Lecture 9 Flashcards
• (blank) of ATP
– Phosphocreatine (PCr) breakdown
– Degradation of glucose and glycogen (glycolysis)
– Oxidative formation of ATP (oxidative phosphorylation)
• (blank) pathways
– Do not involve O2
– PCr breakdown and glycolysis
• (blank) pathways
– Require O2
– Oxidative phosphorylation
• Krebs cycle and electron transport chain
formation
anaerobic
aerobic
3 substrates of ATP production?
carbohydrates, fatty acids and amino acids
(blank) system=ATP-PCR system, glycolysis
(blank) system= krebs cycle, electron transport chain
The (blank) of each of these systems is to meet the cellular
demand for ATP.
anaerobic
aerobic
goal
ATP-PCr System
• Anaerobic, substrate-level metabolism
• Free ATP: provides (blank) energy lasting < 2 sec
• IMPORTANTLY: (blank) = creatine phosphate
• Phosphocreatine (PCr) exists in concentrations 5-6x
higher in resting muscle than free ATP
• Duration: 3 to 15 s
• Because ATP stores are very limited, this pathway is used
to (blank) ATP
immediate
phosphocreatine
reassemble
PCr System • Primary fuel source for (blank) very intense exercise • 10 - 15 seconds • Weight lifting • Sprinting
(blank) gets added to PCR + ADP to form ATP + CR
short
creatine kinase
Carbohydrate
• All carbohydrate converted to glucose
– (blank) kcal/g; ~2,500 kcal stored in body
– (blank) ATP substrate for muscles, brain
– Extra glucose stored as (blank) in liver, muscles
• Glycogen converted back to glucose when needed to make
more ATP (glycogenolysis)
• Glycogen stores limited (2,500 kcal), must rely on dietary
carbohydrate to replenish
4
primary
glycogen
Fat
• Efficient substrate, efficient storage
– 9.4 kcal/g
– +70,000 kcal stored in body
• Energy substrate for (blank), less intense exercise
– High net ATP yield but slow ATP production
– Must be broken down into free fatty acids (FFAs) and (blank)
– Only (blank) are used to make ATP
• Glycerol will be converted to G-3-P for glycolysis
prolonged
glycerol
FFA’s
Protein
• Energy substrate during starvation
– 4.1 kcal/g
– Must be converted into (blank) (gluconeogenesis)
• Can also convert into (blank) (lipogenesis)
– For energy storage
– For cellular energy substrate
gluconeogenesis
FFA’s
Glycolysis
• Process of breaking down glucose or glycogen (carbohydrate) to form ATP without using (blank)
• Glycogen stored in (blank) (also stored in liver)
• Glucose must be transported into muscle from (blank)
oxygen
muscle
blood
Glucose is transported into the cell by (blank)
GLUT4
Important (blank) of Glycolysis
Hexokinase
Glycogen Phosphorylase
Phosphofructokinase
enzymes
Fates of Pyruvate
• (blank) Fate:
– Lactate (Lactic Acid) via
Lactate Dehydrogenase
• (blank) Fate:
– Acetyl CoA via Pyruvate
Dehydrogenase
anaerobic
aerobic
Activating an Enzyme • Some enzymes are present in both an active and inactive form – When inactive activity ~ 0 • (blank) enzyme increases activity
activating
Glycolysis summary:
• 2 ATP from glucose • 3 ATP from glycogen • 2 NADH + H+ • 2 Pyruvate • 2 Acetyl CoA – When PDH is active – Enters into (blank) metabolism where large amounts of ATP are produce
aerobic
Glycolytic System • Anaerobic • Breakdown of glucose via (blank) • ATP yield: 2 to 3 mol ATP/1 mol substrate • Duration: 15 s to 2 min
• Uses glucose or glycogen as its substrate
– Must convert to glucose-6-phosphate
– Costs (blank) ATP for glucose, 0 ATP for glycogen
• Pathway starts with glucose-6-phosphate, ends with
(blank) acid
– 10 to 12 enzymatic reactions total
– All steps occur in (blank)
– ATP yield: 2 ATP for glucose, 3 ATP for glycogen
glycogenesis
1
pyruvic
cytoplasm