NSC 3361 - Chapter 9, BIOL 3370 - Lecture 10, BIOL 3370 - Lecture 9, BIO 3370 - lecture 8, BIOL 3370 - lecture 7
the hormone ghrelin is secreted from the stomach and pancreas when the stomach is empty; it can be thought of as a
hunger hormone
(internal cues trigger thirst steps-osmotic) 7. vasopressin release leads to ?
induces blood vessel constriction and so reduces blood flow to the bladder -- overall water conservation
Obese people are leptin-resistant Overnutrition _________ the hypothalamus - obesity, diabetes, and heart disease
inflames
2) POMC neurons produce pro-opiomelanocortin (POMC) and cocaine- and amphetamine-related transcript (CART): - _______ appetite and _______ metabolism = weight loss
inhibit raise
If you deviate from ______, compensatory action begins.
If you deviate from a SET POINT, your body tries to compensate and keep things balanced
Where in the brain would lesions cause overeating?
If you have lesions in the VENTROMEDIAL HYPOTHALAMUS, obesity may result. In an experiment, VMH lesioned rats overeat until they become obese. Stability and a new SET POINT is made at this heavier weight. Thus, even if you are a scientist and force-feed VMH lesioned rats, the rats, when the force feeding stops, will drop back down to the new set point, as opposed to the original, healthy set-point.
Lesions in the _____ impaired physiological responses but not __________-responses
POA BEHAVIORAL
What do POMC neurons do?
POMC/CART neurons produce pro-opiomelanocortin (POMC) and CART, which do two things for weight loss: INHIBIT appetite and RAISE metabolism
"The main fuel storage for type I muscle fibers is: a) glycogen b) ATP c) creatine d) triglyceride
The correct answer is d) triglyceride "
Oxidative Capacity and the Crossover Point
The crossover point is the exercise intensity where fat and carbohydrate utilization intersect
VO2max (maximal aerobic power)
The maximal rate at which O2 can be used by the body Most important measurement of physical function O2 is used almost exclusively for aerobic ATP production The crossover point: the exercise intensity where fat and carbohydrate utilization intersect
_______ helps to liberate glucose from storage. For long-term storage, energy is stored in ____ tissue.
glucagon adipose
energy is derived primarily from
glucose
"What is the MOST important influencer of BMR? a) age b) appetite c) thyroid hormones d) height
The correct answer is c) thyroid hormones"
True/False The Tensilon test involves placing an ice pack over the eye(s) to evaluate improvement in muscle strength
false
true or false When Jeff's blood glucose level is low, his body can convert amino acids and fatty acids into glucose
false
Defects in leptin production or receptor sensitivity give a ___ ___ ___ __- ____ ____, causing animals to overeat
falsely low report of body fat
Glycogen can then be converted into ____
fat - energy store
fat can be converted to __- ____
fatty acids (ready energy)
the body can make use of _____ or ______ for energy but it requires ____ to use glucose.
fatty acids or glucose insulin
The lateral hypothalamus is what center?
feeding (hunger)
Glycogenesis
formation of glycogen from glucose
_____ is secreted by endocrine cells of the stomach and signals for increase hunger
ghrelin
Before eating, what are the levels of ghrelin and leptin?
ghrelin is high before you eat leptin is low
After eating, what are the levels of ghrelin and leptin?
ghrelin levels are low leptin levels are high
Glycogen (energy source) can be converted back into glucose by _____?
glucagon
is the principal fuel for energy
glucose
brain uses only _____ for energy and does so without ____
glucose insulin
carbohydrates contribute too
glucose pool
is glucose stored for short term in the liver
glycogen
Glucose (ready energy) is converted to _______ for shorter-term energy. Process is promoted by ______.
glycogen insulin
Obesity:
having excessive amount of body fat
(internal cues trigger thirst steps-osmotic) 1. If solute concentration is to ______ then osmotic thirst occurs which is a rise in what?
high blood osmotic pressure
Anorexia nervosa has the ________mortality rate of any psychiatric disorder
highest 0.5% lifetime prevalence in women (.05% in men)
the maintenance of a stable, balanced, internal environment =
homeostasis
__________from the body drive a hypothalamic appetite controller, the ______ nucleus
hormones arcuate
High calorie diets cause ____ _____ and ____ ______ , and 15% reduction of proopiomelanocortin (POMC) neurons, which are normally activated by leptin to block eating and increase energy expenditure
hypothalamic scarring microglial activation
____________is the major control center for homeostasis:
hypothalamus
Ventromedial hypothalamus is what center?
satiety
(internal cues trigger thirst steps-hypovolemic) 4. The signaling of the preoptic area causes what?
signals to initiate drinking
ratio of different muscle types in athletes slow-twitch (type I) and fast-twitch (type II)
sprinters have more fast fibers (type II) than marathon runners. marathon runners have more slow-twitch (type I) than sprinters. However, exercise does not appear to greatly alter the proportion of the different muscle fiber types
1) NPY neurons produce neuropeptide Y (NPY) and agouti-related peptide (AgRP): -________ appetite and ______ metabolism = weight gain
stimulate lower
Circulating angiotensin II acts in the______ organ to signal other brain sites (POA) to initiate drinking
subfornical organ
GLP-1 and peptide YY (PYY) are secreted from the large and small intestines during and after eating. These hormones travel through the blood to the brain where they
suppress hunger
(internal cues trigger thirst steps-osmotic) 4. Signals from preoptic area go to the?
supraoptic nucleus, paraventricular nucleus
Acute bouts of moderate- to vigorous-intensity exercise
temporarily suppress appetite, likely by decreasing ghrelin and increasing GLP-1 and PYY released from the GI tract These hormonal changes are most pronounced with aerobic exercise and are not observed after resistance exercise training.
Lactate threshold is
that point at which blood lactate production begins to exceed the body's ability to clear lactate, resulting in a rapid increase in blood lactate concentration during exerci se of increasing intensity. Generally, individuals with higher lactate thresholds, expressed as a percentage of their VO2max , are capable of better endurance performances.
The Cori Cycle
the cycle of lactate to glucose between the muscle and liver in the liver = Gluconeogenesis in the muscle = Glycolysis
Central Fatigue:
the lack of "driving" or weaker stimulation from CNS to the locomotor muscles Central fatigue can prevent overexertion and protect from damage or even death
Lactate threshold
the maximal effort or intensity that an athlete can maintain for an extended period of time with little or no increase in lactate in the blood.
Lipogenesis
the metabolic formation of fat
(discovery of Leptin - Parabiosis experiments) 3. what happened when the db/db and ob/ob rat were put together?
the ob/ob rat starves due to the strong leptin signal from db/db rat.
True or false: fat can be converted into glucose
(false)
"(T/F) Enzymes raise the activation energy when they are used in a chemical reaction
ANS: False"
"T/F: To make phospho-creatine from creatine, creatine kinase use ADP.
Answer: False"
Ventromedial hypothalamus lesions
cause obesity
Ethnicity is a risk factor of fibromyalgia. True or False?
false
Lesions of ventromedial hypothalamus cause _____?
obesity
"What is the major contributor of energy during short-burst activities lasting up to two-minutes and during the early minutes of longer high-intensity exercise? Choose the best answer. A) ATP-PCr system B) Glycolytic system C) Oxidative system D) Both A and B E) Both B and C
(B should be the answer, given that the activity lasts up to two minutes, because ""A"" is only for the first 15 second, the rest 105 seconds are sustained mostly by ""B"" )"
"If Timmy, a normal adult male, just consumed a large filling meal. Which of the following hormones would be released to indicate to the brain to decrease his appetite? A. Ghrelin B. Leptin C. Peptide YY (PYY) D. Thyroxine
(The answer should be ""C"", body fat is the main source of Leptin, therefore Leptin level is usually stable if there is no significant weight change. Fat consumed in a meal can only be a tiny fraction of fat storage in the body)"
Hormones secreted throughout the peripheral tissues in the body, including the gastrointestinal tract and the pancreas, stimulate specific receptors in the hypothalamus to control glucose metabolism in the liver.
(a) Insulin released by the β-cells (beta-cells) in the pancreas acts through appetite-stimulating (NPY/AgRP) neurons in the arcuate nucleus of the hypothalamus. These neurons are stimulated by the peptide neurotransmitter neuropeptide Y (NPY) and release agouti-related peptide; insulin receptors are also present on these specialized neurons. ( b and c) The pre-opiomelanocortin (POMC) neurons are stimulated by both leptin and glucagon-like peptide 1 (GLP-1). Together these hormones act on neurons in the brain, signaling through the vagus nerve to the liver to decrease glucose production.
True or false: females and males have relatively the same BMR
(false)
True or false: You can increase your VO2 max through training
(true)
7. Describe the by-products of energy production from ATP-PCr, Glycolysis, and Oxidation.
- ATP-PCr by-products: Creatine, Pi and Free energy. Pi, free energy & ADP can be combined to form ATP. - Glycolysis by-products: From glucose - 2 molecules pyruvate, 2 moles NADH, net 2 ATP. From glycogen - 2 molecules pyruvate, 2 moles NADH, net 3 ATP. - Oxidation by-products: CHO oxidation yields H2O, CO2, 38 or 39 ATP molecules per CHO molecule
12. Discuss three mechanisms through which lactate can be used as an energy source.
- Can be taken up in mitochondria and directly oxidized - Lactate shuttle: transported to other cells for oxidization - Transported by blood to liver
Rate-limiting enzyme
- Create bottleneck (blockage), limits overall reaction rate - Usually at an early step - Usually is a point of allosteric feedback regulation
Glycolytic System (Glucose --> Pyruvate)
-Anaerobic (involves no oxygen), occurs in cytosol -Rate-limiting enzyme: PhosphoFructose Kinase-1 (PFK-1) Inhibited by: ATP, H+, citrate Activated by: • AMP: ADP + ADP --> ATP + AMP • Fructose 2,6-bisphosphate (Fru-2,6-BP): regulated by insulin and glucagon signaling, associate with high glucose levels
Characteristics of Successful Athletes in Aerobic Endurance Events
-High VO2max -High lactate threshold when expressed as a percentage of VO2max -High economy of effort, or a low O2 for a given absolute exercise intensity -High percentage of type I muscle fibers
Neural Transmission Fatigue - may occur at the neuromuscular junction, preventing nerve impulse transmission to the muscle fiber membrane.
-The release or synthesis of acetylcholine (ACh), the neurotransmitter that relays the nerve impulse from the motor nerve to the muscle membrane, might be reduced. -Cholinesterase, the enzyme that breaks down ACh once it has relayed the impulse, might become hyperactive, preventing sufficient concentration of ACh to initiate an action potential. -Cholinesterase activity might become hypoactive (inhibited), allowing ACh to accumulate excessively, inhibiting relaxation. -The muscle fiber membrane might develop a higher threshold for stimulation by motor neurons. -Some substance might compete with ACh for the receptors on the muscle membrane without activating the membrane. -Potassium might leave the intracellular space of the contracting muscle, decreasing the membrane potential to half of its resting value.
Basal metabolic rate (BMR): (4)
-energy required to fuel the brain/body and maintain temperature -75% of energy expenditure in average sedentary student •Of women on a diet, the 1/3 who failed to lose weight had low BMRs •Heredity accounts for 40% of a person's BMR. But, spontaneous activity can increase it
Treatment of Obesity (What Works For Sure) (3)
1) Eat less: A daily deficit of 500 to 1000 calories is reasonable. This is the most important part of therapy and most difficult to do. 2) Modify behavior to avoid temptation to pig out. This means lifestyle change. Self-monitoring and social support are essential. 3) Exercise. A lot: Strenuous aerobic activity for over 200 minutes per week maintained for a long time with calorie restriction works. Sad Fact: Moderate exercise like walking 45 minutes a day 5 days a week has minimal effect on weight loss. Exercise does raise your metabolic rate though. Some is better than none.
Hypovolemia causes release of:
1) Vasopressin (antidiuretic hormone) from the posterior pituitary, which induces blood vessel constriction and so reduces blood flow to the bladder 2) Renin from the kidneys
Angiotensin Cascade (4)
1) blood vessels constrict 2) circumventricular organs trigger drinking 3) vasopressin is released 4) aldosterone is released
sequence of events in DOMS
1. (structural damage to muscle fibers) 2. (membrane damage) 3. (calcium leaks out of sarcoplasmic reticulum) 4. (protease activation, results in the breakdown of cellular proteins ) 5. inflammatory response 6. edema and pain
Fatigue factors
1. ATP shortage (fuel depletion) 2. Metabolic by-products accumulation 3. Muscle structural damage / pain 4. Poor economy of effort
4.Describe the essential characteristics of the three energy systems:
1. ATP-PCr System.a. Anaerobic.b. Pi separated from PCr by creatine kinase (CK). Pi combines with ADP & forms ATP using energy from PCr breakdown.c. Main function - maintain ATP levels early in exercise. d. Energy yield = 1 mol ATP per 1 mol PCr. 2. Glycolytic System (glycolysis).a. Anaerobic.b. Glucose/glycogen broken down to pyruvic acid. Pyruvic acid converted to lactic acid when no O2 present.c. Energy yield = 1 mol glucose yields 2 mol ATP, 1 mol glycogen yields 3 mol ATP. 3. Oxidative System (oxidative phosphorylation)a. Aerobicb. Glycolysis, Krebs cycle, Electron Transport Chain (ETC)c. Yields H2O, CO2, 38 to 39 ATP per carb molecule.
Enzymes make life possible
1. Enable reactions at body temperature 2. Increase reaction speed by a factor as large as 10^19 3. Eliminate side reactions and products 4. Dynamic and precise control in reaction rate 5. Release energy at discrete steps 6. High energy efficiency (~38% efficiency) in ATP production
Three direct substrate pools:
1. FFA pool 2. Glucose pool 3. Amino acid pool
"Robert is a 6""0, 185 pound, 25 year old male. Lucy is a 6""0, 185 pound, 25 year old female. What is true statement regarding their BMR? A) Robert will have a higher BMR B) Lucy will have a higher BMR C) They will have the same BMR D) It is impossible to determine who will have a higher BMR
A- correct answer"
ATP-PCr System:
1. Functions as an energy buffer to absorb and release ATP in situtation. 2. Fast / Powerful 3. Anaerobic (involves no oxygen) 4. Low capacity (<5 kcal, 15 sec) In the PCr "shuttle" system (Figure 1), high-energy phosphate is transferred from the ATP formed by means of oxidative phosphorylation in the mitochondria (production site) to Cr, via action of the CKmit, thus generating PCr and ADP. PCr diffuses into the cytoplasm, where under the action of cytosolic isoforms of CK, it generates ATP and Cr. ATP is then used by the ATPases (locations of use), while Cr returns to the interior of the mitochondria. This more easily crosses the mitochondrial membrane than the nucleotides of adenine, besides being present at higher levels in the intracellular medium. By means of this "shuttle" system, PCr performs another important function: it participates in the transfer of high-energy phosphate, present in ATP, from mitochondria to cytosol. CK = creatinine kinase cr = free creatine
Thyroid Hormone Regulates Basal Metabolic Rate in most cells As lipids, thyroid hormones enter the cell by simple diffusion across the plasma membrane
1. Genomic actions: TH nuclear receptors are transcription factors that control genes' expression level 2. Nongenomic actions: regulating activities of channels, metabolic enzymes, signaling pathways
Physiological Causes of Central Fatigue include:
1. Group III/IV muscle afferent neurons exert inhibitory influences on central motor "drive" during exercise. 2. Neural transmission fatigue
sequence of events in DOMS
1. High tension in the contractile-elastic system of muscle results in structural damage to the muscle and its cell membrane. This is also accompanied by excessive strain of the connective tissue. 2. The cell membrane damage disturbs calcium homeostasis in the injured fiber inhibiting cellular respiration. The resulting high calcium concentrations activate enzymes that degrade the Z-lines. 3. Within a few hours there is a significant elevation in circulating neutrophils that participate in the inflammatory response. 4. The products of macrophage activity and intracellular contents (such as histamine, kinins, and K + ) accumulate outside the cells. These substances then stimulate the free nerve endings in the muscle. This process appears to be accentuated in eccentric exercise, in which large forces are distributed over relatively small cross-sectional areas of the muscle. 5. Fluid and electrolytes shift into the area, creating edema, which causes tissue swelling and activates pain receptors. Muscle spasms may also be present.
ACCUMULATION OF METABOLIC BY-PRODUCTS
1. Hydrogen ions: • Primary cause of fatigue and muscle soreness. • Glycolysis is the main source of H+ • Affect enzyme activity, e.g. Ca2+ release from SR, crossbridge cycle, decrease myofibril's sensitivity to calcium • Intake of bicarbonate drink delay fatigue 2. Inorganic phosphate: • Accumulates due to ATP hydrolysis • Lower myosin ATPase activity • Precipitate Ca2+ 3. Heat: • Affect enzyme activity • Blood redirect to periphery to cool • Dehydration
What would weight gain do to leptin levels?
1. Increase leptin levels, food intake will go down, and use more energy.
When you are full after eating food, do you have high or low ghrelin and leptin levels?
1. Low Ghrelin levels, high Leptin levels
1. Which of your organs helps resolve osmotic thirst?
1. OVLT
What are the 2 systems involved in thermoregulation?
1. Preoptic Area: A part of the hypothalamus where lesions result in impaired physiological response, but not behavioral response. Physiological responses include sweating, constriction/dilation of blood vessels, and respiration 2. Lateral Hypothalamus: Lesions here result in the loss of behavioral regulation of temperature.Behavioral responses include shivering and heat-seeking/avoiding behaviors.
The importance of the Cori Cycle
1. Prevent lactic acidosis 2. Recycle NAD+ 3. Recycle lactate to liver for gluconeogenesis 4. Keep glycolysis going at a high rate
What is one drawback of the Body Mass Index?
A. BMI does not take into account percent body fat into its calculations. This means that people who are very muscular with very little percent body fat can register as obese on the BMI scale."
Physiological Central Fatigue: 2. Neural transmission fatigue
1. Synthesis or release of Ach 2. Ach break down become • hyperactive - reduced contraction • hypoactive - interfere with relaxation 3. Neurons or muscles can be depolarized or hyperpolarized, e.g. due to loss of intracellular K+ Neural Transmission Fatigue may occur at the neuromuscular junction, preventing nerve impulse transmission to the muscle fiber membrane. This failure may involve one or more of the following processes: · The release or synthesis of acetylcholine (ACh), the neurotransmitter that relays the nerve impulse from the motor nerve to the muscle membrane, might be reduced. · Cholinesterase, the enzyme that breaks down ACh once it has relayed the impulse, might become hyperactive, preventing sufficient concentration of ACh to initiate an action potential. · Cholinesterase activity might become hypoactive (inhibited), allowing ACh to accumulate excessively, inhibiting relaxation. · The muscle fiber membrane might develop a higher threshold for stimulation by motor neurons. · Some substance might compete with ACh for the receptors on the muscle membrane without activating the membrane. · Potassium might leave the intracellular space of the contracting muscle, decreasing the membrane potential to half of its resting value.
Factors control the rate of energy production
1. concentration of substrate 2. concentration of enzyme and activity levels 3. concentration of substrate vs. concentration of product
Prader-Willi usually caused by deletion of a part of chromosome ____. Defects in the hypothalamus.
15
Regulation of food intake Central control: Hypothalamus
1st order neurons: in the arcuate nucleus "satiety center" appetite-suppressing (POMC expressing neurons) "feeding center" appetite-stimulating (NYP/AgRP expressing neurons) 2nd order neurons: in paraventricular nucleus (PVN) MC3/4R neurons: stimulated by αMSH from POMC -neurons --> anorexigenic reactions and increased energy expenditure Y1/Y5R neurons: stimulated by AgRP --> orexigenic and decreased energy expenditure alphaMSH
Eating Disorders Occur with Other Psychiatric Conditions: Women with Anorexia or Bulimia __% Childhood anxiety disorders __% Obsessive compulsive disorder __% Abuse alcohol or drugs __% Depression Of 246 Women with an Eating Disorder: __% Attempted suicide _% Died
40% 20% 30% 90% 30% 5%
"A new disease wipes out the majority of white fat cells in a person. Which of the following is most likely to occur in the body as a result of this disease? A) There would be significant decrease of stored fat for metabolism B) There would be a significant decrease in heat taken from food C) There would be no change in the body's resting metabolism due to glucose and protein stores D) The ability to uncouple the electron transport chain would be lost
A is the correct answer"
Which of the following is NOT a symptom of FMS? A. Tissue damage B. Cognitive difficulties C. Chronic widespread pain D. Fatigue
A. tissue damage
"Q: What is the importance of pyruvate being removed during muscle energy metabolism? ."
A: Because accumulation of pyruvate can cause acidosis/ muscle soreness and the slow down of glycolysis
Why are there three different kinds of lipase to cut the tails off of triglycerides during triglyceride metabolism?
A: Each individual enzyme looks for a certain configuration of the triglyceride in order to be able to carry out its reaction"
"Q: Explain how a person with a strong urge to eat can distinguish between if they are feeling an increase in hunger or appetite?
A: Hunger is a biological drive, so if this person has not eaten recently or and/or enough, Hunger is the cause of this drive. If this person has eaten a good amount recently, they may explore the psychosocial drive, also known as appetite."
"Q: You have been asked to classify an enzyme based on its function. What is one of the first things you should physically look at?
A: The tertiary structure
Timothy has always been a stellar sprinter and a poor endurance runner, whereas Cameron has excelled at marathons for his entire running career and has never been exemplary at sprinting. Would timothy likely be able to meet or even surpass Cameron if they both put in the exact same amount of training and effort in order to prepare for a marathon? Why?
A: Timothy would likely be able to improve a great deal at marathon running, but it is probable that Cameron would likely remain far better at it than Timothy. This is due to their genetic makeup of the MHC genes causing a drastically different distribution of type 1 muscle fiber and type 2 muscle fibers. Timothy likely has a far larger amount of type 2 fibers compared to Cameron, who likely has a larger number of type 1."
Q: Explain how heat as a by-product can lead to fatigue in an athlete?
A:Heat denatures enzymes, causes dehydration, and even blood redirection to peripheral areas of the body. These factors lead to fatigue.
"Which of the following statements about muscle fatigue is true a) muscle fatigue is caused by a increase in H+ ions and decrease in pH b) muscle fatigue is caused by a decrease in H+ ions and decrease in pH c) muscle fatigue is caused by a increase in H+ ions and increase in pH d) muscle fatigue is caused by a decrease in H+ ions and increase in pH
A; muscle fatigue caused by increase in H+ ions. Increase in H+ ions results in low pH in a muscle cell"
What is anorexia nervosa? What are some symptoms?
ANOREXIA NERVOSA is the refusal to maintain body weight, coupled with fear of weight gain, body image disturbance, amenorrhea, etc. It can be a restricting or a binge-eating/purging type. It is 10x more common in woman than in men
"What will happen in Glycolysis if there is a high concentration of Citrate from the Krebs cycle? A) Activity of PFK-1 will be inhibited and glycolysis will be slowed down B) Activity of PFK-1 will be enhanced and more ATP will be produced C) Activity of PFK-1 will be inhibited and glycolysis will occur at a faster rate D) Activity of PFK-1 will be enhanced and more ATP will be produced
ANS: A "
"If we compare the world's best marathon runner to the world's best sprinter, how will their ratios of fast to slow fibers differ? A) The marathon runner will have equal amounts of fast and slow fibers, while the sprinter will have more fast fibers and less slow fibers B) The marathon runner will have less fast fibers and more slow fibers, while the sprinter will have more fast fibers and less slow fibers. C) Both will have the same amount of fast and slow fibers, but will be altered by the type of exercise performed The marathon runner will have more fast fibers and less slow fibers, while the sprinter will have less fast fibers and more slow fibers.
ANS: B "
"Which activity below is fueled primarily by the anaerobic energy system? a. walking for 30 minutes. b. jogging for 50 minutes. c. taking part in an 400 m race. d. playing football.
ANS: C"
"Which of the following would explain best how a brown fat cell has the ability to undergo non-shivering thermogenesis? A. The large area inside of the cell as fat storage B. Dark brown color attracts more heat from UV radiation C. Uncoupling protein 1 uncouples the production of ATP from the electron transport chain D. High number of mitochondria in the cell produces a small amount of ATP for heat transfer
ANS: C"
"Isocitrate dehydrogenase does the following: a. synthesizes succinyl CoA b. catalyzes the formation of isocitrate c. catalyzes the formation of alpha-ketoglutarate d. catalyzes the formation of oxaloacetate
ANS: C. "
"After digestion carbohydrates breakdown to glucose. Which of the following is FALSE? A. Glucose may then be synthesized to amino acids B. Excess glucose can be converted to glycogen C. Glucose is used for metabolic energy D. Free fatty acids can undergo lipogenesis to convert to glucose
ANS: D"
"All the following are functions of enzymes except: A) Enable reactions at body temperature B) Release energy at discrete steps C) Eliminate side reactions and products D) Increase reactions speed E) Increase the activation energy of chemical reactions
ANS: E "
"Predominantly type ___ fibers would be found in an Olympic weightlifter. They need to perform quick, short movements with high levels of force. This muscle fiber is also fatigue _____ and has a _____ contraction speed. A. I; susceptible; fast B. II; resistant; slow C. II; susceptible; slow D. I; resistant; fast E. None of the above
ANS: E (contraction speed is not accurately matched for either of the type II fibers)"
"What promotes anorexigenic reactions and increased energy expenditure? A) Y1/Y5R neurons B) MC3/4R neurons C) Stimulation by AgRP D) Stimulation by alpha-MSH E) Both B and D
ANS: E"
"What hormone is secreted from adipose tissue? a. ghrelin b. leptin c. insulin d. Cholecystokinin e. None of the above
ANS: b"
"What BMI is considered overweight? a) 26 b) 19 c) 32 d) 36
ANSWER: A- 26"
"Which of these systems is aerobic? a) ATP-PCr system b) Oxidative system c) Glycolytic system d) Both A and C
ANSWER: B- Oxidative system "
"Which of the following are characteristics of enzymes? a) All enzymes possess active sites which participate in the biochemical reactions b) Enzymes are substrate-specific and reaction-specific c) Enzymes are catalyst, they accelerate reactions d) All of the above
ANSWER: D- All of the above "
True or false: the crossover point is the exercise intensity where fat and carbohydrate utilization intersect
ANSWER: TRUE
"Which hormone is the biggest influencer of basal metabolic rate (BMR)? a) progesterone hormone b) thyroid hormone c) cortisol hormone d) insulin hormone
ANSWER: b"
"Which is usually NOT a physiological cause of central fatigue? a) group III/IV muscle afferent neurons exhibit inhibitory influences on central motor drive during exercise b) neural transmission fatigue c) depletion of ATP
ANSWER: c"
"Which of the following is true: a) enzymes enable reactions to happen at body temperature b) enzymes eliminate side reactions and products c) enzymes have high energy efficiency in ATP production d) all of the above
ANSWER: d "
"True or False: Accumulation of pyruvate will cause build-up of acidosis in muscle and speed up glycolysis.
ANSWER: false "
Muscle contraction consumes a lot of
ATP 1 ATP / 0.7-5 msec / power stroke ~300 myosin molecules /thick filament ~1500 thick filament /sarcomere
Overeating causes brain damage?!
Overeating --> hypothalamic inflammation --> inhibits neurogenesis, resets your set point
ATP-PC
ATP is the chemical form of energy that our body uses for all muscle contractions. There is sufficient ATP in the muscles for approximately 2-3 seconds of work; after this more ATP needs resynthesizing (rebuilding). In the ATP-PC system the energy required to resynthesize ATP is provided by phosphocreatine (PC). The simplest of the energy systems is the ATP- PCr system. In addition to storing a very small amount of adenosine triphosphate (ATP) directly, cells contain another high-energy phosphate molecule that stores energy called phosphocreatine, or PCr (sometimes called creatine phosphate). This simple pathway involves donation of a Pi from PCr to ADP to form ATP. Unlike what occurs with the limited freely available ATP in the cell, energy released by the breakdown of PCr is not directly used for cellular work. Instead, it regenerates ATP to maintain a relatively constant supply under resting conditions.
Allosteric inhibition Allosteric activation
Allosteric regulation, broadly speaking, is just any form of regulation where the regulatory molecule (an activator or inhibitor) binds to an enzyme someplace other than the active site. The place where the regulator binds is called the allosteric site. An allosteric inhibitor is a molecule that binds to the enzyme at an allosteric site. This site is not at the same location as the active site
What enzymes are & how they work
Almost all enzymes are proteins Like all proteins, enzyme's function depends on their tertiary structure All enzymes possess active sites which participate in the biochemical reactions Enzymes are substrate-specific and reaction-specific Enzymes are catalyst, they accelerate reactions (in either direction) As all proteins, enzyme structure is unstable, sensitive to environmental conditions, e.g. temperature, pH, ion concentration, chemicals
"In the situation of blood acidosis, what will happen to enzyme structures and the activation energy of the body's metabolism? a. Nothing changes b. Enzymes denature and metabolism activation energy remains normal c. Enzymes denature and metabolism activation energy increases d. Enzymes denature and metabolism activation energy decreases
Ans: C. enzymes catalyzes chemical reactions in the body by lowering the activation energy, an acidic level of pH in the blood would cause enzymes to denature as the enzymes are sensitive to the charge of the acids. "
"What endocrine gland secretes hormones responsible for heavily influencing the body's BMR? a. Adrenal Gland b. Parathyroid gland c. Anterior Pituitary gland d. Thyroid gland
Ans: D. thyroid gland secretes T3 and T4 which are important factors of BMR. "
"Fat can be converted to other substrates T/F
Ans: F"
1. VMH lesions destroy the ____
Anorexigenic Paraventricular Nucleus (PVN)
"If I could build the best marathon runner, what characteristics would I selected for? 1) High lactate threshold 2) Low lactate threshold 3) More type II fibers than type I 4) More type I fibers than type II 5) A high VO2max a) 1, 4, 5 b) 2, 3, 5 c) 1, 3, 5 d) 2, 4, 5
Ans: A "
"Select the correct statement. a) 10 total H+ and 2.5 ATPs are generated from one NADH molecule b) 6 total H+ and 1.5 ATPS are generated from one NADH molecule c) 10 total H+ and 1.5 ATPs are generated from one FADH2 molecule d) 6 total H+ and 2.5 ATPS are generated from one FADH2 molecule
Ans: A"
"Which one of these is a factor of muscle fatigue? Choose all that apply: a. Accumulation of metabolic by-products b. Decreased blood glucose levels c. Increased epinephrine secretions by the adrenal gland d. Shortage of ATP.
Ans: A, B, C. "
"Which of the following is correctly paired? a. Hunger; psychosocial drive to eat b. Appetite; biological drive to eat c. Satiation: Perception of fullness d. Satiety: Determines the duration of the meal
Ans: C"
"Which of the following is true regarding the ATP-Pcr system? a) This system is aerobic (requires energy) b) This reaction is non-reversible/permanent c) Purpose of the ATP- Pcr system is to increase our ready to use ATP reserve d) Has high capacity e) None of the above
Ans: C"
"_______is a hormone made in fat tissue that reduce food intake a) Epinephrine b) Ghrelin c) Leptin d) Insulin
Ans: C"
"At rest, fat and carbohydrates contribute to most of the energy in your body. T/F
Ans: T (Just want to clarify that at rest, fat plays a more prominent role in ATP production. The statement is not only true for rest, but for most other times as well, except when fat and carbs are out, such as during starvation)"
"Exercise can increase thyroid levels, decrease inflammation, and increase metabolism. T/F
Ans: T"
"How does blood lactate level correlate with sports performance? a. An increase in blood lactate levels decrease the ability for a muscle to contract b. Sports training decreases the lactate threshold c. Blood lactate levels do not correlate with sports performance d. None of the above
Ans: a "
"Which of the following is a rate-limiting enzyme? a. PFK-1 b. cAMP c. ATP d. Citrate
Answer is a."
"Combustion reactions tend to release a lot of energy in the form of heat. What can you infer about the nature of their reactants and products? a. There are more chemical bonds in the reactants than the products. b. The reactants release more energy than the products as their bonds are being broken. c. The products release more energy than the reactants as their bonds are being formed. d. There are more chemical bonds in the products than the reactants.
Answer is c."
"Which of the following stories would you share with your friends to show how big your appetite really is? a. After trying this new intermittent fasting trend and skipping breakfast, you can't wait until it's time to eat lunch! b. You make yourself a second sandwich because just one doesn't seem to fill you up. c. For your after-class snack, you remember to pack that apple you were craving last time. d. Your friends actually want to see you win a food-eating contest to prove how big your appetite really is, and you think they're onto you (HINT: it's not this one).
Answer is c."
"Which of the following is NOT the main fuel storage for Type II muscles? a. ATP b. Glycogen c. Creatine phosphate d. Triglycerides
Answer is d."
"Which of the following is true? A. High activity of Creatine kinase occurs in the mitochondria of liver cells B. Glycogneolysis only occurs in muscle cells C. Amino acids can be used to produce glucose D. A&B E. None of the above
Answer. C A. liver shouldn't need high levels of that enzyme for ATP, when they have their own glycogen stores and can make glucose B. can also occur in liver cells, because liver cells have their own glycogen C. Yes in the liver, through an alanine-pyruvate pathway from the muscle to the liver D. they are wrong
"True or False Most triglycerides are stored in the muscle.
Answer: False, the majority of fat is stored in adipose tissue (80,000+ kcal)"
"Why would a person not want to rely on protein for energy? a) Compared to the amount of energy that carbs provide, proteins provide less calories per gram b) Proteins are less efficient at generating energy and are very expensive to the cell c) Neither are true, athletes like bodybuilders consume protein shakes for energy
Answer: b) Proteins are less efficient at generating energy and are very expensive to the cell "
"A carbohydrate is broken down to CO2 and water. Does this process release energy if there are 27 bonds formed and 20 bonds broken? a. Yes, breaking bonds releases energy b. Yes, there are more bonds being formed than bonds broken c. No, there are more bonds broken than bonds formed d. No, the enthalpy for forming CO2 and water is higher than the enthalpy of any carbohydrate plus O2
Answer: ( the correct answer is D, B is inncorrect because the energy released or absorbed for breaking or forming different bonds is different, so the number of bonds and cannot be equated to the amount of energy released or absorbed. e.g. one can use 5 kJ to break one bond and form another 2 bonds that realease 2 KJ each, and at the end lose 1 KJ in the process. D is correct becaause we know anything that can burn always release energy during the process, therefore, the enthalpy is always lower in the products than in the reactants)"
"Connor has a sudden feeling of fatigue on mile 20 of his marathon. This is likely due to: (A) Transition to lipolysis from aerobic glycolysis (B) Transition to lipolysis from anaerobic glycolysis (C) Transition to aerobic glycolysis from anaerobic glycolysis (D) Transition to aerobic glycolysis form lipolysis
Answer: A "
"Which of the following is true about Thyroid hormones? A. Inhibition of Deiodinase-2 would lead to an increase concentration of T-4 B. Thyroid hormones can pass through the muscle cell through facitalited diffusion because they are lipids C. Low Thyroid hormones levels in the blood(hypothyroidism) cannot cause goiter(enlarged thyroid) D. A & C
Answer: A B is wrong because its simple diffusion, don't require channel to pass, its a lipid C is wrong because if there is low T3 and T4 in the blood, it will cause a simtualiton on the hypothalamus TRH instead of inhibition, and that will stimulate the pituitary gland then the thyroid gland. Constant low levels of T3 and T4 and abundant stimulation on the thyroid gland will cause it to enlarge(goiter)"
"Which of the following is FALSE A) Central fatigue does not help someone physically but holds someone back from achieving athletic success B) Muscle soreness can affect one's central drive C) An athlete who has never been injured may have a stronger central drive than an athlete who suffers from frequent injuries D) Central fatigue is both a physiological and psychological effect
Answer: A "
"A marathon runner uses ______ muscle fibers when they run, and they have a _____ contraction rate. A. Type 1, slow B. Type 2, slow C. Type 2, fast D. Type 1, fast
Answer: A"
"Which is true as to how carbohydrate is stored in the human body? A) Most of it is stored in the muscles. B) Most of it is circulating in the blood as plasma glucose. C) Most of it is stored in the liver. D) Glycogen concentration in muscle is about 2 times greater than in liver.
Answer: A"
"Which of the following is true about Neural transmission fatigue? A. Hypoactive activity of Ache will cause increased contraction B. Hyperactive breakdown of Ach will caused increased contraction C. Neurons become depolarized when intracellular K+ decreases. D. B&C
Answer: A"
" Which type of fat has the second largest storage site? A. Adipose tissue B. Serum triglycerides C. Muscle triglycerides D. Serum free fatty acids
Answer: C"
"Tony develops an appetite because of his hunger. He prepares a meal and begins to eat. As he is still eating he begins to feel full. Tony is experiencing: A. Satiation B. Satiety C. A and B D. none of the above
Answer: A" Satiation occurs during an eating episode and brings it to an end. Satiety starts after the end of eating and prevents further eating before the return of hunger
"What is true about muscle ATP generation in different fuels? A) Adipose tissue has the highest potential ATP yield B) Muscle ATP's duration time ranges from 5-20 minutes C) Liver glycolysis is an anaerobic process D) Muscle ATP is an aerobic process
Answer: A; As shown by the chart in lecture 9, it can make around 4,000,000 mmol of ATP, higher than any other fuel counterpart."
"If there is too much of a pyruvate buildup from the glycolytic system, it can: A) Cause acidosis in muscles B) Cause alkalosis in muscles C) Speed up glycolysis D) Fully inhibit glycolysis
Answer: A; Pyruvate generates H+ because it is an acid, and if there is a buildup of it, the blood pH will lower to lethal/near lethal levels."
"Rank the following from best economy of effort to worst. (I) A toddler running to an ice cream truck. (II) An elite marathoner running a 10k. (III) A new runner running their first 5k. (a) I, III, II (b) II, III, I (c) I, III, II (d) Cannot be determined. "
Answer: B
"How does neural transmission fatigue affect central fatigue? A) Ach breakdown will become hypoactive, and there will be increased relaxation B) Ach breakdown will become hypoactive, and there will be decreased relaxation C) Ach breakdown will become hyperactive, and there will be increased contraction D) Ach breakdown will become hyperactive, and there will be decreased relaxation
Answer: B "
"As physical activity intensity increases: a. Aerobic contribution increases b. Anaerobic contribution increases c. Aerobic and anaerobic will contribute equally
Answer: B As activity intensity increases, more energy will come from the anaerobic pathway. "
"In the glycolytic pathway, the breakdown of one molecule of glycose to pyruvic acid results in a net gain of _____ ATP. A) 2 B) 3 C) 6 D) 14
Answer: B (Is not A the correct answer?)"
" Whose economy of effort is best? A. A child playing in Little League B. A female Olympic gymnastic C. A male rookie swimmer D. An elderly man with no sporting experience
Answer: B"
"All of the following is true about an enzyme EXPECT: A. Most enzymes behave like proteins, what ever destroys a protein destroys an enzyme B. In an enzyme, its function does not relate to its structure C. Enzymes can speed up a reaction by lowering its activation energy D. An enzyme's structure is unstable, so it has a sensitivity to temperature
Answer: B"
"Lactate threshold is defined as the ________. A) minimal effort or intensity that an athlete can maintain for an extended period of time with little or no increase in lactate in the blood B) maximal effort or intensity that an athlete can maintain for an extended period of time with little or no increase in lactate in the blood C) maximal effort or intensity that an athlete can maintain for a short period of time with little or no increase in lactate in the blood D) minimal effort or intensity that an athlete can maintain for a short period of time with little or no increase in lactate in the blood
Answer: B"
"Matthew is a patient who suffers from Maple syrup urine disease. His body cannot break down certain amino acids by performing the chemical reactions necessary. What is likely the cause of Matthew's illness? A) A vitamin-D deficiency B) An enzymatic gene mutation C) A diet that contains too much glucose D) A lack of substrates for the necessary chemical reactions
Answer: B"
"Which brain structure connects the brain and spinal cord? A) Medulla B) Brain Stem C) Thalamus D) Hypothalamus
Answer: B"
"Which of the following is a correct pair: A) Satiety center, appetite stimulating B) Satiety center, POMC neurons C) Feeding center, appetite suppressing D) Feeding center: POMC neurons
Answer: B"
"Which of the following was observed in the Leptin gene knockout study of mice? A. The leptin knockout mice had decreased activity levels and were obese B. The leptin knockout mice had increased appetite and were obese C. The leptin knockout mice had decreased appetite and were a normal weight D. The leptin knockout mice had increased activity levels and were a normal weight
Answer: B"
"At the end of the electron transport chain, O2 gains an electron and reacts with the H+ in the mitochondrial matrix to form: A. CO2 B. OH C. H20 D. O2 does not gain an electron
Answer: C "
"Lactate dehydrogenase (LDH) is the enzyme that converts pyruvate to lactate at the end of glycolysis. Which of the following best describes the function of this enzyme: (A) LDH catalyzes the conversion of pyruvate to lactate. (B) LDH catalyzes the conversion of lactate to pyruvate. (C) LDH catalyzes both A and B depending on reaction conditions. (D) LDH catalyzes both A and B by increasing the activation energy.
Answer: C "
"Mechanoreceptors can be found in the: a. Pancreas b. Duodenum c. Stomach d. Small intestines
Answer: C "
"Which of the following organs absorbs lactic acid from the blood to form glucose to be used in the process of metabolism? A. Intestines B. Pancreas C. Liver D. Lungs
Answer: C "
"In the experiment with fentanyl, the experimental group overexerted themselves and their bodies suffered more traumatic stress than would normally have allowed by their bodies because fentanyl: a. Increased the subjects' central fatigue b. Made the subjects more sensitive to pain c. Attenuated Group III and IV muscle afferents in the subjects d. Decreased the subjects' central drive
Answer: C The experimental group was given fentanyl which dulls the feedback mechanism necessary for our protective mechanism to keep our body from overexerting itself. Group III/IV muscle afferents send muscle metabolic perturbation status to CNS and discourage central drive."
"Where is the hormone ghrelin produced? A) Pituitary gland B) Pineal gland C) Stomach D) Pancreas
Answer: C "
"How are proteins stored for energy usage by the body? A. by cytosolic granules B. by phospholipid droplets C. proteins are continuously used and do not have a storage compartment in the body D. by digestive tract
Answer: C "
"A runner is approaching the end of a marathon. Which of the following is TRUE about her energy metabolism? A) ATP from anaerobic glycolysis is increasing and ATP from aerobic catabolism of glucose is decreasing B) ATP from anaerobic glycolysis is increasing and ATP from aerobic catabolism of lipids is decreasing C) ATP from aerobic catabolism of glucose is decreasing and ATP from aerobic catabolism of lipids is increasing D) ATP from anaerobic glycolysis is increasing and ATP from aerobic catabolism of lipids is increasing
Answer: C"
"Is the body mass index (BMI) effective for measuring body fat? A. Yes, because it takes weight, height, and age into account which are the only factors that needed to determine body fat. B. Yes, because all human body compositions are similar enough that only height and weight are needed to calculate body fat. C. No, because it does not account for muscle mass, bone density, body composition, and other important factors for body fat. D. No, because the index needs to account for muscles to be truly accurate.
Answer: C"
"Martha loves to be active and often participates in intense exercise activities. What prevents her muscles from building up pyruvate and becoming acidotic? a. ATP-PCr System b. Glycolysis c. Cori Cycle d. Gluconeogenesis
Answer: C"
"What effect does moderate exercise have on thyroid hormone? A. Increases inflammation B. Decreases free T3 and T4 C. Increases free T3 and T4 D. Decreases metabolism
Answer: C"
"Which of the following is not an effect of thyroid hormones on skeletal muscles? A. Increased glucose uptake B. Increased mitochondria heat production C. Increased expression and production of the slow fibers D. None of the above
Answer: C"
"Which of the following permits an ideal environment for enzymes? A) High temperatures B) pH fluctuation C) Increased enzyme concentration D) Increased inhibitor presence
Answer: C"
"Which one of following systems/pathways does not have feedback regulation? A. Glycolytic system B. Krebs cycle C. Beta-oxidation of fatty acids D. None of the above
Answer: C"
"Why is the rate limiting step in an enzymatic reaction an ideal target for allosteric regulation? a) Rate limiting step is usually early in the reaction, so control over the earlier step will give the regulation more control over the entire reaction b) The rate limiting step usually occurs early in the reaction, and allosteric regulators usually degrade before the end of the entire reaction c) The rate limiting reaction determines the rate of the entire reaction, so control of this step gives the most control of the entire reaction
Answer: C"
"Which enzyme participates both in the Krebs cycle and the electron transport chain? A. Phosphofructokinase-1 B. Isocitrate dehydrogenase C. Succinate dehydrogenase D. Succinyl CoA Synthetase "
Answer: C. Succinate dehydrogenase
"Which of the following outside factors has an inhibiting effect on the hypothalamus? A. Cold B. Circadian rhythm C. moderate exercise D. stress
Answer: D "
"Which fuel source involves maximal rate of ATP production in the muscle? A) Aerobic sources B) Adipose tissue C) Muscle ATP D) Phosphocreatine
Answer: D "
"Choose the answer listing the percent of metabolic rate expenditure in the body from least to greatest: 1) Muscles 2) Liver 3) Brain 4)Digestion a) 4, 3, 1, 2 b) 3, 1,4 ,2 c) 1,3,2,4 d) 4, 3, 2, 1
Answer: D"
"In Delayed-Onset Muscle Soreness (DOMS), what is the first event that happens to the muscle after strenuous exercise? A. Calcium leaks out of the sarcoplasmic reticulum B. An inflammatory response C. Membrane damage D. Structural damage to muscle fibers
Answer: D"
"Marathon runners are able to run longer distances that sprinters. This could be due to: a. Marathon runners could have a greater composition of type I fibers, which are less fatiguable, allowing for more endurance b. Sprinters could have a greater composition of type II fibers, allowing for faster contraction to provide for greater speeds c. There is no difference between marathon runners and sprinters d. a and b
Answer: D"
"The _______ surrounds bundles of muscle fibers A) Myofibril B) Endomysium C) Epimysium D) Perimysium
Answer: D"
"Which of the following is true? A. Appetite is the biological drive to eat B. Hunger is the psychosocial drive to eat C. Satiation is the psychosocial drive to eat D. Satiety is the state of being fed or gratified
Answer: D"
"Which of the following pairs is matched correctly between storage site and approximate energy (respectively)? a) Muscle Glycogen: 400 kcal b) Blood Glucose: 1,500 kcal c) Liver glycogen: 80 kcal d) Muscle Glycogen 1,500 kcal e) None of the above
Answer: D"
"Which of the following products would be affected by the inhibition of isocitrate dehydrogenase (IDH) A) Isocitrate B) Citrate C) Acetyl Co-A D) Alpha-Ketoglutarate
Answer: D"
"Which of these is FALSE about leptin? A) It is made by adipose tissue B) It sends a satiety signal to POMC C) Alongside insulin, it contributes to long-term satiety D) It sends a feeding signal to POMC
Answer: D; Leptin, along with insulin, send satiety signals to the arcuate nucleus (POMC), and are forms of hormone feedback."
"All of the following are causes of fatigue EXCEPT____? A) ATP shortage (fuel depletion) B) Metabolic by-products accumulation C) Muscle structural damage/pain D) Poor economy of effort E) All are causes of fatigue
Answer: E"
"Which of the following aspects of a reaction would be the same with or without an enzyme? A. Reaction rate B. The amount of side reactions and products C. Activation energy D. The way how energy is released E. None of the above
Answer: E. For D, the amount of overall energy change would be the same with or without an enzyme. However, an enzyme can release energy at discrete steps. "
"T/F: Suppose a reaction breaks more bonds than it forms. There will be a net decrease in energy.
Answer: False Each bond break/form carries its own energy value."
"T/F: Short term satiety/feeding signals are controlled only by hormone feedback.
Answer: False Nervous feedback by mechanoreceptors and chemoreceptors from the organs through the vagus nerve (CN-X) to the NTS are short term signals, and hormone feedback (ghrelin, leptin, insulin, etc.) are long-term effects"
"Central fatigue doesn't protect body from damage from overexertion. In fact, central fatigue stimulates body to overexert itself.
Answer: False (Central fatigue prevents overexertion.)"
"[T/F] As central drive increases, activity of the sympathetic nervous system also increases.
Answer: False"
"True or False: Fatty acids can be converted into glucose through the process of lipogenesis.
Answer: False, glucose can be converted into fatty acids but fatty acids cannot convert into glucose molecules."
"True or False: Lactate threshold refers to the blood lactate level at which an athlete can maintain their maximal effort or intensity for an extended period of time with little or no increase in lactate in the blood.
Answer: False. Lactate threshold refers to the activity level/work, not blood lactate level. "
"John has a lactate threshold of 200W. Lacy has a lactate threshold of 275W. Who would be a better athlete in intensive sports?
Answer: Lacy A higher lactate threshold means they can do more work before increasing lactate levels in the blood."
"Beta-oxidation occurs in ____________ only. A. Cytosol B. Mitochondria C. Both D. None of these
Answer: Mitochondria"
_____ is a rate-limiting enzyme in glycolytic system, inhibited by ATP, H+ ion, citrate and activated by AMP, fructose 2,6-bisphosphate.
Answer: PhosphoFructose Kinase.
"Which of these is NOT fatigue factor. A. ATP shortage B. Less release of Ach C. Muscle damage D. Accumulation of metabolic by-products
Answer: Production and release of Ach leads to neural transmission fatigue. Therefore, answer is B."
Jane and Jill has about the same amount of body fat. Jane is less stressed compared to Jill, therefore, based on stress factor Jane has more leptin compared to Jill.
Answer: True (Less stress equal more leptin and more stress equal less leptin.)
"T/F: Beta-oxidation of fatty acids has no feedback regulation.
Answer: True"
"True/False: Moderate exercise can influences the hypothalamus to cause the release of more TH from the thyroid, which can ultimately increase BMR.
Answer: True"
"As Ann endures a short period of high intensity exercise, which of the following two processes occur on the stores of ATP and phosphocreatine (PCr) during her exercise session? a. ATP and PCr supplies energy b. ATP and PCr stores decrease c. ATP decrease, PCr increase d. PCr breakdown for resynthesis of ATP
Answer: a. and d. "
"Joe is in a critical situation where he's been experiencing long term starvation. It is expected that Joe's body will start to use _____ as fuel to produce ATP. a. Carbohydrate b. Triglyceride c. Protein
Answer: c. Protein"
"As Shay undergoes an intense fasting, Ghrelin production ____. a. decreases b. remains the same c. increases d. cannot be determined
Answer: c. increases"
"What energy system is most predominant in 100 meter hurdles? a. Beta-oxidation b. Cori Cycle c. Krebs cycle d. Glycolysis
Answer: d) Glycolysis "
"This system acts by separating phosphate from an amino acid and donating the phosphate to ADP to maintain ATP. It acts quickly, but isn't sustainable since its ability to create energy only lasts for a few seconds. a) The oxidative system b) The glycolytic energy system c) The Beta-oxidative system d) The ATP-Phosphocreatine system e) None of the above "
Answer: d) The ATP-Phosphocreatine system
"The body utilizes _____________ oxygen when metabolizing carbohydrate compared to fat. a. much more b. somewhat more c. the same amount d. less
Answer: d. less"
"Which of the following is false about PFK-1? a. PFK-1 catalyzes the phosphorylation of fructose-6-phosphate to fructose 1,6-bisphosphate and is the key enzyme that sets the pace of glycolysis, the rate-limiting step of the pathway. b. PFK-1 is inhibited allosterically by ATP and citrate, but conversely activated by AMP. Super-regulator for PFK-1 is 2,6-bisphosphate, the most potent activator which overrides the ATP inhibition. c. PFK-1 is a sensor for the energy charge state of the cell. d. PFK-1 is also inhibited by high [H+], which is generated from the production of pyruvate and lactate. This inhibition stops the continuous production of lactate and consequent acidosis. e. None of the above are false.
Answer: e. None of the above are false. "
"True/False. Increased levels of phosphocreatine would be useless for an athlete such as a marathon runner.
Answer: false ( the statement is not true, in any sprots, phosphocreatine would be the fastest contributor until it runs out) "
"Which fuel source will primarily be used for someone who is participating in a 12 boxing round (each round lasting 3 minutes)? A. Adipose tissue B. Muscle ATP C. Glycolysis D. Liver glycogen
Answer: liver glycogen (C is the best answer, it would be better to say aerobic glycolysis in the last few rounds of boxing, and muscle glycogen would be the main fuel)"
"A patient is in the hospital and has been diagnosed with a heart attack. Blood tests were taken immedately after the incident. Which of the following enzymes might found in high levels in the patient's blood? A.Carnitine acyltransferase I B. PFK-1 C. Creatine Kinase D. B & C
Answer:C A common indicator of a heart attack is elevated levels of CK in the blood, due to rapid irregular strong contractions of the heart which leads to heart damage. A. deals with beta oxidation, way too slow a heart attack is very rapid B. glycolysis takes about 5-20 mins and the recovery to resting state is slow, most likely won't be in high levels in the blood with something as fast and strong as a heart attack C. The fastest and powerful process to generate energy and contractions with a very fast recovery to resting state to produce a heart attack"
Released by stomach endocrine cells - Appetite stimulant Rises during fasting; drops after eating =
Ghrelin
Economy of Effort =
As people become more skilled at performing an exercise, the energy demands during exercise at a given pace are reduced.
Interplay between energy systems
At rest / normal activities • Fat contributes 80-90% of the energy • Carbohydrates provide 5-18% During exercise: • ATP depletion quickly activates glycolysis • Glycolysis is fastest to fill the ATP deficit
2. What is the primary substrate used to provide energy at rest? During high-intensity exercise?
At rest, energy the body needs is derived almost equally from breakdown of carbohydrates & fats. During high-intensity exercise, more carbohydrate is used with less reliance on fat to generate ATP.
"In the Cori cycle, pyruvate is converted into lactate in the ____. Released into the blood and carried to the _____. a) liver;muscle b) muscle;liver c) kidney;liver d)muscle;kidney
B"
"A diet completely lacking fat would most likely effect which athlete the most A) 50m sprinter B) long distance runner C) competitive powerlifter D) A & C would both be effected equally
B- long distance runners tend to have more type 1 muscle fibers and type 1 muscle fiber's main fuel source is triglyceride "
"True or False: PhosphoFructose Kinase-1 (PFK-1) is directly activated by elevated ADP levels? a. True b. False
B. False. because ADP needs to be converted to AMP before it can feedback and activate PFK-1."
Which of the following are appropriate WPI and SS scores to diagnose someone with fibromyalgia? A. WPI: 1, SS: 3 B. WPI: 8, SS: 10 C. WPI: 7, SS: 4 D. WPI: 2, SS: 9
B. WPI: 8, SS: 10
What is bulimia? What are some symptoms?
BULIMIA is recurrent binge eating with recurrent inappropriate, compensatory behavior. It often goes on for at least 2x/week for 3 months. Symptoms include thinning of bones, brittle hair and nails, drop in body temperature, low blood pressure, slow breathing, etc.
Hypovolemic thirst _________-in blood vessels and heart detect the initial drop Brain activates thirst and salt craving Arteries constrict to raise BP
Baroreceptors
____ _____ is under homeostatic control and can be adjusted, so dietary changes will not always produce changes in weight.
Basal metabolism
Fats provide a large portion of the energy used during prolonged, less intense exercise.
Body stores of potential energy in the form of fat are substantially larger than the reserves of carbohydrate, in terms of both weight and energy availability. For the average middle-aged adult with more body fat (adipose tissue), the fat stores would be approximately twice as large, whereas the carbohydrate stores would be about the same. But fat is less readily available for cellular metabolism because it must first be reduced from its complex form, triglyceride, to its basic components, glycerol and free fatty acids (FFAs). Only FFAs are used to form ATP
boxing = marathon running = football = power lifting =
Boxing = with 3 min rounds this predominantly uses Lactic Acid System Marathon Running = endurance is the main focus therefore aerobic energy system is dominant Football = Depending on the position played. A goal keeper may use more Creatine phosphate system based on explosive movements. A mid-fielder may be more aerobic energy system with lactic acid system as a close second Power lifting = The competitive lifts are under 10 secs and very explosive, therefore it would be mostly creatine phosphate system
Q3) What is the optimal range of blood ketone levels when self-monitoring?A) 3.0-5.0 mmol/L B) >3mmol/L C) 1.0-3.0 mmol/L D)
C
"Which of the following statements about enzymes is false? a) enzymes are catalysts b) enzyme function depends on its tertiary structure c) enzymes are stable in environmental conditions d) enzymes make life possible
C: enzymes are unstable and affected by environmental conditions such as pH, temperature,etc"
Pyruvate must be removed Accumulation of pyruvate will -
Cause acidosis in muscle • Affect overall muscle activities Slow down glycolysis • Hight [H+] (low pH) inhibits PFK • Accumulation of pyruvate (product) push the reaction to reverse direction • Shortage of NAD+ will slow down glycolysis H+ concentration Hypoxia is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level.
"Which muscle fibers are best suited for sprinting? A) Fast fibers B) Slow fibers
Correct Answer: A"
"Which of the following answers are not likely a result from obesity? A) Heart disease and strokes B) Type 1 diabetes C) Infertility and irregular periods in women D) Sleep apnea, breathing repeatedly stops and starts during sleep
Correct Answer: B"
"Which of the following is false regarding the metabolism pathways? A) Protein breakdown leads to adding to the amino acid pool which can in turn be used for gluconeogenesis. B) Fatty acids from the body's fat stores can convert to glycogen through glycogenesis. C) Excess glucose is fed into fat stores via lipogenesis. D) Fatty acids and glucose contribute more to energy production than amino acids.
Correct Answer: B"
"What is the definition of central fatigue? A) The exercise intensity where fat and carbohydrate utilization intersect B) Difficulty in initiating or sustaining voluntary muscle activities, due to physical and/or mental weariness resulting from exertion C) the lack of "driving" or weaker stimulation from CNS to the locomotor muscles
Correct Answer: C "
"What are the basic substrates for energy production? A) Carbohydrates B) Fat (triglycerides) C) Proteins D) All of the above E) None of the above
Correct Answer: D"
"Which of these processes does NOT occur inside the mitochondria? A. Glycolysis B. Beta oxidation C. Krebs Cycle D. Oxidative phosphorylation
Correct answer is A"
"ATP hydrolysis is the main source of which fatigue causing measure? A. H+ production B. Inorganic phosphates C. Heat production D. All of the above
Correct answer is B"
"Which of these is the rate limiting enzyme of Glycolysis? A. Hexokinase B. Phosphoglycerate Kinase C. Phosphofructokinase D. Pyruvate Kinase
Correct answer is C"
"A patient has a mutant enzyme that converts T3 into T4. Which of the following outcomes should we expect? A. Increase in heat production B. Strong activation of the Pituitary gland C. Decrease in stress levels D. Less effective control of the basal metabolic rate
Correct answer is D"
"Anthony was found to have more type II fibers than type I fibers. Which activity would Anthony be best at? a) 100m dash b) swimming c) marathon d) cycling
Correct answer is a) 100m dash"
"What is the number one cause of fatigue? a) poor economy of effort b) metabolic by-products accumulation c) muscle structural damage/pain d) ATP shortage
Correct answer is d) ATP shortage "
"Not being able to produce neurotransmitters due to over training is an example of what ? a)cumulative fatigue b)normal fatigue c)central fatigue d)none of the above
Correct answer: c"
Which chronic condition could be caused due to a severe case of DKA? A. Pulmonary edema B. Cerebral edema C. Kidney damage D. All of the above
D
"Which of the following is a true statement: A) an excess of glucose is converted to fat stores by lipolysis B) the amino acid pool is the largest contributor to metabolism C) glycerol from the fatty acid pool is stored via lipogenesis D) glucose is stored via glycogenesis "
D is the correct answer
Lipogenesis occurs when ________. A) there is a shortage of fatty acids B) glucose levels drop slightly C) excess proteins are transported through the cell membrane D) cellular ATP and glucose levels are high
D) cellular ATP and glucose levels are high
Which of the following would happen if enzymes were no longer present to aid in the metabolic process? A. Reaction speeds would increase B. ATP would be used more efficiently C. Side reactions would be eliminated during metabolic pathways D. None of the above
D. is the correct answer"
What would weight loss do to leptin levels?
Decrease leptin levels, leads to hypothalamus signaling your body to increase food intake and use less energy.
T4 --> T3
Deiodinase-2 is expressed locally and regulates T3 concentration in each tissue.
What is meant by the crossover concept, and how does it change with endurance exercise training?
Describes the relative balance between carbohydrate (CHO) and fat metabolism during sustained exercise. At rest & during low to moderate intensity (up to 50% of max VO2) of exercise fats serve as the main substrate for generating ATP. During high-intensity exercise (>50% of VO2 max) shift to CHO as the predominant substrate for generating ATP. Crossover point is intensity where fat & carbohydrate utilization intersect.
What is fatigue?
Difficulty in initiating or sustaining voluntary muscle activities, due to physical and/or mental weariness resulting from exertion
Treatment of Obesity (What Might Work)
Don't eat at night: Mice on a diet that ate only during their normal active cycle lose weight, not those who ate during their rest time in daylight
Q1)Insulin plays an inhibitory role in which of these pathways? A) glycogenolysis B) glycogenesis C) gluconeogenesis D) glycolysis E) A & C
E
Bioenergetics Substrates -->
Energy (ATP)
3.What is the role of PCr in energy production, & what are its limitations? Describe the relationship between muscle ATP & PCr during sprint exercise.
Energy from PCr (catalyzed by creatine kinase) can be used to add a Pi molecule to ADP, forming ATP. When a small amount of ATP in cells is used up in intense exercise (being broken down in to ADP & Pi), the ADP increases & thus creatine kinase activity increases. PCr catabolized = more ATP formed.
Etiology of Obesity
Energy imbalance: energy intake > expenditure Genetic factors Behavioral factors
If absolutely necessary, what other form of energy will your brain be willing to use?
FAT- but only if your brain is starving and there is no other glucose left. Lipids and fat tissue are generally for longer-term storage of energy.
Fats (triglycerides) contribute too
FFA pool
Motivation is...
Factors that initiate, sustain, or direct behavior
"True or False. First order neurons are found in the paraventricular nucleus (PVN). While Second order neurons are found in the arcuate nucleus.
False 1st order: arcuate nucleus 2nd order: paraventricular nucleus"
"(T/F) Beta-oxidation is regulated by negative feedback.
False: Beta-oxidation is not regulated by negative feedback. It is regulated by a rate-limiting enzyme known as carnitine acyltransferase 1"
(T/F) Enzymes control the direction of the reaction.
False: Substrate concentration controls direction
1. What are some treatments for anorexia or bulimia?
For anorexia or bulimia, SEROTONIN is LOW. Treating this eating disorder as a mood disorder might be successful. Antidepressants and anti-schizophrenic drugs (like Olazapine) produces some benefit. Dopamine might be involved in some way as well.
A + B <--> C + D
Forward reaction rate = 𝑘1 [A][B] Reverse reaction rate = 𝑘2 [C][D] Over all reaction rate = 𝑘1 [A][B] - 𝑘2 [C][D]
What is Ghrelin?
GHRELIN is released by STOMACH endocrine cells. This is an appetite stimulant that RISES DURING FASTING and DROPS AFTER EATING.
What is the principal energy source, which is also used by your brain?
GLUCOSE. Your body even uses a process called glycogenesis to convert glucose to glycogen for storage
converting glucose to glycogen, using pancreas hormone insulin
Glycogenesis
Glycolysis glucose --> pyruvate
Glycolysis starts with glucose molecules breaking down. Each molecule produces 2 pyruvate and these are either used in the aerobic process or turn into lactate. It also generates 4 ATP (2 each at steps 7 and 10) but consumes 2 of these ATP (1 each at steps 1 and 3). The net is 2 ATP. It will generate 3 ATP if the process starts with glycogen (a long chain of glucose molecules) because then there is no ATP required at step 1. This is a complicated process to produce a small amount of energy, but it is very fast.
What drives physiological motivation?
Homeostatic systems
Gut-Brain Connection
Hormone feedback = Gut hormones: • Cholecystokinin (CCK) • Glucagon-like peptide (GLP)-1 • Peptide YY (PYY) • Ghrelin <-- empty stomach • Chemoreceptors: (small intestine & duodenum) - nutrient composition - satiety peptides - osmolality and pH Nervous feedback Vagus nerve (CN-X) • mechanoreceptors mouth and stomach
Cycles of food intake
Hunger: biological drive to eat Appetite: psychosocial drive to eat Satiation: perception of fullness • develops during a meal • determines the duration of the meal Satiety: state of being fed or gratified • after a meal • determines interval between meals Hyperphagia (polyphagia): abnormally increased appetite
High calorie diets cause __________ and ___________
Hypothalamic scarring and microglial activation
Regulation of Thyroid Hormones The thyroid gland is regulated by thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH). In addition to TRH/TSH regulation by TH feedback, there is central modulation by nutritional signals, such as leptin, as well as peptides regulating appetite
Hypothalamus = Controls of hormone secretions, body temperature, sleep, appetite, emotions, control of the pituitary gland, circadian rhythm, moderate exercise, stress The hypothalamus then releases TRH: Thyrotropin releasing hormone ---> the pituitary which releases TSH: Thyroid stimulating hormone --> thyroid gland which releases T4 - Thyroxine & T3 - triiodothyronine ---> peripheral tissues T4 ---> T3
Triggered by loss of water volume - concentration is not changed
Hypovolemic Thirst
__- _____ is stimulated by low extracellular/intravascular volume
Hypovolemic thirst
1. What is hypovolemic thirst?
Hypovolemic thirst is thirst stimulated by LOW OR LOSS OF EXTRACELLULAR/INTRAVASCULAR (WATER) VOLUME. Your outside cells have less water, and you get low blood pressure. Baroreceptors detect this drop. Arteries constrict to raise BP. NOTE: CONCENTRATION is not changed
(cori cycle)
Hypoxia or intensive exercise ---> Anaerobic metabolism in muscle --> Lactic acid production
Increased insulin levels lead to _______, whereas increased glucagon levels lead to _______
Increased insulin levels lead to more glycogen production and less glucose, whereas increased glucagon levels lead to more glucose production and less glycogen
Basal Metabolic Rate (BMR)
Indicates the amount of energy expended by an endothermic animal to maintain the basic vital processes, e.g. breathing, blood circulation, controlling body temperature, cell growth, brain and nerve function, and contraction of muscles. Expressed as rate of energy expenditure per unit time, e.g. kcal/day. BMR may be measured by gas analysis (CO2 , O2 ) through indirect calorimetry Proper measurement requires a strict set of criteria including: 1) being in a physically and psychologically undisturbed state, 2) in a thermally neutral environment 3) in the post-absorptive state (i.e., not actively digesting food) Estimation formula: P = (10m/1kg + 6.25/1cm - 5.0a/1year + s) kcal/day -S +5 for males and -161 for females -m is mass (kg), -h is height (cm), - a is age (years)
Overeating leads to hypothalamic inflammation, which
Inhibits neurogenesis, resets your set point
Izzy was obese and died of heart failure. How did he get up to 757 pounds?
Izzy might have had leptin deficiency or VMH lesion. We don't exactly know, but it is certain he had a high set point from weight gain that made it hard to diet.
6. What role does oxygen play in the process of aerobic metabolism?
Oxygen is used in the final step of cellular respiration as the final electron acceptor, & is used to create water, without it only glycolysis can occur.
Lesions in what part of your brain would cause refusal to eat?
LATERAL HYPOTHALAMUS. LH lesioned animals stop eating, and stabilize their weight at a new lower level because of a new, lower set point. Perhaps anorexics have a lower set point
___lesions destroy orexigenic LH
LH (lateral hypothalamus)
____ _____ animals stop eating, but resume and stabilize their weight at a new, lower level
LH-lesioned
8. What is lactic acid, & why is it important?
Lactic acid is converted from pyruvic acid in the absence of oxygen. Is used as an actual fuel source during exercise, can be taken up by mitochondria within same fiber & directly oxidized (occurs mostly in cells with high density of mitochondrial type I muscle fibers, cardiac muscle & liver cells. Or it can be transported elsewhere & used for energy by another muscle fiber. Using lactate as a metabolic fuel accounts for ~70-75% of lactate removal during exercise.
Teenage girls with anorexia have (larger/smaller) Insula and (larger/smaller) Orbitofrontal Cortex (OFC)
Larger, larger
What is Leptin?
Leptin is produced by adipocytes (fat cells) and is secreted into the bloodstream. A deficit in leptin production results in a false-low report of body fat, causing animals to overeat. Obese rats and people are leptin-resistant.
Fat (triglyceride) metabolism
Lipase (hormone sensitive) = a pancreatic enzyme that catalyzes the breakdown of fats to fatty acids and glycerol or other alcohols Glycolysis (5% energy) Carnitine acyltransferase I: (rate-limiting) • Inhibited by malonyl-CoA • Malonyl-CoA is the building block for fatty acid synthesis
(internal cues trigger thirst steps-hypovolemic) 1. If volume is low it triggers _____ thirst; which stimulates what two baroreceptors
hypovolemic Cardiac baroreceptors & kidney Baroreceptors
Exercise increases Thyroid hormone level
Moderate exercise ↑ free T3 and T4 ↓ inflammation ↑ metabolism Weekly (1-3 times) strength training: muscle sustain metabolism stretches that increase blood to thyroid gland Continuous low rate movement: e.g. daily walking Periodic high intensity training (up to 70% Max heart rate)
factors that initiate, sustain, or direct behavior
Motivation "to set in motion" Homeostatic systems drive physiological motivation
What is the main homeostatic mechanism?
NEGATIVE FEEDBACK Systems.
Leptin inhibits ____ neurons and stimulates _______ neurons
NPY POMC
11. Describe the possible causes of fatigue during exercise bouts lasting 15 - 30 s and those lasting 2 - 4 hours.
PCr depletion, ATP decreases, muscle glycogen depletion, possible lactic acid accumulation - Glycogen depletion, increased muscle temperature, and loss of water and electrolytes
What neurons respond to a rise in blood osmotic pressure? Where are they found?
OSMOSENSORY NEURONS, which are found in the anterior hypothalamus (OVLT). They respond to increased osmotic pressure by causing the posterior pituitary to release ADH/Vasopressin OVLT=Organum Vasculosum of the Lamina Terminalis
Another approach: treat obesity as an addiction
Obese people share several characteristics with addicts: •They have fewer dopamine D2 receptors and associated lower prefrontal lobe metabolism •Peptides that induce eating target dopamine neurons •Anti-addiction drugs are somewhat effective in weight loss
Leptin-hypothalamus interaction
Observation: Body weight and fat are maintained at a constant level over time in spite of daily fluctuations of food intake leptin goes from fat to brain Leptin: a hormone made in fat tissue that reduce food intake Sleep --> leptin↑ increase Stress --> leptin↓ decrease
The Krebs cycle
Occurs in mitochondria Rate-limiting enzyme: Isocitrate dehydrogenase (IDH) -Inhibited by products: NADH, alpha-ketoglutarate -Activated by availability of substrates: isocitrate, NAD+ or NADP+ Succinate dehydrogenase (SDH) = respiratory complex II the only enzyme that participates in both the Krebs cycle and the electron transport chain Main Products: --> - NADH, FADH2 - feed the electron transport chain. -CO2
β-Oxidation of fatty acid (beta-oxidation of fatty acid)
Occurs in mitochondria Fatty acids can only be metabolized aerobically in the mitochondria Has no feedback regulation
LH lesions destroy the ____
Orexigenic Lateral Hypothalamus (LH)
Distinct Properties of Type 1 & Type 2 Muscle Fibers Organization
Organization type I Motor unit: Small Recruitment order: First type II Motor unit: Large Recruitment order: Later
_____ _____ respond to increased osmotic pressure by causing the pituitary to release antidiuretic hormone
Osmosensory neurons
_____ _____ in anterior hypothalamus (OVLT) respond to rise in blood osmotic pressure organum vasculosum of the lamina terminalis = OVLT
Osmosensory neurons Their cell membranes shrink, opening mechanical-gated Na+ channels
______ ______is stimulated by high extracellular solute concentration
Osmotic thirst
1. What is osmotic thirst?
Osmotic thirst is thirst stimulated by HIGH EXTRACELLULAR SOLUTE CONCENTRATION. Water can leave the cell, but salt cannot. When water leaves the cell, the cell shrinks
What disorder do some obese people have with a problem with peripheral signals?
PRADER-WILLI SYNDROME is when people have abnormally elevated ghrelin levels. These people eat as if they were starving. Main question to ask over the phone to see if the caller's child has Prader-Willi- "Do you have a lock on the fridge?" People with Prader-Willi will eat as much as they can, even if it's rotten food. Imagine having this and trying to diet and maintain a healthy weight.
______ is secreted by endocrine cells of the stomach and signals for appetite suppressing
PYY3-36-
DELAYED-ONSET MUSCLE SORENESS (DOMS)
Pain-producing agents: (stimulating nociceptive nerves) • ATP, released during necrosis (the death of most or all of the cells in an organ or tissue due to disease, injury, or failure of the blood supply.) • H+ (low pH), often associated with inflammation •Edema associated with inflammation
Distinct Properties of Type 1 & Type 2 Muscle Fibers Performance
Performance type I Force produced: Low Contraction speed: Slow Fatigability: Resistant Tasks/Function: Enduring activity e.g. posture muscle Type II Force produced: High Contraction speed: Fast Fatigability: Susceptible Tasks/Function: Quick, short, precise moves e.g. phalangeal muscle
____ _____- "the thermostat of the brain" integrates information from cold and hot sensing neurons to regulate temperature.
Preoptic nucleus
How the "Central Drive" is generated
Psychological aspects (the mental and emotional state of a person) -World View & Beliefs -Values Motives Physiological aspects (functions of body) -afferent sensory feedback -central drive -skeletal muscle
ATP & the Cross-bridge Cycle Ready state = ATP binds myosin = ATPase hydrolyzes ATP to access energy= Myosin heads lift up, stretches forward and binds to a new attachment site = Release of the phosphate group = release of ADP
Ready state: 1. Myosin cross-bridge is tightly bound @ 45 degree to the actin filament. ATP binds myosin 2. - an allosteric phenomenon; induces a conformational change which changes its function. Results: myosin head is able to detach from the actin filament. W/out this binding, the myosin head remains attached to the actin filament (as is the case in muscle cramps when ATP is low). ATPase hydrolyzes ATP to access energy 3. This detachment from the actin filament causes another conformational change - it allows the ATPase to hydrolyze ATP. ADP & Pi remain bound to myosin (two substrate molecules in the pocket now). Myosin heads lift up, stretches forward and binds to a new attachment site 4. Myosin head moves to a 90 degree and binds to new actin molecule Release of the phosphate group = 5. The myosin head releases phosphate which initiates the power stroke, where it tilts back to 45 degree, pulling the thin filament toward the center of the sarcomere release of ADP 6. After the power stroke, the myosin head releases ADP and returns to the ready state. This process continues until the ends of the myosin filaments reach the z-discs or until calcium is pumped back into the sarcoplasmic reticulum
DSM-V Criteria: Eating Disorders Bulimia (3)
Recurrent binge eating Recurrent inappropriate compensatory behavior At least 2x/wk for 3 months
reduction oxidation phosphorylation
Reduction: gain electron Oxidation: loose electron Oxidative phosphorylation: is the process in which ADP is phosphorylated to form ATP using the energy released from electrons transferred from NADH/FADH 2 to O 2 by a series of electron carriers
DSM-V (Diagnostic and Statistical Manual of Mental Disorders) Criteria: Eating Disorders Anorexia Nervosa (5)
Refusal to maintain body weight Fear of weight gain Body image disturbance Amenorrhea (absence of menstruation) Restricting or Binge-Eating/Purging type
Which of your organs helps resolve hypovolemic thirst?
SUBFORNICAL ORGAN; Angiotensin II acts here to signal to other brain sites (such as the POA) to initiate drinking
force transmission
Sarcomere/myofibrils --> sarcolemma --> endomysium --> tendon --> bone
Experiments:
Subjects performed a 5 km cycling time trial • Control group: given nothing or placebo o Experimental group: given fentanyl ( (reduces)attenuates Group III / IV afferents) = Central drive higher than control Exp. group tolerated the metabolic disturbance and muscle fatigue beyond the control groups
Thyroid hormones
T4 - Thyroxine T3 - triiodothyronine (4x more potent) • Made in thyroid follicle cells • Target almost all cells
"If there is too much substrate, a) the reaction happens faster b) the reaction rate stops increasing c) the reaction stops d) the reaction rate is unaffected
The correct answer is b) the reaction rate stops increasing "
You are still trying to lose weight (summer is coming soon). Why do diets fail for most people?
The first week of the diet is probably decently successful. People reduce caloric intake drastically, and see they've lost a lot of weight, 6 pounds. Eating this same amount of food the second week, people see a much less drop in weight, maybe 2 pounds. This happens because your BASAL METABOLIC RATE (the energy required to fuel the brain/body and maintain temperature) falls to PREVENT losing weight. Your body is working against your diet because it is scared you will die! The better strategy, instead of cutting 1000 calories the first week, may be to cut 100 calories the first two weeks, and another 100 the next, and so on, so your body doesn't get used to it. Exercise is helpful, too (but not as essential as reduced intake)!
NPY/AgRP neurons produce neuropeptide Y and agouti-related peptide. What do these do?
They STIMULATE appetite and LOWER metabolism. Weight gain Leptin inhibits NPY neurons and stimulates POMC neurons
7. What is economy of effort? How is it measured? What is its relationship to sport performance?
This means using less energy during activity and therefore being able to exercise for longer periods of time
Most important influencer of BMR
Thyroid hormones
is triggered by a loss of fluid volume
hypovolemic thirst
The two metabolic thyroid hormones share similar functions
Triiodothyronine and thyroxine increase the metabolic rate of almost all tissues and can increase the body's basal metabolic rate by as much as 60% to 100%. These hormones also -increase protein synthesis (including enzymes); -increase the size and number of mitochondria in most cells; -promote rapid cellular uptake of glucose; enhance glycolysis and gluconeogenesis; -and enhance lipid mobilization, increasing FFA availability for oxidation.
Distinct Properties of Type 1 & Type 2 Muscle Fibers Molecular & Cellular & Metabolism
Type 1 - type I MHC human gene: MYH 7 Myosin ATPase: slow Mitochondria density: High Main fuel storage: Triglyceride Myoglobin (red): Yes Oxygen usage: Aerobic SR: Moderate Type II - Type II (a, b, x) - type 2 MHC human gene: MYH 1, 2, 4 Myosin ATPase: fast Mitochondria density: Medium-low Main fuel storage: Glycogen, ATP, creatine phosphate Myoglobin (red): No Oxygen usage: Anaerobic (glycolysis) SR: Highly developed MHC = myosin heavy chain
Type I fibers: greater oxidative capacity Type II fibers: better for glycolytic energy production
Type I fibers - More mitochondria - High oxidative enzyme concentrations Type II - better for glycolytic energy production
______lesions destroy anorexigenic PVN (paraventricular nucleus)
VMH
___- _____animals exhibit overeating until they become obese
VMH-lesioned (ventromedial hypothalamic) Increased weight stabilizes - this weight is maintained even after food manipulations
Vasopressin and Renin are released due to hypovolemic thirst. What are their functions, respectively?
Vasopressin (ADH) - Released from posterior pituitary, blood vessel constriction, less blood flow to bladder, more water retention Renin - Released from the kidneys when blood volume decreases, plays a major role in the Angiotensin cascade
1. Within the hypothalamus, the __________ is the satiety center, and the _____ is the hunger center.
Ventromedial hypothalamus VMH Lateral hypothalamus (LH)
enzyme _____ binds to substrate phosphocreatine to increase the rate of production of ______.
creatine kinase creatine
When a bond is broken, energy is released. When a bond is made, energy is stored.
When a bond is broken, energy is released. When a bond is made, energy is stored.
White, Brown, and (Perhaps) Beige Fat in Humans
White Fat: fat storage and breakdown to meet metabolic demands Brown fat: transfer energy from food directly into heat. Inner membrane of mitochondria has a specialized protein called uncoupling protein that uncouples the electron transport chain from the creation of ATP
What is glycogen, and how is it made?
Your body makes glycogen through a process called glycogenesis to convert glucose into glycogen for short-term storage in the liver. Glycogenesis involves the use of insulin.
1. What are effective treatments for obesity?
a. -Eat less, modify behavior to avoid temptation to pig out, and exercise b. -Giving a cannabinoid receptor antagonist. However, if you block cannabinoids, you get suicidal thoughts. Not a viable option. c. -If you treat obesity as an addiction, for instance, REDUCING D2 receptors and DECREASING IN PREFRONTAL METABOLISM, the treatment may be somewhat effective. d. -GASTRIC BYPASS SURGERY is the best, in which GHRELIN IS REDUCED and PYY AND GLP-1 IS INCREASED, reducing hunger. 25% average weight loss in patients is long lasting, reduces mortality, and has many health benefits
Jeff is about to run a 100 meter race, which of the following can reduce his central drive to his muscles? a. He thinks he has very little hope to win the competition, even though his chance is very high b. He drank soda instead of orange juice before the race c. His beloved family is watching his race d. His ankle pain just got a lot better
a. He thinks he has very little hope to win the competition, even though his chance is very high
There are two internal cues (signals) that trigger thirst - what are they?
a. osmotic thirst b. hypovolemic thirst
using parabiotic mice (sewn together) to investigate genetic influences on obesity, it was found that (all answers are true)
a. paired ob/ob mice with normal mice slowed the weight gain of ob/ob mice. b. if db/db mice were paired with normal mice, the normal mice would starve. c. if db/db mice were paired with ob/ob mice, the ob/ob mice starved.
"Which of the following organs utilizes the smallest percentage of energy of the Basal Metabolic Rate? a.) heart b.) muscles c.) brain d.) liver"
a.) heart
9. Why do athletes with high VO2max values perform better in endurance events than those with lower values?
ability to perform at increased VO2max and being able to maintain VO2max for prolonged times indicates the person is able to take more oxygen to be converted into energy for endurance activity
Many variables including __________, ___________, ____________, ___________, ____________, and _________ are balanced at homeostasis
acidity saltiness water level oxygenation temperature energy availability
proteins contribute too
amino acid pool (minimal contribution)
If blood volume decreases, kidneys release renin, which triggers formation of
angiotensin II
"Which of these is NOT a function of enzymes? A) Controlling reaction rate B) Increasing side products made C) Allowing reactions to occur at body temperature D) Releasing energy in discrete steps
answer: B; Enzymes speed up reactions, and to make the reactions more efficient, they eliminate side reactions and products."
"What molecule inhibits Phosphofructosekinase-1? A. ADP B. ATP C. citrate D. B and C E. all of the above
answer: D
"Which of the following is the biggest cause for muscle fatigue? a. ATP shortage after muscle movement b. Accumulation of metabolic by products, like lactate c. Damage to muscle fibers, leading to pain d. Low economy of effort through unwanted muscle contractions
answer: a"
"Exercise increases TH levels leads to all of the following except ? ( select all that apply) a) increase T3 and T4 b) decrease T3 and T4 c) increase metabolism d) increase inflammation
answer: b and d are wrong; inflammation would decrease "
"Which of the following muscle group(s) protect locomotor muscle from metabolic damage? a) Group I b) Group III & IV c)Group I & II d) Group I & III e) none of the above
answer: b"
"John is obese and is looking to lose some weight. What is one of the best ways to increase his basal metabolic rate? a. Engaging in high intensity exercise 5 days a week b. Decreasing the amount of sleep he gets, in order to make more room for exercise and activity c. Engaging in moderate exercise or continuous low rate movements d. Going on a low protein, low carb diet
answer: c"
"Which of the following is the correct endocrine pathway? a) posterior pituitary gland -----> releases TSH ---> hypothalamus ----> synthesizes TRH ----> thyroid b) hypothalamus -------> releases TRH ----> parathyroid ----> releases PTH ------> posterior pituitary gland -----> thyroid c) hypothalamus -------> releases TRH ------> anterior pituitary gland -----> produces TSH ----> thyroid ---> thyroxine released d) hypothalamus -----> releases TRH -------> posterior pituitary gland ------> produces TSH ----> thyroid ----> thyroxine released
answer: c"
"Accumulation of pyruvate in the body is dangerous. Which of the following is NOT one of the reasons why pyruvate must be removed from the body? a. Accumulation of pyruvate will cause acidosis in the muscles b. Accumulation of pyruvate will push glycolysis in the reverse direction, slowing down ATP production c. During intense exercise, excess pyruvate will be converted to Lactic acid, which decreases a persons ability to contract their muscles d. Accumulation of pyruvate increases all protein function in the body "
answer: d - Acidic pH changes a protein's tertiary structure, which worsens each activity (myosin head, sodium potassium pump, etc)
"How many ATP, NADH, FADH2, and CO2 are produced from Kreb's Cycle with 25 acetyl coA for eukaryotes? a) 50 ATP, 75 NADH, 25 FADH2, 25 CO2 b) 50 ATP, 25 NADH, 50 FADH2, 25 CO2 c) 25 ATP, 50 NADH, 25 FADH2, 50 CO2 d) 25 ATP, 75 NADH, 25 FADH2, 50 CO2
answer: d"
T/F: Moderate exercise increases TH level.
answer: true
Enzyme concentration: Increasing enzyme concentration will speed up the reaction, Substrate concentration: Increasing substrate concentration also increases the rate of reaction to a certain point.
as long as there is substrate available to bind to.
11. What adaptations have been shown to occur in muscle fibers with anaerobic training?
at higher intensities: type I muscle fibers type II are recruited being recruited; type IIa and IIx muscle fibers increase in their cross-sectional areas
Which of the following will slow down the production of phosphocreatine? Choose all that apply A high level of ATP B high level of ADP C high level of creatine D high level of inhibitor of creatine kinase
b -high level of ADP d - high level of inhibitor of creatine kinase
What is the name of the protein that is lacking in DMD patients, that eventually causes patients to experience progressive muscle weakness? a) Titin b) Dystrophin c) Desmin d) Troponin
b) Dystrophin
Which of the following contributes most ATP when Michael Phelps swam a 1:53.93(one minute and 53.93 seconds) to break his own world record in 200 meter butterfly? a. ATP-PCr system b. Anaerobic Glycolysis c. Aerobic Glycolysis d. Lipolysis
b. Anaerobic Glycolysis
Which of the following is not true regarding the "crossover concept" of carbohydrate and fat utilization? a. After months of training, the crossover point between carbohydrates and fats is shifted right b. Based on the crossover concept, more total fat calories will be burned walking for 30 minutes than jogging for same amount of time c. At rest, both fats and carbohydrates provide energy to the cells of the body d. At very high intensities of exercise, carbohydrates predominate as the energy source e. At low intensities of exercise, fats serve as the primary fuel source
b. Based on the crossover concept, more total fat calories will be burned walking for 30 minutes than jogging for same amount of time
"If the body's utilization is calculated to be 48% of energy derived from fat and 48% of energy derived from carbohydrate, what is this called? a. Poor economy point b. Crossover point c. Crossbridge cycle d. Pre-exercise mean
b. Crossover point"
Which of the following descriptions fits type I muscle fibers? Choose all that apply a. appear pale or whitish b. have a higher number of mitochondria c. take longer time to fatigue during contraction d. exhibit higher contraction speed
b. have a higher number of mitochondria c. take longer time to fatigue during contraction
Q2) Which of the following is the main electrolyte of concern when replenishing electrolytes in a patient with diabetic ketoacidosis? a.Chlorine b.Potassium c.Sodium d.Hydrogen
b. potassium
"What happens to the reaction rate as the substrate concentration increases? a.) increases b.) increases then plateau c.) decreases d.) decrease then plateau"
b.) increases then plateau- (correct answer)
Homeostatic systems use our ________- to keep things balanced
behavior
BMI
body mass index (BMI) is the most widely used clinical standard to estimate obesity because of its simplicity.
regulation of food intake
brain integrates insulin & glucose levels w/ other info to decide when to start/stop eating. central signals, external factors, peripheral signals play a role.
(internal cues trigger thirst steps-hypovolemic) 2. The cardiac baroreceptors stimulate the _____ & the kidney baroreceptors stimulate the ____ ______ which in turn stimulates what?
brainstem angiotensin II subfornical organ
Lipolysis
breakdown of fat
Glycogenolysis
breakdown of glycogen to glucose
Chemical reactions in a living cell are catalyzed
by an enzyme
Dr. James is a pediatrician and is seeing a new patient today. His mother tells Dr. James that her four year old son, Steve, has trouble walking and is prone to falls. Dr. James asks Steve to lie down on a mat before asking him to get up again. Steve struggles with this simple task, using his arms and shoulders to "walk up" his body in order to get up again. What is the name of the movement that Steve engaged in to get up again? a) Proximal weakness b) Elephant's posture c) Gower's sign d) Gower's posture e) None of the above
c) Gower's sign
Jeff's crossover point is higher than three month ago, this means __ a. Jeff has a higher lactate tolerance now b. Jeff has a higher anaerobic power now c. Jeff has a higher aerobic power now d. Jeff has a higher muscle volume now
c. Jeff has a higher aerobic power now
"Which of the following statements is false? Accumulation of pyruvate in glycolytic system, a. Accelerates the reverse reaction b. Lowers pH level c. Results in excess NAD+ d. Slows down glycolysis "
c. Results in excess NAD+ ( the answer)
Why would myasthenia gravis patients be prescribed an antiacetylcholinesterase? a. To halt auto-antibody production b. To stop acetylcholine release c. To hinder release of acetylcholinesterase d. To prevent acetylcholine attachment to receptors
c. To hinder release of acetylcholinesterase
Jeff went through partial gastrectomy (removal of stomach) recently, how will the procedure influence his appetite? a. no difference b. it will increase his appetite c. it will reduce his appetite
c. it will reduce his appetite
"What enzyme participates in both the Krebs Cycle and Electron Transport Chain? a.) fumarase b.) aconitase c.) succinate dehydrogenase d.) isocitrate dehydrogenase"
c.) succinate dehydrogenase- (correct answer)
Adipose tissue is an endocrine organ
capable of synthesizing a number of biologically active compounds exerts an impact on whole-body metabolism
Multiple organ systems are involved in the metabolism of
carbohydrate, fat, and proteins
Three basic substrates for energy production
carbohydrates fat (triglycerides) protein
Lesions of lateral hypothalamus
causes starvation
Endurance training --> cellular adaptions ---> Oxidation of FFAs increased
cellular adaptations Mitochondria number and size ↑ ( increase) oxidative enzymes↑ β-oxidation ↑ ( beta-oxidation) electron transport chain ↑
primary sites of fatigue:
central fatigue: central nervous system peripheral fatigue: peripheral nervous system & skeletal muscle fibers Other possible sites of fatigue: heart, lungs, kidneys, endocrine glands
Metabolism
chemical reactions in the body
Gastrointestinal distention caused by a full stomach triggers the release of the hormone
cholecystokinin (CCK), which stimulates afferent fibers of the vagus nerve to send signals to the brain to suppress hunger.
The main hormones that regulate appetite and satiety are
cholecystokinin, leptin, peptide YY, GLP-1, insulin, and ghrelin. These hormones can be categorically split into those that are anorexigenic, meaning that they suppress appetite, and those that are orexigenic, meaning that they stimulate appetite
"Which of the following is NOT true about enzymes? a. enzymes are substrate and reaction specific b. enzymes make chemical reactions more manageable by controlling each step c. enzymes enable the chemical reactions at body temperature d. enzymes increase the amount of side reactions and products answer:
d - enzymes actually eliminate side reactions and products to increase efficiency"
Which of the following is allowed for MG patients (in terms of exercise routines)? a) Resistance training b) Strength training c) Aerobic exercises d) Both a and c
d) Both a and c
By what mechanism do anti-AChR antibodies prevent proper function of the NM junction? a) Destruction of the postsynaptic membrane via MAC formation b) Internalization/degradation of AChR c) Allosteric inhibition d) a and b e) All of the above
d) a and b
"The PCr can be generated in: a) The cytosol b) Intermembrane space of the mitochondria c) The mitochondrial matrix d) a and b e) all of the above"
d) a and b ( answer)
Which of the following inhibits PhosphoFructose Kinase-1 (PFK-1) ? a. fructose b. ADP c. Fructose 2,6-bisphosphate d. Citrate
d. Citrate
Which of the following is false? a. Pituitary gland directly stimulates thyroid gland to release T3 and T4 through TSH b. T3/T4 increases BMR by modulating genes' expression level and various ion channels activities c. T4 is more abundant in the blood than T3 d. T3 can be converted to T4 in target tissues and cells
d. T3 can be converted to T4 in target tissues and cells
Which of the following contribute to the coloration of the brown fat? a- heat production- baking effect b -high uncoupling protein c - low mitochondria content d - high level of vascularization
d. high level of vascularization
(discovery of Leptin - Parabiosis experiments) 1. What happenend when the normal rat and db/db rat were joined? Parabiosis (anatomical joining of two organisms in this experiment it was rats )
db/db = diabetes & ob/ob = obese normal rat starves due to signal from db/db; db/db insensitive to normal rats signal.
In _____- _______, vasopressin is not produced - kidneys send more urine to the bladder, resulting in chronic thirst
diabetes insipidus,
The two most common forms of heart disease in DMD are: a) Dilated cardiomyopathy b) Coronary artery disease (CAD) c) Arrhythmia d) a and b e) a and c
e) a and c
Ghrelin levels are ________ in Prader-Willi syndrome
elevated
estimated energy stores in humans: energy source = ATP/CP (adenosine triphosphate/creatine phosphate)
energy source = ATP/CP -storage site: various tissues -approximate energy: 5kcal
estimated energy stores in humans: energy source = carbohydrate
energy source = carbohydrate -storage site & approximate energy : blood glucose (80 kcal, fuel for brain), liver glycogen (400 kcal), muscle glycogen(1500 kcal)
estimated energy stores in humans: energy source = fat
energy source = fat storage site & approximate energy = serum free fatty acids (7 kcal), serum triglycerides (75 kcal), muscle triglycerides (2,500 kcal), adipose tissue (80,000+ kcal)
estimated energy stores in humans: energy source =protein
energy source =protein storage site & approximate energy = muscle protein (30,000 kcal)
energy stored =
energy stored = energy in - energy out energy in = • Hunger • Appetite energy out = • Basal Metabolic Rate (BMR) : 60% • Thermic Energy of Food : 10% • Non-exercise Costs : 10-20% • Exercise : 10%
The Creatine Phosphate system is
extremely fast and it has no negative by-products. The drawback is that there is only enough creatine phosphate in the body to last 5-8 seconds when an athlete is competing at high intensity. Thus, it is very useful for a quick jab in boxing, a short sprint in soccer or basketball, for jumping or a 100 m dash. It has no use in an endurance race as it will be gone after a few seconds and if there should be a need for a sprint at the end it will not be available. So for the initial few seconds of intense activity, the most important system is the creatine phosphate system. But after 1-2 seconds the anaerobic glycolytic system is also heavily involved.
(Fad Diets - why don't they work?) Energy expenditure is adjusted in response to nutrition •At the start of a diet, the basal metabolic rate will ___ - to prevent losing weight •Body will work to _________ it's set point even if that set point is too _____
fall maintain high
(True or False): Increasing Leptin and decreasing Ghrelin levels are an effective method for treating obesity
false
True or False. Myasthenia gravis usually affects men under the age of 42 and women over the age of 45.
false
The metabolic by-products that have received the most attention in discussions of fatigue are
inorganic phosphate, heat, lactate, and hydrogen ions. Inorganic phosphate increases during intense short-term exercise as PCr and ATP are being broken down. It now appears that Pi , which accumulates during intense short-term exercise from the breakdown of ATP, may be the largest contributor to fatigue in this type of exercise. 17 Excess Pi directly impairs contractile function of the myofibrils and can reduce Ca 2+ release from the sarcoplasmic reticulum. Increases in both Pi and ADP also inhibit ATP breakdown through negative feedback. Heat and temperature Exercise in the heat can increase the rate of carbohydrate utilization and hasten glycogen depletion, effects that may be stimulated by the increased secretion of epinephrine. It is hypothesized that high muscle temperatures impair both skeletal muscle function and muscle metabolism Lactic Acid and Hydrogen Ions Lactic acid often has been blamed for fatigue, but it is generally not directly related to fatigue during prolonged endurance exercise and may serve as a fuel source (see chapter 2). In short-duration exercise, like sprinting, it is actually the H+ generated by dissociation of lactic acid that often contributes to fatigue. The accumulation of H+ decreases muscle pH, which impairs the cellular processes that produce energy and muscle contraction.
While ______ is needed in order for most of the body to use glucose, the_____can use it directly.
insulin brain
Brain integrates ______ and ________ levels with other information to decide when to start/stop eating
insulin and glucose
The oxidative capacity of muscle (Q̇ O2)
is the muscle's maximal capacity to use oxygen.
Arrhenius equation
k=Ae^(-Ea/RT) 𝑘 = rate constant A = pre-exponential factor 𝐸𝑎 = activation energy R = universal gas constant T = absolute temperature (in Kelvin) A + B --> C + D reaction rate = 𝑘 [A][B]
Teenage girls with anorexia have •larger _______- brain area active when you experience disgust •larger ______ _______ - brain area that tells you 'you shouldn't do that'
larger insula larger orbitofrontal cortex
Lesions in the ____ _______ of rats abolished behavioral regulation of temperature
lateral hypothalamus
Ghrelin is transmitted through the blood to the brain where it crosses the blood-brain barrier to act on the hunger areas in the
lateral hypothalamus After eating, ghrelin concentrations decrease
But the brain can recover, if overeating stops: Newborn hypothalamic cells become NPY/AgRP- and POMC neurons These new neurons are responsive to fasting and _____.
leptin
Fat cells produce _______ and secrete it into the bloodstream
leptin
________ is secreted by fat cells and monitor bodys long term energy reserves
leptin
helps to regulate energy balance by inhibiting hunger
leptin
leptin =
leptin is primarily secreted by fat cells and acts on receptors in the hypothalamus to decrease hunger
generally fat levels are proportional to
leptin levels
If you want to lose weight you want ??
less ghrelin levels
for long-term storage, are fat tissue
lipids
Increasing Leptin and Decreasing Ghrelin are generally not effective... (3)
•Unless you have a specific mutation... •Only 5-10% of obese people are leptin deficient •Obesity leads to Leptin resistance and low Ghrelin levels
Enzymes _______- the activation energy of chemical reactions
lower
proteins -
molecule = amino acids cellular storage = muscle
carbohydrates -
molecule = glycogen cellular storage = cytosolic granules
fats -
molecules = triglycerides cellular storage = lipid droplet
percent of basal metabolic rate BMR
muscles 20% digestion 10% liver 19% kidneys 7% heart 8% fat 3% brain 17%
__________feedback systems are the main homeostatic mechanisms If a desired ____ _______ is deviated from, compensatory action begins
negative set point
Homeostatic mechanisms employ _____________feedback systems to stay within a ____ _____ rather than a rigid ____ _______.
negative set zone set point
(discovery of Leptin - Parabiosis experiments) 2. what happened when the ob/ob rat and normal rat were put together?
normal unaffected, but its weak leptin signal slows the ob/ob's weight gain
For a child born with a mutation in the ___ gene.= Leptin therapy has dramatic effects
ob Leptin Deficiency
(internal cues trigger thirst steps-osmotic) 2. _______ neurons in the _____ _____ (OVLT) respond to the rise in osmotic blood pressure. What happens to their membranes? During their response, they cause the pituitary to release what?
osmosensory anterior hypothalamus their cell membranes shrink which open mechanically-gated Na+ channels. Anti-diuretic hormone
Most of the body's water is contained within the (our cells) intracellular compartment. However, water moves back and forth between the extracellular compartment and intracellular compartments through what process?
osmosis
the passive movement of water molecules through a semipermeable membrane until uniform concentration of solute is achieved on both sides of the membrane=
osmosis
occurs when the extracellular fluid becomes too salty
osmotic thirst
8. What is the relationship between oxygen consumption and energy production?
oxygen is required to breakdown substrates for energy; increased oxygen consumption means being able to breakdown more substrates and being able to substrates quicker, being able to provide more energy for exercise and burning more calories 9. Why do athletes with high
(internal cues trigger thirst steps-hypovolemic) 3. brainstem and subfornical organ both signal the
preoptic area
(internal cues trigger thirst steps-osmotic) 3. signals from step three cause signaling in?
preoptic area
Further, loss of function in one part of the system usually can be compensated for by the remaining parts, which is known as ___________. We see an example of this process in temperature, which is sensed and regulated in the _________ by two independent sets of thermosensitive neurons in the _______ (POA) and _________ hypothalamus.
redundancy hypothalamus preoptic area lateral
Lateral hypothalamus (LH) lesions
refusal to eat
blood signals that stimulate appetite
rising ghrelin
T/F] One possible symptom of Duchenne's Muscular Dystrophy includes calf hypertrophy
true
True or False: Counseling services for stress management, depression, and anxiety, is encouraged for patients diagnosed with Fibromyalgia.
true
_____ separate thermoregulatory systems exist in the mammalian hypothalamus. Homeostatic systems show ________
two redundancy
(internal cues trigger thirst steps-osmotic) 6. supraoptic nucleus, paraventricular nucleus stimulates the release of?
vasopressin
Three Energy Systems
‒ ATP-PCr system (anaerobic) ‒ Glycolytic system (anaerobic) ‒ Oxidative system (aerobic) β-Oxidation (fatty acid) (beta-oxidation) Krebs cycle Electron transport chain Anaerobic exercise is a type of exercise that breaks down glucose in the body without using oxygen
How we obtain energy from chemicals (food)
• Breaking chemical bonds cost energy. • Forming new chemical bonds releases energy.
Physiological Central Fatigue: 1. Group III/IV muscle afferents discourage central drive
• Group III/IV muscle afferents send muscle metabolic perturbation status to CNS • Decrease the central drive to locomotor muscle • Increase the activity of sympathetic nervous system (stress response) • Protect locomotor muscle from metabolic disturbance based damage Group I= myelin sheath: thick conductance speed: 72-120m/s where: muscle spindle, GTO stimuli: Group II= myelin sheath: thick conductance speed: 31-71m/s where: muscle spindle stimuli: Group III= myelin sheath: thin conductance speed: 2.5-30m/s where: connective tissue stimuli: mechanical group IV = myelin sheath: none conductance speed: 2.5m/s where: small vessels stimuli: metabolic
Complications of obesity:
• Heart disease and strokes • Type 2 diabetes • Certain cancers • Digestive problems: e.g. heartburn, gallbladder disease and liver problems • Infertility and irregular periods in women • Erectile dysfunction in men • Sleep apnea, breathing repeatedly stops and starts during sleep • Osteoarthritis, especially in weight-bearing joints
Electron Transport Chain & Oxidative Phosphorylation
• NADH and FADH give away high energy electrons • Electron transfer down the energy hill to empower H+ pump • O2 receives the electrons --> O- • O- absorbs H+ to form H2O NADH --> 10 H+ --> 2.5 ATP FADH --> 6 H+ --> 1.5 ATP
Factors that determine oxidative capacity
• O2 availability versus O2 need • Fiber type composition • Enzyme activity
Satiety Score of Food
• Protein, fiber, and water contents of the test foods correlate positively with satiety score scores • Fat content is negatively associated with satiety score scores Highly processed food makes you eat more calories before you feel full
Economy of Effort (Management of effort)
• Using the "right" muscles • Optimize movement logistics - Find the best way to accomplish the work with least effort • Optimize body conditions: joint, ligaments, warm up • Practice makes perfect: e.g. children's economy of effort is worse than adults
Body mass index (BMI):
• is a measure of body fat based on height and weight • interpretation for adults and for children is different >18.5 is underweight 18.5-24.9 is normal 25-29 is overweight 30-34.9 is obese 35< is extremely obese
3,175 students in grades 5 to 8 surveyed:
•30% dieting •10% fasting •2% using diet pills •5% vomiting
Gastric bypass surgery (3)
•Weight loss averages 25% and is long-lasting (compared to 5%-10% with dieting and relapse within a year) •Reduces ghrelin and increases PYY and GLP-1, reducing hunger •Reduces mortality and has many health benefits
Other symptoms of anorexia (6)
•thinning of the bones •brittle hair and nails, dry and yellowish skin •mild anemia, muscle weakness and loss, lethargy •severe constipation •low blood pressure, slowed breathing and pulse •drop in body temperature
7. What metabolic adaptations occur in response to endurance training?
↑ size of mitochondria↑ number of mitochondria↑ concentration of oxidative enzymes↑ blood flow in trained muscle↑ concentration of fat-metabolizing enzymes↑ muscle respiratory capacity↓ catecholamine release increase size of mitochondria
