Physiology of Exercise Which scantron? (green scantron 882)
Exam I Review
Calculators allowed, but
Smartphones, Tablets or Laptops Energy Metabolism
Identify caloric yield from the three macronutrients.
○ Carbs: 4 kcal/g, Fats: 9 kcal/g, Proteins: 4 kcal/g
Identify caloric content released when splitting one molecule of ATP.
○ 7.3 kcal of energy
Explain which programming variable (i.e., volume or intensity) influences fuel utilization most significantly.
■ Intensity requires a more efficient fuel source. When you increase intensity, you need carbs. Compared to fat utilization at lower intensities
Explain the basic role and timing of use of each energy system.
Highestintensity, very shortduration
Limited energy Fast
Blood/muscle glucose, glycogen
Highintensity, shortduration Lactate
Glucose, glycogen, FFA, proteins
Lowerintensity, longerduration Slow ATP
Duration of event
0 – 6 seconds
6 – 30 seconds
Phosphagen and Fast
30 – 120 seconds
2 – 3 minutes
Fast Glycolytic and
> 3 minutes
● Identify carbohydrate storage locations and quantities.
○ Blood glucose: 515 g (in small quantities because blood stream is a delivery system that allows us to deliver glucose to vital organs like the brain and CNS)
○ Liver: 90110g (replenished as we eat daily, our reserve for when blood sugar drops) ○ Muscle tissue: 250600g
○ Total= 2000 kcal
● Define basic energy pathway terminology (e.g., lipolysis, gluconeogenesis).
: Fat oxidation requires mobilization of stored triglycerides process of breaking down stored fats in fat cells to FA + glycerol
: Transformation of glycogen to glucose or pyruvate occurs in the liver a metabolic pathway that results in generation of glucose from noncarbohydrate sources (pyruvate)
: Accumulation of excess AcetylCoA (from FFA breakdown or not enough oxaloacetate) results in build up of ketone bodies (KB)
○ Amino acid deamination:
■ Remove amino groups for glucogenic or ketogenic amino acids:
■ Glucogenic have ability to be converted to glucose thru pyruvate
(manufacture of glucose from noncarbohydrate source =
■ Ketogenic can only be converted to intermediate products that feed into metabolic pathways to make energy or FFAs.
Converted to acetylCoA
● Explain the meaning behind the terms ‘caloric quantity’ and ‘caloric quality’.
○ quantity = how many calories you burn total overall despite their source
○ quality = where the kcals are coming from (fat/carb/amino acids)
● Discuss the role of lactate production. •
Pyruvate suffers 2 fates:
○ Most is shuttled to the mitochondria to continue oxidative metabolism
Amount determined by O availability.
○ Excess (beyond aerobic pathway capacity/ when low O is present) is converted to
Hydrogen ions from step 6 (slide 39 Module 1ppt) binds with pyruvate to form lactate.
• Glycolysis depends upon H ions being picked up by NAD (step6).
○ Inability to remove accumulating H ions forces lactate formation to remove H
○ The formation of lactate from pyruvate is catalyzed by lactate dehydrogenase by adding 2 hydrogen ions:
NADH + Pyruvate←(LDH enzyme)→ NAD + Lactate
○ Converted back to pyruvate and used for ATP or glucose