Bioenergetics Flashcards
metabolism
sum of all chemical reactions that occur in the body - two general categories
catabolic reactions
breakdown of molecules
anabolic reactions
synthesis of molecules
cell membrane
barrier to out and in, semipermeable
cytoplasm
gel-filling, suspends the organelles
nucleus
store DNA, instructions to build protein
mitochondria
“powerhouse” , makes energy (ATP)
bioenergetics
process of converting foodstuffs (fats, proteins, carbs) into usable energy for cell work
endergonic reaction
requires that energy be absorbed to the reactants
- endothermic
exergonic reaction
energy is released when the reactants combine
- exothermic
coupled reactions
reactions that are linked with the liberation of free energy in one reaction being used to “drive” a second reaction
oxidation-reduction reactions
oxidation: lose electron
reduction: gain electron
a molecule cannot be oxidized unless it donates electrons to another atom
*coupled reaction
enzymes
-special type of protein that acts as a catalyst
-speed of cellular chemical reactions is regulated
-role in regulation of metabolic pathways in the cell
-do not cause a reaction to occur
factors that influence enzyme activity
body temp and pH
Role of NAD & FAD
electron carriers for molecules during bioenergetic reactions
NAD
nicotinamide adenine dinucleotide
- oxidized form: NAD +
- reduced form: NADH
FAD
flavin adenine dinucleotide
- oxidized form: FAD
- reduced form: FADH2
rate-limiting enzymes
an enzyme that regulates the rate of a metabolic pathway
1. levels of ATP & ADP + Pi
2. calcium stimulates aerobic ATP Production
ATP/ ADP Pi levels
substrate phosphorylation
- PCr
- Anaerobic glycolysis
- aerobic metabolism
oxidative phosphorylation
- aerobic metabolism
ATP-PC System
substrate: phosphocreatine
enzyme:
ATP Production: 1 ATP per PC
RLE: creatine kinase
Location: cytoplasm
- activated at the onset of exercise, short term, high intensity ( 5- 15 seconds)
Glycolysis/Glycogenolysis
substrate: glucose or glycogen
enzyme:
ATP Production: 2 ATP for glucose, 3 ATP glycogen
RLE: aerobic: phosphofructokinase
anaerobic: lactate dehydrogenase
Location: cytoplasm
- most active when doing high intensity PA with limited O2 availability, activities 10 seconds to 2-3 minutes
aerobic respiration
substrate: carbohydrates, fats, proteins
enzyme:
ATP production: glucose: 32 ATP, glycogen: 33 ATP
Beta Oxidation: production of ATP from fatty acids
RLE: krebs cycle: isocitrate dehydrogenase
ETC: cytochrome???
Location: cytoplasm and mitochondria
- active in activities lasting longer than 3 minutes unitl substrates run out
