Appl in Exercise and Sports Science Ch 3

During a 6.2 mile run (10 km), the predominant energy system activated is _________ however, at the end of the race, when the runner is sprinting to the finish line, _______ is the predominant energy system

oxidative phosphorylation; ATP-PC

Which biochemical reaction provides energy for 5-10s of sustained muscular contraction?

PCr + ADP -> ATP + Cr

During high-intensity exercises (e.g., an 800-m run), which enzyme or enzymes are responsible for regulating the anaerobic glycolytic pathway?

PFK

All of the following are characteristics of the creatine phosphate bioenergetic system EXCEPT

1 PCr = 3 ATP

How many ATP molecules are generated from 1 molecule of glucose in glycolysis?

2 ATP

If an athlete completes a maximum sprint interval in 10 seconds as part of an interval training workout, which of the following is a recommended length of the rest period before the next sprint?

2 min

The oxidative system results in the production of approximately _________ ATP from the degradation of one glucose molecule

36-38

Approximately how many net ATP are produced via the oxidative energy system from the metabolism of 1 glucose molecule?

38

Which of the following energy substrates cannot be depleted during extreme exercise intensities or durations?

ATP

Which of the following is the ultimate source of energy for a muscular contraction?

ATP

Which of the following reactions is the primary cause of metabolic acidosis (i.e., the decrease in intramuscular pH during high-intensity, fatiguing exercise)?

ATP ->ADP + Pi + H+

The highest RATE of energy production is from

ATP-PC system

Chronic training involving the fast glycolytic energy system results in improved buffering of which of the following substances?

Hydrogen ions

The following factor(s) influence enzyme activity

Temp; pH; increased H+

The law of mass action states which of the following?

The concentrations of reactants or products will drive the direction of the reactants

Anaerobic metabolism utilizes primarily _________ as an energy substrate

carbohydrate

which of the following substances can be metabolized anaerobically?

carbohydrate

The excess postexercise oxygen consumption experienced by athletes is caused by all of the following EXCEPT

decreases in body temp

When ATP is broken down within the muscle cells and energy is released from the chemical bonds, this process is an

exergonic reaction

T or F? Anabolic reactions break down large molecules into smaller molecules

false

T or F? Carbohydrates are stored in the liver, skeletal muscle and fat cells. CHO stored in the liver is termed liver glycogen, CHO stored in the muscle is termed muscle glycogen, and CHO stored in fat cells is termed free fatty acids

false

T or F? The creatine-kinase reaction produces ATP aerobically when creatine kinase gives up a phosphate to ADP

false

Which of the following substances can be metabolized anaerobically?

glucose

Glycolysis is stimulated by

high concentrations of ADP, P, and ammonia; slight decrease in pH; AMP (all of the above)

An aerobic endurance athlete is trying to give himself a competitive edge over his opponents. To improve his lactate threshold, what type of training should he engage in, and in what direction would this shift his threshold?

high intensity, shifts to the right

The energy system used for physical activity depends PRIMARILY on the exercise

intensity

Which of the following is a branched-chain amino acid?

isoleucine

Source of Krebs cycle intermediates include all of the following EXCEPT

ketone bodies

The highest lactic acid concentration in the muscle would be observed with

maximal activity lasting 1-2 min

During higher-intensity exercises, athletes often experience peripheral fatigue. Which of the following is believed to be the reason for this type of fatigue?

metabolic acidosis

The Krebs cycle occurs in which portion of the cell?

mitochondria

Which of the following describes the portion of the total energy cost of exercise that must be supplied through anaerobic mechanisms due to the slow response of the aerobic system to the initial increase in the demand for energy?

oxygen deficit

The initiation of all exercise is supported by the _________ energy system

phosphagen

Which of the following energy systems produces ATP at the quickest rate?

phosphagen

2 athletes are competing in upcoming competitions, a weightlifting meet and a marathon. Which energy systems will each be primarily using, respectively?

phosphagen and oxidative

The predominant energy system used during a training session depends primarily on the

session intensity

An athlete is used to performing high-intensity (90% VO2max) aerobic exercise; however, she will now be changing to longer-duration, submaximal exercise on a regular basis. This change in training strategy will typically result in what changes concerning energy supply?

transition from almost exclusively carbohydrate to mostly fat

T or F? A decrease in pH inhibits PFK; therefore it decreases the rate of anaerobic glycolysis

true

T or F? Activation of anaeroibc (fast) glycolysis results in the production of lactic acid

true

T or F? During high intensity exercise, lactate production is greater than lactate removal and contributes to the observed lactate threshold (LT) observed on graph paper

true

T or F? During high-intensity exercise, an increase in ADP concentration in the muscle cell stimulates the rate-limiting enzyme PFK

true

T or F? During high-intensity exercise, the pH decreases in the muscle cell, thus contributing to the onset of muscular fatigue

true

T or F? Enzymes are chemicals that primarily control the RATE of metabolic chemical reactions without changing the structure of the enzyme itself

true

T or F? Enzymes are important catalysts for biochemical reactions because they lower the energy of activation

true

T or F? Fatty acids stored in fat cells provide the greatest amount of stored energy and are utilized during low-intensity exercise (i.e., a 26.2-mile run)

true

T or F? NAD and FAD are electron carriers used in oxidative metabolism and must be present in sufficient quantities for aerobic metabolism to proceed at optimal levels

true

T or F? Rate-limiting enzymes in bioenergetic pathways play an integral role in controlling the rate of energy-yielding pathways

true

T or F? The chemical reactions of the glycolytic system occur in the sarcoplasm of the muscle cell

true