Chapter 6 - Energy Transfer in the Body Flashcards
What is the Energy Currency of the Body?
- ATP
What provides major sources of potential energy?
- Macronutrients
How does ADP form?
- When ATP joins with water
What enzyme catalyzes the reaction of ATP and Water to form ADP?
- Adenosine Triphosphatase (ATPase)
What are the Cells’ two major energy-transforming activities?
- Extract potential energy from food/conserve it within ATP bonds
- Extract/transfer chemical energy in ATP to power biological work
How much ATP does the body store at resting condition?
- 80-100g ATP
How long can resting stores of ATP in the body provide energy?
2-3 seconds of Maximal Exercise
Which ways can the mitochondria produce ATP?
Methods
- Citric Acid Cycle
- Respiratory Chain (Aerobic)
Fuel sources
- fatty acids
- Pyruvate from glucose
- Some deaminated amino acids
Which ways for ATP production occur in the Cytosol?
- anaerobic glycolysis
-using glucose and glycogen - adenylate kinase
- Glycerol
- Some Deamniated Amino Acids
- Phosphocreatine shuttle
Where does Aerobic ATP production occur?
- Mitochondria
Where does Anaerobic ATP production occur?
- Cytosol
Where does ATP production from phosphocreatine occur?
- Cytosol
What happens with the anaerobic splitting of a phosphate from Phosphocreatine?
- ATP resynthesis
How much Phosphocreatine do cells store compared to ATP?
- 4-6 times
How long can Phosphocreatine provide energy for?
- around 10s
What does Adenylate Kinase Reaction represent?
- single-enzyme mediated reaction for ATP
- 2 adp -> atp + amp
cellular oxidation: Where does most energy for phosphorylation derive from?
oxidation of:
- Carbohydrates
- Lipids
- Protein
cellular respiration: What do oxidation reactions do?
- Donate electrons
cellular respiration: What do Reduction reactions do?
- Accept Electrons
cellular respiration: What constitutes the biochemical mechanism that underlies energy metabolism?
- RedOx Reactions (oxidation - reduction)
cellular respiration: What do redox reactions provide from catabolism of stored macronutrients?
- Hydrogen Atoms
cellular respiration: what do the carrier molecules in mitochondria do?
- Remove electrons from hydrogen (oxidation)
- Pass them to oxygen (reduction)
- Synthesize ATP through redox
cellular oxidation: What catalyze’s hydrogen’s release from the nutrient substrate?
- substrate-specific dehydrogenase enzymes
cellular oxidation: What accepts pairs of electrons from hydrogen?
- coenzyme component of the dehydrogenase
cellular respiration: What happens when Nicotinamide Adenine Dinucleotide (NAD+) gains hydrogen and two electrons?
-Reduces to NADH
cellular respiration: What happens to the other Hydrogen when one pairs with NAD+?
- Appears in the cell fluid as H+
cellular respiration: How many electrons does Flavin Adenine Dinucleotide accept?
- Two
cellular oxidation: What are NAD+ and FAD?
- Electron Acceptors
electron transport: What are Cytochromes?
- A series of Iron-protein electron carriers dispersed on the inner membranes of the mitochondrion
electron transport: What do cytochromes do
pass pairs of electrons carried by NADH and FADH2 down the chain
electron transport: what is electron transport
final common pathway where electrons extracted from hydrogen pass to oxygen
electron transport: What drives the respiratory chain? How?
Oxygen
- serving as final electron acceptor to combine with hydrogen to form water
electron transport: What happens for each pair of hydrogen atoms that reach the cytochrome?
- Two Electrons flow down the chain and reduce to one atom of oxygen
electron transport: What is released during the passage of electrons down the chain?
- Enough energy to re-phosphorylate ADP to ATP`
oxidative phosphorylation: How does oxidative phosphorylation synthesize ATP?
- Transfer of electrons from NADH and FADH2 to oxygen
oxidative phosphorylation: How much ATP synthesis occurs in the respiratory chain by oxidative reactions coupled with phosphorylation?
> 90%
oxidative phosphorylation: How many coupling sites during the electron transport does energy transfer from NADH to ADP to reform ATP?
- three distinct places
oxidative phosphorylation: Why do only 2 ATP molecules form for each hydrogen pair oxidized from FADH2?
- FADH2 enters respiratory chain at lower energy level, beyond point of first ATP synthesis
oxidative phosphorylation: how much energy is generated since the shuttling of hydrogen in the electron transport chain requires energy?
On Average
- NADH produces 2.5 ATP
- FADH2 produces 1.5 ATP
How much energy does 1 mole of ATP formed from ADP + P conserve?
- 7kcal energy
What is the relative efficiency level for harnessing chemical energy via the electron transport oxidative phosphorylation?
- 34%
Coupling electron transport-oxidative phosphorylation: What is created by electron transport energy-releasing reactions in the mitochondria?
- Proton (H+) gradient across the inner mitochondrial membrane
What provides the electrochemical basis for coupling electron transport to oxidative phosphorylation to form ATP?
- energy from NADH and FAD2H are used to pump H+ into intermembrane space
- flow of H+ into mitochondria matrix down gradient generates energy to rephosphorylate ADP