W4 Carbohydrates (Fructose Metabolism) Flashcards
What’s the role of CHO in the body? (List 3)
- Energy provider for the body
- CHO is stored in the Liver/Muscles.
- Glycated proteins
- Glycosaminoglycans
Terminology: What does... mean? - Olysis = ... - Genesis/Synthesis = ... - Glucose Uptake = ... - Glucose Synthesis = ... - Glycolysis = ... - Gluconeogenesis = ...
- Olysis = Breaking down
- Genesis/Synthesis = Building Up
- Glucose Uptake = Tissue take glucose from blood into them
- Glucose Synthesis = Making glycogen from glucose
- Glycolysis = Breaking down of glucose
- Gluconeogenesis = Making glucose from carbon sources
Where does Fructose Metabolism occur?
Is fructose bad for the body?
- Mainly in the Liver
- No if active but yes if sedentary
What does the Pancreas do?
- Secrets enzymes that help with digestion
- Exocrine (Digestive enzymes)
- Endocrine (body hormones into blood stream)
- Insulin (increases glucose uptake)
Why is insulin important with glucose in the liver?
- It increases Glucokinase volumes which change glucose into glycogen in the liver cell.
(therefore, maintaining a higher gradient of glucose in the blood compared to the liver cell - meaning more glucose will keep entering the liver)
What is the importance of Blood Glucose in the brain?
Glucose is important for:
- Turnover
- Neurotransmitter Synthesis
- 20% glucose in the brain (LOADS!)
- Not insulin mediated (VERY GOOD)
“Glucose is taken in through … then either fully oxidised or converted into lactate.”
Which Glut is used in the sentence above?
“Glucose is taken in through Glut 3 then either fully oxidised or converted into lactate.”
What do Glut 1-5 do?
Glut 1: Sit in cell membrane & transports glucose into the cell from the blood stream.
Glut 2: Glucose Uptake, facilitates the diffusion of glucose across the cell’s membranes.
Glut 3: Facilitates the transport of glucose across the cell’s plasma.
Glut 4: Glucose Transporter, Translocated too membrane. It’s an insulin-regulated transporter to help with glucose.
Glut 5: Transports fructose from the intestinal lumen into the enterocyte via diffusion.
Name another way to increase glucose in a cell.
Calcium increases glucose in the cell (its released when the muscle is contracted).
What is glucose important for?
- Brain (ketones)
- Turnover
- Neurotransmitter synthesis
Once glucose has entered the skeletal muscle cell can it leave again?
- Glucose cannot leave once it has entered because of the concentration gradient.
- It is either stored or oxidised (used as energy)
Where are the main storage points for CHO? Which storage place is the biggest?
- Liver & Muscles
- The liver has a bigger capacity however, there are more muscles
Why is insulin important in the liver?
- Insulin in the liver is important because it increases Glucokinase which change glucose in to glycogen. Therefore, maintaining a lower concentration gradient in the cell so glucose keeps flooding into the liver cell.
Storing glycogen in the brain as astrocytes (cell in CNS) is important because…
- It means the brain doesn’t have to store glycogen in the neurones but the neurones can still use the glycogen because its stored as astrocytes in the support cells.
What is the role of insulin in skeletal muscle cells?
- Moves GLUT 4 to the membrane (which allows extra glucose into the cell)
- This doesn’t happen in the liver!