Metabolism and Energy Flashcards
what is metabolism
the set of chemical reactions that happen in living organisms to maintain life
metabolism is usually divided into what two categories
catabolism
anabolism
define catabolism
breaks down organic matter;. for example to harvest energy in cellular respiration
define anabolism
uses energy to construct components of cells such as proteins and nucleic acids
energy metabolism occurs via ___ production pathways
ATP
energy (ATP) demand is set by the activation of muscle contraction
1) myosin ATPase type (the fiber type) and SERCA protein type
- MHC 1 or MHC IIx ect
- SERCA1a or SERCA2a
2) the peak force and mechanical nature of contraction
- isometric, isotonic ect
when you start to do work your muscles use energy (ATP) at a rate that matches the work load demand of the activity. ATP demand is set by
the activation of muscle contraction
typically the amount of ATP need to perform a standard workload is similar or different between trained or untrained individuals
similar between trained and untrained individuals
what is ATP homeostasis
the balance of energy utilized by cellular ATPases and energy produced by metabolic pathways
at rest ATP utilization =
0.01 umol ATP/g muscle/second
during exercise ATP utilization =
10umol ATP/g muscle/second
the net depolarization of ATP in muscle rarely goes below ___% why?
30
because ATP utilization pathways are tightly coupled to ATP metabolic pathways
what are the three ways ATP is created (3 delivery systems)
1) high energy phosphate transfer (anaerobic pathways )
2) glycolysis (anaerobic pathway)
3) oxidative phosphorylation (aerobic pathways)
does high energy phosphate transfer use O2
no
what is high energy phosphate transfer
transfer of a phosphate group from phosphocreatine to ADP to regenerate ATP
does glycolysis use O2
no
what is glycolysis
degradation of glucose or glycogen (glycogenolysis)
what is oxidative phosphorylation
complete combustion of fats and or CHOs
does oxidative phosphorylation use O2
yes
high energy phosphate transfer is anaerobic ____
alactic
what are the steps of high energy phosphate transfer
ATPase
creatine kinase
adenylate kinase
AMP deaminase
what is the ATPase reaction
ATP +H2O converts through ATPase to ADP +Pi +H + ATP
what is the creatine kinase reaction
ADP +PCr + H ATP + Cr(PCr stores 3-4x greater then stored ATP)
what is the adenylate kinase reaction
ADP + ADP ATP + AMP
AMP deaminase reaction
AMP —> IMP + NH3
what are the 2 segments of glycolysis
energy investment
energy generation
glycolysis can power about ___ seconds of contraction
30 seconds
if you start with glycogen how many ATP used in the energy investment stage of glycolysis is used
1
what are the three stages of oxidative phosphorylation
1) formation of acetyl-CoA
2) oxidation of acetyl groups
3) oxidation of NADH and FADH2 in the electron transport chain
explain the formation of acetyl-CoA
from carbohydrates via glycolysis or from fats via beta-oxidation or in extreme conditions from amino acids
explain oxidation of acetyl groups
in krebs cycle to form NADH and FADH2
explain oxidation of NADH and FADH2 in the electron transport chain
this process harnesses electrons to generate a proton gradient to power the formation of ATP from ADP and Pi
what is the difference between untrained and trained HEPT
untrained
- accumulation of ADP is countered by HEPT + glycolysis (ADP accumulates)
trained
- HEPT + glycolysis are not relied upon quite as heavily after training
why is HEPT + glycolysis not relied on as much in trained athletes
because oxidative phosphorylation is able to contribute to the removal of ADP sooner during exercise
what is the difference between untrained and trained oxidative phosphorylation
untrained
- it is activated and makes enough ATP to fuel the contractions
trained
- activated much earlier!
why does the oxidative phosphorylation activate much earlier in the trained state
due to an increase in mitochondria, an increased sensitivity of metabolic enzymes for ADP and an increase in oxygen delivery to working muscle. collectively these parameters contribute to a tight coupling of ADP production with ATP regeneration
does oxidative phosphorylation remain elevated in both the train and untrained state after exercise stops?
yes
untrained
- in order to remove ADP by regenerating PCR
trained
- in order to remove ADP by regenerating PCR. however the total ADP content is less in a tightly coupled system so the oxygen debt is paid back much faster
