Term
| Lactic Acid – Implications for Performance |
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Definition
Lactic acid alters the pH of the cell
The higher acidity of the cell as a
result of lactic acid production alters enzymatic activity (reactions occur at a slower rate)
The more lactic acid an athlete can produce, the greater power output the athlete can generate
A speed athlete must produce and tolerate great amounts of lactic acid to be successful
Lactic acid does not cause muscle soreness
lactic acid= muscle fatigue
creatine kinase = muscle damage |
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Term
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Definition
Lactate exits the cell via a co-transport mechanism (Monocarboxylate Transporter)
-Transports both lactate and H+ across cell membrane
-RBCs can take up lactate to transport it to other tissues
Lactate Shuttle Mechanism
some lactate can be oxidized to muscle. |
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Term
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Definition
Radioactive tracer studies have suggested:
70% - oxidized by other tissues
20% - converted to glycogen or glucose in liver (Cori Cycle)
10% - converted to amino acids
lactate converted to glucose then converted to pyruvate then converted to amino acid. |
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Term
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Definition
Terms lactic acid and lactate used interchangeably
Lactate is the conjugate base of lactic acid |
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Term
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Definition
is produced in glycolysis
Rapidly disassociates to lactate and H+
this acid dissociate and release hydrogen ions called conjugate base because of the close relationship.
The ionization of lactic acid forms the conjugate base called lactate |
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Term
| Non-oxidative System (Fast glycolysis) |
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Definition
1)Non-oxidative energy sources in muscle are the breakdown of glucose (simple sugar) and glycogen (stored in liver).
2)The breakdown of glucose: Glycolysis
The breakdown of glycogen: Glycogenolysis
glucose--------2 ATP + 2 lactate glycolysis
3. In skeletal muscle, the concentration of free glucose is very low so the
most of potential energy available from non-oxidative energy sources
comes from the breakdown of glycogen .
4. Non-Oxidative system offers about 15 Kcal/mole energy for total
muscle mass that is greater than immediate energy system
(11.1 Kcal/mole)
after 14 second our body use the first phase of glycolosis. |
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Term
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Definition
Aerobic ATP production occurs inside the mitochondria and involves the interaction of 2 cooperating metabolic pathways.
1)Krebs Cycle (TCA cycle)
2)Electron Transport Chain (ETC |
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Term
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Definition
Primary function is to complete the oxidation (H+ removal) of CHO, Fats or proteins using NAD & FAD as hydrogen (energy) carriers.
H+ molecules (their electrons) contain the potential energy in food molecules.
This energy (H+ molecule) can be used in ETC (Electron Transport Chain) to combine: ADP + Pi -------ATP. |
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Term
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Definition
Oxygen DOES NOT participate in the reaction of the Krebs cycle.
Oxygen is used as the final hydrogen acceptor (or carrier) at the end of the ETC (electron transport chain).
2H + O ------- H2O
Thus, the process of aerobic ATP production is also called
oxidative phosphorylation. |
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Term
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Definition
Krebs cycle (citric acid cycle)
-Pyruvic acid (3 C) is converted to acetyl-CoA (2 C)CO2 is given off
-Acetyl-CoA (2C) combines with oxaloacetate (4 C) to form citrate (6 C)
-Citrate is metabolized to oxaloacetate
.Two CO2 molecules given off
-Produces three molecules of NADH and one FADH
-Also forms one molecule of GTP
Produces one ATP |
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Term
Aerobic ATP Production
Krebs cycle (citric acid cycle |
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Definition
| pyruvate three carbon molecule) is broken down to form acetylcoA (2Carbon) and the remaining carbon is given off as co2. next acetyl-coA combines with oxaloacetae (6 carbon)what follow is a series of reactions to regulate oxaloacetate and two molecules of co2 and the pathways begin all over again. |
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Term
Aerobic ATP production
krebs cycle |
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Definition
| for every molecules of glucose entering glycolosis 2 molecules of glucose pyruvate are formed and in the presence of o2 they converted to two molecules of acetyl-CoA. this mean that each molecule of glucose result in two turns of the krebs cycle. each turn of krebs cycle 3 molecule of NADH and ! molecule of glucose result in two terms of krebs cycle, 3 molecule fo NADH and 1 molecule of FADH are formed 1 ATP |
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Term
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Definition
Oxygen does not participate in the reaction of the Krebs Cycle but it is the final H+ acceptor at the end of the ETC.
Remember- ATP Tally for:
NADH=2.5 ATP
FADH=1.5 ATP |
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Term
| Fats and Proteins in Aerobic Metabolism |
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Definition
Triglycerides glycerol and fatty acids
Fatty acids acetyl-CoA
Through Beta-oxidation process
Glycerol:
1. converted to an intermediate of glycolysis
2. It is not an important muscle fuel during exercise |
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Term
Fats and Proteins in Aerobic Metabolism
Protein |
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Definition
Breakdown into amino acids
Step 2: Amino acids are converted to:
- Glucose
- Pyruvic acid
- Acetyl-CoA
- Krebs cycle intermediates |
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Term
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Definition
Electron transport chain results in pumping of H+ ions across inner mitochondrial membrane (from inner compartment to outer compartment)
Results in H+ gradient across membrane
Energy released to form ATP as H+ diffuse back across the inner membrane (from outer compartment to inner compartment) |
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Term
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Definition
-Oxidative phosphorylation occurs in the mitochondria
-Electrons removed from NADH and FADH are passed along a series of carriers (cytochromes) to produce ATP
Each NADH produces 2.5 ATP
Each FADH produces 1.5 ATP
-H+ from NADH and FADH are accepted by O2 to form water |
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Term
| Efficiency of Oxidative Phosphorylation |
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Definition
Aerobic metabolism of one molecule of glucose
Yields 32 ATP
-Aerobic metabolism of one molecule of glycogen
Yields 33 ATP
-Overall efficiency of aerobic respiration is 34%
66% of energy released as heat
Efficiency of fast glycolysis? |
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Term
| Beta Oxidation is the Process of Converting Fatty Acids to Acetyl-CoA |
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Definition
Breakdown of triglycerides releases fatty acids Triglygeride -----3 Fatty Acids + Glycerol
-Fatty acids must be converted to acetyl-CoA to be used as a fuel
-Fatty acid “chopped” into 2 carbon fragments forming acetyl-CoA
Acetyl-CoA enters Krebs cycle and is used for energy |
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Term
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Definition
Protein primarily utilized to build and repair tissue
Contributes only small percentage of total energy production
2-3% of total energy at rest
12-15% of total energy at maximal, exhaustive exercise |
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Term
Control of Bioenergetics
Rate-limiting enzymes |
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Definition
| An enzyme that regulates the rate of a metabolic pathway |
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Term
Control of Bioenergetics
Modulators of rate-limiting enzymes |
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Definition
Levels of ATP and ADP+Pi
High levels of ATP inhibit ATP production
Low levels of ATP and high levels of ADP+Pi stimulate ATP production
Calcium may stimulate aerobic ATP production |
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Term
| Interaction Between Aerobic/Anaerobic ATP Production |
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Definition
Energy to perform exercise comes from an interaction between aerobic and anaerobic pathways
Effect of duration and intensity
Short-term, high-intensity activities
Greater contribution of anaerobic energy systems
Long-term, low to moderate-intensity exercise
Majority of ATP produced from aerobic sources |
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