View
229
Download
0
Category
Tags:
Preview:
Citation preview
The Purpose
Transfer the energy in macromolecules (like glucose) into a more efficient form for cells (ATP)
ATP can then transfer smaller units of energy for cellular work
2 Types
AerobicWith oxygenProduces a lot
of ATPNeeds
mitochondria
AnaerobicWithout
oxygenProduces a
little ATP
Who Goes Through Respiration?
All living organisms go through some sort of cellular respiration (though many do not use the complete process) to make ATP
Plants still go through cellular respiration!
Glycolysis
Occurs in all cells ever studied.No oxygen required, no
mitochondriaProbably evolved in the
earliest forms of life
Krebs Cycle
If oxygen present, the pyruvate heads into the Mitochondria
Series of enzyme-catalyzed reactions
Krebs Cycle
Rest of sugar broken into Carbon Dioxide (exhale!!!)
2 more ATP madeElectrons and H+ picked up by
NAD+ to form NADH (and another electron carrier)
So Far…
Some ATP made (4), but we have a lot of electron carriers (NADH and others) which carry energy in (e-)
Final Stage
NADH & other carriers drop off H+ and electrons to the final stage called Oxidative Phosphorylation.
In OXPHO concentration gradients of H+ are made using the energy of electrons to PUMP H+ from low to high.
This process uses an electron transport chain (like in photosynthesis) which allows for the transfer of energy!
Transfer energy to ATP BOND The concentration gradient of H+ has
potential energy.
The only place for energy to move from high to low is in a molecule called ATP synthase.
Here the FACILITATED DIFFUSION of H+ turns (kinetic) the molecule of ATP synthase and allows for the formation of the bond (chemical)between the phosphates.
Why do we breathe? At the end of the
oxidative phosphorylation process there are
e- and H+ hanging out
Oxygen picks them up and makes water
If O2 is absent???TBC…
Review Oxidative Phosphorylation
LOTS of ATP made (about 34) as electrons are passed from NADH through a series of proteins to O2 to form water
What was that about No Oxygen?
No Oxidative phosphorylation
No Krebs Cycle
Only source of ATP is glycolysis
No O2, No problem!
Well for like a minute
BUT… Glycolysis needs NAD+, and with no OXPHO the cell
runs out of NAD+
because NADH cant drop off e- & H+ b/c there’s no O2 to pick up at end…
If you don’t have oxygen you cannot “clean up” the electrons & H+ & the process comes to a halt. Thus, you cannot produce enough ATP…and then your cells will die.
Enough cell death & then you’ll die
We go through LACTIC ACID FERMENTATION
This changes pH which is why it’s temporary
ALSO why muscles hurt after working out (b/c your O2 demand is REALLY high during a work out that your cell can’t keep up with O2 even if you are breathing like crazy! So you switch to L.A.F
Other organisms do ALCOHOLIC FERMENTATION and we use them to make beer, bread, wine…
Recommended