Midterm condensed Flashcards
cori cycle
conversion of lactate to glucose, prevents excess accumulation of lactate under anaerobic conditions
gluconeogenesis
non carb substrates turned into glucose
oxidative phosphorylation
make ATP by transferring electrons from NADH and FADH2 to O2
lactate vs lactic acid
lactic acid dissociates to release H+ and the remaining compound binds with sodium ion to form acid salt called lactate
energy release from fat
called beta oxidation, yields 460 ATP, is the main fuel source when glucose is depleted, results in hydrogens for ETC
protein breakdown
deamination of AA (ie removal of nitrogen), and the carbon skeleton enters metabolic pathways to produce ATP
ATP-PCr energy system
supplies immediate energy for first 10 sec of high intensity PA. each muscle kg contains 3-8 mmol of ATP and 4-6x more PCr
Short term glycolytic energy (anaerobic)
anaerobic glycolysis breaks down muscle glycogen, which gives energy to phosphorylate ADP during short and intense PA
lactate producing capacity
increases w training and decreases due to motivation, glycogen stores and glycolytic enzymes
long term energy (aerobic)
balance between energy requirements by work muscles and ATP production
limits of steady rate aerobic metabolism
fluid loss and electrolyte depletion
factors determining VO2max
arterial O2 saturation, mixed venous saturation, O2 capacity of blood, circulation rate
PCr - energy reservoir
also high energy phosphate compound! anaerobic source of phosphate bond energy, 4-6x more PCr than ATP, reaches mac energy yield in 10 sec
cellular oxidation
oxidation of macros creates energy for phosphorylation, providing hydrogen atoms from catabolism
ATP synthesis is an oxidation-reduction reaction
electron transport
electrons extracted from hydrogen pass to oxygen, and enough energy is released to phosphorylate ADP to ATP
macro catabolism stages
1 absorption, digestion and assimilation
2 degrading AAs, glucose and FA into acetyl CoA
3 acetyl CoA degrades into CO2 and H2O
energy release from carbs
only anaerobic substrate, quicker than fat breakdown, supplies most energy for ATP resynthesis, CNS requires carbs, needed for fat catabolism
anaerobic vs aerobic glycolysis
need for ATP determines which type. Anaerobic rapidly creates ATP and lactate but only extracts 5% of energy. Aerobic extracts 95%, converts pyruvate to acetyl CoA and incl ETC
glycolytic process
regulated by levels of fructose 1,6 diphosphate, oxygen and 4 key enzymes. includes 10 step creation of 2 pyruvate from anaerobic breakdown of glucose
3 factors causing EPOC
body temp, blood returning to lungs, restoring O2 dissolved/bound to myoglobin
rationale for interval training
rapid recovery and high intensity, effective overload, rapid O2 uptake recovery, relative balance between energy requirements and transfer
specificity principle
local changes: greater BF in active tissue from incr circulation and more effective redistribution
vo2max: engage same muscles as in activity at level sufficient to stress CV system
metabolic adaptations to anaerobic training
incr levels of anaerobic substrates, anaerobic enzymes, capacity to produce lactate and glycolytic enzymes
metabolic adaptations to aerobic training
incr mitochondrial activity by 50% and capacity for respiratory control, and incr fatty acid oxidation
CV adaptations to aerobic
cardiac hypertrophy, incr in PV, SV, CO, O2 extraction, BF distribution. Decr RHR And BP
Pulmonary adaptations to aerobic
incr VE, TV, endurance. Decr O2 cost, breathing frequency
contributions of high energy phosphates
food energy stored in ATP bonds, extract and transfer chemical energy for biologic work
lactate formation & accumulation
lactate prod and clearance are equal at <50% of aerobic capacity. some produced at rest by RBC metabolism and enzyme activity limits. diffuses into blood or provides substrate for glycolysis
role of CAC
releases 95% of energy, 34 ATP yield, formed when hydrogen oxidizes
ATP yield from macros
fat - 460 ATP, aerobic
carb - 32 ATP, anaerobic
protein - carbon skeletons help form ATP, aerobic
fat in a carb flame
fatty acids require intermediates from carb breakdown, and needs sufficient oxaloacetate to combine with acetyl CoA formed during beta oxidaton –> forms citrate, enters cycle
interconversions
fat - nonessential AAs
carbs - fats, nonessential AAs
protein - carbs/fats
lactate threshold
muscle cells cannot meet energy demands aerobically nor clear lactate and rate of production. untrained: accumulation at 50-55% of aerobic capacity. trained: accumulation at 80-90%
recovery O2 uptake
decreases by 50% every 30 sec. small deficit after light PA cause quickly reaches SR, takes longer to recover after mod/intense cause takes longer to reach SR
implications of EPOC
resynthesize ATP and PCr, resynthesize lactate to glycogen, O2 to blood, restore temp,HR and ventilation
blood lactate concentration
decr formation and incr clearance thru endurance training
infusing lactate - effect on glucose oxidation
decr glucose oxidation –> decr demand for blood glucose –> decr production to maintain homeostasis
glycogenesis
synthesis, facilitated by glycogen synthase , low cellualr activity
glycogenolysis
breakdown, in high cellular activity, glycogen phosphorylase removes a glycose from glycogen chain
