Presentation on theme: "Breakdown of glucose Glycolysis Inside the Mitochondria Fermentation Cellular Respiration Spring 2013 - Althoff Reference: Mader & Windelspecht Ch. 8)"— Presentation transcript:
Breakdown of glucose Glycolysis Inside the Mitochondria Fermentation Cellular Respiration Spring Althoff Reference: Mader & Windelspecht Ch. 8) Lec 10
Cellular Respiration A _________ process that requires oxygen and gives off carbon dioxide. Most often it involves the ______________ _____________ of glucose C 6 H O 2 6CO 2 + 6H ENERGY CELLULAR RESPIRATION: C 6 H 12 O 6 is oxidized, O 2 is reduced
Some key, basic facts….. Glucose is a _______________ molecule The breakdown products, CO 2 and H 2 0, are low- energy molecules Facts 1 & 2 mean this is an ______________ process—a chemical reaction that releases energy As noted in previous slide…. A) Glucose is oxidized (losses electron) B) O 2 is reduced (gains electron) The slower this reaction (cellular respiration) the more efficient the use of the glucose molecule
Expanding on –slower is better The cellular respiration “pathway” allows the energy within a glucose molecule to be released ___________ so that the ATP can be produced gradually. If glucose molecule breakdown was all-at- once then most energy released (in the form of heat) would be lost Slow “pathway” results in 36 or 38 ATP molecules per glucose molecule or about ____ of the energy available in glucose.
NAD + and FAD: Important _____________ _____ = nicotinamide adenine dinucleotide _____ = flavin adenine dinucleotide Part of NAD + Cycle, a key _______ reaction in the process of cellular respiration Sometimes FAD subs for NAD + in the cycle Key here is that NAD + accepts ____________ plus a _______________ (H + ) and NADH results
____________: “splitting sugar” Occurs _____________ the mitochrondria Does NOT require the presence of oxygen, therefore glycolysis is ____________ (vs. aerobic = O 2 required) For all other phases of cellular respiration, the “action” is __________ the mitochondria where O 2 is present and used.
The ______________ of Cellular Respiration... Glucose is broken down in the cytoplasm to 2 molecules of pyruvate: GLYCOLYSIS Pyruvate enters a mitochondrian (i.e., the “______________________” of the cell) and is oxidized, and NADH is formed. CO 2, a _______ ______, is removed. Cycle happens twice (2x) to process pyruvate molecules: ________________
…phases 3 & 4 of Cellular Respiration... Cyclical series of oxidation reactions in the matrix of the mitochondrion result in NADH and FADH ( NAD + cycle ), _______________, and _________ __________. _______________producing total of 2 ATP molecules per glucose molecule ________ ___________ (i.e., 2 x = 2 ATP) Series of “carriers” inside the mitochrondrial membrane move from one to the next electrons that were removed from the glucose and pass them until they are received by O 2, that eventually turns to water (H added). Result ___________. Known as the __________________________
GLYCOLYSIS Glucose pyruvate PREP REACTION 2 1 C A C 3 ELECTRON TRANSPORT CHAIN 4 CYTOPLASMA MITOCHONDRION This is CELLULAR RESPIRATION ___________________________
Glycolysis PYRUVATE Pyruvate is a ________________ in cellular respiration If O 2 is not available to the cell, ______________ occurs in the cytoplasm leading to “some serious consequences”… During fermentation, glucose is ______________ metabolized to lactate or to CO 2 and alcohol (it is species specific)…result can be net gain of only 2 ATP per molecule verses 32 – 34 under normal cycle just described
GLYCOLYSIS: outside the mitochondria Again, process where glucose metabolized to 2 pyruvate molecules This process is _________________ found—in other words, in all organisms regardless of domain –suggest common “ancestry”. It occurs in the __________. Remember, Bacteria & Archea (prokaryotic cell types) do not have mitochondria. Because eukaryotic cells have mitochondria, the citric acid cycle and electron transport chain __________________ ADVANCEMENTS that result in more efficient ATP production in this organelle type. Because in cytoplasma, may be why O 2 not required
Inside the Mitochondria - Summary Phases 2-4 occur __ mitochrondrion (not outside) Starts with pyruvate ( which resulted from glycolysis breaking down glucose molecule to 2 pyruvate molecules ) being brought in to this organelle Ends with ____ and ____ transported out to the cytoplasm The CO 2 _________ ( i.e., no energy required ) out of the cell and into the bloodstream H 2 0, a by-product of cellular respiration, can a) ____ in the mitochondria, somewhere else in the cell (cytoplasm), or b)enter the blood stream and ________ by the kidneys as needed.
Inside the Mitochondria – Details - A _____________________________ (so-named because it occurs before the citric acid cycle). It occurs in the ______ portion. Pyruvate goes to 2-carbon acetyl group attached to a coenzyme (CoA) and CO 2 is given off. ___________________________ takes place in the _________ portion. Also known as Krebs cycle (after ___________, 1930s). See inputs and outputs of this phase in the next slide.
Inside the Mitochondria – Details - B ELECTRON TRANSPORT CHAIN – is a series of ____________ that pass electrons ( what else?...dah ) from one to the other. “These” electrons brought in by NADH an FADH 2 molecules. Turns into a series of ___________ _____________ reactions Most of the carriers are ________________, a ____________ that is a tightly bound heme group with central atom of iron.
Inside the Mitochondria – Details – B-1 ELECTRON TRANSPORT CHAIN con’t–the end of the chain is when O 2 accepts the electrons…therefore _____________ cellular respiration because no ATP are produce. Cristae—has a special arrangement here to allow pumping of ___ ions across the matrix to intermembrane space (recall this is a _______________ area = ________________) Here CHEMIOSMOSIS (ATD + P ATP) takes place
______________ and CHEMIOSMOSIS…. Some ______________ poisons stop CHEMIOSMOSIS Some “gum it up” by over-doing the H + gradient (i.e., over pump H + across membrane)…others reduce the pumping ability Either way, _____________________ is greatly and immediately reduced….thus, cells ______! !
Other ATP facts Any point in time, only enough ATP available collectively to sustain human life ___________ _______________. Mitochrondria produce approximately ___________________________ every day. _____________________. Muscle contractions remain…thus, stiff. Will hold contraction for up to 12 hours. Finally, things breakdown over hours.
Heads up exam question…. Read ECOLOGY FOCUS handout from Mader (2007) to understand how carbon monoxide poisoning “poisons”….. Be prepared to answer what is going on at the __________________ —can’t just say the CO is bad for you!!
FERMENTATION It is an _______________ process. 1) anaerobic means _____ oxygen used 2) it is a ________ process Example: lots of anaerobic species of bacteria. Many in your __________ (good thing—usually). Example: ___________ (cud-chewing animals) rely largely on these anaerobic bacteria to breakdown cell walls to obtain nutrient from plants grazed/browsed. Thus, ________________…ruminating that is!
LACTIC ACID FERMATION Can provide a _____________of ATP (therefore energy) initially…good example in muscles. ___________ lactate produced that is toxic to cells…they can’t handle it. Main effect of the _______ would be that it changes the ______ environment Muscles fatigue and cramp leading to __________ debt. Key to “paying off” oxygen debt is to get O 2 …that’s why you are still breathing heavy _______ extensive exercise.
Make sure you know these terms and where they “fit” in Pyruvate Prep Reaction Citric Acid Cycle Glycolysis Electron Transport Chain ATP Fermentation Anaerobic vs. Aerobic Cellular respiration = 1 2 3 4 Mitochondrion—what happens “inside” and “outside” during cellular respiration Cristae Cytochrome Electron transport chain
THIS _____ CELLULAR RESPIRATION !!!! ___ ATP ________ATP