Intoduction to Glycolysis Flashcards
What are the anaerobic pathways for energy in the body?
1) ATP -> ADP + Pi
2) PCR + ADP -> ATP + Cr
3) Glycolysis
These can occur in the absence of oxygen (also in presence)
What are the aerobic pathways in the body?
4+5) Krebs cycle -> oxidative phosphorylation
Can only occur in presence of oxygen
What is ATP made up of?
A triphosphate, a ribose and an adenine
How long does the ATP pathway last?
Body stores around 80-100g of ATP and it lasts for 1-2 seconds
What does PCr do?
It is the body’s energy reservoir and helps recycle ATP for further muscle contractions.
Can indirectly power high intensity exercise for 10-15 seconds
How does the body synthesise creatine?
From non-essential amino acids (arginine,glycine, methionine)
Provide a brief description of glycolysis
It is essentially the breakdown of carbohydrate, containing 10 enzymatic reactions where a 6 carbon molecule is converted to 2 x 3 carbon molecule and it occurs in the cytoplasm
What is step 1 of glycolysis?
Glucose -> glucose-6-phosphate
Glucose now trapped in cell as glucose 6 phosphate contains an ionized phosphate group
Energy investment of 2 ATP
What is step 2 of glycolysis?
Glucose-6-phosphate -> fructose-6-phosphate
No more energy is invested at this step
An isomerase changes a hexose ring to a pentose ring
What is step 3 of glycolysis?
Fructose-6-phosphate -> fructose 1,6-diphosphate
Using PFK as enzyme
This step gains an additional phosphate
The enzyme PFK is the rate limiting enzyme during high intensity exercise
What occurs at reaction 4+5 of glycolysis?
Fructose 1,6-diphosphate -> GAP -> glycolysis branch one
Fructose 1,6-diphosphate -> DHAP -> GAP -> glycolysis branch two
This is the stage where the 6 carbon molecules splits to 2 3 carbon molecules
What is step 6 of glycolysis?
Glyceraldehyde 3 phosphate 1,3 - diphospoglycerate
This step needs NAD to operate
If intensity is low-mod then NADH is used in aerobic metabolism
In high intensity, hydrogen is passed on to pyruvate to form lactic acid
What happens at step 7 of glycolysis?
1,3 diphospoglycerate 3 phosphoglycerate
This is the first step something is gotten back from the reaction - where 2 ATP are formed (2 branches)
What is step 8 of glycolysis?
3, phosphoglycerate 2, phosphoglycerate
A mutase moves the functional group
The phosphoryl group of phosphoglycerate is moved from 3rd carbon to 2nd carbon
What is reaction 9 of glycolysis?
2, phosphoglycerate phosphoenolpyruvate
A water molecule is removed at this stage from 2, phosphoglycerate
Produces an enol hence name
