Thermodynamics and Energy balance Flashcards
Thermic Effect of Food TDEE%
15-30%
Thermic Effect of Feeding TDEE%
10%
Resting Metabolism TDEE%
60-75%
RMR is proportional to lean body mass and decreases approximately _____ kcal\min for each 1% increase in body fatness.
0.01 kcal/min
Adenosine triphosphate (ATP)
chemical compound that provides energy to drive muscle contraction, transmission of nerve impulses, and the vast majority of chemical reactions that facilitate human life.
TDEE (Total daily energy expenditure)
the estimated calorie needs per day, by age, sex, and physical activity level. The total number of calories a person needs each day varies depending on a number of factors, including the person’s age, sex, height, weight, and level of physical activity, thermic effect of feeding (TEF), resting metabolic rate (RMR), and non-exercise activity thermogenesis (NEAT).
The basic energy need of an average human being (TDEE) is approximately ______ calories per day, depending on age, sex, and physical activity, as well as other factors
2000 calories
metabolism
The ability to perform human movement requires a constant supply of energy and the process of generating kinetic energy from sources of potential energy
One Metabolic Equivalent (MET)
3.5 ml O2 / Kg/min
Light intensity activities <MET 3
sleeping, sitting down, slow walking, walking
moderate intensity activities MET 3-6
light effort biking, walking at 3 mph, light calisthenics,
vigorous intensity activities MET >6
jogging, high effort calisthenics, running, jump rope
During normal sleep patterns, metabolic rate __________ by around 15% and reaches a minimum in the morning in a standard circadian pattern, or REM sleep patterns
reduces
Thyroid hormones stimulate metabolism through ______________________ and rates of _____ breakdown
increased oxygen consumption, ATP breakdown
hyroid hormones stimulate both _________ and ________; although, when TH levels are __________ fat loss is __________
lipogenesis, lipolysis, elevated, enhanced
____________________ stimulate almost all aspects of carbohydrate metabolism, including increasing insulin-dependent entry of glucose into cells and glycogenolysis to break down glycogen for energy during exercise and recovery
thyroid hormones
_________________________ creates a condition characterised by increased resting energy expenditure, weight loss, reduced cholesterol levels, increased lipolysis and gluconeogenesis
hyperthyroidism
________________________, is characterised by reduced resting energy expenditure, weight gain, increased cholesterol levels, reduced lipolysis, and reduced gluconeogenesis
hypothyroidism
______________ is produced by the adrenal glands and is released in response to stress.
cortisol
The adrenal glands produce several hormones, including….
adrenaline, aldosterone and cortisol.
Cortisol is within a class of hormones called _________
glucocorticoids
Function of cortisol
works to quickly increase blood glucose levels and works against insulin to try and keep glucose levels elevated by stimulating gluconeogenesis.
Role of testosterone
lays a key role in carbohydrate, fat and protein metabolism.
has a major influence on body-fat composition and muscle mass in men
Testosterone deficiency is associated with an……
increased fat mass (central adiposity in particular), reduced insulin sensitivity and impaired glucose tolerance
_______________ helps control pathways involved in glycolysis, glycogen synthesis and lipid and cholesterol metabolism
testosterone
hormone produced by adipose cells that decreases appetite when released
leptin
role of leptin
ends a signal to the brain signaling that enough food has been consumed and appetite should be inhibited
ghrelin
hormone that is produced and released primarily by the stomach, with small amounts also released by the small intestine, pancreas, and brain
role of ghrelin
stimulates appetite, fat deposition and growth hormone release, leading to increased hunger and fat storage
CCK (Cholecystokinin)
hormone released in the gastrointestinal system and is responsible for stimulating the digestion of fat and protein
______ is secreted by cells of the upper small intestine
CCK
function of CCK
-released when amino acids or fatty acids enter into the stomach or beginning of the small intestines
-stimulates the gallbladder to contract and release stored bile into the intestine to help breakdown fat and protein.
NPY (Neuropeptide Y)
-neuropeptide hormone linked to the autonomic nervous system
-a specialized hormone produced in the hypothalamus
neuropeptide
small protein-like molecules used by neurons to communicate with each other
role of NPY
helps stimulate the sympathetic nervous system, which stimulates appetite and fat storage
hormone produced by the pancreas that is released when blood glucose levels are high, promoting the uptake of glucose for fuel or storage as glycogen
Insulin
Role of insulin
-helps keeps blood-sugar levels from getting too high
-increases glucose uptake in peripheral tissue (e.g., skeletal muscle) while also decreasing the production of glucose by the liver
Glucagon
hormone that is released when blood sugars decrease below a certain threshold
role of glucagon
stimulates the breakdown of stored glucose (glycogen) in the liver, releasing additional glucose into the bloodstream for fuel.
The human body can only store approximately ___ to _______ grams of ATP, which is only enough energy for a few seconds of high-intensity activity.
80 to 100 grams
ATP-PC stands for
adenosine triphosphate-phosphocreatine
ATP-PC pathway
uses the energy released from the breakdown of phosphocreatine (also called creatine phosphate) for an immediate source of energy and then uses the phosphate molecule to produce more ATP.
chemical compound stored in the muscles in limited supply.
Phosphocreatine (PC)
the quickest way to resynthesize ATP, but can only resynthesize ATP for very brief periods (5-15 seconds)
ATP-PC system
in the ATP-PC pathway, the synthesis of ATP comes from….
stored PC (phosphocreatine)
the enzyme that breaks down phosphocreatine (PC) into creatine and an inorganic phosphate (Pi).
Creatine kinase
PC stores are replenished after about ______________ of rest.
2 minutes
Glycolysis
The first step of carbohydrate metabolism, an anaerobic pathway, that breaks glucose or glycogen down to pyruvate.
The __________________ system provides energy for medium to high-intensity bursts of activity that last from 10 seconds to 2 minutes.
anaerobic glycolytic
If glucose is used in glycolysis, ____ ATP are created
2 ATP
if glycogen is used in glycolysis, _____ ATP are created
3 ATP
Anaerobic glycolysis involves the breakdown of glucose to ________ when limited amounts of oxygen are available.
lactate
1 glucose molecule = ____ ATP
36 ATP
end product of glycolysis
pyruvate
role of pyruvate
either transported and used to support further energy production in the Krebs cycle or converted into lactic acid (lactate + hydrogen ion).
If lactic acid becomes the end product, it is called _________________
anaerobic glycolysis
If pyruvate is used further in the Krebs cycle, it becomes part of ____________________ or ____________ respiration.
aerobic glycolysis, aerobic respiration
Lactate
an energy substrate that is used to support metabolism during high-intensity exercise
which system if most utilized?
aerobic
As the intensity increases, more __________________ are used than _____
carbohydrates, fat
During short duration, high-intensity exercise (100 m sprint), energy is provided by stored _____ and _____.
ATP and CP
As the distance or time of the exercise continues, _______________, or ________________________, becomes the dominant energy system.
aerobic respiration, or oxidative phosphorylation
respiratory exchange ratio (RER)
the ratio between the amount of carbon dioxide (CO2) produced in metabolism and oxygen (O2) used.
An RER is about _____ at rest, representing a mixed diet.
0.8
Calculation of RER is commonly measured during a ________ test.
VO2 max
An RER of 0.70 indicates that _____ is the predominant fuel source.
fat
An RER of _______ suggests a mix of fat and carbohydrates.
0.85
A value of 1.00 or above is indicative of ____________ being the predominant fuel source.
carbohydrates
beta-oxidation
When fat is broken down into free fatty acids and glycerol (lipolysis), the free fatty acids are transported into the mitochondria where the carbon atoms are used to produce acetyl-CoA
-does not directly produce ATP
one molecule of palmitic free fatty acid can produce _________ ATP
129 ATP
