Chapter 17: Metabolism Flashcards
What is the average Kcal per Liter of O2 consumed ?
4.825
What is the equation for the mass balance of energy ?
energy stored + energy in - energy out
What does Ghrelin do ?
increases feelings of hunger
- produced in the stomach
What is your BMR ?
(basal metabolic rate) lowest amount of energy required to keep your body alive
What is your MR ?
(metabolic rate) total energy expenditure of the body regardless of the conditions
- BMR + any activity
What can influence your BMR ?
- age: the older you are=the lower your BMR, you can eat more at a younger age because you’re building functional tissue
- sex: more lean muscle mass=higher BMR, males have more testosterone and more lean muscle mass
- hormones: excessive hormones=higher BMR, if you have a condition where you have more of a hormone like hyperthyroidism then your BMR is higher
-What can influence your MR ?
- muscle activity: using more skeletal muscles= higher MR (skeletal muscle uses a lot of energy so your total energy expenditure rises)
- food/diet induced thermogenesis: more food processed by liver=higher MR (if you eat more than your digestive system uses more energy increasing the total energy expenditure)
What is the equation to calculate BMI ?
- weight (kg)/height^2 (m)
- weight (lb) x 703/ height^2 (in)
What is the BMI ratio for being overweight ?
BMI>25
What is the BMI ratio for being obese ?
BMI>30
What does direct calorimetry measure ?
heat production
What does indirect calorimetry measure ?
metabolism
What is the Fed-State describe ?
- absorptive state
- your GI tract is full and its absorbing the nutrients
- nutrients are being used or stored
- increased glucose concentrations
What does the Fasted-State describe ?
- post absorptive state
- nutrients are being pulled from storage and added to the pool
What is the LDL cholesterol carrier ?
Low Density Lipoproteins
- “bad cholesterol” that stays in your bloodstream longer
- <100 mg/dL is optimal
What is the HDL cholesterol carrier ?
High Density Lipoproteins
- “good cholesterol” that gets out of your bloodstream
- carries the cholesterol to the liver so it can dump it into the bile and to other glands that produce steriods
In what nutrient state is insulin released ?
fed/absorptive state
In what nutrient state is glucagon released ?
fasted/postabsorptive state
How does insulin respond to sympathetic system activity (activation and action) ?
activation: stress
action: inhibits release of insulin
How does insulin respond to parasympathetic system activity (activation and action) ?
activation: feedforward in response to eating
action: stimulates release of insulin
What is the homeostatic purpose of insulin ?
to prevent hyperglycemia
(>120 md/dL)
What is the homeostatic purpose of glucagon ?
to prevent hypoglycemia
(<60 mg/dL)
Are GLUT4 transports insulin dependent or independent ?
dependent
Are GLUT2 transports insulin dependent or independent ?
independent
What is the purpose of cortisol at normal and stress levels for your blood nutrient levels ?
normal levels: permissive hormone for glucagon function
- allows liver, and adipose tissue to function during the fasted-state
- maintains normal enzyme levels
stress levels:
- reduces sensitivity to insulin
What is the purpose of growth hormone at normal and stress levels for blood glucose nutrient levels ?
normal levels: protein production and growth
stress levels: anti-insulin effects
What is the purpose of glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP) for blood nutrient levels ?
stimulated to release when there is food in your duodenum which will cause your pancreas to start secreting insulin early
What happens in Diabetes Mellitus ?
- no insulin (GLUT4) or no functional insulin receptors
- glucosuria (glucose in urine)
- osmotic diuresis
- polydipsia
- polyphagia
What happens in Diabetes Insipidus ?
- lack of vasopressin or no functional vasopressin (ADH) receptors
- water diuresis
What is polydipsia ?
excessive thirst
What is polyphagia ?
excessive hunger
- you have no insulin to signal to your satiety center to know that you’re full
What is primary hypothermia ?
exposure to cold air to water
What is secondary hypothermia ?
improper functioning of thermo-regulating system
- problem with your body
What does the hypothalamus have to do with body temperature ?
regulates body temperature
What is endogenous pyrogen ?
(interleuken-1) induces fever by telling your hypothalamus to raise your thermal set point and helps maintain a high core temp
What is endogenous cryogen ?
prevents excessive fever and resets your thermal set point
What are the nutrient conversions that would release nutrients in the plasma ?
- gluconeogenesis
- glycogenolysis
- lipolysis
What is the glucostatic theory ?
explains the concentration of blood glucose in our bloodstream
- Less blood glucose will stimulate the feeding center and inhibit satiety
- More blood glucose will inhibit the feeding center and stimulate satiety
What is the lipostatic theory ?
how much adipose tissue we have and what our lipid stores are
What is type I diabetes ?
- can’t make insulin
- insulin-dependent
- usually genetic
What is type II diabetes ?
- can make insulin but doesn’t respond effectively
- usually get through diet
- insulin-independent
What are Kcalories (Kcal) ?
the amount of heat needed to raise the temperature of one kilogram of water by one degree Celsius
- I Kcal= 1,000 calories (c)
What is the equation for your metabolic rate ?
L O2 consumed/day x 4.825 Kcal/ L O2
What does Glycogenesis do ?
makes glycogen
- takes glucose out of the pool and puts it into the glycogen storage
What does Glycogenolysis do ?
breaks down glycogen
- takes glycogen from storage, splits it up, and puts it back into the glucose pool for body to use
What does Gluconeogenesis do ?
makes glucose
- takes a non-carbohydrate out of it’s pool and makes glucose by adding it back into the pool
Where is the only places you can do Gluconeogenesis ?
the liver and kidneys
Can you perform Gluconeogenesis anywhere ?
no
- only in the liver and kidneys
What does Lipogenesis do ?
makes lipids (fats)
- takes free fatty acids out of the pool and puts it into the fat storage
What does Lipolysis do ?
breaks down fats
- takes the fats out of storage, splits it up, and puts it back into the free fatty acid pool
What are the Liver ketones for ?
our nervous system can’t use fats as a source of energy so the liver has to turn the fatty acids into ketones that the nervous system can use
Can all cells in the body use fats for energy ?
no, the NS can’t
- the brain for example can’t
What does Protein Synthesis do ?
makes proteins
- takes amino acids out of the pool and makes body proteins
What does -lysis imply ?
“breaking down”
- catabolism
- takes out of storage and makes available for use
What does -esis imply ?
“building up”
- anabolism
- takes out of the pool and puts into storage
What are the uses for Glucose ?
ATP production, synthesis of fats
What are the uses of Adipose tissue (fatty acids) ?
ATP production, synthesis of lipoproteins (LDL and HDL cholesterol carriers), and synthesis of steriods
What are the uses of amino acids ?
- mostly protein synthesis for structural, clotting factors, or enzymes
- hormones
- neurotransmitters
What are our 2 sources of cholesterol ?
- dietary cholesterol: aminal fats, saturated fats, and trans-fatty acids
- cholesterol synthesis: GI tract and liver
What is the issue of creating ketones for the nervous system to use ?
can cause ketosis and ketoacidosis
What GLUT transporter do we need for insulin to work ?
GLUT4
