Glycolysis Flashcards
How does glucose enter the cell
- carrier proteins: glucose transporters
- uses insulin to help with this in tissue cells, by binding to receptors on cells, insulin lets GLUT4 molecules come
1)
- glucose enters the cell through glut4 molecules
- kinase enzyme adds PO4 to lock glucose in, and form g6p
- costs 1 ATP
2)
- conversion of g6p to f6p
- conversion from aldose sugar to ketose sugar
- phospho isomerase=enzyme
3)
- f6p gains another phosphate
to produce f-1,6-bp - enzyme pfk is a major regulator
- costs 1 ATP
4)
- cleaving
- f-1,6 is split into half
- 6C- 2 3Cs
- produces g3p and DHAP
- enzyme: aldolase
5)
- converting DHAP to g3p
- enzyme: triose phosphate isomerase
How many ATP have been lost in the energy investment stage?
How many ATP have been gained?
lost: 2 ATP (1,3)
gained: 0 ATP
6)
- oxidize g3p
- electrons go to nad+ to become nadh, reducing nad+
- g3p gains a phosphate to become 1,3-bpg
7)
- substrate level phosphorylation
- 1,3-bpg has a po4 removed
- adp converted to atp
- po4 is moved directly by enzymes
- produces 3-pg
- gain of 2 atp
steps 8) and 9)
- movement of po4 group, to make it more accessible
- 3-pg — 2-pg — pep
Differences between step 8) and 9)
In step 8, 3PG is converted to its isomer 2PG
In step 9, 2-PG loses a molecule of water becoming PEP
10)
- substrate level phosphorylation
- PEP has a po4 removed
- ADP is converted to ATP
- PO4 is moved directly by enzymes
- production of pyruvate or pyruvic acid
- gain of 2 atp
energy yield in anaerobic glycolysis
- 4 atp created
- net gain of 2 atp
- 2 nadh’s carrying electrons
- no o2 required
- 1 nad+
which steps of glycolysis are irreversible?
1,3,10 (possibly 7)
how many times does energy harvesting occur?
twice
when is atp lost (what stages)?
1,3 (1 atp lost each)
when is atp gained (what stages)?
7, 10 (2 atp gained each)
how many NADH is gained per 1 molecule of glucose
1 molecule of glucose= 2 NADH molecules
why does a molecule have to transform into its isomer, for ex. G6P into F6P?
- increases energy yield from glucose metabolism by increasing high energy phosphate bonds that can generate more ATP to store more energy
- increases the number of molecules available for further metabolism in the later stages of glycolysis.
why is energy lost when po4 is gained
the energy from the po4 breaking off turns ATP into ADP, negative charges repel each other
why is energy gained with po4 is lost
the broken po4 joins an ADP to form ATP
