Basal metabolic rate/ resting metabolic rate
absolute minimal amount of energy expenditure
What are the forms of energy expenditure?
a. ingestion of food b. nonshivering thermogenesis c. spontaneous unconscious physical activity d. occupational labor and purposeful exercise
1. referred to as diet induced thermogenesis
2. refers to energy expended to produce heat, either obligatory or facultative manner
4. labor and exercise; greatest need variations in caloric intake
1. ingestion of food 2. nonshivering thermogenesis (5-15%) 3. spontaneous unconscious physical activity (20-30%) 4. occupational labor and purposeful exercise
where cells derive energy to perform work: oxidation of glucose, fatty acids, amino acids and ketone bodies
On an average what happens when ATP is oxidized?
All fuel comes from the diet
What are the four metabolic phases?
1. digestive or absorptive phase 2. interdigestive or postabsorptive 3. fasting 4. strenuous exercise
Where does the brain get its energy?
- it cannot obtain energy from FFAs - AA pool --> NT - depends on blood glucose
- impaired blood glucose, vision, cognition, muscle coordination, lethargy, weakness - severe forms may lead to death and weakness
What is major role of hormones in metabolic homeostasis?
maintain blood glucose levels above 60 mg/ 100 mL
Diabetes mellitus incompatible with life
Too much blood glucose leads to..
stresses on cell functions, increase in morbidity and shortens life
Which organs use ketone bodies and nondietary fuel?
What are the 3 ways that ATP is generated/ oxidation from what?
3 main phases involves in oxidizing gluose to full extent:
1. transport and trapping 2. glycolysis 3. tricarboxylic acid (TCA) cycle and oxidative phosphorylation
In the first phase of (before) glycolysis involves...
1. GLUTS: bidirectional facilitative glucose transporters 2. glucose-6- phosphate (G6P)-- facilitated by hexokinase
Where is hexokinase expressed? and is designated glucokinase
- 2 mol of ATP/mol of glucose (yield) - needs NAD+ --> NADH NADH ---> NAD+ (needs O2/ red. of pyruvate/ anaerobic glycolysis) - pyruvate is the main product in oxidative phosphorylation
The third process of carbs --> ATP include:
2. acetyl coA
3. TCA cycle
3. oxidative phosphorylation via. electron transport chain
-20x more ATP than glycolysis - mitochondria may also rely on anae glycolysis - oxid phospho is also bad because it produces reactive oxygen species (ros)
What is the process of making ATP from free fatty acids?
2. Fatty acyl CoA
3. CPT-I/ CPT-II transporters
How are they metabolized?
--> repetitive, cyclic process of beta oxidation 4. acetyl coA 5. oxidized through the TCA cycle and oxidative phosphorylation
What does CPT- I and CPT- II stand for?
What does a cycle of ATP --> free fatty acid produce?
Which is more efficient (glucose or carbon)
1. acetyl coa 2. 1 molecule FADH2 and NADH 3. 17 ATP molecules via oxidation phosphorylation
What happens when AA --> ATP? Conversion involves the ff:
1. conversion to intermediates 2. pyruvate 3. acteyl coA 4. a- ketoglutarate 5. succinyl coA 6. fumarate 7. oxaloacetate 8. ammonia (use of AAs for energy must be coupled to urea cycle in liver)
What happens when ketone bodies --> ATP:
What are the 4 carbon molecules?
Where do they come from?
What enzyme is needed to to convert ace coa?
Can the liver use thio?
- acetoacetate - b- hydroxybutyrate
- synthesised from acetyl coa of the liver and exported into blood
What are the storage forms of energy?
1. glycogen 2. triglyceride 3. dietary triglyceride 4. low- density lipoprotein and cholesterol economy 5. high density lipoprotein and reverse cholesterol transport 6. catabolism of triglycerides in adipose cells 7. protein
What is the enzyme in glycogenesis?
- large polymer of glucose molecule - G6P --> glucose-1-phosphate
- glycogen synthase
glucose- 6- phosphate (G6Pase)-
primary enzyme in glycogenolysis
G6P converted to glucose
transports glucose out of the cell
What organs contribute to blood glucose levels?
1. liver (d) 2. intramyocellular glycolysis 3. muscle glycogen (id) --> lactate
muscle glycolysis generates lactate, which is converted back to glucose by liver