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61 Cards in this Set
- Front
- Back
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List and briefly discuss the functions of the three major components of cell structure.
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1 CELL MEMBRANE(plasma membrane)
barrier that separates cell from extracellular fluid. 2 NUCLEUS contains d.n.a. regulates protien synthesis 3. CYTOPLASM fluid portion of the cell, contains organelles such as mitocondria |
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briefly describe coupled reactions?
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are reactions that are linked with the liberation of free energy in one reaction used to drive the second reactions.
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describe what endergonic or endothermic are...
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require energy to be added to the reactants before reactants proceed
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exergonic reactions or exothermic
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Reactions that give off energy during as result of chemical process....
occur in cellular oxidation. |
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bioenergetics (metabolic pathways)
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1. formation of ATP by PHOSPHOCREATINE(PC) breakdown... ANEROBIC
2. formation of atp via glucose or glycogen(called glycolysis). ....ANEROBIC 3.OXIDATIVE formation of ATP..Aerobic |
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1Discuss the role of enzymes as catalysts. 2What is meant by the expression “energy of activation”?
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Enzymes are protiens that regulate 1speed of metabolic pathways. enzymes lower energy required for catalyst activation
2reqiured energy to initiate chemical reactions, |
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what is oxidation?
what is reducton? |
the process of removing and electron from and atom or a molecule.
the addition of an atom or a molecule |
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Oxidoreductases is?
Transferases is ? Lyases is? |
Catalyze oxidation-reduction reactions
Transfer elements of one molecule to another Groups of elements are removed to form a double bond or added to a double bond |
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Isomerases
Ligases? |
Rearrangement of the structure of molecules
Catalyze bond formation between substrate molecules |
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1Discuss the role of enzymes as catalysts. 2What is meant by the expression “energy of activation”?
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Enzymes are protiens that regulate 1speed of metabolic pathways. enzymes lower energy required for catalyst activation
2reqiured energy to initiate chemical reactions, |
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Where do glycolysis, the Krebs cycle, and oxidative phosphorylation take place in the cell?
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in the cytoplasm...
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what is oxidation?
what is reducton? |
the process of removing and electron from and atom or a molecule.
the addition of an atom or a molecule |
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Oxidoreductases is?
Transferases is ? Lyases is? |
Catalyze oxidation-reduction reactions
Transfer elements of one molecule to another Groups of elements are removed to form a double bond or added to a double bond |
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Isomerases
Ligases? |
Rearrangement of the structure of molecules
Catalyze bond formation between substrate molecules |
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Factors That Alter Enzyme Activity
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Temperature
---Small rise in body temperature increases enzyme activity ---Exercise results in increased body temperature pH---Changes in pH reduces enzyme activity ----Lactic acid produced during exercise |
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what are Carbohydrates?
what do Carbohydrates do? |
atoms composed of C H O,
they rapidly provide the body with energy. |
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Define the terms glycogen,
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termed used for the polysaccharide stored in animal tissue. linked glucose molecules. during exercise individual miuscle break down glycogen into gluclose
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Define the term glycogenolysis, and glycolysis.
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during exercise the breakdown of glycogen into glucose.
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Define the terms glycolysis.
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involves the breakdown of glucose or glycogen to form to molecule of pyruvic or lactic acid. this occurs in the sarcoplasm of the muscle cell and produces a net gain of 2 MOL of ATP and two MOL pyruvic/lactic acid per gluclose mol
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1What are the high-energy phosphates?
2. Explain the statement that “ATP is the universal energy donor.” |
1. Atp, adp and Pi,
2. is often called the universal donor because it couples energy released from the breakdown into usable form of energy required by all cells |
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Briefly discuss the function of glycolysis in bioenergetics.
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Glycolysis involves the breakdown of glucose or glycogen to form two molecules of pyruvic acid or lactic acid. (is an anaerobic pathway used to transfer bond energy from glucose to rejoin Pi to ADP
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What role does NAD play in glycolysis?
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NAD accepts one of the hydrogens, while the remaining hydrogen is free in solution.
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Discuss the operation of the Krebs cycle and the electron transport chain in the aerobic production of ATP. What is the function of NAD and FAD in these pathways?
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During the Krebs cycle, 3NADH and 1FADH are formed - For every FADH molecule - enough energy is available to produce 1.5 ATP.
In the Electron Transport Chain - Aerobic production of ATP is possible due to a mechanism that uses the potential energy available in NADH and FADH to rephosphoylate ADP to ATP. |
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What is the efficiency of the aerobic degradation of glucose?
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the aerobic metabolism of one molecule of glucose results in the production of 32 ATP molecules, whereas the aerobic ATP yield for glycogen breakdown is 33 ATP
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What is the role of oxygen in aerobic metabolism?
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Aerobic respiration requires oxygen in order to generate energy. It is the preferred method of pyruvate breakdown from glycolysis and requires that pyruvate enter the mitochondrion to be fully oxidized by the Krebs cycle. The product of this process is energy in the form of ATP (Adenosine Triphosphate), by substrate-level phosphorylation, NADH and FADH2
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What enzyme regulates glycolysis? The Krebs Cycle
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Glycolysis regulation - Phosphofructokinsase.
Krebs cycle regulation - Isocitrate dehydrogenase |
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What is the efficiency of the aerobic degradation of glucose?
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the aerobic metabolism of one molecule of glucose results in the production of 32 ATP molecules, whereas the aerobic ATP yield for glycogen breakdown is 33 ATP
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What is the efficiency of the aerobic degradation of glucose?
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the aerobic metabolism of one molecule of glucose results in the production of 32 ATP molecules, whereas the aerobic ATP yield for glycogen breakdown is 33 ATP
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Discuss the operation of the Krebs cycle and the electron transport chain in the production of ATP. What is the function of NAD and FAD in these pathways?
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During the Krebs cycle, 3NADH and 1FADH are formed - For every FADH molecule - enough energy is available to produce 1.5 ATP.
In the Electron Transport Chain - Aerobic production of ATP is possible due to a mechanism that uses the potential energy available in NADH and FADH to rephosphoylate ADP to ATP. |
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Briefly discuss the function of glycolysis in bioenergetics. What role does NAD play in glycolysis.
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Glycolysis involves the breakdown of glucose or glycogen to form two molecules of pyruvic acid or lactic acid. (is an anaerobic pathway used to transfer bond energy from glucose to rejoin Pi to ADP. NAD accepts one of the hydrogens, while the remaining hydrogen is free in solution.
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Explain the statement that "ATP is the universal energy donor"
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because it produces a usable form of energy required by all cells
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Factors that alter enzyme activity
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Temperature - raise in body temp. increases the activity of most enzymes - this enhances bioenergetics by speeding up rate of reactions
pH - similar to temp. however if pH is altered from the optimum, the enzyme activity is reduced. |
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"carrier molecules" of hydrogen (and electrons)
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Oxidized form of NAD, Reduced form is NADH.
Oxidized form of FAD, Reduced form is FADH. |
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Interaction between aerobic/anaerobic ATP production
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Energy to perform exercise comes from an interaction of anaerobic and aerobic pathways.
In general, the shorter the activity (high intensity), the greater the contribution of anaerobic energy production. In contrast, long term activities (low to moderate intensity) utilize ATP produced from aerobic sources. |
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Control of Krebs Cycle
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rate limiting enzymes are isocitrate dehydrogenase and cytochrome oxidase,
In general, cellular levels of ATP and ADP + Pi regulate the rate of metabolic pathways involved in the production of ATP. High levels of ATP inhibit further ATP production, while low levels of ATP and high levels of ADP + Pi stimulate ATP production. Evidence also exists that calcium may stimulate aerobic energy metabolism |
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Control of Glycolysis
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most important rate-limiting enzyme is phosphofructokinase (PFK) PFK is located near the beginning of glycolysis. Another regulatory enzyme is phosphorylase, which is responsible for degrading glycogen to glucose.
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Control of ATP-PC system
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regulated by creatine kinase activity
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Control of Bioenergetics
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Metabolism is regulated by enzymatic activity. An enzyme that regulates a metabolic pathway is termed the "rate-limiting" enzyme.
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Efficiency of Oxidative Phosphorylation
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the overall efficiency of aerobic respiration is approximately 34%, with the remaining 66% of the energy being released as heat
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Aerobic ATP Tally
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the aerobic metabolism of one molecule of glucose results in the production of 32 ATP molecules, whereas the aerobic ATP yield for glycogen breakdown is 33 ATP
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Aerobic/Anaerobic Interaction in Exercise
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- Energy Production - a combination of Aerobic and Anaerobic metabolism.
- shorter duration and higher intensity: more anaerobic and less aerobic - Longer duration and lower intensity: more aerobic and less anaerobic |
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High-Energy phosphates
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ATP - structure is made of 1. adenine portion, 2. a ribose portion and 3. three linked phosphates ---- formation of ATP occurs by combining ADP and inorganic phosphate (Pi) - requires a large amount of energy
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Fats CH3(CH2)nCOOH
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1. Fatty Acids - primary type used by muscle cells for energy
2. Triglycerides - 3 FAs + 1 glycerol -1g > 9kcal energy/ TG > FAs > energy production / slow energy release / energy reserve > 70,000kcal 3. Phospholipids - not an energy source during exercise 4. Steroids - not used as energy sources during exercise |
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Carbohydrates CHO
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1. Monosaccharides - simple sugars
--Glucose (C6H12O6) "blood sugar" 2. Disaccharides - table sugar - maltose and sucrose 3. Polysaccharides - Glycogen - storage form of glucose in muscle and liver... turning glycogen to glucose is Glycogenolysis. +1g makes 4kcal energy Rapidly available for energy production Energy reserve: ~ <2,000 kcal of energy |
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Fuels for Exercise
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the body uses carbohydrate, fat, and protein nutrients consumed daily to provide the necessary energy to maintain cellular activities both at rest and during exercise
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Enzymes
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Enzymes reduce the energy of activation - this increases the speed of chemical reactions and therefore increases the rate of product formation
+structure is a large protein molecule with a three dimensional shape, they have ridges and grooves that form pockets (called active sites). These active sites make it possible to form a "lock and Key" connection with a substrate. +molecules form a complex known as the "enzyme-substrate complex" - so now the energy of activation needed for reaction is lowered |
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Oxidative Reduction Reaction
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+coupled oxidation-reduction reactions are analogous to a bucket brigade, with electrons being passed along in the buckets.
+reactions in cells often involve the transfer of hydrogen atoms rather than free electrons. +in many reactions pairs of electrons are passed along btwn molecules as free electrons or as pairs of hydrogen atoms |
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Cellular Chemical Reactions
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1. endergonic reactions
2. exergonic reactions 3. coupled reactions |
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phosphofrctokinase (PFK)
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rate-limiting enzyme in glycolysis that is responsive to ADP, Pi and ATP levels in the cytoplasm of the cell
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phosphocreative (PC)
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a compound found in skeletal muscle and used to resynthesize ATP from ADP
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oxidative phosphorylation
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mitochondrial process in which inorganic phosphate (Pi) is coupled to ADP as energy is transferred along the electron transport chain in which oxygen is the final electron accepto
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NAD
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coenzyme that transfers hydrogen and the energy associated with those hydrogens; in the Krebs cycle, NAD transfers energy from substrates to the electron transport chain
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lactic acid
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an end product of glucose metabolism in the glycolytic pathway; formed in conditions of inadequate oxygen and in muscle fibers with few mitochondria
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Krebs cycle
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metabolic pathway in the mitochondria in which energy is transferred from carbohydrates, fats, and amino acids to NAD for subsequent production of ATP in the electron transport chain
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isocitrate dehydrogenase
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ate-limiting enzyme in the Krebs cycle that is inhibited by ATP and stimulated by ADP and Pi
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inorganic phosphate (Pi)
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a stimulator of cellular metabolism; split off, along with ADP, from ATP when energy is released; used with ADP to form ATP in the electron transport chain
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FAD
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flavin adenine inucleotide. Serves as an electron carrier in bioenergetics
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Chemiosmotic hypothesis
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he mechanism to explain the aerobic formation of ATP in mitochondria
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Beta oxidation
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breakdown of free faty acids to form acetyl-CoA
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ATP-PC system
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term used to describe the metabolic pathway involving muscle stores of ATP and the use of phosphocreatine to rephosphorylate ADP. This pathway is used at the onset of exercise and during short term, high intensity work.
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ATPase
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enzyme capable of breaking down ATP to ADP + Pi + energy
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