Lecture 18 Flashcards
What is energy
Capacity to do work
What does ATP stand for
adenosine triphosphate
What is ATP
- Medium of energy exchange
- Energy current of cell
From what is ATP generated
- Glucose metabolism
- Fatty acid metabolism
- Some from AA metabolism
WHERE is ATP generated
- Glycolysis
- Krebs cycle
What produces reducing equivalents of NADH and FADH2
- Glycolysis
- Beta oxidation
- Krebs cycle
What do NADH and FADH2 supply
Protons (H+) and electrons (e-) to electron transport chain
Where is most of the bodies ATP made
ETC
What is the process called when ATP is generated without O2
Phosphocreatine (PCr) degradation
Can ATP be generated without O2
Yes
How long can ATP be generated for without O2
9-10 seconds
Explain decomposition of ATP in Phosphocreatine
ATP — ADP + Pi
What is the end product of glycolysis in anaerobic conditions
Lactate
What is an example of anaerobic ATP productions
Sprints
How is most energy stored
As triglycerides (fat)
What energy is produced from carbs
Glycogen and glucose
Where is glycogen stored
- Liver
- Muscle
- Little bit in blood
When is protein used as an energy source
- Starvation
- Caloric restriction
What are the pros of carbs as fuel
- Aerobically, can generate ATP slightly faster than fat
- Anerocially, can also generator ATP
What are the cons of carbs as fuel
- Holds lots of water
- heavier/ less dense than fat
What are the pros of fats as fuel
- Doesn’t hold water so 2x as energy dense as carbs
- Represents most abundant energy reserve
What are the cons of fats as fuel
- Cannot provide energy anaerobically
When does the absorptive state take place
- 3-4 hours after a meal
What is the absorptive state
- When energy (macronutrients) are stored (anabolism)
Where is glycogen stored in an anabolic state
- Liver
- Muscle
Where are triglycerides stored in an anabolic state
- Adipose tissue
- Liver
- Muscle
What happens to excess calories as glucose and AAs
Get converted to fats
What is the postabsorptive state
A state of fasting
What is catabolism
- Stored macros are mobilized for energy
What happens during the postabsorptive state
- Catabolism
- Glucose spared for NS
What is gluconeogenesis and where does it occur
- Making of glucose from noncarbohydrate precursors
- Occurs in liver and kidneys
What are blood glucose levels
-Blood sugar
- The amount of glucose per L of blood
What is the normal fasting blood glucose level
4-5.5 mmol/L
What is fasting hyperglycemia
- Blood sugar is too high
- Over 7 mmol/L
What is fasting hypoglycemia
- Blood sugar too low
- Under 3.5 mmol/L
What are the risks of hypoglycemia
Glycosylation of AA in:
– Kidneys
– peripheral nerves
– and lenses of eyes
What is glycosylation:
Attachment of carbohydrates to protein causing damage
Why is blood glucose maintained so tightly
- Many cells require glucose
- To maintain osmotic balance
- To avoid risk of hyperglycemia
What is osmotic balance
Optimal concentrations of electrolytes, and nonelectrolytes
When is blood sugar increased
After a meal
What decreases blood sugar
- Insulin secretion
- Decrease of glucagon
What kind of feedback loop is glucose regulation via insulin
Negative feedback loop (body tries to return to normal state)
When is blood sugar decreased
During fasting
What increases blood sugar
- Glucagon secretion
- Decrease of insulin
What kind of feedback loop is glucose regulation via glucagon
Negitive
What is the main fuel contributor for prolonged low intensity exercise
-Mainly blood glucose and fatty acids
- Some muscle triglycerides and glycogen
What is the main fuel contributor of moderate to high intensity exercise
Mainly muscle glycogen and triglycerides; blood glucose and fatty acids
What is the main contributing fuel of high intensity exercise
Muscle glycogen and phosphocreatine
