fuels Flashcards
1
Q
Oxidation of fatty acids
A
- Fatty acid chains broken into 2 carbon acetic acid molecules
- Each acetic molecule combines with enzyme CoA to form acetyl CoA
2
Q
Oxidation of amino acids
A
- Excess amino acids produced from digesting proteins are transported to the liver
- Amino acid degradation produces sugars that can be converted to glucose or utilised in the Krebs Cycle
3
Q
Fed state
A
- Nutrients absorbed from meals will supply energy for ~ 4 hours.
- Nutrients are stored as glycogen and fat to give energy until the next meal
4
Q
Fasting state
A
Cells rely on energy that has been stored
5
Q
nutrient preferences for brain
A
Glucose (ketone bodies)
6
Q
nutrient preferences for skeletal muscle
A
Fatty acids, glucose, ketone bodies
7
Q
nutrient preferences for heart muscle
A
Fatty acids, lactate, ketone bodies
8
Q
nutrient preferences for RBCs
A
Glucose
9
Q
nutrient preferences for many cancers
A
Glucose (warburg effect)
10
Q
When you’re starving your cells can use…
A
- Ketone bodies
- Glucose made by the liver from amino acids and lactate
11
Q
When the brain lacks glucose…
A
- Headache
- Ringing in ears
- Sweatiness
- Trembling
- Blurry vision
- Increased HR
- Hunger
- Anxiety
- Weakness/fatigue
- Irritability
12
Q
organs with the most energy usage (kJ/day)
A
- Brain
- Skeletal muscle
- Liver
13
Q
organs with the most energy usage (kJ/kg wet weight/day)
A
- Heart
- Kidneys
- Brain
14
Q
How much ATP from nutrients?
A
- There is more energy available per gram of fatty acid than per gram of glucose (106 ATP vs 32 ATP)
- Aerobic metabolism of glucose produces much more energy than anaerobic metabolism (32 ATP vs 2 ATP)
- Fatty acids are not used to produce ATP in the absence of O2
15
Q
Starving: after 30 hours
A
- Brain starts using ketone bodies rather than glucose
- Other tissues stop using glucose
- Liver makes ketone bodies from fatty acids (which were oxidised to acetyl CoA)
- Liver and kidney make glucose from amino acids
16
Q
Ketoacidosis
A
High blood and urine concentrations of ketone bodies
17
Q
Starvation ketoacidosis
A
- Occurs when body has been deprived of glucose and relies on fatty acids
18
Q
Diabetic ketoacidosis (DKA)
A
- Life-threatening complication of uncontrolled diabetes
- Lack of insulin
