Tumor Metabolism Flashcards Preview

Human Function- Exam 4 Material > Tumor Metabolism > Flashcards

Flashcards in Tumor Metabolism Deck (11):
1

after initial increase in glucagon, what is maintaining blood glucose?

glycogenolysis

2

prolonged increases in glucagon, what maintains blood glucose?

gluconeogenesis

3

why is gluconeogenesis slower than glycogenolysis?

gluconeogenesis enzymes are induced, meaning they have to be transcribed and translated before they are active

4

what do tumors use for energy?

glucose only
never switch to alternate fuel sources- not responsive to glucagon

5

how do surface tumor cells do metabolism?

aerobically

6

how do deep tumor cells do metabolism?

anaerobically
tumor induced cytokines promote cachexia by activating muscle proteolysis and adipose lipolysis

7

what is cachexia?

unexplained weight loss

8

what is hypoxia inducing factor?

allows tumors to adapt to hypoxic conditions
switches surface cells to lactate usage by increasing GLUT1 transporters and inducing glycolytic enzymes to inhibit PDH-->forcing everything to lactate usage (takes lactate from cells under hypoxic conditions)

9

when does the brain switch to ketone body usage?

3 days after depletion of dietary glucose, shortly after depletion of body glycogen

10

how many ATPs are obtained from full oxidative phosphorylation? how many are obtained under anaerobic conditions?

aerobic- 30-32 depending on which shuttle is used
anaerobic- 2 from substrate level phosphorylation

11

what are products of muscle proteolysis and adipose lipolysis used for and why?

muscle proteolysis- tumor protein synthesis
adipose lipolysis- body energy production
to same glucose for tumor