Location and Importance
Where does the Krebs cycle take place in a eukaryotic cell?
Matrix of mitochondria
What is the first step of the Krebs cycle often referred to? *Acetyl CoA and oxaloacetate to citrate*
“The condensation stage”
True or false: The Krebs cycle is a respiratory cycle for producing large quantities of ADP.
False
What is another name for the Krebs cycle?
The citric acid cycle (CAC) or the TCA cycle (tricarboxylic acid cycle)
Where does the Krebs cycle take place in a prokaryotic cell?
Cytosol
What is the second step of the Krebs cycle called? *Citrate to isocitrate*
Isomerization
Fill in the blank: While the Krebs cycle does produce carbon dioxide, this cycle does not produce significant chemical energy in the form of _____.
ATP
Where does the fuel for the Krebs cycle come from?
Fuel for the Krebs cycle comes from lipids (fats), carbohydrates, and proteins which produce the molecule acetyl coenzyme-A (acetyl-CoA)
Why doesn't the Krebs cycle take place in the same location as the eukaryotic cell when it comes to the prokaryotic cell?
Prokaryotic cells don't have a mitochondria
True or false: In some cells, GDP (guanosine diphosphate), is used instead of ADP forming GTP (guanosine triphosphate) as a product.
True
How many molecules of NADH are produced in each cycle?
3
Is the Krebs Cycle a central driver of cellular respiration? [Yes or No]
Yes
True or false: The series of reactions in the Krebs cycle are responsible for most of the energy needs in complex organisms.
True
Which enzyme catalyzes step 4 *α-ketoglutarate to succinyl CoA*?
α-ketoglutarate dehydrogenase
True or false: 4 molecules of carbon dioxide are produced in 1 cycle.
False
If the Krebs cycle stopped halfway, what would happen?
The molecules that are produced in the Krebs cycle reactions can be used as building blocks for a large number of important processes, including the synthesis of... (State 3 things it helps synthesize)
Fatty acids (Steroids and Cholesterol), Amino acids for building proteins, the purines and pyrimidines used in the synthesis of DNA, or NADH
In step 5 *succinyl CoA to succinate*, what is being replaced by the CoA to make ATP?
A phosphate group
Does the Krebs cycle reaction need oxygen while producing carbon dioxide, and if yes explain.
This reaction sequence does not require any oxygen. Instead, this cycle produces NADH and FADH2, which feed into the respiratory cycle
Why do living organisms only have a small amount of oxaloacetate in their cells?
It is constantly being regenerated