Carb Metabolism Flashcards
For quick sprints, do we rely on glycolysis or TCA cycle?
Glycolysis
For long runs, do we rely on glycolysis or TCA cycle?
TCA cycle
In glycolysis, how much pyruvate and ATP does one 1 glucose molecule produce?
2 pyruvate
2 ATP
Where does anaerobic respiration occur?
Cells that lack mitochondria (mainly RBCs)
Important in overworked muscles that lack oxygen
Glucose is the only fuel that _______ can use and is the only fuel that _______ uses under non-starvation conditions.
RBCs
Brain
How do we get de novo synthesis of glucose?
Gluconeogenesis in the liver
The initial step of glucose metabolism involves transport of glucose into the cell. Glucose cannot cross cell membrane (due to polarity) so it needs a transporter, which are called…
GLUTs
This GLUT is ubiquitous but has high expression in RBCs and brain. High affinity.
GLUT1
This GLUT is the main transporter in the liver. Low affinity.
GLUT2
This GLUT is the main transporter in neurons. High affinity.
GLUT3
This GLUT is present in skeletal muscle, heart, and adipose tissue. It is insulin-dependent.
GLUT4
What GLUTs are unregulated? Meaning they utilize passive facilitated transport by moving down concentration gradient?
GLUT1
GLUT2
GLUT3
If a GLUT has a high Km, what does that mean for its affinity?
Affinity is low
***Km is INVERSELY proportional to affinity
GLUT4 is sequestered in _______ in cells. Insulin signaling causes fusion of _______ with plasma membrane and placement/insertion of the transporter in the membrane.
Vesicles
Vesicles
Increased GLUT4 in the membrane means increased ________ uptake.
Glucose
