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86 Cards in this Set
- Front
- Back
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How do typical heterotrophs derive energy?
[Lecture 4 Slides] |
Energy is initially derived from glucose (or lipids) via cellular respiration.
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What is the chemical reaction for cellular respiration?
[Lecture 4 Slides] |
C6H12O6 + 6O2 -> 6CO2 + 6H2O + Energy
glucose + oxygen yields carbon dioxide, water, and energy. |
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What form does the energy produced by cellular respiration take and how much is it, how efficient is it?
[Lecture 4 Slides] |
About 29 ATP (2820 kJ/mol)
This process is approx 65% efficient which is very high. |
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There are 4 key facts to know about ATP, name them:
[Lecture 4 Slides] |
1. ATP is the main energy carrier in cells
2. Removal of a phosphate group provides energy (ATP, adenosine triphosphate becomes diphosphate, ADP, or monophosphate, AMP) 3. Every cell makes its own ATP in mitochondria 4. ATP is not stored anywhere |
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What are the 4 stages of cellular respiration?
[Lecture 4 Slides] |
1. Glycolysis
2. Krebs cycle (citric acid cycle) 3. Electron transport chain 4. Oxidative phosphorylation |
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What occurs in the absence of oxygen? This should be 2 steps
[Lecture 4 Slides] |
1. Glycolysis
2. Fermentation |
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What are the 2 phases of glycolysis?
[Lecture 4 Slides] |
1. investment phase (requires 2 ATP)
2. payoff phase (yields 4 ATP, 2 NADH2) |
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What occurs in the investment phase?
[Lecture 4 Slides] |
Investment phase requires 2 atp:
-glucose via ATP becomes fructose. -fructose via ATP becomes glyceraldehyde. |
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What occurs in the payoff phase?
[Lecture 4 Slides] |
This yields 4 ATP and 2 NADH2
-2 glyceraldehyde add H to (2) NAD forming 2 NADH2 -then 2 ADP are phosphorylated forming 2 ATP -water is produced -2 more ADP become ATP -final result is 2 Pyruvic Acid |
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What is the net result of glycolysis?
[Lecture 4 Slides] |
Glucose + 2 NAD + 2 ADP + 2Pi -> 2 pyruvate + 2 NADH2 + 2 ATP + 2 H2O
glucose is oxidized forming pyruvate |
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What is pyruvate? How many carbons does it have?
[Lecture 4 Slides] |
pyruvate = pyruvic acid. It is a 3 carbon compound
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Where is the majority of energy released in cellular respiration? What processes release the bulk of energy?
[Lecture 4 Slides] |
In the mitochondria during the Krebs Cycle (citric acid cycle) and the Electron transport chain and oxidative phosphorylation.
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What occurs in the Krebs Cycle? What is its alternate name?
[Lecture 4 Slides] |
The citric acid cycle.
-Pyruvic Acid (3C) charges NAD and produces CO2 (b/c it lost a carbon) -this forms Acetyl Coenzyme A (2C) -a lot of poppycock happens. -bonds are rearranged many times. -products: 2 CO2, 3 NADH2, 1 FADH2, ATP. |
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What is the summary of the Krebs Cycle?
[Lecture 4 Slides] |
A 2C compound (acetyl coenzyme A) is added to a 4C compound (oxaloacetate) and then there are 8 steps of bond rearrangement.
2 CO2 are produced total (reducing a NAD, both times) 3 NAD are reduced to NADH2 1 FAD is reduced to FADH2 ADP is phosphorylated to ATP |
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Where would Lipids enter the krebs cycle?
[Lecture 4 Slides] |
Lipids meet up with Acetyl coenzyme A, a 2C compound after pyruvic acid produces 1 CO2 and 1 NADH2
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What is the final product from Pyruvic acid after the krebs cycle?
[Lecture 4 Slides] |
Oxaloacetate (4C)
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What occurs in the ETC?
[Lecture 4 Slides] |
Electrons are carried by NADH2 and FADH2, they go to a chain of enzymes in the inner mitochondrial membrane.
-each enzymes uses some electrons energy to pump H+ thru the membrane. -Finally, O2 is reduced to water. -The protein gradient drives ATP synthase to phosphorylate ADP => ATP |
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What is the yield from aerobic catalysis of glucose?
[Lecture 4 Slides] |
Total yield is 29 ATP. See slide 12
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Where does glycolysis occur?
[Lecture 4 Slides] |
Cytosol aka cytoplasm fluid
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Briefest summary of glycolysis, GO:
[Lecture 4 Slides] |
Glucose -> 2 Pyruvate (6C -> 3C)
+2 ATP +2 NADH |
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Briefest summary of pre-Krebs Cycle bit, GO
[Lecture 4 Slides] |
2 Pyruvate -> 2 Acetyl CoA (3C -> 2C) then enters cycle
+1 CO2 per Pyruvate +1 NADH2 per Pyruvate |
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Briefest summary of Krebs Cycle starting with Acetyl Coenzyme A, GO
[Lecture 4 Slides] |
Acetyl CoA + Oxaloacetate (2C+4C) -> lots of steps
+2 CO2 +3 NADH2 +1 FADH2 +1 ATP [each of these values is per 1 Acetyl Co-A] |
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Where do the NADH2 and FADH2 go after Krebs? NADH2 produced from glycolysis joins them there
[Lecture 4 Slides] |
ETC for oxidative phosphroylation and chemiosmosis
[think chemi-osmosis] |
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What are the total counts of ATP produced, summarized?
[Lecture 4 Slides] |
2 from glycolysis (glucose)
2 from Krebs (2 Acetyl CoA) 25 from ETC/ Oxidative phosphorylation |
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What is different about the ATP formation in glycolysis and krebs vs the ETC?
[Lecture 4 Slides] |
glycolysis and krebs are substrate-level phosphorylation. ETC is oxidative phosphorylation.
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Where does each of the 3 stages take place?
[Lecture 4 Slides] |
Glycolysis - cytosol
Krebs and ETC: Mitochondria |
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What is necessary to turn carbon bond energy into ATP?
[Lecture 4 Slides] |
Oxygen
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What are the primary roles of NADH2 and FADH2?
[Lecture 4 Slides] |
Carry electron energy
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What occurs in the absence of oxygen? What is this condition called?
[Lecture 4 Slides] |
Anaerobic conditions = no oxygen.
Fermentation allows for ATP to generated in 2 ways |
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What are the forms of fermentation that produce ATP?
[Lecture 4 Slides] |
1. Production of lactic acid
2. Production of ethanol |
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What occurs in Production of lactic acid?
[Lecture 4 Slides] |
-Glycolysis occurs producing a net 2 ATP and net 2 NADH2. The result is 2 Pyruvate.
-Then, the just produced 2 NADH2 along with lactate dehydrogenase, an enzyme, produce 2 lactate |
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What are the pros and cons of lactic acid production?
[Lecture 4 Slides] |
CONs:
-it only generates 2 ATP -it doesn't work in all tissues, like brain Pro: it is an important source of energy though |
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what occurs in Production of Ethanol?
[Lecture 4 Slides] |
Glycolysis first. Then 2 pyruvate release 2 CO2 forming 2 acetaldehyde. Via 2 NADH2, this becomes 2 Ethanol.
Yeast do this poppycock. |
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What are the 4 Mechanisms of ATP production (in order from most to least effective)?
[Lecture 4 Slides] |
1. Aerobic metabolism using O2
2. Anaerobic glycolysis 3. Phosphagen use (anaerobic) 4. Aerobic metabolism using O2 from internal stores. (3 and 4 are virtually non-contributors) |
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Tell me a little more about Phosphagen use
[Lecture 4 Slides] |
Just know that CP and AP (creatine and arginine phosphate) don't need lipid or oxygen or energy stores but produce ATP. Then they drop the phos. suffix and are just creatine and arginine.
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Describe the state of operation and rate of ATP production for the 4 main forms of ATP production
[Lecture 4 Slides] |
1. Aerobic catabolism is always occuring (steady state), it's the most efficient yield but it's slow.
2. glycolysis is nonsteady but it's very fast production when it begins. 3. Phophagen use (anaerobic) and 4. aerobic catabolism using existing O2 are both nonsteady but very fast with low yields |
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What are the ATP yields per episode of use (for each of the 4 methods of production)?
[Lecture 4 Slides] |
1. aerobic catabolism: very large. ~200 in a marathon
2. glycolysis: moderate (1.5) 3. Phosphagen and 4. Aerobic catabolism using existing O2 are small, 0.4 and 0.2 respectively |
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What is the method of ATP production used over time?
[Lecture 4 Slides] |
1. Starting a 100-m dash, it's almost all anaerobic; glycolysis and phosphagen.
2. As the race continues, phosphagen runs out first as it doesn't have CP or AP left. 3. Glycolysis runs out 4. ATP from areobic catabolism occurs using glycogen and glucose and is the main producer of ATP 5. Near marathon lengths, aerobic catabolism using lipids produces ATP. |
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What occurs at the beginning of a sprint in terms of oxygen intake and energy use?
[Lecture 4 Slides] |
Oxygen intake is insufficient. Thus, glycolysis and phosphagen produced ATP is what matters
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What is the Pay-as-you-go phase?
[Lecture 4 Slides] |
O2 intake meets demand and aerobic catabolism takes over.
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What happens as you rest?
[Lecture 4 Slides] |
When you stop moving, your resting rate of O2 consumption drops sharply but you're still taking in lots of O2 so consumption overwhelms demand.
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What is burst exercise?
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sudden, intense exercise
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What is sustained exercise?
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exercise that can be continued at a steady rate for a long period
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What is P(sub)i?
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Stands for an inorganic phosphate ion (HPO4 2-)
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How does ATP hold energy?
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When ATP is formed, ADP and Pi need energy from food to bond. When ATP turns back into ADP and Pi, this energy is released for use.
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What happens with the carbons from glucose during cellular respiration?
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Every carbon becomes CO2.
Glucose -> 2 Pyruvic Acid 2 Pyruvate -> 2 Acetyl CoA (releasing total of 2 CO2) 2 Acetyl CoA -> Oxaloacete (release total of 4 CO2) thus, 6C in glucose becomes 6 CO2 |
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What is the full reaction version of:
NAD+ + 2H -> NADH2? |
(NAD+) + 2H -> NADH + (H+)
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What does the full Krebs cycle consist of?
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The pre Krebs (my words, not accurate, not textbook): which is pyruvic -> acetyl
followed by Krebs (acetyl - oxaloacetate) |
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What does the full Krebs cycle produce?
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6 CO2 (2 from pyruvic, 4 from krebs)
8 NADH2 (2 from pyruvic, 6 from krebs) 2 FADH2 (both in real krebs) 2 ATP all values in given per glucose |
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How are 2 ATP produced in the Krebs Cycle? (the circular part)
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2 GDP -> 2 GTP
2 GTP + 2 ADP -> 2 ATP and 2 GDP (this is per glucose aka per 2 pyruvic aka per 2 acetyl coA) |
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Where is O2 used in aerobic catabolism?
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NOT in Glycolysis or Krebs, only used once we get to ETC and oxidative phophorylation
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What are NAD and FAD and why?
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NAD and FAD are only electron acceptors. They were close by and convenient. But the body has to use them to shuttle e- back and forth because other wise, cells would run out of NAD and FAD, bringing glycolysis and krebs to a halt.
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What is the electron transport chain made of? ETC for the rest of the questions. Tell me about the constituents
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4 major protein complexes (I-IV). Each is located in the inner membranes of mitochondria and are capable of undergoing reversible reduction and oxidation. Everything takes place in a specific order.
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What is the last compound in the ETC?
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Complex IV aka cytochrome oxidase.
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What does the ETC do?
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It transfers e- from NADH2 and FADH2 into different compounds and finally into O2 which is voided as H2O
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Why is oxygen the last e- carrier?
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Because O2 is constantly coming in the body and the product of its reduction, water, can be voided into the environment.
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What is oxidative phosphorylation?
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It's the process of forming ATP from ADP using the energy released by transferring electrons in the ETC
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Where does the energy to make ATP come from in the ETC?
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Molecular O2 had a much higher affinity for e- than NAD and FAD. When the e- move to water, there's a great decrease in free energy which is captured in bonds forming ATP. There's also something to do with a proton gradient in the mitochondria
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What are the functions of the enzyme protein complexes in the ETC, I -> IV?
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1. NADH-dehydrogenase: takes H from NADH2
2. Succinate-dehydrogenase: passes H to FAD forming FADH2 used by ubiquinone (both pass H to ubiquinone which passes them to...) 3. Cytochrome b-c1: passes e- to cytochrome c 4. Cyctochrome oxidase, passes e- to form H2O |
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Group the enzyme protein complexes of the ETC for me by functionality, please
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I, III, IV are transmembrane so they pump H+ from their reactants into the mitochondrial intermembrane space, forming a gradient as the H+ cannot escape.
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What is the P/O ratio?
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# of ATP formed per atom of oxygen reduced to water.
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What is coupling?
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linkage of ET with oxidative phosphorylation. It can be graded by its completeness. Usually, relatively tight.
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What does ATP synthase do?
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It takes the high [H] in the mitochondrial intermembrane space and pumps them back into the mitochondrial matrix (core) as ATP to be used. This is oxidative phosphorylation. (gain of e- energy via phosphate groups)
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What is Uncoupling Protein 1? (UCP1)
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It takes H+ from the intermembrane space and produces heat, pumping the H back into the matrix
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What is redox balance?
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It's the balance of reduction to oxidation reactions in a cell. If one overwhelms the other, the cell function slows down because there's a build up of either carriers without e- or too many carriers with e-.
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The production of lactic acid from glucose is also known as...
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Anaerobic glycolysis
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What are the reactants, products, and intermediates of anaerobic glycolysis?
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Reactants: glucose or glycogen
Products: 2 ATP from glucose, 3 for glycogen, lactic ACID Intermediate: 2 NAD -> 2 NADH2 -> NAD, repeat again, glucose -> pyruvic -> lactic acid via LDH |
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What is a steady state (mechanism)?
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1. ATP is produced as fast as it is used
2. it uses raw materials no faster than they are replenished 3. chemical by products are voided as fast as they are made 4. it has no other changes on cell function. |
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What is a nonsteady state (mechanism)?
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supplies are depleted, products are accumulated, it alters its own conditions to the point that the reaction is self limiting or self terminating.
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What's the comparison between steady and nonsteady?
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Well, both terms are relative. But steady can theoretically go on forever.
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How do phosphagens produce ATP?
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creatine and arginine phosphate combine with ADP (and their respective kinase which is a an enzyme) to form ATP.
This is an equilibrium reaction so it kicks in when product ATP is low. |
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Why can aerobic catabolism not accelerate quickly whereas anaerobic glycolysis (lactic acid), phosphagen use, and use of preexisting O2 can?
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Aerobic catabolism is not self contained in cells. The other three are. Burst exercise depends on the last 3 methods of ATP production
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What is each mechanism's peak rate (in comparison)?
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Phosphagen > anaerobic glycolysis ~ using existing O2 > aerobic catabolism using environmental O2
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How rapidly can each mechanism be reinitialized (in comparison)?
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phosphagen use ~ existing O2 > anaerobic glycolysis
b/c anaerobic glycolysis has to wait for lactic acid to dissipate, and normal aerobic glycolysis is always happening so it does't really reinitialize. |
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What are slow oxidative fibers? (SO) Describe them in terms of ATP production
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contract and develop tension relatively slowly. They are designed to produce ATP via aerobic glycolysis and have lots of mitochondria to do so. [Red] Low intensity, long time
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What are fast glycolytic fibers? (FG) Describe them in terms of ATP production
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contract and develop tension quickly. They produce ATP fast through phosphagen use and anaerobic glycolysis so then have many phosphagens and enzymes like LDH. [White] High intensity bursts
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define maximal and submaximal exercise and supramaximal exercise
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exercise that requires the maximum possible O2 consumption for an individual. Sub is below, supra is above.
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What is the phase at the beginning of high intensity known as and why?
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The oxygen deficit phase because your body isn't taking enough O2 in to rely on aerobic catabolism. Energy comes from anaerobic processes like phosphagen and anaerobic catabolism
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What is the official name for "breathing hard"? It occurs after the pay as you go phase
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EPOC -> excessive postexercise oxygen consumption
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Give examples in various species of different muscle fibers and why?
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Leopard frog; fast escape, rely of anaerobic glycolysis and thus have many white (FG) fast glycolytic muscles for bursts. Western toad jump slow and steady with red (SO) slow oxidative muscles. Sprinters vs marathoners
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What are hypoxia or anoxia?
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low O2 levels in tissues and absence of O2 in tissues, respectively.
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what is metabolic depression?
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a state that organisms switch into that won't harm their life but maintains a lower metabolism to deal with reduced O2 influx.
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How are animals adjusted to lives in anoxia?
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Normal vertebrates that experience low O2 conditions (hypoxia) produce lactic acid but have no ways of voiding it. Invertebrates adapted to anoxia have anaerobic catabolic pathways that are complex and produce waste that they do excrete.
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What happens when air-breathing vertebrates dive?
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They use up the O2 they have until the slowly start cutting off O2 to non essential body areas and rely on anaerobic processes for those bits.
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Name a few animals that can survive for very long times in anoxia
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Trachemys turtle
Chrysemys turtle Curcian carp Blind Goby |
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What's an anaerobe?
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animals that can survive whole body anoxia for long times. Also, crucian carp produce ethanol to rid themselves of carbon bonds in anoxia.
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