Ch 5: Cellular Respiration Flashcards
What is cellular respiration?
A series of chemical reactions that produce energy for the cell
What does cellular energy come in the form of?
ATP (adenosine triphosphate)
When energy is required for a process in the cell, what will the cell do?
Hydrolyze (break) the bond between the 2nd and 3rd phosphate molecules on ATP. A molecule of adenosine diphosphate (ADP) and a molecule of phosphate remain.
What is the equation for cellular respiration?
Glucose + oxygen —> carbon dioxide + water + ATP
C6H12O6 + 6 O2 —> 6 CO2 + 6 H2O +6 ATP
Where does glycolysis occur?
Cytoplasm
What are the substrates for glycolysis?
Glucose, 2 ATP
What are the products of glycolysis?
Pyruvate, ATP, NADH
Is oxygen needed for glycolysis?
No
Where does PDC occur?
mitochondria
What are the substrates for PDC?
Pyruvate
What are the products of PDC?
Acetyl Co-A, NADH, CO2
Where does the Krebs Cycle occur?
mitochondria
What are the substrates of Krebs cycle?
Acetyl- CoA, oxaloacetic acid
What are the products of the Krebs cycle?
Oxaloacetic acid, NADH, ATP, FADH2, and CO2
Where does electron transport/ oxidative phosphorylation ocurr?
inner membrane of mitochondria
What are the substrates of electron transport?
NADH, FADH2, ADP, P
What are the products of electron transport?
NAD+, FAD, ATP
Most of the energy released from the breakdown of glucose is ______
stored as electrons on electron carriers
When an “empty” electron carrier accepts a pair of electrons, it is _____. When it gives these electrons up it becomes _____
Reduced, oxidized
What are the 2 most common electron carriers (and the ones used during cellular respiration)?
NAD+ and FAD
NAD+ can accept _______ to become NADH
a pair of electrons and a hydrogen ion
FAD can accept _______ to become FADH2
a pair of electrons and 2 hydrogen ions
What happens during glycolysis (sugar splitting)?
1 molecule of glucose is split in half to produce 2 molecules of pyruvate
What is needed to start the process of splitting the glucose molecule in glycolysis?
2 ATP molecules and 2 NAD+ molecules
What is the equation for glycolysis?
C6H12O6 + 2 ATP + 2 NAD+ —> 2 Pyruvate + 4 ATP + 2 NADH
Glycolysis occurs without oxygen which means it is _____.
Anaerobic
What is the PDC (pyruvate dehydrogenase complex)?
A group of enzymes that prepares pyruvate to enter the 3rd step of cellular respiration (the Krebs cycle)
Pyruvate contains ___ carbon atoms and the Krebs cycle can only accept a molecule with ___ carbon atoms. So PDC’s job is ______.
to remove one of the carbons from pyruvate and attach the remaining 2-carbon structure to a coenzyme called Acetyl Co-A
The carbon that is removed in PDC leaves in the form of ____.
CO2
Because there are 2 molecules of pyruvate at the end of glycolysis, what is produced in PDC?
2 molecules of acetyl Co-A, 2 molecules of NADH, and 2 molecules of CO2.
The process of glycolysis produces ATP and NADH by converting one molecule of ______ to 2 molecules of ______.
glucose, pyruvate
The pyruvate dehydrogenase complex is found in the _____ of the mitochondria.
Matrix
______ is made of many glucose molecules bonded together, and its function is to store energy.
Glycogen
During the PDC, a molecule of pyruvate is converted to _____, a molecule of _______ is produced, and _____ is lost.
Acetyl Co-A, NADH, CO2
What is a process that indirectly requires oxygen?
Pyruvate dehydrogenase complex
What is a process of cellular respiration that takes place in the cytoplasm?
Glycolysis
What is a process of cellular respiration that takes place in the inner membrane of the mitochondria?
Electron transport chain
What is regenerated each time the Krebs cycle is completed?
The first molecule (oxaloacetic acid)
What happens during the Krebs cycle?
Acetyl Co-A is combined with oxaloacetic acid to form citric acid. Citric acid is broken down and rearranged to form the original oxaloacetic acid molecule. 3 molecules of NADH, 1 of FADH2 and 1 ATP are made. CO2 is released.
The principal substance that enters the Krebs cycle is ______.
Acetyl Co-A
Oxygen is also known as the ______
final electron acceptor
One of the goals of electron transport is to _____ the electron carriers back to “empty.”
oxidize
Electron transport occurs along the _______ of the mitochondria.
inner membrane
The products of the Krebs cycle are 3 molecules of _______, 1 molecule of _____, and 1 molecule of _____.
NADH, FADH2, ATP
ATP synthase relies on the facilitated diffusion of ___ ions down their gradient to produce ATP.
H+
In the last step of the electron transport chain, oxygen accepts electrons to form ______.
Water
What are the primary goals of electron transport and oxidative phosphorylation?
to oxidize electron carriers
use the energy from those electrons to make ATP
What does ATP synthase do?
It allows the H+ ions back into the matrix
How many ATP molecules are produced for each molecule of glucose that’s broken down?
about 36
Fermentation produces _____ in yeast and _____ in muscle cells.
Ethanol, lactic acid
Do anaerobic organisms conduct glycolysis?
Yes
Anaerobic respiration (fermentation) produces ____ ATP than aerobic respiration.
Less
In fermentation, NADH is _____ to NAD+, and pyruvate is _____.
Oxidized, reduced
Do anaerobic organisms conduct the Krebs cycle?
No
How many ATP are created from fermentation?
The 2 net ATP from glycolysis.
What is created at the end of glycolysis?
2 molecules of pyruvic acid, 2 ATP. and 2 NADH
