Bio 161 Topic 17 Vocabulary

Muscle Control & Energetics

Motor Unit

• all the muscle fibers that ONE motor neuron control

• size depends on muscle function

Recruitment

contraction of subsequent motor units will increase strength of muscle contraction

Aerobic Respiration

Converts ADP to ATP by metabolizing glucose, fatty acids and proteins in mitochondria

• many steps = takes time so a lot of ATP

  • most efficient ATP production

  • can use many food sources

    • glucose, fatty acids, and proteins

• requires oxygen

• ideal for sustained contraction, if sufficient oxygen is present

Anaerobic Respiration

Glucose is metabolized to produce lactic acid + ATP

• fewer steps = faster but les ATP

• only uses glucose

• produces lactic acid

• no oxygen required

• 30-90 seconds (high intensity, low duration)

Phosphorylation

Turns ADP into ATP by taking the phosphate from the CP

• At Rest:

  • muscle stores energy from ATP in the form of CP

• During Exercise:

  • creatine phosphate used to convert ADP back to ATP

  • ADP + creatine phosphate = creatine + AT

• One Step = Super Fast, produces only 1 ATP

• no oxygen required

• ~15 seconds (high intensity, short duration) used at the very start of exercise

Duration Exercise

increases blood flow to muscles, number of mitochondria, and myoglobin in muscle

Intensity Exercise

increases size of muscle fibers, number of mitochondria, and glycogen stores in muscle

Lactic Acid

causes the '“burning” sensation associated with intense exercise