Question

Describe the mechanisms for providing energy to the skeletal muscle cell during exercise (immediate, short-term, etc.).

Answer 1

Ans:-

concept:-

i) immediate:- PHOSPHO CREATINE SYSTEM

ii) short term:- GLYCOLYSIS LACTIC ACID SYTEM

iii) long term :- AEROBIC SYSTEM.

ENERGY SOURCES FOR THE EXERCISING
MUSCLE
Three important sources supply energy for the exercising muscle.
They are:
Phosphocreatinine system
Glycogen - lactic acid system
Aerobic system

Phosphocreatinine System
Also called creatine phosphate present in muscle
The high energy bond of creatine phosphate release 10,300
calories per mole energy. It is very high when compared to the
one released by ATP hydrolysis (7,300 calories/mole)"
Muscles have two to four times more phosphocreatine than ATP
The energy released by creatine phosphate can sustain exercise
for 8-10 seconds
Therefore, this system is mainly useful for maximal short bursts
of muscle power (Example - 100 meter run)

Glycogen - I
- Lactic Acid System
Glycogen stored muscle gets breakdown to glucose which is used to produce ATP.
initially , ATP formation happens without oxygen termed as anaerobic metabolism.

The end product of such anaerobic metabolism is lactic acid

If lactic acid accumulates and reaches a critical level (termed
lactate threshold), it causes pain and muscle fatigue
This Glycogen - lactic acid system provides energy to sustain
activity up to 1.3 - 1.6 minutes

Aerobic System
Here, glucose and fatty acids are oxidized in mitochondria to
synthesize ATP
Mainly useful during prolonged activities like long distance
running (endurance type)