Week 4: Introduction to metabolism Flashcards
Is the fed state an open or closed system?
Open system
Is the fasting state an open or closed system?
Closed system
What does the body store excess energy as?
- Carbohydrates (Glycogen)
- Fat (Adipose)
- Amino Acids (to an extent)
What is accomplished in the fed state?
recharge energy levels
->
rest goes to Storage
How is glucose stored?
Glycogen
Where is glycogen located
liver and skeletal muscle are glycogen storage organs
Energy expenditure %s
- 20% physical activity
- 10% Adaptive thermogenesis
- 70% Basal metabolic rate
How does cardiac muscle store glucose?
small glycogen supply (2 minutes worth)
if cardiac muscle becomes ischemic, flutters and then stops
How does the body send different amounts of glucose to different types of cells?
By using different transporters
Difference GLUT 1 and GLUT 4
GLUT 1 is constantly open and uses the glucose concentration gradient for facilitated diffusion
GLUT 4 is on skeletal muscle and only takes up glucose during the fed state (if GLUT 4 was open all of the time, we would go into a hypoglycemic shock)
What activates GLUT 4?
Insulin
GLUT 2
lower affinity than GLUT 1 and 4
Has a greater Km with higher concentrations of glucose
GLUT 2 is in the liver for glycogen storage so this is why the Km is so high as to not bring more glucose into the liver during a fasting state
Cardiac muscle glucose transporters
GLUT 1 and some GLUT 4
RBC Glucose transporter
GLUT 1
Beta Cells glucose transporter
GLUT 2
Describe the different phases
