BY 30 – Fall 2001
8-9.1. Overview to
Cellular Respiration
a. ___________________ refers to the group of catabolism reactions in which food fuels are broken down, and some of the energy is captured in the form of _____________________.
b. ATP production occurs by ___________________________ phosphorylation and _____________________________ phosphorylation. Of the two, ______________________ phosphorylation is anerobic and takes place in the ______________________, and _______________________ phosphorylation is aerobic meaning that ______________________ is required, and it takes place within _______________________________________.
c. An oxidation reaction is one in which _____________________ are lost from a molecule, either as actual _______________________ or in the form of _______________________ atoms.
d. The oxidation of food fuels involves the step-by-step removal of pairs of ___________________ atoms until only _______________________ is left. These H atoms are ultimately combined with __________________ to form __________________________.
e. A reduction reaction is one in which a molecule ______________________ electrons (or _____________________ atoms). During cellular respiration, it is often ____________________ which accept the H atoms and are thus reduced. Two examples of these coenzymes are _____________________ and ________________________. In this case the oxidized forms of these molecules are ______________________ and _______________________, respectively; and the reduced forms are __________________________ and _______________________, respectively.
f. In terms of energy flow, when a substance is oxidized, it _______________ energy, whereas when a substance is reduced, it ______________________ energy.
g. In the complete oxidation of glucose, the balanced reaction is: _______________ + ____________________ ® ___________________ + __________________ + ____________________.
h. The complete oxidation of glucose involves three sets of reactions: _____________________________, _______________________________, and ____________________________________.
i. The ________________________________ is the region between the plasma membrane and nuclear envelope which contains a fluid phase called the ____________________________. It is within the _____________________ that the enzymes for glycolysis are found
j. The number of ______________________ vary with the energy requirements of a cell: the higher the energy requirement, the ______________________ the mitochondria.
k. Mitochondria have _____________________ membranes. It is the inner membrane that is thrown into folds called _______________________.
8-9.2. Glycolysis
a. Glucose enters the cell by _________________________, at which point it is _____________________ by an enzyme called ________________________ to form ___________________________________.
b. The hexokinase reaction serves to _______________________ glucose within the cell because the electrical charge of glucose 6-phosphate prevents it from _________________ across the membrane. This reaction also keeps glucose concentrations within the cell _______________________ which maintains the ____________________________.
c. The net reaction of glycolysis is to take a ________________ carbon glucose molecule and make ________________ molecules of _________________, each containing only ___________________ carbons. In the process, a total of ________________ ATP are made, but a net of only ________________ ATP because 2 are used. In addition, _________________ NADH are made.
d. All glycolysis reactions take place within the ___________________ and _______________ require O2.
e. Within glycolysis, it is _______________________ which gets oxidized and _____________________ which gets reduced.
f. When O2 is available, pyruvate diffuses into the _____________________ and is converted to ____________________. This reaction involves the production of a _________________ molecule and a _________________.
g. When O2 is limited, pyruvate is converted to _______________________ while at the same time producing a _______________________ which allows glycolysis to continue. If the O2 supply remains limited, the buildup of lactic acid will cause cellular pH to __________________ and will eventually cause tissue ______________________________.
8-9.3. The Krebs
Cycle
a. Acetyl CoA enters the cycle by combining with ________________________ (which is ___________ carbon molecule) to form _____________________ (which is a ________________ carbon molecule.
b. Within the Krebs cycle, the 2 carbons of acetyl CoA are converted to ___________________.
c. During each cycle, a total of ________________ ATP are made. So for one glucose molecule to be completely broken down, this involves ___________ cycles producing a total of ________________ ATP.
d. During each cycle, a total of ____________ NADH and _________________ FADH2 are produced. So for one glucose molecule to be completely broken down, this involves a total of ______________ NADH and ______________ FADH2.
8-9.4. Electron
Transport Chain / Oxidative Phosphorylation
a. The _______________________ refers to a series of 3 enzyme complexes embedded within the ______________ membrane of the mitochondria. These enzymes contain ___________________, which are iron-containing pigments.
b. The first enzyme complex contains the __________________________which oxidizes NADH to ______________________. The ____________________ are shuttled along the transport chain such that each member is first ______________ (as it receives the electrons) and then __________________ (as it gives up the electrons). As the electrons move along the chain, there is an energy ___________________.
c. The final acceptor of H atoms is an enzyme called ____________________ which transfers the H atoms to _______________ to form H2O.
d. As the electrons are shuttled down the chain, H+ are pumped to the _____________________ space creating a _____________________ gradient across the inner mitochondrial membrane in which the pH is ________________ in the intermembrane space compared to the inner mitochondrial matrix. There is also a voltage gradient across the inner membrane in which the intermembrane space is ______________ relative to the inner mitochondrial matrix.
e. ATP generation occurs as a result of _________________ flow through an enzyme called the ________________________. The H+ flow __________ their concentration gradient. As a result of this system, each NADH that is oxidized is responsible for producing _______________ ATP and each FADH2 is responsible for producing _________________ ATP.
f. With regard to metabolic poisons, ______________ blocks the flow of electrons to O2 while _______________ agents increase the inner membrane permeability to ___________________.
8-9.5. Summary of
Cellular Respiration
a. For each glucose molecule, glycolysis produces a net of ____________ ATP and _________________ NADH.
b. For each glucose molecule, the conversion of pyruvate molecules to acetyl CoA produces _________________ ATP and ____________________ NADH.
c. For each glucose molecule, the Krebs cycle produces a net of ____________ ATP; __________________ NADH; and ____________________ FADH2.
d. As a result of oxidative phosphorylation, the ______________ NADH produce _________________ ATP and the ________________ FADH2 produce _________________ ATP.
e. As a result of all these process, the total ATP production for the complete oxidation of 1 glucose molecule is _____________ ATP, of which we subtract ________________ ATP giving a grand total of ________________ ATP.