Type 2 Diabetes (Intro) Flashcards
(slides 1-24)
Normally, how does glucose break down?
in the presence of O2, it breaks down to form CO2 and water
What is the source of energy for all cells?
glucose
Where is glucose absorbed?
into the bloodstream and intestines
muscle & fat cells absorb it for energy storage and usage
Normal ______ _______ requires a continuous supply of glucose
cerebral function
Normally, how does the body respond to increase in blood sugar levels?
by stimulating the pancreas to release insulin which binds to cell surface membranes, making them more permeable to glucose
What happens after glucose is absorbed? (3)
it is either:
- used for energy
- stored as glycogen in the liver/muscle
- converted into fat
After a meal, how much glucose enters the bloodstream?
Where does the rest go?
about 2/3 of glucose from a meal enters bloodstream
the rest is stored as glycogen in the liver (if that storage is full, it is converted to fat)
The pancreas’ secretion of insulin does what?
helps the liver store glucose as glycogen & regulates blood sugar levels
When can glycogen in the liver or fat can be converted back to glucose?
when the body needs a boost of energy
(e.g., during exercise or fasting).
When the body needs more energy, _______ and ___ can be converted back into glucose
glycogen and fat
especially after a high carb mean, excess glucose can be excreted in _____
urine
How does the body get glucose in between meals?
the liver releases glucose into the bloodstream and the pancreas releases a small (basal) amount of insulin
What is the most dense form of fuel storage?
Fat
What is triglycerides from fat broken down into during metabolization?
glycerol molecule & 3 fatty acids
What can the glycerol molecule do?
Can enter glycolytic pathway and be used with glucose for energy
Fatty acids are stored in ______ and can be used for ______
BUT what can they create?
tissue; energy
ketoacidosis
How can fat metabolism lead to ketoacidosis?
The body doesn’t prefer fat as a primary energy source but may use it during starvation, which can lead to ketoacidosis (undesirable accumulation of ketones in the blood).
What are the building block of proteins?
amino acids
In the absence of carbs and fats, what can be broken down into energy?
protein may also be broken down for energy, though this is not the body’s preferred source.
excessive amounts of amino acids can only be stored…?
in limited amounts in the body
During glycolysis, a glucose molecule is broken down into what? (3)
- pyruvate
- NADH
- ATP
Glucose must _____ _____ to be properly utilized, as excess glucose in the bloodstream is not effective for _____ use.
enter cells;
energy
What is glycogenesis?
Process of glycogen formation from glucose.
When glucose intake exceeds immediate energy needs, what happens?
it is converted into glycogen and stored.
during glycogenesis, the amount of glycogen formed depends on what?
the energy demand (ex: sitting vs exercising)
Glucose is stored in cells to a saturation point for how long?
about 12-24 hours
what is the reverse process of glycolysis?
glycogenesis
What is glycogenolysis?
The breakdown of stored glycogen to glucose.
(Stored glycogen in the liver is converted back to glucose to restore blood sugar levels)
When does glycogenolysis occur?
when blood glucose levels are low → in response to hormonal and neural signals
What produces the hormonal and neural signals that begin glycogenolysis? (3)
- epinephrine
- glucagon
- insulin
What does glycogenolysis inhibit?
glucogenesis
What is gluconeogenesis?
The synthesis of glucose from non-carbohydrate sources (like fat and protein)
Gluconeogenesis is the opposite process of what?
glycolysis
Where does gluconeogenesis primarily occur?
in the liver
During gluconeogenesis, _____ ____ and ____ are converted to glucose
amino acids and fats
During gluconeogenesis, fats are broken down into what?
fatty acids and/or glycerol
During gluconeogenesis, amino acids are broken down into what?
lactic acid
gluconeogenesis can lead to the development of what?
ketones
Gluconeogenesis plays a role in maintaining what?
acid-base balance
What is glucagon?
Is a hormone produced by alpha cells in the pancreas. It is released in response to a drop in blood sugar, prolonged fasting, exercise and protein-rich meals.
In the pancreas, what endocrine cells does the Islets of Langerhans contain?
beta, alpha, delta, and F/PP cells
Beta cells in the pancreas produce what?
insulin and amylin
alpha cells in the pancreas produce what?
glucagon
delta cells in the pancreas produce what?
somatostatin
F/PP cells in the pancreas produce what?
pancreatic polypeptide
alpha cells in the pancreas stimulate what?
Stimulate the liver to break down glycogen into glucose (glycogenolysis)
what does somatostatin do?
plays a role in regulating the effects of insulin
What does insulin stop? (5)
- gluconeogenesis
- glucogenolysis
- lipolysis
- ketogenesis
- proteolysis
List the actions of insulin (5)
- glucose uptake in muscle and adipose tissue
- glycolysis
- glycogen synthesis
- protein synthesis
- uptake of ions
What is insulin?
a hormone released by beta cells in the pancreas to help regulate blood sugar levels.
What is insulin required for?
required by the body cells to initiate active transport of glucose into the cell
In skeletal muscle cells, insulin promotes the storage of glucose as ______
glycogen
In adipose tissue, insulin stops the release of ____ ____
fatty acids
In the liver, insulin stops ____________, and instead promotes the production of _______ and ____
gluconeogenesis;
glycogen;
fat
Insulin also plays a role in producing ____ ____, which helps maintain healthy endothelial tissue and supports ____ ____ health
nitric oxide;
beta cell
What happens to insulin levels after a meal?
they spike to help bring blood glucose levels down
What does amylin do? (2)
- slows glucose absorption in the small intestine
- suppresses glucagon secretion (manages postprandial blood sugar)
what does somatostatin do? (3)
- decreases GI activity
- suppresses glucagon and insulin secretion
- secreted with heavy fat/high carb meal
what are counter-regulatory hormones?
Hormones that counteract insulin and raise blood glucose levels when needed
list the counter regulatory hormones
Epinephrine
Cortisol
Growth hormones
What does glucagon-like peptides (GLP-1) do? (5)
- Released after a meal
- Stimulates insulin secretion
- Suppresses glucagon
- Delays gastric emptying
- Increases satiety (feeling full)
what does estrogen increase?
what may this help explain?
it increases beta cell activity, which may help explain the cardioprotective effects seen in premenopausal women
List the functions of glucagon (3)
- Causes the liver to breakdown stored glycogen to produce glucose (Glycogenolysis)
- Activation of gluconeogenesis in the liver
- Activates lipase, to break down adipose tissue into fatty acids
List the actions of insulin on glucose metabolism (3)
- increases glucose transport into skeletal muscle & adipose tissue
- increases glycogen synthesis
- decreases gluconeogenesis
List the actions of insulin on fat metabolism (3)
- promotes fatty acid and triglyceride synthesis by the liver
- increases transport of fatty acids to triglycerides
- maintains fat storage by inhibiting breakdown of stored triglycerides by adipose cell lipase
List the actions of insulin on protein metabolism (3)
- increases active transport of amino acids into cells
- increases protein synthesis
- decreases protein breakdown
List the actions of glucagon on glucose metabolism (2)
- promotes glycogen breakdown
- increases gluconeogenesis
List the action of glucagon on fat metabolism
activates adipose cell lipase, making increased amounts of fatty acids available to the body to use as energy
List the action of glucagon on protein metabolism
increases amino acid uptake by liver cells & conversion to glucose by gluconeogenesis
what is the difference between insulin vs glucagon in regards to balancing blood glucose?
Insulin is released when blood sugar is high to lower it.
Glucagon is released when blood sugar is low to raise it.
when do…
high insulin levels occur?
low insulin levels?
high glucagon levels?
High insulin levels → ab an hour after meals.
Low insulin levels → occur during fasting (e.g., overnight).
High glucagon levels → occur during fasting to help raise blood glucose levels.
what is the normal glucose level range?
70-100
what is the prediabetic glucose level range?
101-125
what is the glucose level for diabetics?
greater than 126
what are the classifications of diabetes? (5)
Type 1 → 1A and 1B
Type 2
Pre-diabetes
Gestational
Drug induced
What is the difference between Type 1A and Type 1B diabetes?
Type 1A → autoimmune destruction of pancreatic beta cells
Type 1B → Idiopathic diabetes
Women with gestational diabetes are at higher risk for developing what?
Type 2 Diabetes (however it is not a certainty)
