Chapter 3 (Bioenergetics) - Powers Flashcards
This fluid portion of the cell contains the organelles of the cell.
cytoplasm
Endergonic reactions
require energy to be added
Exergonic reactions
release energy
Coupled reactions
liberation of energy in an exergonic reaction drives an endergonic reaction
What type of reaction is the breakdown of glucose?
exergonic
What type of reactions are oxidation-reduction reactions?
coupled
In cells, oxidation-reduction reactions often involve the transfer of what atom?
hydrogen (one electron)
What is the primary mechanism through which enzymes speed up reactions?
lowers activation energy required for the reaction
What are the primary factors affecting enzyme activity?
temperature, pH
What are the primary fuels for exercise?
carbohydrates and fat
Which enzyme breaks down ATP?
ATPase…not exactly rocket science
ATP is composed of what?
adenine, ribose, three linked phosphates
What are the three mechanisms for ATP production?
phosphocreatine, glycolysis, oxidative phosphorylation
Which mechanisms for ATP formation are anaerobic?
phosphocreatine and glycolysis
Which mechanisms for ATP production are aerobic?
oxidative phosphorylation
Which enzyme catalyzes the phosphocreatine system?
creatine kinase
What is the requirement of the energy investment phase of glycolysis?
2 ATP
What are the products of the energy generation phase of glycolysis?
4 ATP, 2 NADH, 2 pyruvate or 2 lactate
What are the electron acceptors?
NAD and FAD
Oxygen is normally available in the mitochondria to accept hydrogens from NADH produced in glycolysis. In anaerobic conditions, what is the adaptation?
pyruvic acid accepts hydrogen and electrons from NADH to form lactic acid
Kreb’s cycle (citric acid cycle)
aerobic ATP production, completes the oxidation of substrates and produces NADH and FADH to enter the electron transport chain
____ accepts the hydrogens from NADH and FADH to form _____.
Oxygen, water
What molecule enters the Kreb’s cycle?
acetyl CoA
The Chemiosmotic Hypothesis of ATP Formation
electron transport chain results in pumping of hydrogen ions across inner mitochondrial membrane, results in hydrogen gradient across the membrane, energy released to form ATP as hydrogens diffuse back across membrane
Aerobic ATP production results in how many molecules of ATP per NADH and FADH?
2.5 ATP per NADH and 1.5 ATP per FADH
Aerobic metabolism of 1 molecule of glucose yields how many ATP?
32 ATP
Aerobic metabolism of 1 molecule of glycogen yields how many ATP?
33 ATP
What is the overall efficiency of aerobic respiration (production of ATP)?
34%
How does high levels of ATP affect ATP production?
inhibits
How does high levels of ADP (low levels of ATP) affect ATP production?
stimulates
Does oxidative phosphorylation occur inside or outside the mitochondria?
inside
Does glycolysis occur inside or outside the mitochondria?
outside
Rate-limiting enzyme of ATP-PC system.
creatine kinase
Rate-limiting enzyme of glycolysis.
phosphofructokinase
Rate-limiting enzyme of Kreb’s cycle.
isocitrate dehydrogenase
Rate-limiting enzyme of ETC.
cytochrome oxidase
1 MET =
3.5 mLO2/kg/min
1 L O2 =
5 kcal
