Metabolism
•all the chemical reactions by which cells use and acquire energy.
•Anabolism:
•involves building of complex molecules from simple molecules
•this requires energy
•Catabolism:
•involves the breaking down of complex molecules into smaller ones
•this process results in the acquisition of energy
•in the form of adenosine triphosphate or ATP
•Cellular Metabolism (Cellular Respiration):
•how each cell transfers glucose and oxygen into ATP
ATP
(Adenosine Triphosphate)
Dehydration Synthesis
Hydrolysis
Glucose Regulation
Pancreas
Pancreatic Cells
Pancreatic
Cell
Physiology
Glucagon
Insulin
Glucose
Triggers
Insulin
Release
Pancreatic
Beta Cell
•Glucose enters cell
•And generates ATP
•ATP Closes K+ channels
•And opens Ca++ channels
•Ca++ untethers Insulin
•Allowing Insulin Release
Mitochondria
Anatomy
Inner Compartment
Outer Compartment
Inner Membrane
Outer Membrane
Cytoplasm
Cristae
Cellular Respiration - Summary
Input:
Four Steps:
1. Glycolysis
2. Pyruvate
Oxidation
3. TCA Cycle
4. Electron
Transport
Chain
Output: 6 CO2
6 H2 O
32-34 ATP
+ 6 O2
1. Glycolysis
•first step in cellular respiration
•occurs in the cytosol
•does NOT require O2
input is:
1 glucose molecule
2 ATP molecules
output is:
2 pyruvate molecules
4 ATP molecules
2 NADH molecules
2 H+ ions
yield is:
2 pyruvate molecules
2 ATP molecules
2 NADH molecules
2 H+ ions
2. Pyruvate
Oxidation
requires O2
input is:
2 pyruvate molecules
output is:
2 acetyl CoA molecules
2 CO2 molecules
2 NADH molecules
2 H+ ions
yield is:
2 acetyl CoA molecules
2 CO2 molecules
2 NADH molecules
2 H+ ions
3. KREBS
Cycle
requires O2
input is:
2 acetyl CoA molecules
output is:
9 biochemical reactions
yield is:
2 ATP molecules
4 CO2 molecules
6 NADH molecules
6 H+ ions
2 FADH2 molecules
2 GTP molecules
4. Electron Transport Chain
requires O2
•input is:
10 NADH molecules
10 H+ ions
2 FADH2 molecules
•output is:
10 NAD+ molecules
2 FAD+ molecules
32-34 ATP molecules
•yield is:
32-34 ATP molecules
Other Glucose Modifications
Glycolysis
Glycogenesis
Glycogenolysis
Gluconeogenesis
from proteins
Gluconeogenesis
from lipids
Diabetes Mellitus
Type I (IDDM): Juvenile Onset (childhood and puberty)
•Insulin-Producing cells are impaired
•Greatly reduced or absolute deficiency of insulin
•Polydipsia (excessive thirst)
•Polyphagia (excessive eating)
•Polyuria (excessive urination)
Type II (NIDDM): Maturity Onset (usually >40)
•Risk increases with age and excessive weight (80% are obese)
•90% of all Diabetes cases
•Can often be maintained with diet and exercise
•Insulin-Producing cells are functional
•Cells may make enough or too much insulin
Table 4-7, p. 122