Option D unit D5 Glucose absorption (HL)

Question 1

amounts of blood glucose

Answer 1

• Homeostasis: 4/0 mmol/L - 4.5 mmol/L
• Pre exercise: higher glucose levels post: lower
• Pre ingestion: lower glucose level post: higher

Question 2

Hypoglycemia

Answer 2

(low blood sugar)
* Can hit hypoglycemia fast (high impact)
* Insufficient food intake
* Excessive exercise
* High insulin levels among diabetics

Question 3

Hyperglycemia

Answer 3

(high blood sugar)
* Takes a longer time to reach hyperglycemia (slow impact)
* Infections such as colds or flu
* Low insulin levels in diabetics
* Slow development (days)

Question 4

Glucose absorption/uptake: (from bloodstream into cells)

Transportation of glucose across the cell membrane when at rest:

Answer 4

• Glucose uptake into a cell is facilitated by the glucose transport proteins GLUT4 and GLUT1
• Muscle fibers also contain glucose transport proteins GLUT1 and GLUT4
  1. During rest, most glucose enters cells via the GLUT1 transporters
  2. GLUT4 transporters are stored inside intracellular vesicles that are translocated to the cell membrane, when needed, to allow for greater glucose movement into the cell
  3. GLUT4 transporters can be stimulated during rest by raised levels of insulin after eating
  4. Glucose taken into the muscle cells is quickly converted to glucose-6-phosphate; this ensures that the concentration gradient for glucose movement is maintained

Question 5

Glucose absorption/uptake: (from bloodstream into cells)

Transportation of glucose across the cell membrane during exercise:

Answer 5

• Muscle contractions (Ca2+) stimulate the translocation of GLUT4 transporters to the cell membrane

Question 6

Effect of training on an athletes ability to take in glucose at the cellular level:

Answer 6

• Training leads to more muscle mass
• More muscle mass leads to more GLUT4 proteins in the muscle
• More GLUT4 can be translocated leading to faster glucose uptake into the muscle