Bio 1100 Pyruvate Oxidation, Citric Acid Cycle, and Oxidative Phosphorylation Vocab

In pyruvate oxidation, what is oxidized and what is reduced?

Pyruvate is oxidized (the reduction agent) and NAD+ is reduced (the oxidized agent)

What is the waste product and usable product from pyruvate oxidation

acetyl coA is the usable product and CO2 is the waste product

What is pyruvate oxidation?

Pyruvate is oxidized prior to the citric acid cycle

Inner membrane of the mitochondria

location of the Electron transport chain

Matrix of the mitochondria

gel-filled space surrounded by the inner membrane, contains enzymes, mitochondrial DNA, and ribosomes

Cristae of the mitochondria

folds of the inner membrane, increase the inner membrane’s surface area, provides space for the enzymes an proteins complexes for the ETC

Intermembrane space

narrow region between the outer and inner membrane ; contains proteins that shuttle electrons during cellular respiration

Why does the citric acid cycle happen in the matrix?

because the matrix contains all the necessary enzymes, co-enzymes, and substrate supply to efficiently run the cycle and link it to the final stage of cellular respiration

What does acetyl coA give to the CAC?

acetyl coA gives 2 carbons to oxaloacetate becomes citrate, citrate has 6 carbons

What is the waste product of the CAC?

CO2

How much NADH and FADH2 does 1 acetyl coA get us?

3 NADH, 1 FADH2, and 1 ATP

How do we return to oxaloacetate?

by giving off CO2, and P+ to ADP, loses a total of 2 Carbons to become oxaloacetate which is a 4 C molecule

What are the total products of 1 glucose molecule of from just the CAC

6 NADH, 2 FADH2, and 2 ATP

What type of phosphorylation makes ATP in the CAC

ATP comes from Redox reactions, substrate-level phosphorylation

Including glycolysis, pyruvate oxidation, and the CAC what is the total NADH and FADH2

10 NADH, 2 FADH2, and 6 ATP

Why do we want e- to flow in the correct order, can they flow the opposite direction?

to maintain the H+ gradient, they cannot flow backwards, they flow towards O2

What is the ETC made of?

4 protein complexes, I, II, III, and IV

Why is the ETC described as a staircase

because free energy is released at each step, oxygen is the final electron acceptor and drives the e- down the stairs to the O2

Which e- carriers go to protein complex I?

NADH, complex I carries 3 e- at a time

Which e- carriers go to protein complex II?

FADH2, complex II carries 2 e- at a time

What happens to hydrogen ions as electrons pass down the ETC?

energy from the e- pump H+ into the membrane space, creating an electrochemical gradient

How many proton pumps are activated when NADH gives e-?

3 pumps because protein complex II does not connect through the entire membrane to a pump

How many proton pumps are activated when FADH2 gives e-?

2 pumps, FADH2 enters the chain through complex II, which doesn’t have a pump

What is chemiosmosis?

the movement of ions, H+, across the membrane to generate energy, ATP

Where does potential energy come from that is transformed into kinetic in the ETC

The electrochemical gradient, H+ flows down the gradient as a source of PE

What enzyme do ions pass through during chemiosmosis?

ATP synthase, converts PE to KE then to chemical energy

What type of phosphorylation is driven by chemiosmosis?

Oxidative phosphorylation, meaning it involves oxygen

What happens to e- when they get to the end of the ETC?

O2 is the final e- acceptor (also the strongest e- acceptor), and after accepting the e- it becomes water.

How energy efficient is cellular respiration?

Far more efficient than glycolysis alone, captures 34% of the energy in 1 glucose molecule = 32 ATP (giver or take)

How much energy is lost as heat in aerobic cellular respiration?

66%

Why is the stair case going down?

Free energy decreases/leaves the proteins so it slopes down, this energy is sent/used to move things (H+ across the membrane)

As e- move from complex I to III to IV what type of reaction is this?

These are redox reactions until the e- reach O2

Why is O2 an excellent e- acceptor?

because it has a strong electronegativity

What is the last byproduct of the ETC?

H2O

Which e- carrier has higher energy?

NADH, also why complex I is stronger for sending 2 H+ at a time

What is the rotor of ATP synthase?

F0 motor, as protons flow down their gradient, they cause the rotor (ring of c-subunits) to spin

What is the internal rod of ATP synthase?

also called the F1 motor, rotation of the rotor is transferred to the F1 motor’s central gamma subunit

What is the catalytic knob of ATP synthase?

also called F1 complex, rotation from F1 motor is transmitted though the central stalk, which is made of alpha and beta subunits, where this energy is used to open, loose and tight ADP and P together to form ATP

Is the amount of NADH always the same?

No, 2 NADH come from glycolysis which happens in the cytoplasm, so those 2 carriers don’t always make it to ETC