HMS4601 Nutrition to Fuel Sports Performance
Table of contents
Case 1 Fuel for the body ................................................................... Fout! Bladwijzer niet gedefinieerd.
Case 2: Running on empty ................................................................ Fout! Bladwijzer niet gedefinieerd.
Case 3 Substrate shopping ............................................................... Fout! Bladwijzer niet gedefinieerd.
Case 4 Periodized nutrition .............................................................. Fout! Bladwijzer niet gedefinieerd.
Lecture Substrate metabolism ......................................................... Fout! Bladwijzer niet gedefinieerd.
Lecture Carbohydrates before, during and after exercise ............... Fout! Bladwijzer niet gedefinieerd.
Lecture Periodized nutrition............................................................. Fout! Bladwijzer niet gedefinieerd.
Case 1 Fuel for the body
Learning goals:
1. What is glycolysis, citric acid cycle and oxidative phosphorylation?
Glycolysis (takes place in cytosol)
The start of glucose metabolism is glycolysis. This process converts glucose into pyruvic acid, which
can later be converted to Acetyl Co-enzyme A. The glycolysis process has a net ATP production of 2
ATP and 2 NADH per glucose molecule.
,Pyruvate oxidation (takes place in mitochondrial matrix)
After glycolysis, 2 pyruvate molecules are converted into two Acetyl CoA molecules.
Citric acid cycle (krebs cycle) (takes place in mitochondrial matrix)
The Acetyl CoA molecules enter the citric acid cycle (Krebs cycle).
Oxidative phosphorylation (takes place in mitochondrial matrix)
After the Krebs cycle, the produced electron carriers (NADH and FADH2) proceed into the oxidative
phosphorylation. This process, taking place in the mitochondria, makes use of the changing proton
gradient in between the mitochondrial membranes to produce ATP. These reactions split each
,hydrogen atom into a hydrogen ion and an electron and use the electrons eventually to combine
dissolved oxygen of the fluids with water molecules to form hydroxyl ions. Then the hydrogen and
hydroxyl ions combine with each other to form water. This produces energy to form ATP.
Extra details from an old case: Electron transport chain is a series of proteins and organic molecules
found in the inner membrane of the mitochondria. Electrons are passed from one member of the
electron transport chain to another in a series of redox reactions. Energy released in these reactions
is captured as a proton gradient, which is then used to make ATP in a process called chemiosmosis.
Together, the ETC and chemiosmosis make up oxidative phosphorylation.
All the electrons that enter the ETC come from NADH and FADH2 molecules produced during earlier
stages of cellular respiration: glycolysis, pyruvate oxidation and the citric acid cycle.
- NADH is very good at donating electrons in redox reactions → so it can transfer its electrons
directly to complex I, turning back into NAD+. Electrons move through complex I in a series of
, redox reactions, energy is released and the complex uses this energy to pump protons from
the matrix into the intermembrane space.
- FADH2 is not as good at donating electrons as NADH so it cannot transfer its electrons to
complex I. instead it feeds them into the transport chain trough complex II, which does not
pump protons across the membrane.
- Both complex I and complex II pass their electrons through ubiquinone delivering the
electrons to complex III.
- As electrons move through complex III, more H+ ions are pumped across the membrane, and
the electrons are ultimately delivered to another mobile carrier called cytochrome C.
- Cytochrome C carries the electrons to complex IV, where final batch of H+ ions is pumped
across the membrane.
- Complex IV passes the electrons to O2, which splits into two oxygen atoms and accepts
protons from the matrix to form water.
- Proton gradient with a higher concentration of H+ in the intermembrane space and lower
concentration in the matrix represents a stored form of energy, which can be used to make
ATP.
Chemiosmosis
Complexes I,III and IV of the ECT are proton pumps → as electrons move energetically downhill, the
complexes capture the released energy and use it to pump H+ ions from the matrix to the
intermembrane space. This pumping forms an electrochemical gradient across the inner
mitochondrial membrane.
- H+ ions cannot pass directly through the phospholipid bilayer so they move down their
concentration gradient only with the help of channel proteins that form hydrophilic tunnels
across the membrane.
- In the inner mitochondrial membrane, H+ ions have just one channel available → membrane
spanning protein known as ATP synthase. As ATP synthase turns, it catalyzes the addition of a
phosphate to ADP, capturing energy from the proton gradient as ATP.
Summary of the oxidation of 1 glucose molecule:
- NADH starts in the first complex → 3 H → 3 ATP
- FADH2 starts in the second complex → 2 H → 2 ATP
Table of contents
Case 1 Fuel for the body ................................................................... Fout! Bladwijzer niet gedefinieerd.
Case 2: Running on empty ................................................................ Fout! Bladwijzer niet gedefinieerd.
Case 3 Substrate shopping ............................................................... Fout! Bladwijzer niet gedefinieerd.
Case 4 Periodized nutrition .............................................................. Fout! Bladwijzer niet gedefinieerd.
Lecture Substrate metabolism ......................................................... Fout! Bladwijzer niet gedefinieerd.
Lecture Carbohydrates before, during and after exercise ............... Fout! Bladwijzer niet gedefinieerd.
Lecture Periodized nutrition............................................................. Fout! Bladwijzer niet gedefinieerd.
Case 1 Fuel for the body
Learning goals:
1. What is glycolysis, citric acid cycle and oxidative phosphorylation?
Glycolysis (takes place in cytosol)
The start of glucose metabolism is glycolysis. This process converts glucose into pyruvic acid, which
can later be converted to Acetyl Co-enzyme A. The glycolysis process has a net ATP production of 2
ATP and 2 NADH per glucose molecule.
,Pyruvate oxidation (takes place in mitochondrial matrix)
After glycolysis, 2 pyruvate molecules are converted into two Acetyl CoA molecules.
Citric acid cycle (krebs cycle) (takes place in mitochondrial matrix)
The Acetyl CoA molecules enter the citric acid cycle (Krebs cycle).
Oxidative phosphorylation (takes place in mitochondrial matrix)
After the Krebs cycle, the produced electron carriers (NADH and FADH2) proceed into the oxidative
phosphorylation. This process, taking place in the mitochondria, makes use of the changing proton
gradient in between the mitochondrial membranes to produce ATP. These reactions split each
,hydrogen atom into a hydrogen ion and an electron and use the electrons eventually to combine
dissolved oxygen of the fluids with water molecules to form hydroxyl ions. Then the hydrogen and
hydroxyl ions combine with each other to form water. This produces energy to form ATP.
Extra details from an old case: Electron transport chain is a series of proteins and organic molecules
found in the inner membrane of the mitochondria. Electrons are passed from one member of the
electron transport chain to another in a series of redox reactions. Energy released in these reactions
is captured as a proton gradient, which is then used to make ATP in a process called chemiosmosis.
Together, the ETC and chemiosmosis make up oxidative phosphorylation.
All the electrons that enter the ETC come from NADH and FADH2 molecules produced during earlier
stages of cellular respiration: glycolysis, pyruvate oxidation and the citric acid cycle.
- NADH is very good at donating electrons in redox reactions → so it can transfer its electrons
directly to complex I, turning back into NAD+. Electrons move through complex I in a series of
, redox reactions, energy is released and the complex uses this energy to pump protons from
the matrix into the intermembrane space.
- FADH2 is not as good at donating electrons as NADH so it cannot transfer its electrons to
complex I. instead it feeds them into the transport chain trough complex II, which does not
pump protons across the membrane.
- Both complex I and complex II pass their electrons through ubiquinone delivering the
electrons to complex III.
- As electrons move through complex III, more H+ ions are pumped across the membrane, and
the electrons are ultimately delivered to another mobile carrier called cytochrome C.
- Cytochrome C carries the electrons to complex IV, where final batch of H+ ions is pumped
across the membrane.
- Complex IV passes the electrons to O2, which splits into two oxygen atoms and accepts
protons from the matrix to form water.
- Proton gradient with a higher concentration of H+ in the intermembrane space and lower
concentration in the matrix represents a stored form of energy, which can be used to make
ATP.
Chemiosmosis
Complexes I,III and IV of the ECT are proton pumps → as electrons move energetically downhill, the
complexes capture the released energy and use it to pump H+ ions from the matrix to the
intermembrane space. This pumping forms an electrochemical gradient across the inner
mitochondrial membrane.
- H+ ions cannot pass directly through the phospholipid bilayer so they move down their
concentration gradient only with the help of channel proteins that form hydrophilic tunnels
across the membrane.
- In the inner mitochondrial membrane, H+ ions have just one channel available → membrane
spanning protein known as ATP synthase. As ATP synthase turns, it catalyzes the addition of a
phosphate to ADP, capturing energy from the proton gradient as ATP.
Summary of the oxidation of 1 glucose molecule:
- NADH starts in the first complex → 3 H → 3 ATP
- FADH2 starts in the second complex → 2 H → 2 ATP
