quiz #1- bioenergetics

metabolic process of converting food into energy used to perform biological fxns

• rest: 1.2-1.5kcal/min
• exercise: 15-30kcal/min

breakdown of large molecules into smaller molecues --> release energy

synthesis of larger molecules from smaller ones

energy releasing reactions (catabolic)

require energy

Glucogenesis is the formation of glycogen by linking glucose molecules together, whereas glycogenolysis is the breakdown of glycogen into glucose

synthesis of glucose from glycerol, amino acids, and lactate

metabolic pathway in cells which glucose is degraded into pyruvate or lactate

breakdown of triglycerides in adipose tissue to free fatty acids and glycerol for transport ot tissues for metabolism

breakdown of fatty acids to form acetyl CoA

• CHO and Fat are primary
• protein

• glucose in blood
• glycogen stored in muscles nad liver

• Fa transported to skeletal muscle to fuel contraction
• glycerol: indirect fuel for muscle contraction

• intramuscular stores of ATP (storage enough to fuel <3 sec
• ATP-PCr (phosphocreatine): simple and most rapid production of ATP, primarily for high intensity short term activity (5-8 sec)

requires ATP and occurs only during recovery- why you need 2-3 minutes of recovery

glycolysis- primary fuel for high intensity 10-30 seconds

• energy investment: requires ATP, ATP is phostphate donor
• energy generation: generates ATP

• NO oxygen: H is taken from NADH, pyruvic acid is made and lactic acid frees up NAD so glycolysis can continue
• IS oxygen: pyruvic acid enters the KREB cycle directly or is converted to Acetyl Coa and enters KREB

• glycolysis: 6-8 ATPs
• generation of acetyl CoA: 14 ATPs
• Krebs Cycle: 36 ATPs
• Oxidative Phosphorylation in ETC: ATP, Co2, H2O final products

• for glycolysis to continue
• transported to liver to convert to glucose or glycogen
• used by skeletal muscle and heart as energy substrate

only when it accumulates and inhibits PFKinase and lipolysis

breakdown of CHO, free fatty acids, and proteins

deficiency of skeletal muscle enzyme phophorylase so cant use CHO for exercise

• ATP in muscles and ATP-PCr for initial exercise
• Glycolysis for early exercise
• protein is NOT major source of energy during exercise

• energy from aerobic metabolism of fat but carbs also
• 70% fat
• 30 % carbs

• CHO starts low, ends high (CHO ONLY fuel for MAX work)
• Fat starts high, ends low

• high intensity >70% VO2 CHO
• low intensity <30% VO2 fats

• CHO starts high and ends low
• Fat starts low and ends high

well trained individual will use more fat, and less CHO than untrained person

• the flame of the carbs...
• diminished glycogen stores result in a decrease in the rate of ATP production from fat metabolism

• > 30 minutes: low intensity, fat>carbs
• > 2 hours: gylcogen is depletes, kreb cylce intermediates reduced
• 3-5 hours: prtoein may reach 5-15% (under 2% in an hour of exercise)

3500

% contribution of CHO and fat to energy metabolism during steady state exercise

• r= .85: =CHO and fat
• r<.85: fat>CHO
• r>.85: CHO>fat

• Excess Post Oxygen Consumption
• =oxygen debt
• magnitude and duration of EPOC is influence d by intensity of exercise

• replenish ATP, PC, and O2 stored in muscle
• supply additional oxygen where needed to ^ HR and BP post exercise

greatest rate of oxygen uptake by body

• ability of CV system to deliver oxygen to contracting muscle
• ability of muscles to take up oxygen and produce ATP aerobicallys
• genetics and exercise training

• onset of blood lactate accumlation
• when blood levels of lactic acid increase exponentially

• T: 65-80%
• UT: 50-60%

• hypoxia in muscles
• accelerated glycolysis (can't move H's quick enought to ETC)
• ^ recruitment of FT fibers (FT fibers promote conversion of pyruvic acid to lactic acid)
• decrease rate of lactate removal

• work at or slightly above OBLA for 20-50 minutes
• interval training
• in the field exercise at lactate threshold corresponds to ventilation threshold

• 1:3: for immediate energy systems (anaerobic training)
• 1:2: for glycolysis
• 1:1: for aerobic systems

• Submax: little or no lactic acid accumulation so passive recovery best
• Max: activity recovery best for lactic acid removal at about 35-60% VO2 max

• ^ in # and size of mitochondira
• 2x increase in aerobic system enzymes
• muscle fiber type and size
• CV

• VO2 max will increase 15% with training (can increase up to 40% in untrained individuals)
• 50% Vo2 max change come from ^ in max CO
• 50% VO2 max change comes from ^ in systemic a-vO2 difference

• ^ anaerobic energy susbtrates
• ^ enzymes for anaerobic energy pathway (FT fibers)
• ^ capacity to generate and tolerate ^ blood lactate levels during max exercise