Energy systems

define metabolism

chemical processes that occur within a cell to maintain life

what breaks down ATP?

ATPase to release high energy from bonds

what does falling levels of ATP cause?

stimulates release of creatine kinase which breaks PC bond to release energy

what are the products of PC hydrolysis and what are they used for?

energy and a phosphate molecule used to resynthesise ATP

define a coupled reaction

when the products of one reaction are used in another

where does the ATP/PC system take place

muscle/mitochondria sarcoplasm

5 advantages of ATP/PC system

• anaerobic so no o2 needed

• PC is readily useable in muscles

• fast resynthesis of ATP

• automatically stimulated by ATP decrease

• no fatiguing by-products

3 disadvantages of ATP/PC system

• limited amount of ATP and PC stored

• small energy yield 1:1

• only provides energy for 3-10 seconds

what duration and intensity is ATP/PC system used?

short duration and high intensity

describe the process of anaerobic glycolytic system

decrease in PC stores stimulates GPP to break down glycogen to glucose

rising ADP stores stimulate PFK to break down glucose into pyruvic acid, releasing energy to resynthesise 2 ATP

LDH converts pyruvic acid to lactic acid

what are the controlling enzymes in glycolytic system

GPP, PFK, LDH

intensity and duration of glycolytic system

high intensity

10 secs to 3 mins

what are the by-products of glycolytic system

lactic acid

yield and location of glycolytic system

1:2

sarcoplasm

advantages of glycolytic system

glucose readily available in muscle cells

high force of contraction

disadvantages of glycolytic system

lactic acid by-product

low yield

limited by lack of oxygen

only supplies energy for 10s to 3mins

effect of lactic acid in muscle cells

hydrogen ions in lactic acid dissociate and are the cause of acidity and pain as nerve signal blocked

causes pH to decrease which inhibits enzymes

prevents fuel breakdown to resynthesise ATP

leads to OBLA

training adaptations of glycolytic system

increase tolerance to lactic acid

delays OBLA/fatigue

increase glycogen stores and body’s efficiency to use glycogen

what are the three phases of the aerobic system

aerobic glycolysis

krebs cycle

electron tansport chain

describe the first stage of the aerobic energy system

same process of anaerobic glycolysis

in the presence of oxygen, pyruvic acid reacts with coenzyme A to form acetyle CoA

acetyle CoA reacts with oxaloacetic acid to form citric acid

describe the first second of the aerobic energy system

krebs cycle

citric acid is oxidised in mitochondria matrix

releases hydrogen which produces enough energy for synthesis of 2 ATP

oxaloacetic acid regenrated into cycle to react back with acetlye coA

describe the first third of the aerobic energy system

electron transport chain in cristae folds

hydrogen atoms released carried along ETC by NADs and FADs

splits hydrogen into H+ and electrons

H+ oxidised and removed as water

electrons release energy for resynthesis of 34 ATP

Compare ATP resysnthesis between nads and fads

nads - 30

fads - 4

by products of aerobic system

co2 and water

total yield of aerobic system

1:38

site of aerobic system

sarcoplasm

matrix

cristae

fuel of aerobic system

glycogen/glucose or triglycerides

duration of aerobic system

3+ mins

controlling enzymes of aerobic system

GPP, PFK, coenzyme A

describe recovery of PC stores

50% in 30 seconds

100% in 3 mins

describe recovery of O2 stores

stored in myoglobin

100% myoglobin replenished with o2 in 3 mins during rest or low intensity exercise

describe recovery of lactic acid

OBLA - delayed blood lactate

low intensity exercise oxidates lactic acid so it is either removed or converted to glycogen

how does higher aerobic capacity affect recovery

delays OBLA

increased buffering capacity

faster O2 transport

faster oxidation of lactic acid

state and define EPOC

excess post-exercise oxygen consumption

volume of oxygen consumed after exercise above which is usually consumed at rest

state a describe 2 components of EPOC

fast alactacid - resynthesis of ATP and PC, replenishment of myoglobin oxygen stores

slow lactacid - remove lactic acid and convert to oxygen, elevate circulation, increase temp

timing and o2 use of components of EPOC

fast alactacid - every 2 mins use 0.5L

slow lactacid - 1-2 hrs total using 5-8L

describe 3 factors effecting EPOC

intensity of training - increase body stores to increase efficiency of fast component

work relief ratio - 1:3 (ATP/PC), 1:2 (lactic acid), 1:1 (aerobic)

cool downs - maintain body temp and circulation