Chapter 3 Study Questions (Part 4) Flashcards
what are the three pathways of cellular respiration?
- glycolysis
- Krebs Cycle
- oxidative phosphorylation
the Krebs cycle of cellular respiration, aka
citric acid cycle, tricarboxylic cycle, TCA cycle
TCA cycle completes the _____ of _______ that was started by _____
TCA cycle complete the oxidation of glucose that was started by glycolysis
what enzyme has the greatest regulatory effect in glycolysis?
PFK
where in the cell does the TCA cycle occur?
interior, mitochondrial matrix
what are the sources used to make acetyl CO-A?
pyruvate + carbon = acetyl group
acetyl group + coenzyme A = acetyl-CoA
what happens to all the carbon that enters as acetyl CoA?
2 CO2 are released from each acetyl CoA
what do we get from the TCA cycle?
generates NADHs and the electrons used in oxidative phos. to make ATP
what do we use to feed the TCA cycle?
pyruvate
where do we get pyruvate from?
glycolysis
how many carbons do we start with in TCA?
3
how do we lose one carbon in TCA?
CO2.
what happens when CO2 and water combine?
it makes carbonic acid. increases the protons and decreases pH, causing acidic conditions
what happens to ALL the carbon that enters as acetyl COA?
it’s lost as CO2. we only keep electrons
why is FAD used instead of NAD in the Krebs cycle and why does it matter?
because FAD is tethered to the inner mitochondrial membrane, not inside the matrix
what does the TCA cycle ultimately do?
completes oxidation of glucose, captures electrons with NAD and FAD
what does the TCA cycle ultimately do? (2)
completes oxidation of glucose, captures electrons with NAD and FAD
why do we need to exhale?
to keep our bodies from making carbonic acid and getting too acidic
where do the steps in oxidative phosphorylation occur in the cell?/
inner membrane of the mitochondria
what two processes make up oxidative phosphorylation
- electron transport chain
- chemiosmosis
what is the role of O2?
the final electron acceptor
how is ATP produced?
throughout the cycle, and primarily in ox. phos.
what is the role of the ETC and how does it do that?
role: creates a proton gradient
how: proton pump
what is the role of chemiosmosis and how does it do that?
what: convert kinetic to chemical energy to make ATP.
how: gradient. redox reactions, so we need oxygen present.
what form of energy is produced during glycolysis?
a couple electrons and ATPs
what form of energy is produced during the TCA cycle?
FAD
NADH
CO2
e-
what form of energy is captured during oxidative phosphorylation?
which pathway (glycolysis, TCA, oxidative phosphorylation) produces the most ATP and which produces the least?
glycolysis = TCA < oxidative phosphorylation
how does cellular respiration operate under aerobic and anaerobic conditions?
how is ATP produced in the absence of oxygen?
role of NAD, FAD, and O2 in cellular respiration?
