Human Energy Flashcards
What is mechanical energy?
What is chemical energy?
What is heat energy?
Mechanical - Capacity to do metabolic work
Chemical - Storage form of energy
Heat energy - Product of metabolism
Equation for work is:
Equation for power is:
Work = force x distance
Power = work / time
1 kilogram = _______ pounds
1 inch = _______ centimeters
1 kg = 2.2 pounds
1 inch = 2.54 centimeters
What does direct calorimetry do?
It measures the heat production of the subject.
What does an indirect calorimetry do?
It measures the gas gas exchange (O2 and CO2) of subject which is directly related to what is being metabolized.
What are 5 ways energy is stored in our bodies?
- ATP (adenosine triphosphate)
- PCr (phosphocreatine) - Stored in muscle and converted to ATP when needed.
- Carbohydrate
- Fat
- Protein
- ATP and PCr are good for short bursts of energy.
- CHO, fat, and protein can be metabolized to ATP and PCr for energy but it takes more time.
Aerobic glycolysis is the oxidation of:
glycogen or glucose
Aerobic lipolysis is the oxidation of :
Fatty acids through beta oxidation.
Aerobic proteolysis (limited energy production) is the oxidation of :
Glucogenic or ketogenic amino acids.
Acidosis makes in difficult to get maximum oxygen and nutrients into the system which makes it more difficult to produce:
Energy from CHO and fats
Where are these found:
chylomicrons, VLDL, LDL, HDL, FFAs
Chylomicrons - Dietary, intestines
VLDL, LDL, HDL, Albumin (which only carries NEFAs) - Liver
What are nutrients that are necessary for human energy systems?
Water
B vitamins: Thiamin, niacin, pantothenic acid, riboflavin, perodoxin, Biotin, folate, B12
What are the minerals involved in the enzyme activation?
(Metaloenzymes)
Magnesium, manganese, copper, iron, phosphate.
Carnitine (involved in transport of NEFAs into mitochondrial membrane for beta oxidation.) Body makes by itself.
Coenzyme Q10 ETA intermediate
What is BMR
Basal Metabolic Rate-Done while fasting! Amount of energy used just to keep body going. Effected by weight, height, age, and gender.
Convert to REE (Resting metabolic expenditure???
Done over 24 hours.
What is TEF
Thermic Effect of Food. Energy it takes to digest and absorb food. Small amount but contributes to total energy expenditure. Varies from 5-10%.
What is EMR?
Exercise metabolic rate.
Total daily energy expenditure (TDEE) is a sum of what????
BEE (REE), TEE, and TDEE?????
Metabolism represents the sum total of _____, _____, & ______ changes that take place within the body.
Mechanical, chemical, & heat.
What is a quick way to estimate daily resting energy expenditure (REE) ?
1 calorie per kilogram of body weight per hour, burned.
Nicotine and caffeine increase metabolic rate by up to ?
10%
What energy sources are used during rest?
60% of energy from fat
40% energy from CHO
Small amount of energy from protein
What are the 3 types of muscle fiber?
Type 1 - Slow twitch. Slow oxidative (SO) property. Red fiber.
Type 2a - Fast twitch. Fast oxidative-glycolytic FOG) so they can do anaerobic. Red fiber.
Type 2b - Fast twitch. White fiber. Even more anaerobic glycolysis. (FG)
Ways to
Ergometer
Lactic acid energy system (OBLA onset of blood lactic acid)
Oxygen energy system (VO2 max)
At what VO2 max percentage do we start breaking down glycogen.
80%
What is a MET
Metabolic equivalent
The amount of oxygen consumed while sitting at rest and is equal to 3.5 ml O2 per kg body weight x min.
What is a kilocalorie?
The amount of heat needed to raise 1 kg of water 1 degree.
1 calorie is equal to _____.
4.2 kilojoules
To calculate TDEE, what is needed?
(AKA TEE)
TDEE-Total Daily Energy Expenditure
BEE-Basal Energy Expenditure
TEF-Thermal Effect of Food
TEE-Thermic Effect of Exercise
What is EER?
Estimated Energy Requirement
Defined as the dietary energy intake needed to maintain an adult healthy weight.
Key Factor: PAL (physical activity level) which is calculated by dividing the TDEE by the BEE.
(Table 3.7)
Harris Benedict Equation
What are the predominant energy systems in runners?
Anaerobic power- ATP and PCr 6-20 seconds.
Anaerobic endurance- Anaerobic glycolysis, lactic acid. 43-103 seconds
Aerobic power- Aerobic glycolysis 12-26 minutes.
Aerobic endurance- Lipolysis 125-360 minutes.
Explain aerobic energy sources during exercise.
Aerobic-
Muscle glycogen, blood glucose (CHO)
Muscle triglycerides, blood NEFAs (Fat)
Amino acids, minor source of energy (Protein)
How do you calculate your maximum heart rate?
220 - age = MHR
Reasons for fatigue during exercise:
Table 3.10
Branched chain amino acids-we use L form so D form would be product contamination. Not as good for body.
What are some nutritional strategies to delay fatigue when exercising?
Remember, training makes us use these nutrient more efficiently. Also, training makes more mitochondria make more energy using aerobic methods.
What is RQ and how is it calculated?
Volume of CO2 produced / Volume of O2 being consumed.
CHO-
Fat-
Protein-
How does the sympathetic nervous system affect hunger?
When activity increases - signals to stop eating
When activity decreases - signals to eat
Leptin is the protein hormone of the _____ cells. Increases with larger fat mass. Decreases with less fat mass. Works with peptide Y.
Gherlin is the hormone of the ______cells
Leptin-Fat cells
(When fat stores are high, leptin concentration is high)
(When fat stores are low, leptin levels are low)
How your brain knows you are full?
Gastric stretching causes vagal nerve to be stimulated. Satiety causes catabolic neuropeptides.
Circulating Nutrient Levels: Neurons detect changes in blood glucose. Amino acids and dietary fat promote satiety (tryptophan). Apolipoprotein on the chylomicrons signal satiety. Absence of these will signal hunger. Fat also delays stomach emptying so makes you feel fuller longer.
Gastrointestinal Hormones: Cholecystokinin (CCK)-released in intestines when fat is present and stimulates satiety.
GLP-1 (Glucagon like peptide)
Ghrelin in stomach
Enterostatin in intestinal tract
Peripheral hormone peptide
Endorphins-Natural body tranquilizer that prompts body to eat.
Serotonin- Neurotransmitter released after CHO intake. High levels of serotonin decrease desire to eat and induce calmness
What is Ghrelin?
Mainly produced by stomach and stimulates appetite.
What is high neuropeptide Y levels in the cerebrospinal fluid associated with?
High food intake and decreased activity.
What is the arcuate nucleus?
The arcuate nucleus (ARC) of the hypothalamus is particularly regarded as a critical platform that integrates circulating signals of hunger and satiety reflecting energy stores and nutrient availability.
What is corticotropin-releasing hormone?
CRH is released by the hypothalamus in response to stress.
Corticotrophin-releasing hormone causes release of adrenocorticotropic hormone from the pituitary gland. Adrenocorticotropic hormone in turn travels in the bloodstream to the adrenal glands, where it causes the secretion of the stress hormone cortisol.
Trauma
When stress hormones are released from adrenal glands, (cortisol corticosteroids) it promotes gluconeogenesis which raises blood sugar. Which substrates are usually used for gluconeogenesis?
Amino acids from muscle degradation
Hypermetabolism can be due to a stress like burns, infection, surgery, trauma, and renal failure (not mental stress like going to college). What are some of the complications that happen when hypertabolism occurs?
Hyperglycemia reduces wound healing and increases infection, ischemia (part of body not getting enough blood), sepsis, and death.
Trauma
Cortisol release in severe stress response will cause:
Increase rate of protein breakdown
Catabolism of muscle protein for gluconeogenesis.
Fat catabolism increases for glycerol (for gluconeogenesis) and fatty acids (for energy/beta oxidation for ATP/ketones) but body likes to use glucose.
*ER dietitians sometimes need to give insulin to help body return to homeostasis.
What are the hormones of stress and hypermetabolism?
Cortisol
glucagon
catecholamines
growth hormone
*Also insulin resistance is common. BMR, blood glucose, and free fatty acid levels are elevated. Ketone bodies do not increase as in fasting so protein stores are not conserved (Negative N balance)
What are cytokines
They are proteins that stimulate the immunes system and start inflammation.
What are cytokines TNF, IL 1 and IL 6 which are present along with catecholamines and glucagon in times of trauma/stress/fight or flight?
Tumor Necrosis Factor- Suppresses fat synthesis,
Interleukin 1- Proteolysis in skeletal muscle
Interleukin 2- Causes secretion of acute phase proteins (APP) like fibrinogen, clotting factors, & proteins that cause fever to fight against infection.
Fuel use during stress versus starvation:
Starvation: Adipose tissue provides glycerol and NEFAs to produce ketone bodies. Muscles can use fatty acids for fuel through beta oxidation. Liver makes ketone bodies for other tissues to spare glucose. Glycerol can be used for gluconeogenesis. Muscle can provide some amino acids for gluconeogenesis as well and produce urea> Body has time to excrete ammoniu
Fuel used-FATTY ACIDS
Trauma- Adipocytes breakdown NEFAs and glycerol goes to gluconeogenesis, fatty acids go to liver. Amino acids make acute phase protein, glycogenolysis, gluconeogenesis provide glucose for fuel. Lactate and alanine from muscle can be used for gluconeogenesis.
Fuel use is GLUCOSE
Where are acute phase proteins synthesized?
Liver
What are some of the acute phase proteins?
(their are positive and negative ones)
C-reactive protein
Alpha 1 acid glycoprotein
Heptoglobin
Mannose-binding protein
Fibrinogen
Alpha 1 antitrypsin
Complement components C3 and C4
Albumin
Name some positive acute phase proteins.
Positive:
C-reactive- inflammatory marker for atherosclerosis. Increases with smoking, obesity, coffee consumption, TG, diabetes and periodontal disease.
Serum amyloid-A: SAA1, SAA2, SAA4 markers for inflammation like CRP.
Mannan-Binding Lectin: important for innate immunity.
Fibrinogen: Blood coagulation factor to support platelet aggregation and formed at site of vessel injury.
Lactoferrin: Find with iron. Found in saliva
Ceruloplasmin
Ferritin: Storage form of iron
Name some negative acute phase proteins.
Albumin and Transferrin- Decrease during inflammation to starve bacteria. Transferrin binds with iron so reduce availability of iron to bacteria. (Low alubumin=protein deficiency but it’s involved in inflammatory response so can’t be used to show protein deficiency anymore)
Retinol- (RTP) retinol binding protein is important in growth and differentiation of tissues. Binds with prealbumin or transthyretin and is a carrier of thyroid hormones .
What is the Ebb and Flow state of hypermetabolism?
Ebb- Initial response to shock/injury (stabilize body, fluids, glucose, aminoacids, and electrolytes. Gi tract dysfunction because blood flow goes to other parts of body to maintain homeostasis.
Flow- Body stabilized, may still be in ICU. Reduction in catabolic hormones. Enteral or parenteral nutrition.
*During this state may correct hyperglycemia with insulin.
Fed starving soldiers steak and they died because of???
When starving, the urea cycle intermediates are depressed because it’s not working. Glutaminase which takes glutamine to glutamate removes 1 nitrogen then from glutamate to alpha-ketoglutarate, which removes another nitrogen, so nitrogen builds up. If that happens in kidney…excrete through urine. Liver has to get use to excreting nitrogen in the form of urea.
Die of ammonium (or ammonia) toxicity.
During starvation what happens to electrolyte balance?
Concentration drops.
When refeeding start with…
Simple CHOs, electrolytes, and fluid
