Glucose Metabolism Flashcards
amino acids are used as an energy source during ___ or ____; excess amino acids ingested are converted to ____ and stored
fasting; metabolic stress; carbs
plasma glucose concentration is the result of:
intake, production, and tissue utilization
insulin is secreted by ____; glucagon secreted by ____
beta cells; alpha cells (both are pancreatic cells)
insulin signaling cascades transfer the signal from the insulin molecule to target molecules such as ____ in key pathways or the membrane glucose transporter, ____
regulatory enzymes; GLUT-4
insulin promotes anabolism in ____, ____, and ____
liver; adipose tissue; muscle
glucose transport in muscle and adipose tissue is mediated by the ____ and is insulin dependent; glucose transporter in the liver is ____ and is insulin independent
GLUT-4 transporter; GLUT-2
in humans, insulin doubles recruitment of the ___ to ____
transporter; cell membrane
muscular contraction ____ the expression of GLUT-4 ____ of insulin
increases; independently
fatty acids ___ the expression of GLUT-4 in ____
decrease; muscle
main contributors to type II diabetes
inadequate synthesis of insulin, secretion, and most commonly unable to exert normal effect
glucagon (anti-insulin hormone) functions
- mobilized glucose
- increases blood glucose
- stimulates catabolism
- suppresses anabolism
glucagon action is confined to the ____
liver
epinephrine is a catecholamine that is secreted by the ____; it inhibits ____ and ____, but stimulates ____
adrenal gland; glycolysis; lipogenesis; gluconeogenesis
____ occurs while eating and for several hours afterward
high insulin/ low glucagon (fed state)
____ occurs when fasting between 6-12 hours (fasting state)
low insulin/high glucagon
gluconeogenesis key substrates
lactate, alanine, glycerol
glucose contribution from ____ increases as fasting continues
gluconeogenesis
____ are major energy substrate during prolonged fasting or starvation
free fatty acids
anti-insulin hormones
epinephrine (epi), glucagon, and cortisol
response to stress
decreased anabolism (glycogen synthesis and lipogenesis) increased catabolism (glycogenolysis, lipolysis, proteolysis, and increased insulin dependent glucose uptake)
the response to stress is ____ and is broadly analogous to ____
catabolic; fasting
diabetes leads to ___ and ____
microangiopathy; macroangiopathy
microangiopathy includes:
kidney failure, blindness, impaired nerve function
macroangiopthy includes:
heart attack, vascular disease, cardiovascular disease
type 1 diabetes characterized by destruction of ____
beta cells
type 1 diabetics prone to ____ and are dependent on ____
ketoacidosis; insulin
type 2 diabetes involves ____ and impaired ____
insulin resistance; insulin secretion
gluconeogenesis and lack of uptake causes ____ in type 1 diabetics
fasting hyperglycemia
____ is major complication of type 1 diabetes
ketoacidosis
____ and ____ contribute to vascular complications
oxidative stress; glycoxidation
____ can be modified by glycation
hemoglobin
