CARBOHYDRATES&GLUCOSE TESTING Flashcards
are organic compounds composed of
carbon, hydrogen and oxygen
Carbohydrates
Carbohydrates Chemical composition:
Cn(H2O)n
- carbonyl group in the middle linked to 2 other carbon atoms
Ketose
Two forms of CHO
aldose
ketones
- terminal carbonyl group called aldehyde group
Aldose
are the major constituents of physiologic
system: brain, erythrocyte, and retinal cells in humans.They
are also the major source of energy.
Carbohydrates
-simple sugars that cannot be hydrolyzed to a simpler form
- can contain 3 or more carbon atoms
Monosaccharides
types of Monosaccharides
-Glucose
-Fructose
-Galactose
is directly used as energy source and or stored as
glycogen in the liver or muscles.
Glucose
most important CHO; major metabolic fuel
Glucose
two monosaccharides are joined by a glycosidic linkage
Disaccharides
types of Disaccharides
Sucrose
Lactose
Maltose
Fructose + Glucose
Maltose
Glucose + Glucose
Maltose
Galactose + Glucose
Lactose
-linkage of many monosaccharide units
-on hydrolysis, will yield more than 10 monosaccharides
Polysaccharides
types of Polysaccharides
starch
glycogen
chitin
storage form of glucose in the body
Glycogen
fibrous substances consisting of polysaccharides
and forming the major constituent in the exoskeleton of
arthropods and the cell wall of fungi
Chitin
As food enters the mouth and oral cavity, food begins to be
broken down by _____, an enzyme produced by the parotid gland that helps in the initial metabolism of food
ptyalin
When food reaches the stomach, the acidity inactivates ptyalin and acid hydrolysis occurs. There is no carbohydrate digestion in the stomach, but protein digestion happens
through the enzyme _______.
pepsin
When food reaches the intestines, _______, an enzyme produced by the pancreas, further degrades the food and
convert polysaccharides into monosaccharides.
amylopsin
After 2 hours glucose levels go
back to normal
After 30 min glucose levels
rise
After 1 hour glucose levels
peak
What are the Glucose Metabolic Pathway
Embden-Meyerhoff Pathway
Hexose- Monophosphate Shunt
Glycogenesis
a Glucose Metabolic Pathway that can be aerobic and anaerobic
Embden-Meyerhoff Pathway
a pathway that provides energy for the body
Embden-Meyerhoff Pathway
glucose to pyruvate
Aerobic
glucose to lactate
Anaerobic
a pathway for production of reduced
NADPH and ribose-5-phosphate
Hexose- Monophosphate Shunt
glucose to pyruvate or lactate to produce
energy
Glycolysis
– formation of glucose-6-phosphate from
non-carbohydrate sources
Gluconeogenesis
– breakdown of glycogen to glucose for
energy
Glycogenolysis
– glucose to glycogen for storage
Glycogenesis
– conversion of carbohydrates to fatty acids
Lipogenesis
– Decomposition of fat
Lipolysis
- produced by the β cells of the islets of Langerhans in the
pancreas - only hormone that decreases glucose
- promotes glycolysis, glycogenesis, lipogenesis
Insulin
- produced by the α cells of the islets of Langerhans in the
pancreas - primary hormone that decreases glucose for increasing
glucose levels - promotes glycogenolysis and gluconeogenesis
Glucagon
immediate precursor of insulin
proinsulin
test that is based on the presence of proinsulin
that helps in the differential diagnosis of Type 1 from type 2
Diabetes Mellitus and the diagnosis of insulinomas
c peptide
- produced by the δ cells of the islets of Langerhans in the
pancreas - inhibition of pancreatic hormone release of insulin and
glucagon - inhibition of gastric acid secretion
Somatostatin
- produced by the zona fasciculata of the adrenal cortex
- promotes hepatic gluconeogenesis and lipolysis
Cortisol
- produced by the chromaffin cells of the adrenal medulla
- inhibits insulin secretion and promotes glycogenolysis
Catecholamines