bioenergetics and exercise metabolism - week 2 Flashcards
what is bioenergetics ?
flow and exchange of energy within a living system
what is metabolism ?
sum of all chemical reactions that occur int he body
what’s an anabolic reaction?
synthesis of molecules
what is a catabolic reaction?
breakdown of molecules
what is an endergonic reaction ?
requires energy to be added to the reactants
what’s an exergonic reaction?
releases energy
what’s a coupled reaction?
liberation of energy in an exergonic reaction drives an endergonic reaction
(release of energy provides energy for another reaction)
what is oxidation-reduction reactions ?
coupled reactions
oxidation - removes an electron
reduction - gains an electron
how does FAD and NAD play roles in oxidation and reduction ?
they act as carrier molecules
help with transfer of H+ in the electron transport chain
what is an enzyme ?
proteins that lower the activation energy and accelerate chemical reaction
what is meant by kinase ?
adding of a phosphate group
what is meant by dehydrogenase ?
remove hydrogen atoms
what’s meant by oxidases ?
catalyses oxidation
reduction reactions involving oxygen
what’s meant by isomerases ?
rearrangement of the structure of molecules
how does anaerobic pathways help form ATP (2)
doesn’t involve oxygen
phosphocreatine breakdown + glycolysis
how do aerobic pathways help form ATP? (2)
require oxygen
oxidative phosphorylation
depend on respiratory and CV system to deliver O2
what is the ATP-PC system ? (3)
most rapid method of producing ATP
phosphocreatine breakdown
deplete after 10-15 secs
PC+ADP»_space; ATP+C
what is glycolysis ?
30-90 seconds
glycolic pathway
produce 2 NADH, 2 pyruvate or 2 lactate
for chemical reactions in ___ to continue, adequate amounts of __ must be available to accept __
glycolysis
NAD+
H+
how can NAD+ rapidly reform from NADH ? (2)
sufficient O2: H+ shuttled to mitochondria
insufficient O2: pyruvate can accept H+ to form lactate
- lactate formation allows recycling of NAAD+ so glycolysis can continue without O2
how does the citric acid cycle produce ATP ? (4)
pyruvate enters mitochondria and converted to acetyl CoA + makes CO2
acetyl CoA combines with oxaloacetate to form citrate, generates 2CO2
each cycle released 3NADH and FADH2
provides electrons for electron transport chain
how does the electron transport chain work ? (4)
NADH and FAD are reoxidised from H+
electrons are passed down electrons carries (cytochromes) and pumping of H+ into inter membrane space
movement of H+ through ATP synthase produces ATP
O2 accepts the H+ passed along making H2O
what is the total ATP produces from 1 glucose molecule ?
known as 32 molecules
historically it is 38 molecules
what is an oxygen deficit ?
discrepancy between initial demand/atp production and oxygen consumption
why do trained individuals have lower O2 deficit than untrained ? (3)
better developed bioenergetic capacity :
- greater regional blood flow to active muscle
- increased cellular adaptation efficiency
- increased mitochondrial volume in fibres reduces lactate production at start of exercise
what is EPOC ? and what is it most influenced by ? (2)
excess post-exercise oxygen consumption
magnitude and duration of EPOC influenced by intensity of exercise
what is the rapid portion of EPOC ?
resynthesis of stored PC in muscles (60-120s)
replenish muscle and blood O2 stores
what is the slow portion of EPOC?
evaluated HR and breathing increase O2 demand
elevated body temp increases metabolism
elevated blood levels of epinephrine + norepinephrine = increased metabolic rate
what is conversion of lactic acid to glucose?
gluconeogenesis
what metabolic response is used for short term high intensity exercise <5secs?
ATP from ATP-PC
what metabolic response is used for intense exercise > 5 secs ?
shift to ATP production via glycolysis
what metabolic response is used in events lasting more than 45 secs ?
ATP-PC, glycolysis and aerobic systems
50/50 aerobic and anaerobic
what metabolic response occurs in prolonged exercise over 10 mins ?
ATP primarily from aerobic metabolism
