T8.2 Cell Respiration Flashcards
Oxidation
loss of electrons (and energy)
Reduction
gain of electrons (and energy)
Electron carriers
Molecules that easily accept and give electrons
Electron carriers used in respiration
NAD+ and FAD+
Overall products of glycolysis
2 pyruvate, net gain 2 ATP, 2NADH
How much ATP is spent in glycolysis
2 ATP to phosphoralate glucose
Where does glycolysis happen?
in the cytoplasm
What is the phosphorylated glucose called? (right before it splits)
fructose, 1, 6, bisphosphate
What are the general steps of glycolysis in order?
- Phosphorylation
- Lysis
- Oxidation
- ATP formation
Phosphorylation
Addition of phosphate to an organic molecule
What does phosphorylation do to a molecule?
It makes the whole molcecule more unstable and likely to react or break down
In the step of phosphorlyation in glycolysis, where do the two phosphates come from?
2ATP which donates a phosphate to become 2ADP
What is the product of lysis in glycolysis?
2 Triose phosphate molecules
Describe lysis in glycolysis
A fructose,1,6,bisphosphate is split apart to form two triose phosphates. (this sounds real funky with words, id suggest a picture to make it make some sort of sense.)
pcitrue, but it says glyceraldehyde instead of triose phosphate. Triose phosphate is just glyceraldehyde but with another phosphate.
Describe oxidation in glycolysis
1 NAD+ comes in and takes an electron from one triose phosphate. This happens twice per glucose molecule as one glucose produced two triose phosphates
Describe ATP formation in glycolysis
2 ADP come in a yoink the two phosphates off of the triose phosphate to form 2 ATP and one pyruvate molecule. This also happens twice per one glucose molecule.
Where does the Link Reaction take place?
the mitochondrial matrix
Decarboxylation
Where carbon and oxygen is removed from a molecule in the form of CO2
Purpose of Link Reaction
To move pyruvate into the cytoplasm and to allow it to start the Kreb cycle
Steps of the Link reaction
Pyruvate is decarboxylated and loses one carbon atom in the form of CO2.
Then it is oxidized and loses one electron. NAD+ to NADH + H+
Finally Coenzyme A binds to the two carbons to form Acetyl Coenzyme A (CoA)
Products of link reaction
2CO2, 2NADH, and 2 Acetyl-CoA
Where does the Krebs Cycle take place
Mitochondrial matrix
What is the purpose of the Krebs Cycle?
To form as many electron carriers as possible.
Steps of Krebs Cycle
1) Coenzyme A is removed from acetyl-Co2 and is recycled
2) The acetyl group binds to oxaloacetate (which has 4 carbons) to form a 6 carbon chain called citric acid.
3) The molecule is then decarboxylated twice and oxidized twice, forming 2 CO2 and 2 NADH
4) The molecule has lost both carbons that it previously gained, but still has a phosphate group and extra electrons that can be taken away.
5) One ADP molecule comes in and takes a phosphate
6) The molecule is then oxidized by FAD+ once to form the electron carrier FADH2.
7) The molecule is oxidized again by NAD+ to form another NADH
8) The molecule is at its original state of oxaloacetate, and the cycle repeats with the next Acetly CoA
Products of the Kreb Cycle
The kreb cycle happens twice per glucose molecue.
Overall forms 6 NADH, 2FADH2, 2ATP, and 2CO2
Where do all the electron carriers go after being formed?
To the ETC for Oxidative Phosphorylation
Where does the electron transport chain take place?
In the cristae of the mitochondria
Why is oxidative phosphorylation called oxidative phosphorylation?
The oxidation of NADH or FADH2 by the electron transport chain happens at the same time as ATP synthesis (where phosphorylation occurs)
What do the protein pumps in the electron transport chain do?
They pump protons (H+ ions) to the inner membrane from the mitochondrial matrix in order to cause a concentration gradient to form (higher amount of protons in the inner membrane compared to the mitochondrial matrix). This allows chemiosmosis to occur through the ATP synthase.
What gives energy to the electron transport chain?
The electron carriers formed from glycolysis, link reaction, and the Krebs cycle donate electrons to the protein pumps, allowing the pumps to cause the concentration gradient.
Chemiosmosis
Where H+ moves across a membrane down the concentration gradient.
What do the used up electrons in the electron transport chain go to?
They are recieved by an Oyxgen atom (2 electrons per oxygen atom), which then has two H+ atoms join to the oxygen atom, forming water.
2e- + 2H+ + 1/2O2 -> H2O
How are the ATP’s made in the electron transport chain
The H+ ions flow into the ATP sythase. While they go through, they spin around a lot, which creates enough kinetic energy to pass the activation energy needed to phospharylate an ADP molecule.
End products of the electron transport chain
Around 30 ATP and water
