Cellular Respiration Flashcards
What are the inputs of cellular respiration?
Glucose + Oxygen
What are the outputs of cellular respiration?
Carbon dioxide, water, and ATP
What is the main function/purpose of cellular respiration for cells and organisms?
To break down glucose (or other metabolites) in order to extract energy and produce ATP molecules to run cellular processes
Where does glycolysis occur?
The cytoplasm of the cell
Does glycolysis require oxygen?
No, it is an anaerobic process
Glycolysis begins with __________. (Input)
Glucose
Glycolysis ends with _____________, __________, and _________. (Outputs)
2 pyruvate molecules
2 net ATP
2 NADH
How much ATP is produced per glucose molecule as a direct result of glycolysis?
2 net ATP
(4 ATPs are made, but 2 ATPs were used at the start of the reaction, so there is only a net gain of 2 ATPs at the end of glycolysis)
What electron carrier is reduced in glycolysis to be used later in the electron transport chain?
NADH (from NAD+)
If oxygen is available, where will the pyruvate go next?
To the prep reactions in the mitochondria
What is the option after glycolysis if no oxygen is available?
Glycolysis can lead to fermentation (alcoholic or lactic acid fermentation) if oxygen is not available for the aerobic cellular respiration pathway in the mitochondria
What types of organisms will use glycolysis?
All organisms, both prokaryotic and eukaryotic. Glycolysis occurs in the cytoplasm, so no specialized cellular structure is required, allowing the reaction to occur in simple prokaryotic cells, as well as in complex eukaryotic cells.
Each of the following is a product of cellular respiration EXCEPT
ATP
Carbon dioxide
Oxygen
Water
Oxygen
Per glucose molecule, the net gain of ATP molecules from glycolysis is
2
A pathway that begins with glucose and ends with pyruvate is…
Glycolysis
The pyruvate created by glycolysis can be used for
Entering the mitochondria for the prep reactions if oxygen is available.
Converting to alcohol or lactic acid in fermentation if oxygen is not available.
Where do the prep reactions occur
matrix
Where does the Krebs reaction occur
matrix
Where does the ETC occur
Inner membrane
If a certain enzyme inhibitor affects enzymes in glycolysis reactions, what types of organisms will this inhibitor impact?
All organisms, both prokaryotic and eukaryotic, would be affected b/c all organisms perform glycolysis.
What are the inputs of the Prep Reaction
Pyruvates (also coA and NAD+)
What are the outputs of the Prep Reaction
Acetyl CoA, NADH, and CO2
Steps of the Prep Reaction
Prep reactions convert a 3-carbon pyruvate into a 2-carbon acetyl CoA.
Carbon is removed from pyruvate forming the 2-c acetyl and CO2 is released.
Coenzyme A is added to the acetyl and forms acetyl CoA which enters the Krebs cycle.
(This process is the same for both pyruvates.)
What molecules are produced from the Krebs cycle?
CO2, 2 ATP, NADH, and FADH2
Which of these molecules is/are given off as waste?
CO2, 2 ATP, NADH, and FADH2
CO2
Which of these molecules continue on to the Electron transport chain?
CO2, 2 ATP, NADH, and FADH2
NADH and FADH2
What are the inputs of the ETC?
O2, NADH, FADH2 (also ADP + P)
What are the outputs of the ETC?
H2O, 32-34 ATP (also NAD+ and FAD)
What happens to the electrons in the ETC?
High-energy electrons will be released from the electron carriers (NADH and FADH2) and move along the inner membrane of the mitochondria, passing from one carrier protein to the next, giving energy as they go for the pumping of H+. Electrons will then be received by oxygen, the final electron acceptor.
What happens to the NAD+ and FAD after the ETC?
They will return to the earlier stages to be reduced/“recharged” again.
Energy from the ETC is used to pump H+ from _______ to _______________________.
Matrix
Intermembrane space
During chemiosmosis in mitochondria, H+ builds up in the _____________. When these H+ flow _________ their concentration gradient into the matrix, _______ is produced from ADP + P.
Intermembrane Space
Down
ATP
Explain the importance of oxygen in the ETC.
Oxygen is the final electron acceptor and needs to be there to collect the electrons at the end of the ETC. ETC relies on oxygen to be present in order to occur. Since the bulk of ATP is made in the ETC, without oxygen, aerobic cellular respiration could not happen, which greatly reduces the amount of energy that can be released for the cell to use.
Water is the final product of cellular respiration. How is this water produced?
Oxygen picks up the electrons from the ETC and the H+ that have diffused through the ATP Synthase, forming water molecules, which will be released from the mitochondria
Cellular respiration yields what percentage of the energy of the glucose input?
About 39% of the energy in glucose is harvested to produce ATP
ATP can be produced by substrate-level phosphorylation and oxidative phosphorylation. In which stages of respiration will you find each type?
Glycolysis and Krebs’s cycle use substrate-level phosphorylation
ETC uses oxidative phosphorylation (chemiosmosis)
How much ATP is produced in each stage of cellular respiration?
Glycolysis: 2 (net) ATP
Prep Reactions: 0 ATP
Krebs Cycle: 2 ATP
ETC: 32-34 ATP
Total: 36-38 ATP
The process that evolved first was
Chemiosmosis
Glycolysis
The electron transport chain
Krebs cycle
Glycolysis
Which is NOT an event of the prep reactions?
Breaks down pyruvate
Converts a citric acid molecule
Oxidizes pyruvate
Generates acetyl-CoA
Converts a citric acid molecule
Select the process with the greatest yield of NADH per glucose molecule.
Glycolysis
Krebs cycle
Prep reaction
Electron transport chain
Kreb’s Cycle
Which of the following does NOT result in NADH?
Glycolysis
Krebs cycle
Electron transport chain
Prep reaction
ETC
The coenzyme that carries the acetyl group from the prep reactions to the Krebs cycle is
Coenzyme A
The final acceptor of electrons in cellular respiration is
Oxygen
Which of the following reactions occurs in the cristae of the mitochondria?
ETC
The process directly responsible for most of ATP formed during cellular respiration is
Chemiosmosis
FADH2 is only produced where?
Kreb’s Cycle
