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BIO 2310 - Exam 3 (Muscles) > Muscle Energy > Flashcards

Flashcards in Muscle Energy Deck (12):

energy for mm contraction



3 pathways for ATP regeneration

1. direct phosphorylation of ADP by creatine phosphate

2. aerobic respiration

3. anaerobic glycolysis and lactic acid formation


direct phosphorylation of ADP by creatine phosphate

- creatine phosphate (CP) is high energy molecule found in mm fibers (not in other cell types)

- creatine travels from liver to other tissues where its converted into CP

- creatine is produced form glycine, arginine, and SAM (S-adenosyl-L-Methionine)


Creatine Phosphate (CP)

ATP phosphorylates creatine to create CP in rxn catalyzed by creatine kinase

- provides small resevoir of high energy phosphate that readily regenerates ATP form ADP

- plays role during early stages of exercise in mm

- creatine aids in transports of high energy phospate from the micochondria to actomysoin fibers


how long atp and cp last

MM cells store about 5 times more CP than atp

atp lasts 4-6 s

cp supplies last 20 s


aerobic respiration

w/ O2

at rest and during light to moderate exercise 

95% of ATP used for mm activity comes form aerobic respiration(AR)

occurs in mitochondiria and uses oxygen (oxidative phosphorylation which is formation of high energy bonds)


process of aerobid respiration

1. glucose broken down to Co2 + H2o

2. some of the energy released form breakfown is captures in bonds of ATP molecules

3. AR provides a rich ATP supply ( 36ATP/1 glucose) it is slow and requires continuous deliver of o2 and nutrition


anaerobic glycolysis and lactic acid formation

w/o o2

Glycolysis: initial stage of glucose breakdown, occurs in cytosol, broken down into pyruvic acid

small amounts of ATP captures ( 2 atp/1 molecule)

-PA enters aerobic pathway to procude more ATP

- When mm activity too greatmaking o2 and glucose inadequete to meet exercise demand, slow aerobic mechanisms can not keep up, so PA generated turns into LACTIC acid = anaerobic glycolsis


Amount ATP created AR vs ANR

Ana - 5% as much ATP as AR

However, Ana is 2.5 times faster and can provide most of ATP needed for 30-60 seconds of strenous activity

Ana accumulates lactic acid promoting mm fatigue and mm soreness


mm fatigue

occurs when mm is unable to contract even though its being stimulated usually bc oxygen debt

- when deprived, it makes LA iva Ana

- atp runs low, so with increase of LA and decrease of ATP, less mm contraction, one reason we increase rbeathing in exercise


muscle tone

the state of continuous partial contractions of sk mm

occurs bc different motor units eing stimulated by nervous system


effects of exercise on mm

no stimulation - atrophy; stimulation - hypertrophy

- stronger, more flexible mm: bc blood supply increases, more mm cells form, more mitochondira form, more o2 storage, improve digestion, increase metabolism, less changes stroke ect..

- building mm mass comes from anaerobic type work with resistance, result is break fown and build up of muscle tissue