8) Fundamentals of Human Energy Transfer Flashcards
Define:
- Metabolism
- Anabolic
- Catabolic
Metabolism → the total amount of the biochemical reactions involved in maintaining the living condition of the cells in an organism
* Anabolic reactions → synthesis of molecules (growth)
* Catabolic reactions → breakdown of molecules
What is bioenergetics?
Study of transformation of energy; study of the chemical pathways that convert substrate to energy that can be used by the cell (ATP)
ie converting foodstuffs to energy
Carbohydrates, fats, proteins
Why do we need to regenerate ATP?
Cells store a limited quantity of ATP
Energy Substrates
Carbohydrate
* Composed of:
* 1 gram CHO → ? kcal
(1 kcal = 1000 calories = 1 Calorie)
Carbohydrate (CHO)
* Carbon, hydrogen, oxygen
* 1 gram CHO → 4.1 kcal
* (1 kcal = 1000 calories = 1 Calorie)
Glucose
* Most important monosaccharide
* Primary energy source for brain
* Glycolysis → breakdown of
glucose to create energy; primary
energy source for intense exercise (15 sec – 2 min)
* Gluconeogenesis → creating glucose from non-CHO sources (glycerol, lactate, amino acids); primarily in liver
Glucose
* Most important ?
* Primary energy source for ?
* stored in muscle and liver as ?
* Depleted during ? exercise
Glucose
* Most important monosaccharide
* Primary energy source for brain
* stored in muscle and liver as glycogen
* Depleted during prolonged, intense exercise
-
Glycolysis → breakdown of
glucose to create energy; primary
energy source for intense exercise (15 sec – 2 min) - Gluconeogenesis → creating glucose from non-CHO sources (glycerol, lactate, amino acids); primarily in liver
Glucose: Energy Substrate
? → breakdown of
glucose to create energy; primary
energy source for intense exercise (15 sec – 2 min)
? → creating glucose from non-CHO sources (glycerol, lactate, amino acids); primarily in liver
? → turning glucose into glycogen for storage
? → breakdown of glycogen to glucose
Glucose
Glycolysis → breakdown of
glucose to create energy; primary
energy source for intense exercise (15 sec – 2 min)
Gluconeogenesis → creating glucose from non-CHO sources (glycerol, lactate, amino acids); primarily in liver
Glycogenosis → turning glucose into glycogen for storage
Glycogenolysis → breakdown of glycogen to glucose
Glucose
* Most important monosaccharide
* Primary energy source for brain
* stored in muscle and liver as glycogen
* Depleted during prolonged, intense exercise
Glucose: Energy Substrate
What is Glycolysis?
Glycolysis → breakdown of
glucose to create energy; primary
energy source for intense exercise (15 sec – 2 min)
Glucose
* Most important monosaccharide
* Primary energy source for brain
* stored in muscle and liver as glycogen
* Depleted during prolonged, intense exercise
What is Gluconeogenesis?
Gluconeogenesis → creating glucose from non-CHO sources (glycerol, lactate, amino acids); primarily in liver
Glycogenosis → turning glucose into glycogen for storage
Glycogenolysis → breakdown of glycogen to glucose
Glycolysis → breakdown of
glucose to create energy; primary
energy source for intense exercise (15 sec – 2 min)
What is Glycogenosis?
Glycogenosis → turning glucose into glycogen for storage
Glycogenolysis → breakdown of glycogen to glucose
Glycolysis → breakdown of
glucose to create energy; primary
energy source for intense exercise (15 sec – 2 min)
Gluconeogenesis → creating glucose from non-CHO sources (glycerol, lactate, amino acids); primarily in liver
What is Glycogenolysis?
Glycogenolysis → breakdown of glycogen to glucose
Glycolysis → breakdown of
glucose to create energy; primary
energy source for intense exercise (15 sec – 2 min)
Gluconeogenesis → creating glucose from non-CHO sources (glycerol, lactate, amino acids); primarily in liver
Glycogenosis → turning glucose into glycogen for storage
How does Fat breakdown make ATP?
Triglycerides: storage form of fat
TG → glycerol + Free Fatty Acids (FFA)
FFA (only) → ATP
1g fat = 9.4kcal
proteins as energy source
Protein:
- broken down into ?
- excess protein consumed is stored as ?
- ATP from ?
- ? = formation of glucose from non-carbohydrate carbon substrates
- 1g Protein → ? kcal
Protein:
- broken down into amino acids
- excess protein consumed is stored as fat
- ATP from Amino Acids (only AA’s make energy)
- Gluconeogenesis = formation of GLUCOSE from non-carbohydrate carbon substrates (Amino Acids)
- 1g protein → 4.1 kcal
Immediate Energy Sources: (2)
(1) ? //
Aerobic or anaerobic?
(2) ? system //
Aerobic or anaerobic?
Fast Energy source: (1)
Sustained Energy Sources: (2)
Immediate Energy Sources:
(1) Stored ATP (already present and does not need to be synthesized) = Anaerobic
(2) ATP-phosphocreatine (ATP-PCr) system (Anaerobic)
Fast Energy source: (1)
- Glycolysis (carbohydrates) ending in lactate (Anaerobic)
Sustained Energy Sources: (2)
- Glycolysis (carbohydrate) ending in pyruvate → pyruvate enters Krebs cycle → ETC (oxidative phosphorylation) (Aerobic)
- Beta oxididation (Fats) → ETC (Oxidative Phosphorylation) Aerobic
Fast Energy source: (1)
- ? (carbohydrates) ending in ?
- Aerobic or Anaerobic?
Immediate (2)
Sustained (2)
Fast Energy source: (1)
- Glycolysis (carbohydrates) ending in lactate (Anaerobic)
Immediate Energy Sources:
- Stored ATP (already present and does not need to be synthesized) = Anaerobic
- ATP-phosphocreatine (ATP-PCr) system (Anaerobic)
Sustained Energy Sources: (2)
- Glycolysis (carbohydrate) ending in pyruvate → pyruvate enters Krebs cycle → ETC (oxidative phosphorylation) (Aerobic)
- Beta oxididation (Fats) → ETC (Oxidative Phosphorylation) Aerobic
Sustained Energy Sources: (2)
Aerobic or Anaerobic?
(1) ? (carbohydrate) ending in ? → enters ? cycle → ETC
(2) ? (Fats) → ETC
Sustained Energy Sources: (2)
(1) Glycolysis (carbohydrate) ending in pyruvate → pyruvate enters Krebs cycle → ETC (oxidative phosphorylation) (Aerobic)
(2) Beta oxididation (Fats) → ETC (Oxidative Phosphorylation) Aerobic
Immediate Energy Sources:
- Stored ATP (already present and does not need to be synthesized) = Anaerobic
- ATP-phosphocreatine (ATP-PCr) system (Anaerobic)
Fast Energy source: (1)
- Glycolysis (carbohydrates) ending in lactate (Anaerobic)
Sustained Energy Sources: (2)
- Glycolysis (carbohydrate) ending in pyruvate → pyruvate enters Krebs cycle → ETC (oxidative phosphorylation) (Aerobic)
- Beta oxididation (Fats) → ETC (Oxidative Phosphorylation) Aerobic
Stored ATP:
- allows for ?
- Energy from ?
Stored ATP:
A very small amount of ATP stored in the cytoplasm (Sarcoplasm) of the mm cell
- Allows for immediate activation of mm upon neural stimulation
- Source of energy for the first 1-3 seconds
ATP Hydrolysis: Breakdown of ATP releasing energy
H2O + ATP → ADP + Pi + Energy + H+
Immediate source of energy
- ATP already present and does not need synthesized)
- Anaerobic
ATP-PCr System
ATP-PCr System
- Increased cellular ? levels (from ? ATP hydrolysis) during first 1-3 seconds stimulate ?enzyme?
- Converts ADP into ATP using Pi from ?
ATP-PCr System
- Increased cellular ADP levels (from cytoplasmic ATP hydrolysis) during first 1-3 seconds stimulate creatine kinase
- Converts ADP into ATP using Pi from creatine phosphate
(2) ATP-phosphocreatine (ATP-PCr) system (Anaerobic)
- Primary supplier of energy for first 3-15 sec of intense exercise
- Anaerobic; cell cytoplasm
- 1 mol ATP per 1 mol PCr
- Energetic capacity dependent on concentration of creatine phosphate
- 1 mol ATP per 1 mol PCr
(1) Stored ATP // ATP Hydrolysis: Breakdown of ATP releasing energy
H2O + ATP → ADP + Pi + Energy + H+
ATP-PCr System
ATP-PCr System
When is the ATP-PCr system the primary supplier of energy?
ATP-PCr System
- Primary supplier of energy for first 3-15 sec of intense exercise
(2) ATP-phosphocreatine (ATP-PCr) system (Anaerobic)
- First 1-3 seconds: Stored ATP → ATP hydrolysis → ↑[ADP] → stimulate creatine kinase
- Next 3-15sec: Creatine kinase Converts ADP into ATP using Pi from creatine phosphate
- Anaerobic; cell cytoplasm
- 1 mol ATP per 1 mol PCr
- Energetic capacity dependent on concentration of creatine phosphate
What is the net gain of ATP after glycolysis:
When starting from ? = +2 ATP
When Starting from ? = +3 ATP
What is the net gain of ATP after glycolysis:
- When starting from glucose = +2 ATP
- When Starting from glycogen = +3 ATP
Conversion of glucose to G-6-P requires 1 ATP = making net 1 atp less
Oxidative system
Oxidative System:
- Aerobic or Anaerobic?
- Occurs where?
- Rate of response vs energy production?
- What type of activities?
- Why is oxygen required?
- Aerobic
- Occurs in Mitochondria
- Slow to turn on; large energy-producing capacity
- Endurance activities
- Oxygen is the final acceptor of H+ and e- (form H2O) and is called oxidative phosphorylation
(1) ?
- simple sugar glucose broken down
- Occurs in cytosol
(2) Pyruvate (product from glycolysis) is transformed into ? in the ? when sufficient oxygen present
(3) The citric acid cycle (? cycle)
- where ? is modified in the mitochondria to produce energy precursors in prepartion for the next step
(4) oxidative phosphorylation
- Electron transport from energy precursors from the CAC leads to ?, producing ?
- occurs in ?
(1) Glycolysis
- simple sugar glucose broken down
- Occurs in cytosol
(2) Pyruvate (product from glycolysis) is transformed into Acetyl CoA in the mitochondria when sufficient oxygen present
(3) The citric acid cycle (Kreb’s cycle)
- where acetyl CoA is modified in the mitochondria to produce energy precursors in prepartion for the next step
(4) oxidative phosphorylation
- Electron transport from energy precursors from the CAC leads to the phosphorylation of ADP, producing ATP
- occurs in mitochondria
CAC= citric acid cycle
Where does oxidative phosphorylation fit into cellular respiration (2 processes)
(1) Electron Transport chain
(2) Chemiosmosis
(1) Electron Transport chain
- H+ ions combine iwth coenzymes NAD and FAD to form reduced NADH and FADH2
- Carry electrons to ETC (MIT protein complexes in the inner MIT membrane)
(2) Chemiosmosis
- H+ travel down the proton gradient via chemiosmosis which provides the energy for a phosphate group to join with ADP, forming ATP
Where does oxidative phosphorylation fit into cellular respiration
(1) Electron Transport chain
- ? combine with coenzymes NAD and FAD to form reduced ? and ?
- Carry electrons to ? (MIT protein complexes in the inner MIT membrane)
(1) Electron Transport chain
- H+ ions combine with coenzymes NAD and FAD to form reduced NADH and FADH2
- Carry electrons to ETC (MIT protein complexes in the inner MIT membrane)
(2) Chemiosmosis
- H+ travel down the proton gradient via chemiosmosis which provides the energy for a phosphate group to join with ADP, forming ATP
Where does oxidative phosphorylation fit into cellular respiration
(2) Chemiosmosis
- H+ travel down the proton gradient via ? which provides the energy for a phosphate group to join with ADP, forming ?
(2) Chemiosmosis
- H+ travel down the proton gradient via chemiosmosis which provides the energy for a phosphate group to join with ADP, forming ATP
Oxidative phosphorylation also in:
(1) Electron Transport chain
- H+ ions combine iwth coenzymes NAD and FAD to form reduced NADH and FADH2
- Carry electrons to ETC (MIT protein complexes in the inner MIT membrane)
Beta oxidation is the process of breaking down ?
Beta oxidation is the process of breaking down fats
Coenzyme A attaches to end of fatty acid chains and begins splitting fatty acid chain into 2 carbon chains called Acetyl CoA
- makes several acetyl CoA that enter Kreb’s cycle
- Glycerol enters gluconeogenesis
- 2 pyruvate enter mitochondria and become Acetyl CoA which enters Krebs cycle
Beta Oxidation: Fat Breakdown
Beta oxidation:
? attaches to end of fatty acid chains and begins splitting ? into 2 carbon chains called ?
- makes several ? that enter Kreb’s cycle
- Glycerol enters ?
Beta Oxidation (Fat breakdown)
Coenzyme A attaches to end of fatty acid chains and begins splitting fatty acid chain into 2 carbon chains called Acetyl CoA
- makes several acetyl CoA that enter Kreb’s cycle
- Glycerol enters Gluconeogenesis
What happens to the glycerol after Beta-oxidation (breakdown) of fats
Glycerol enters gluconeogenesis -> glucose
Gluconeogenesis = production of glucose through non-carbohydrate (CHO) sources
Fatty acid chain is broken down into 2 carbon chains (Acetyl-CoA) via Coenzyme A
What is the current theory regarding Energy Substrates (which are used and when?)
Key: ATP-PCr dominates in first 5-6s in terms of rate and total proportion of ATP generated
- Anaerobic Glycolysis: occurs almost immediately at onset of exercise; slower ATP regeneration due to more reations (Slower source than Phosphocreatine system)
ATP-PCr system can rapidly regenerate ATP
- Creatine Phosphate stored in cytosol of mm cell, close to site of energy utilization
- oxygen independent
- Few metabolic reactions required
Old Theory: ATP-PCr system was solely responsible for ATP regeneration during initial 10-15s of exercise
- Anaerobic glycolysis occurred at onset of CP depletion
Glycolysis (Anaerobic- Ends in ?)
- Energy Release Rate?
- Total Capacity/Total available energy?
Glycolysis (Anaerobic- Ends in lactate)
Energy Release Rate?
- Very fast
Total Capacity/Total available energy?
- Very limited
- Due to build up of lactate and acid
Glycolysis (Aerobic)
- Energy Release Rate?
- Total Capacity/Total available energy?
Glycolysis (Aerobic)
- Energy Release Rate?
-Moderate to slow (pyruvate enters Mito. Slower (more steps))
- Total Capacity/Total available energy?
-2hr energy capacity
-Marathoners use aerobic glycolysis
Beta-oxidation
- Energy Release Rate?
- Total Capacity/Total available energy?
Beta-oxidation
Energy Release Rate?
- very slow
Total Capacity/Total available energy?
- Can sustain exercise for several hours
—–Well-fed healthy individual
—-ultramarathoners (higher potential to make energy)
Requires spliting of the glycerol and FA chains that make up fat
- glycerol enters Gluconeogenesis
- Acetyl-CoA enter Krebs cycle
