Chapter 7: Respiration and Glycolysis
How does alcohol fermentation work? What happens to NADH during this process?
It takes C3 pyruvate and splits it into CO2 and C2 acetaldehyde. -NADH electrons and H+ protons are transferred to acetaldehyde, forming ethanol and recycling NAD+.
What happens in the Electron-transport chain?
Occurs in the inner mitochondrial membrane(cristae). -ATP is synthesized by chemiosmosis and oxidative phosphorylation. -Oxygen is the final electron acceptor -high energy e- are transferred from NADH and FADH2 through electron carriers and pump protons out the matrix into the innermembrane space. -At the end, oxygen receives energy spent e- and combines with hydrogen to form WATER. -when ETC is active, intermembrane space has lower pH than matrix.
What is the first stage of fatty acid breakdown? Can fats be metabolized without oxygen?
Fats cannot be metabolized without oxygen. -The first stage of fatty acid breakdown is C2 acetyl groups are removed until the entire fatty acid is converted, which is called beta-oxidation. -then, each acetyl group is combined with CoA, which enters the Krebs cycle. -yields 36 ATP.
What is "oxygen debt" in association with lactic acid fermentation?
When oxygen isn't present in a sufficient amount during exercise.
How many NADH, FADH, and ATP can be derived from one molecule of acetyl Co-A in the Krebs cycle
-1 ATP -3 NADH -1 FADH2
After going through the electron transport chain, what is the theoretical ATP yield for each of the following: one NADH derived from glycolysis, one NADH derived from processes within the mitochondrion, and one FADH
-1 NADH: yields 1.5 ATP -1 NADH from processes within the mitochondrion: 2.5 ATP -1 FADH2: 1.5 ATP
How many NADH and ATP can be derived from one molecule of glucose in glycolysis?
-2 ATPs -2 NADH
How do fats and amino acids get broken down (write the terms associated with each process)?
-Catabolism(fats) -deamination(amino acid)
What happens in the Krebs cycle?
-Cyclic Metabolic Pathway; takes place in the mitochondrial matrix. 1.) 9 reactions: CoA carries C2 acetyl group to join C4 oxaloacetate molecules=forms C6 citrate. 2.) Oxidation H+, 2e- forms NADH. 3.) Decarboxylation C forms CO2 4.) Oxidation 2...same as #2 5.) same as #3 6.) substrate-level phosphorylation to yield ATP 7.) Oxidation H+, 2e- forms FADH2 8.) Oxidation H+, 2e- forms NADH 9.) Oxaloacetate is regenerated. 4 CO2, 6 NADH, 2 FADH2, 2 ATP per molecule of glucose
How does lactic acid fermentation work? What is produced at the end, and what materials are required?
-Electrons and H+ are transferred directly from NADH to pyruvate, forming C3 lactate and recycling NAD+ -When oxygen is available, lactate is converted back pyruvate by reducing NAD+ to NADH -O2 is required to metabolize lactate
What is the difference between substrate-level phosphorylation and oxidative phosphorylation?
-Sub-level phos. transfer a phosphate directly to ADP from another molecule. (used in glycolysis and Krebs cycle) -Oxidative-phos uses ATP synthase(enzyme) and energy derived from a proton gradient (H+) to make ATP. (used in ETC)
Why is the actual yield of ATP less than the theoretical yield?
-the inner mitochondrial membrane is leaky. some of the protons leak into the matrix without passing through ATP synthase. -proton gradient is used for other things as well.
How many NADH can be derived by oxidizing one molecule of pyruvate to produce CO2 and acetyl CoA
1
What are the stages in glucose breakdown?
1. Glycolysis 2. Pyruvate-oxidation 3. Krebs Cycle 4. Electron transport chain
How many molecules of pyruvate are produced from 1 molecule of glucose after glycolysis is complete?
2
What is the role of glucose in glycolysis and respiration?
Glucose metabolizes in the presence of oxygen to release energy.
What happens in each stage of Glucose breakdown?
Glycolysis: Occurs in the cytoplasm -Glucose is split into 2-three carbon pyruvate molecules. -does NOT require oxygen -yields 2 ATP, 2 NADH, 2 pyruvate molecules per glucose. -water gets removed and yields two PEP molecules, each with high energy phosphate bond which get removed by 2 ADP to produce 2 ATP.
How does the electron transport chain produce ATP? REVIEWWWWW!!
High energy electrons enter the chain and gradually go through 3 proton gradients driving ATP production.
What happens in pyruvate oxidation?
If oxygen is present, the pyruvate will exceed onto Aerobic respiration. If not, pyruvate will exceed onto Fermentation. -With oxygen: occurs in the mitochondria. -each pyruvate(2) is converted to C2 acetyl group and attached to CoA. -1 carbon dioxide is released per pyruvate. (2 per glucose) -1 NADH is produced per pyruvate. (2 per glucose) -pyruvate dehydrogenase removes 1 CO2 from each pyruvate and sends H+ and 2e- to NAD+...reduced to NADH.
What is the final electron acceptor in the electron transport chain, and what does it become after it accepts the electrons?
oxygen is the final electron acceptor and becomes water after accepting electrons.