Glycolysis 1 Flashcards
Briefly Describe glycogen conversion to lactate
- glycogen undergoes glycolysis to become glucose in the bloodstream
- glucose in the bloodstream undergoes glycolysis to become lactate
Briefly describe how lactate is concerted to glycogen
- lactate undergoes gluconeogenesis to become glucose in the blood
- glucose in the blood undergoes glycogenesis to become glycogen
What are the glucose consuming processes?
- Glycogenesis
- glycolysis
What are the glucose producing processes?
- Glycogenolysis
- gluconeogenesis
Outline the function of glucose transporters/ glucose uptake
Glucose is taken into the cell through trans membrane proteins called GLUT transporters
It is taken up along its concentration gradient
-uses facilitated diffusion (requires no ATP)
Where are GLUT 1 transporters located?
Brain and erythrocytes
Where are GLUT 2 transporters located?
Liver
Where are GLUT 3 transporters located?
Neurons, placenta and testes
Describe the GLUT 4 transport protein
Adipocytes, skeletal and cardiac muscle
- insulin dependent - increases in number with the presence of insulin
Describe SGLT as glucose transport proteins
SGLT: intestinal cells, renal tubules
- secondary active transport - Uses sodium gradient for glucose absorption, maintained by the Na- K ATPase channel
Describe the tissue specific metabolism of glucose in the brain
Glucose is completely metabolized to CO2 in the brain
Describe the tissue specific metabolism of glucose in the liver
Liver: completely metabolized to CO2, lactate , divert to fat, deliver glucose to blood
Describe the tissue specific metabolism of gluc9se in adipose tissue
Adipose: metabolized to Acetyl CoA, then fat
Describe the tissue specific metabolism of glucose in the muscle
Muscle: completely metabolized to CO2, lactate
Describe tissue specific metabolism of glucose in erythrocytes
Erythrocytes: glucose metabolized to lactate
What is glycolysis?
One of the principal pathways for ATP generation- considered as a catabolic pathway
In brain; erythrocytes and actively contracting skeletal muscle
Why does red blood cells contain mitochondria?
Because glycolysis is the only source of ATP they have
Where are glycolysis enzymes present?
Present in the cytosol
Glycolysis can generate ATP in the presence and absence of __________ and __________
Oxygen
Mitchondria
What are the input and output of glycolysis?
Glycolysis consumes 2 ATP but produces 4 ATP (net gain of 2)
Also converts 2 NAD+ to 2 NADH
What is the difference between aerobic glycolysis and anaerobic glycolysis ?
Aerobic glycolysis: NADH produces from conversion of Glyceraldehyde 3-P to 1,3-bisphosphoglycerate is used for oxidative phosphorylation
Anaerobic glycolysis: NADH produced from conversion of Glyceraldehyde 3-P to 1,3 bid-phosphoglycerate is used in the conversion of Pyruvate to lactate(reversible)
What is the overall yield of one molecule of glucose in aerobic glucose?
2 ATP and 2 NADH
What is the overall yield of of anaerobic glycolysis?
Anaerobic glycolysis
-2 ATP (NADH is used to convert Pyruvate to lactate)
What is the energy investment stage of glycolysis?
- preparatory phase
- phosphorylation of glucose and it’s conversion to Glyceraldehyde 3-phosphate
- net loss of 2 ATP