quiz four/start exam 2 Flashcards
what are the four main types of carbohydrates
monosaccharides
disaccharides
oligosaccharides
polysaccharides
define monosaccharide. what are the three basic types
basic unit of carbohydrates
glucose, fructose, and galactose
define disaccharide, and name the three basic types (and how they are created)
2 joined monosaccharides
maltose= glucose+glucose
sucrose= glucose+fructose
lactose= glucose+galactose
define oligosaccharides
3-10 connected monosaccharides
define polysaccharides and name 2 common ones
long chains of monosaccharides
starch
cellulose
how are polysaccharides absorbed
they must first be fully broken down into monosaccharides
where does digestion begin
the mouth
what does saliva contain
a-amylase, which breaks down some polysaccharides into oligosaccharides
define chyme
chewed up, partially digested food
what is released when chyme enters the small intestine
cholecystokinine
what does pancreatic a-amylase do
break down polysaccharides into oligosaccharides
what does the brush boarder secrete?
oligosaccharidasis and disaccharidasis
maltase-maltose=
sucrase-sucrose=
lactase-lactose=
2 glucose
glucose+fructose
glucose+galatose
what are the products of digestion
glucose, fructose, and galactose
where does true digestion occur
the small intestine
do transporters require energy or not
no
describe glucose absorption
Na glucose symporter on the brush boarder
allows monosaccharide into epithelial cell
contains one glucose and 2 Na
what is the goal of absorption
to get into the blood
describe GLUT 2
diffusion and transports glucose to the blood stream (hepatic portal system)
what makes the HPS different
it connects to the organs, not the heart
describe fructose absorption
GLUT 5 transports fructose in and out of the epithelial cell for absorption and blood stream
define glucose transportation
glucose travels through the blood stream freely since no energy is required
what GLUTs are insulin independent
1, 2, and 3
describe GLUT1
found in small amounts on all cells of the body
highly concentrated on erythrocytes and blood brain barrier
high affinity for glucose
needs high concentration to transport glucose into cells
describe GLUT2
aids in absorption of glucose and delivers to hepatic blood portal
found on hepatocytes and pancreatic cells in high concentration
low affinity for glucose
needs high concentration to transport glucose into cells
describe GLUT3
similar to 1, but a different location
highly concentrated on neurons, which have a high affinity for glucose
what GLUT is insulin dependent
GLUT 4
describe GLUT4
found on muscle and adipose tissue
present on membrane when insulin is present
when is high blood glucose seen
after eating a meal
why does the pancreas release insulin
high blood glucose
define fed state
right after a meal is consumed and insulin is high
define glucagon
secreted by pancreas when insulin isn’t secreted to maintain blood glucose
define fasted state
animal hasn’t eaten anything recently
define carbohydrate metabolism
glucose goes through a long process to be broken down into 2 pyruvate
what is another name for carb metabolism
glycolysis
where does glycolysis take place
the cytosolic portion of the cell
what is the point of glycolysis
to create energy (ATP) for cell
how many parts of the pathway are there? what is the first committed step? which steps are repeated?
2 (priming and obtaining energy)
3
5-9
describe step 1
glucose goes to glucose 6-phosphate via ATP–>ADP, glucokinase and hexokinase
step 2
glucose 6-phosphate goes to fructose 6-phosphate via phosphoglucose and isomerase
step 3
fructose 6-phosphate goes to fructose 1,6biphosphate via ATP–>ADP and phosphofructokinase
step 4
fructose 1,6biphosphate goes to glyceraldehyde 3-phosphate and dihydroxyacetone phosphate via aldolase
step 4a
dihydroxyacetone phosphate goes to glyceraldehyde 3-phosphate via triose, phosphate, and isomerase
step 5
glyceraldehyde 3-phosphate goes to 1,3 biphosphoglycerate via NAH+–>NADH, H+, glyceraldehyde, 3-phosphate, dehydrogenase
step 6
1,3 biphosphoglycerate goes to 3-phosphoglycerate via ADP–>ATP, phosphoglycerate, and kinase
step 7
3-phosphoglycerate goes to 2-phosphoglycerate via phosphoglycerate and mutate
step 8
2-phosphoglycerate goes to phosphoenolpyruvate via enolase, and produces water
step 9
phosphoenolpyruvate goes to pyruvate via ADP–>ATP, pyruvate, and kinase
