Exercise Physiology Final

Most control systems of the body operate via

negative feedback.

Body temperature increases during exercise. A 2°C increase in muscle temperature during exercise would likely

increase enzyme activity.

Recent technological advancements make it possible to perform large-scale measurements of specific classes of molecules in cells; collectively, these techniques are known as

omics

Evidence-based practice in medicine refers to the process of:

evaluating all of the research evidence available to make an informed decision about how to best treat disease.

The rate-limiting enzyme in the electron transport chain is

cytochrome oxidase.

The conversion of pyruvate to lactate requires

the enzyme lactate dehydrogenase and NADH +

Stress proteins (i.e., heat shock proteins) are manufactured by cells in response to exercise and other stresses. Importantly, increasing the cellular levels of heat shock proteins

can repair damaged cellular proteins and restore homeostasis.

The actual net ATP yield from aerobic metabolism of one molecule of glucose is different from the theoretical yield because

it accounts for the fact that the energy provided by NADH and FADH is required not only for ATP production but also to transport ATP across the mitochondrial membrane.

The formation of mRNA in the cell is called

transcription

The rate-limiting enzyme in glycolysis is

phosphofructokinase.

Skeletal muscle fibers store carbohydrate in the form of glycogen rather than individual glucose molecules because

storage of individual glucose molecules in the cell increases the osmotic pressure between the inside and outside of the cell.

In order to maintain blood glucose homeostasis, which of the following events would likely occur in response to a significant rise in blood glucose?

increased uptake of glucose by cells

Autocrine signaling occurs when a cell produces

and releases a chemical messenger into the extracellular fluid; this messenger then acts upon the cell that produced the messenger.

The gain of a biological control system can be thought of as the

precision with which the control system maintains homeostasis.

The calculated efficiency for aerobic respiration is approximately

34%.

Exercise physiologists use the term steady state to denote

a steady and unchanging level of a physiological variable.

By definition, an endergonic reaction is

a chemical reaction that requires energy to be added to the reactants before the reaction will take place.

The term “lactate” refers to

a potential end-product; the salt of lactic acid; the conjugate base of lactic acid

The metabolic process of converting foodstuffs into a biological usable form of energy is called

 bioenergetics

Negative feedback is an important class of biological control systems in the body that serves to restore normal values of a variable to maintain homeostasis. Which of the following examples illustrate a negative feedback control system of the body?

All of the above answers are correct

The cellular factor that “turns on” genes to promote the production of mRNA is called a

transcriptional activator

Translation is the production of a protein from mRNA; this occurs at the

 ribosome

Epigenetics is a new and rapidly developing field that

investigates the changes in gene function that occur without alterations in the DNA sequence of the gene.

In general, the higher the intensity of exercise, the greater the contribution of

anaerobic energy production

Which of the following statements about glycolysis is correct?

 Glycolysis involves the breakdown of glucose into two molecules of pyruvate or lactate

Aerobic production of ATP occurs in the

 mitochondria in a process called oxidative phosphorylation.

The rate-limiting enzyme in the Krebs cycle is

 isocitrate dehydrogenase.

Three molecules of NADH are produced during one turn of the citric acid cycle. How many total ATP molecules can be produced from these three NADH molecules?

7.5 ATP

Which of the following search engines is NOT considered to be a primary search engine for performing literature searches in exercise physiology?

Enzymes are catalysts that increase the rate of reactions by

lowering the energy of activation.

Which of the following statements about exercise-induced gene expression is correct?

Exercise training results in activation of cell signaling pathways in the active skeletal muscles; dissimilar mode of exercise promote the expression of different genes; exercise training activates specific transcriptional activators

The total ATP tally from the aerobic breakdown of glucose is

32 ATP.

The process of beta-oxidation involves

a series of reactions converting fatty acids into acetyl-CoA.

A class of enzymes called kinases are responsible for

adding phosphate groups to a molecule (i.e., phosphorylation of substrates).

A series of interconnected components that serve to maintain a physical or chemical parameter of the body near a constant value is called

a biological control system.

The general components of a biological control system include the

receptor, control center, and effector.

The immediate source of energy for muscular contraction is

ATP.

Which of the following statements are true about a correlation coefficient?

Although a high correlation coefficient suggests that a strong relationship exists between two variables, a numerically high correlation coefficient does not prove cause and effect between the two variables; correlation coefficients are expressed as values between +1.5 and -1.5

If muscle glycogen is the initial substrate, the net production of ATP resulting during glycolysis is.

3 molecules.

A chemical messenger that is released from one cell and stimulates nearby cells is an example of

paracrine signaling.

Each pair of electrons passed through the electron transport chain from NADH to oxygen releases enough energy to produce

2.5 ATP.

Rate-limiting enzymes are often located

near the beginning of a metabolic pathway.

The term cell signaling refers to

a system of communication between cells.

The activity of creatine kinase is increased by a rise in_________ levels in the muscle fiber.

ADP

Extracellular vesicles are a unique signaling mechanism that uses

both paracrine and endocrine signaling to convey messages.

Exercise training can improve homeostatic control via

cellular adaptation.

The primary function of the Krebs cycle is to

complete the oxidation of carbohydrates, fats, and proteins (i.e., form NADH and FADH).

Compared to NADH, FADH produces less ATP because

the electrons from FADH enter the electron transport chain at a later stage than those by NADH.

The term “gene knockout” refers to a technique to inactivate a specific gene (i.e., gene is removed from the cell). The end result is that following the “knockout” the affected cells cannot manufacture the specific protein produced by this gene. This type of experimental approach is often called a

“loss of function” experiment.

The two most important electron carriers in bioenergetic chemical reactions are

NAD and FAD.

In negative feedback, the response of the system is

opposite to that of the stimulus.

A microRNA (miRNA) is

a small RNA molecule that regulates gene expression by binding to messenger RNA and preventing the production of a specific protein.

During 60 minutes of constant-load submaximal exercise, the body temperature reaches a plateau after 35-45 minutes. This is an example of

a steady state.

The researcher that was instrumental in discovering the Citric Acid Cycle was _______.

Hans Kreb

Coupled reactions are defined as

reactions that are linked together, with the liberation of free energy in one reaction being used to drive the second reaction.

When a muscle transitions from rest (no contractile activity) to exercise (increased contractile activity), ATP breakdown increases. This breakdown of ATP results in a rise in cytosolic levels of both_________ and_________; this activates the rate-limited enzyme in both the Krebs (citric acid) cycle to increase ATP production.

calcium, ADP

The caloric (kcal) yield of one gram of protein is approximately

4 kcal/g.

Stored polysaccharides (i.e., carbohydrates) in muscle and other tissues in animals are called

glycogen.

A high level of_________ in the muscle fiber would slow glycolysis by inhibiting its rate-limiting enzyme.

ATP

The relationship between hormesis/exercise intensity/duration is best described by

a bell-shaped curve.

The journal_________ is a numerical score that reflects the number of times recently published articles are cited in the scientific literature. This number is called the journal

impact factor

Triglycerides are comprised of

FFA and glycerol.

The scientific method involves a_________ process that begins with the conception of a research question and ends with the publication of the research findings.

six-step

The simplest and most rapid pathway for producing ATP during exercise is through

ATP-CP system.

Which of the following professional organizations associated with exercise physiology and sports science has the largest number of members?

American College of Sports Medicine

Recent evidence reveals that exercising skeletal muscles release extracellular vesicles (EVs). These EVs can be described as

small membrane-bound sacs containing bioactive molecules.

Which of the following statements is true concerning the electron transport chain?

The primary purpose of the electron transport chain is to harvest the energy from electrons moving down this pathway to produce ATP and water.

The director of the Harvard Fatigue Laboratory was

David Bruce Dill.

What is the last component of a research article?

references

The membrane-bound vesicles (i.e., small sacs) that can transport important molecules from skeletal muscles to other cells are called

extracellular vesicles

The fats stored in muscle and adipose tissue that play an important role as an energy substrate are

triglycerides

Endocrine signaling involves the release of_________ into the bloodstream.

hormones

Cellular adaptation to environmental stress (i.e., hot environment) is called

acclimation

The primary purpose of the Krebs cycle is to

complete the oxidation of foodstuffs using NAD and FAD as hydrogen (electron) carriers.

Both the first and second proton pumps in the electron transport chain transport_________ protons (H+) across mitochondrial inner membrane whereas the third proton pump moves ______ protons (H+) across mitochondrial inner membrane.

 4, 2

The enzyme that catalyzes the formation of lactate from pyruvate is

lactate dehydrogenase.

The European scientist who was awarded a Nobel Prize for his work measuring heat production during muscle contraction and recovery from exercise was

A.V. Hill.

The term homeostasis is defined as

the maintenance of a constant internal environment.

During exercise, plasma volume tends to decrease. Assuming that a hormone in circulation is produced at the same rate as before exercise started, the blood concentration of this hormone will be_________

increased.

Which of the following factors could explain the rise in blood lactic acid at the lactate threshold?

Both "an increased rate of lactate production" and "a decreased rate of removal of lactic acid from the blood" are correct.

Hormones are defined as:

chemical messengers released into the blood.

The excess post-exercise oxygen consumption is generally higher following heavy exercise when compared with moderate exercise because heavy exercise

results in greater body heat gained, greater CP depleted, higher blood levels of epinephrine and norepinephrine, and higher blood lactate levels.

One of the mechanism(s) responsible for activation of proteases during long-duration exercise is

an increase in cytosolic levels of free calcium in the muscle.

Which of the following statements is true about muscle ATP production during exercise?

 During severe, short-duration exercise (e.g., 10 seconds), muscle ATP production is dominated by the ATP-PC system.

Growth hormone

is released from the anterior pituitary; increases gluconeogeneis in the liver; spares plasma during exerci

In a healthy individual consuming a nutritionally-balanced diet, most of the carbohydrate used as a substrate during very heavy exercise comes from

muscle glycogen stores.

Which of the following hormonal concentrations decreases during exercise, whereas the concentrations of the other hormones will increase during exercise?

insulin

As exercise intensity increases, there is a progressive increase in the reliance of carbohydrate metabolism in the exercising skeletal muscles. This observation is described as the

crossover concept.

In response to maximal intensity exercise, trained individuals typically release_________ concentrations of catecholamines than their untrained counterparts.

 higher

Circulating levels of this hormone are increased significantly when plasma osmolality is high and plasma volume is diminished due to exercise.

antidiuretic hormone (ADH)

During a bout of high-intensity exercise (i.e., 10 minutes at 80% VO2max), the plasma concentration of hormones that stimulate fatty acid mobilization from adipose tissue increase significantly. The plasma-free fatty acid concentration, however, actually decreases. Why does this occur?

Lactic acid interferes with fatty acid mobilization.

The RER can rise above 1.00

when the buffering of lactic acid stimulates an increase in alveolar ventilation to eliminate CO2; during very heavy exercise; if VCO2>VO2

Steroid hormones exert their primary effect by

regulating gene expression.

The term describing the cessation of the menstrual cycle resulting from lower estrogen levels in some female athletes is

amenorrhea.

The mobilization of free fatty acids from adipose tissue and glucose from liver glycogen would be stimulated by

a decrease in insulin and an increase in glucagon.

A hormone that is released from the pancreas at a higher rate during exercise to mobilize liver glucose and adipose tissue fatty acids is

glucagon.

After the first few minutes of moderate-intensity (constant-load) exercise, oxygen consumption reaches steady state, indicating that

the ATP requirements of this exercise is being met aerobically.

Which of the following hormones is part of the General Adaptive Syndrome and is called the "stress" hormone?

cortisol

The term oxygen deficit refers to the

lag in oxygen consumption at the beginning of exercise.