Exercise Physiology

Kreb's cycle in production of ATP

2 NADH are formed when the formation of 5 ATP. a total of 6 NADH and 2 FADH therefore the total ATP yield for the aerobic degradation of glucose is 32 ATP. the aerobic ATP yield for glycogen breakdown is 33 ATP because the net glycolytic production of ATP by glycogen is one ATP more than glucose

functions of the cell membrane

2 most important functions are to enclose the components of the cell and to regulate the passage of various types of substances in and out of the cell

Which enzymes are considered "rate-limiting" in the production of ATP?

PC, it provides energy for muscular contraction at the onset of exercise and during short-term, high-intenisty exercise (lasting fewer than 5 seconds) it only occurs during recovery from exercise

lipases

a family of enzymes that regulated lipolysis. the glycerol released by lipolysis is not a direct energy source for muscle but can be used by the liver to synthesize glucose

the role of the sensor in a biological control system.

a receptor in the body capable of detecting change in the variable in question

glycolysis

a second metabolic pathway capable of producing ATP rapidly without the involvement of O2. involves the breakdown of glucose or glycogen to form two molecules of pyruvate or lactate

Discuss the impact of changes in body temperature and pH on enzyme activity.

a small rise in body temperature above normal increases the activity of most enzymes. This is useful during exercise because muscular work results in an increase in body temp. the resulting elevation in enzyme activity would enhance bioenergetics (ATP production)... pH of body fluids also have a large effect on enzyme acidity. the relationship between pH and enzyme activity is similar to temp/enzyme relationship. individual enzymes have pH optimum. if the ph is altered the enzyme activity is reduced.

positive feedback

act to increase the original stimulus. the response is in the same direction as the stimulus

What is ATP and how is it produced in our body?

adenosine triphosphate is the immediate source of energy for muscle contraction in high-energy phosphate compound. the simplest and most rapid way to produce this involves the donation of a phosphate group and its bond energy from PC to ADP to from ATP (33, 36, 37)

What is negative feedback?

an important class of biological control systems in the body that serves to restore normal values of variable to maintain homeostasis

role of the effector organ in a biological control system.

bring about the appropriate response to correct the disturbances (desired effect)

What are the three main nutrients that are used as fuels during exercise?

carbohydrates (1g=4kcal), fats (1g=9kcal), proteins (1g=4kcal)

glycogenolysis

cells store glycogen as a means of supplying carbs as an energy source. (ex: during exercise, individual muscle cells break down glycogen into glucose and the use of glucose as a source of energy for contraction; it also occurs in the liver with the free glucose being released into the bloodstream and transported to tissues throughout the body)

triglyceride

composed of 3 molecules of fatty acids and one molecule of glycerol. although largest storage site is fat cells, these molecules are also stored in many cell types, including skeletal muscle

functions of the nucleus

contains cellular genetic components (genes). Genes regulate protein synthesis, which determines cell composition and controls cellular activity

Why is the oxygen debt greater after high intensity exercise?

elevated heart rate and breathing = increased energy need, elevated body temp= increased metabolic rate,

What type of chemical reactions occur in our body?

endergonic, exergonic, and coupled reactions

How does steady state differ from homeostasis?

homeostasis is commonly used to denote a relatively constant and normal internal environment during resting conditions. Steady state does not mean that a physiological variable is at resting values but that the physiological variable is constant and unchanging (example: body temps during exercise)

Give a biological example of negative feedback.

in the respiratory system's regulation of the CO2 concentration in extracellular fluid. In this case, an increase in extracellular CO2 above normal levels triggers a receptor, which sends information to the respiratory control center (integrating center) to increase breathing. The effecters in this example are the respiratory muscle. This increase in breathing will reduce extracellular CO2 concentrations back to normal, thus reestablishing homeostasis. This type of feedback is termed negative because the response of the control system is opposite to the stimulus

role of the integrating center in a biological control system.

integrates the strength of the incoming signal from the sensor and sends an appropriate message to the effectors

What is homeostasis?

maintenance of a relatively constant internal environment

glycogen

polysaccharides stored in animal tissue. it is synthesized within cells by linking glucose molecules using action of the enzyme glycogen synthase

functions of the mitochondria

powerhouse of the cell. involved in the oxidative conversion of foodstuffs into usable cellular energy

coupled reactions (functions and examples)

reactions that are linked, with the liberation of free energy in one reaction being used to "drive" a second reaction (ex: energy released by an exergonic-requiring reaction ((endergonic reaction)) in the cell. this is like two meshed gears in which the turning of one causes the movement of the second. in other words energy-liberating reactions are "coupled" to energy-requiring reactions)

Cite an example of a biological homeostasis control system

regulation of body temperature, regulation of blood glucose

lipolysis

the process of breaking down triglycerides into fatty acids and glycerol, and is regulated by a family of enzymes

What role do enzymes play in cellular chemical reactions?

the speed of cellular chemical reactions are regulated by these catalysts. proteins that play a major role in the regulation of metabolic pathways in the cell, do not cause reactions to occur big regulate the rate or speed at which the reaction takes place. It does not change the nature of the reaction nor its final result