Sensor: Alpha & beta cells of pancreas
Afferent pathway: none
Integrating center: Alpha and beta cells of pancreas
Efferent pathway: Insulin
Effector: Hepatocytes, skeletal muscle cells, adipocytes
Effectors action: Increase in GLUT 2 & GLUT 4 activity; glycogenesis and lipogenesis
Response: decrease in blood glucose
Feedback loop for decrease in blood glucose
Stimulus: Decrease in blood glucose
Sensor: Alpha and beta cells of the pancreas
Afferent pathway: None
Integrating center: Alpha and beta cells of the pancreas
Efferent pathway: Glucagon
Effector: Hepatocytes only
Effectors action: Increased GLUT-2 activity, Glycogenolysis
Response: Increase in blood glucose
As the cells work, the demand for ______ increases
ATP adenosine triphosphate
All the chemical reactions in the body
Reactions that release energy and result in the breakdown of large biomolecules
Metabolic pathways that require a net input of energy & that synthesize small molecules into larger ones
What is digestion?
Chemical & mechanical breakdown of foods into smaller units that can be absorbed
What is absorption?
Transfer of substances from the lumen of the kidney of gastrointestinal tract to the extracellular space
What is incidence?
Rate, range or amount of occurrence or influence
An excess of glucose in the bloodstream, often associated with diabetes mellitus
Disease characterized by lack of or abnormal action of insulin
Fuels enter the body as food molecules, and the digestive system is responsible for?
Breaking them down (digesting) into smaller molecules that can be absorbed int he intestine. Some of the absorbed molecules will be used as building blocks for cellular structures, & others will be used as fuels for making ATP
The process of breaking down stored carbohydrate into its monomer is called?
Final product of glycolysis pathway?
In order to enter an energy pathway, fatty acids must be converted to?
Which pathway does Acetyl CoA enter?
What is the process of breaking down the fatty acid into acetyl CoA called?
What are the primary fuels for making ATP? What about protein?
Glucose and fatty acids. Protein can be catabolized to amino acids, which in turn can be converted to glucose in the liver (gluconeogenesis). But this will only happen to a significant degree if the body is running low in carbohydrate stores
Most important fuel for the cells.
Glucose. This carbohydrate is preferred fuel in the CNS. It is the primary fuel for high intensity, short duration physical exertions that last 20 seconds or more
The initial steps in the breakdown of glucose is?
An anaerobic process, but under aerobic conditions, the byproduct of glycolysis can be further broken down in the aerobic pathways
Fuel with the largest potential energy stores in the body
Fat can only be broken down by?
Aerobic processes. Therefore, energy from fat is not as readily available as that from carbohydrate, particularly when demands for oxygen increase
Rather than requiring neurons to deliver messages, endocrine cells secrete signal molecules called?
Hormones, which are delivered to their target cells through the blood stream. Target cells are those with receptors for that hormone
There are 3 chemical categories for hormones
Amines, peptides, and steroids
An amine hormone is derived from?
A single amino acid
Epinephrine is derived from?
The amino acid tyrosine
Peptide hormones are produced through?
Protein synthesis, and are chains of amino acids
Because amines and peptides are polar molecules, they bind to?
Membrane receptors to communicate with their target cells
Steroid hormones fall into what category?
The lipid or fat biomolecule category
Because steroids are non polar and lipophilic, they can?
Either bind to membrane receptors or pass through cell membranes and bind to receptors in the cytoplasm or cell nucleus
The non polar steroid hormones are?
Hydrophobic, and as a result they need to be attached to a protein carrier while they are in the blood
Because steroids can enter the cell, they often act as?
Transcription factors-turning genes on or off to stimulate or reduce protein synthesis by the cell
Cells of the adrenal cortex produce?
Only one class or hormones. For example, the cells of the adrenal medulla only produces amines, whereas the cells of the adrenal cortex produces steroid hormones
What are the names of the hormones produced there?
In which chemical class do these hormones belong?
Oxytocin & vasopressin (ADH).
Into which chemical class does this hormone fall?
Which type of hormone is it?
Those hormones most directly involved in glucose metabolism are?
Insulin and glucagon
These pancreatic peptide hormones are antagonistic to each other
Insulin and glucagon
When is insulin released
When blood glucose levels are high, and glucagon when glucose levels are low
During and immediately following the ingestion of food, insulin levels typically?
Increase to stimulate cells to put fuels into storage
Glucagon communicates with cells when blood glucose is?
Low and needs to be taken out of storage and made available for the cells
The academy of nutrition and dietetics, formerly the American dietetic association, has been promoting the concept of a?
The recommendations by the organization the academy of nutrition and dietetics, are based on current understanding of?
Nutritional demands on the body
The concept of nutrition or macromolecule balance should match the needs of the body in terms of?
Providing building blocks and fuel for optimum function
Dietary proteins are required for what?
Providing building blocks for the cells proteins
Fats are required for?
Production of cell membranes, steroid hormones, and stored fuel
Carbohydrates are essential as a fuel, but also for?
Production of hybrid molecules (e.g. glycoproteins)
Having too much or too little of any one of these biomolecule groups (fat, carbohydrates, proteins), may leave the systems of the body in a?
When eating food that is high in simple sugars (monosaccharides) and little else, blood glucose levels can?
Dramatically increase in a short period of time. This spike in blood glucose can be followed by a rapid drop, leaving the person feeling fatigued. If the high-monosaccharide intake was accompanied by other macronutrients (fat,protein), on the other hand, carbohydrate absorption from the gut would be slowed, reducing the probability of blood glucose spike
Blood glucose homeostasis involves?
Constantly functioning feedback loops
During and following a meal, blood glucose levels rise. What detects glucose levels?
The alpha and beta cells of the pancreas detect glucose levels and release hormones as needed to signal target cells to remove glucose from the blood when its high, or to release glucose into the blood when its low
The body cells responsible for taking up glucose and putting into storage are the?
Hepatocytes (liver) and skeletal muscles
What do hepatocytes (liver) and skeletal muscle cells do?
Responsible for taking up glucose and putting into storage. They will convert the glucose to glycogen, the storage form of carbohydrate in the body
Storage form of carbohydrates
Can adipocytes also remove glucose from the blood?
Yes but it is converted to and stored as fat called triglyceride
Storage form of fat
What happens when insulin binds to hepatocytes, skeletal muscle cells, and adipocytes?
They increase the activity of glucose transporters
What reduces blood glucose levels?
Once insulin is released and blood glucose returns to normal what happens?
The amount of insulin secreted by the beta cells of the pancreas is reduced
Between meals, glucose levels will fall. To maintain blood glucose levels, the liver will?
Transport glucose back into the blood
Acts as a warehouse and processing center for nutrients
The availability of glucose for transport into the blood is increased when?
The hormone glucagon binds to the hepatocytes
Glucagon is secreted from the?
Pancreatic alpha cells when blood glucose is low
Skeletal muscle cells do not release their glucose. What do they do?
They keep it in storage as glycogen until the cells need it to make ATP. Because adipocytes converted the glucose to fat, it is no longer available to return to the blood
What happens when liver glycogen is depleted?
Blood glucose levels are maintained by the breakdown of protein (primarily from skeletal muscle)
Proteolysis (the breakdown of proteins or peptides into amino acids by the action of enzymes) is followed by?
Deamination (the removal of an amino group from an amino acid or other compound) of the amino acids and the products are converted to glucose
Where does gluconeogenesis take place?
Primarily in the liver, can also take place in the kidney, but it only contributes significantly during starvation or when there is liver failure
Clinical measures of blood glucose are used to identify?
Individuals with or at risk for developing metabolic diseases such as diabetes mellitus. Also used in research settings to examine how the body handles the glucose in different foods or under different conditions (e.g. exercise, rest, stress, etc.)
What is the fasting blood glucose test?
Blood glucose is measured following an 8-12 hour fast. The individual will refrain from eating or drinking (except water), or of anything that might alter metabolism
What is the glucose tolerance test?
Requires the individual to fast for 8 to 12 hours. It begins with a fasting measure, then the person consumes a specific amount of glucose (75 grams). The blood glucose levels are monitored over a 2 hour period to see how levels change over that time
Normal: (Less than) <100-110 mg/dL
Normal: Remains less than 200 mg/dL over 2 hours and less than or equal to 140 mg/dL by 2 hours post ingestion
What is the hemoglobin A1C (HbA1c) test?
Reflects glucose exposure over the previous 3 months. Use to be used to monitor long-term glucose exposure in diabetes, but now it is also being used to diagnose diabetes mellitus.
Diabetes mellitus is?
The hemoglobin A1C (HbA1c) is often the preferred test because?
It does not require the individual to fast. However this test is not valid for all patients. There are certain racial/ethnic groups for whom the test lacks accuracy. Also does not reflect how the body handles glucose in the short-term, as a glucose tolerance test will
Tests conducted during annual physical exams may include?
The fasting blood glucose or the HbA1C test. These tests can alert clinicians to the development of diabetes mellitus
The main sign of diabetes mellitus is?
Increased blood glucose hyperglycemia
There are different causes of hyperglycemia, and these differences are distinguished by the?
Type of diabetes mellitus
There are two main types of diabetes mellitus
Type 1 and type 2
Ten percent of diabetes mellitus cases are?
Type 1 which is an autoimmune disease. The immune system targets and destroys the beta cells of the pancreas, which are responsible for producing insulin
What is insulin? What does lack of insulin result in?
The signal molecule responsible for communicating with cells that are responsible for removing glucose from the blood. Lack of insulin results in a reduction in glucose uptake by the cells, and more remaining in the blood
What is type 2 diabetes
Considered a lifestyle disease, meaning there are ways of avoiding or reducing the probability of developing that disease. One of the fastest growing diseases in developed or developing nations
Between _____ and ______, the incidence of diabetes in the United States has increased over ____%
1980 and 2011
Understanding this disease is very important for students pursuing careers in the allied health professions
According to the Centers for Disease Control and Prevention (CDC), risk factors for type 2 diabetes include
Older age, obesity, family history of diabetes, prior history of gestational diabetes, impaired glucose tolerance, physical inactivity, and race/ethnicity
Who is at a high risk for type 2 diabetes
African Americans, hispanic/latino americans, american indians, and some asian americans and pacific islanders
Some risk factors can be altered to reduce the risk or even reverse the disease state of diabetes type 2
Dietary and physical activity changes have been shown to reverse the signs of type 2 within weeks
Although obesity is often referred to as a "cause" of diabetes mellitus, changes in lifestyle do not reverse the amount of fat in 6 weeks. In many studies on the effects of lifestyle changes, the sign of type 2 diabetes have been completely reversed while?
The person remains obese.
One method of controlling obesity is bariatric surgery. Studies have reported that bariatric surgery in severely obese individuals with type 2 diabetes can?
Reverse or eliminate the disease in some individuals. However it is unclear whether the reversal was due to the surgery or the reduction in caloric intake following the procedure
The cause of type 1 diabetes is clearly identified.
When the cells that produce insulin are destroyed, effector cells do not receive messages because the efferent pathway, insulin, is not present
In pre-diabetes, insulin is?
Insulin levels are higher than normal, yet blood glucose levels remain above normal. What this suggests is that there is a breakdown in communication between the signal molecule insulin and its target cells
Diseases are often a result of the?
Breakdown of the cellular workers
In the case of type 2 diabetes mellitus, there may be a problem with the?
Receptors for insulin, glucose transporters, or any of the intermediates in the communication pathways inside the target cells
What is insulin resistance?
Decreased responsiveness of the cells to insulin
One proposed mechanism for the decreased responsiveness of the cells to insulin (insulin resistance), is a?
Decreased number of receptors or transporters. This would result from down-regulation of these proteins. Alternatively, there may be enough receptors, but they are failing to respond to the signal molecule that bind to them. This decreased responsiveness is known as desensitization
What is desensitization?
A decreased responsiveness of receptors. There may be enough receptors, but they are failing to respond to the signal molecule that bind to them
As the condition progresses from pre-diabetes to type 2 diabetes and becomes more severe, the response of the beta cells to increases in blood glucose begins to? Repeated exposure to high levels of glucose, glucose spikes, may be related to?
The development of the disease
What is glucose spike
Repeated exposure to high levels of glucose
The treatment for early stages of type 2 diabetes and pre-diabetes include
Dietary changes and increases in physical activity
Exercise increases the number of?
Glucose transporters (GLUT-4) in skeletal muscle, decreases insulin resistance
The increase in glucose transporters is due to?
Up-regulation of the protein synthesis for these transporters
Lifestyle changes have been shown to reverse the symptoms of?
Type 2 diabetes within 6 weeks of regular exercise and dietary adjustments
Obesity, particularly abdominal fat, is related to?
Increased insulin resistance or glucose intolerance (inability to handle the glucose correctly)
Abdominal obesity has been associated with?
Diets in high fructose. This is due to the fact that the typical american diet contains a great deal of more fructose than the body is able to handle. As a result, the excess fructose is converted to fat, and much of it remains in the visceral region of the body and even within the liver
Protein should make up how much percent?
45-65% carbohydrate (including complex, simple and fiber) with only 5-15% of total calories coming from added sugar (sucrose, and table sugar)
Any calories in excess will be?
Converted to body fat
Failure to control or reverse diabetes mellitus can result in various debilitating conditions including
Retinopathy, neuropathy, nephropathy, vascular disease, hypertension and heart disease
Most diabetics die from?
Heart attack or strokes
An important mechanism of the physical complications associated with diabetes mellitus is?
Glycation of proteins around the body. The high concentration of glucose in the body increases the probability of glucose forming hybrid molecules where it shouldn't
Knowing that the structure of a protein determines its function, imagine what happens to proteins that have glucose residues added to them. Destroying the workers of the cells will lead to?
Cell, organ and system failure