Deck 23: Muscle Energetics Fatigue and Training

Question 1

La ctic ac id is pro du ce d b y ex er cis ing m us cle

A) W hen cytopla sm ic [pyruv ate] a nd [N AD H ] rise
B) W hen NADH production outstrips its oxidation
C) During times of rapid glycolytic flux
D) To regenerate NAD + so that glycolysis can continue
E) All of the above

Answer 1

E

Question 2

One of the "purposes" of making lactic acid is that

A) It regenerates NAD+ ne ed ed in g lyco lysis
B) Is painful and so reduces muscle activation and metabolism
C) C ar rie s e ne rg y to th e m us cle m itoc ho nd ria
D) Carries energ y to glycolytic fibers
E) Both A and C are correct

Answer 2

E

Question 3

A short-term effect of exercise is to Increases glucose uptake by muscle cells by

A) O pe nin g u p a ch an ne l for glu co se en try in to th e c ell
B) Increasing the synthesis of m ore Gluco se transporters
C) Inserting more copies of GLUT4 into the musc le fiber sarcolemma
D) Inserting copies of SGLT1 into the surface mem brane
E) Both A and C are correct

Answer 3

C

Question 4

The "duty cycle" in muscle physiology refers to the

A) Tim e a m uscle is active
B) Fraction of time in a contraction when ATP is being used up
C) Fraction of total time that a muscle is active
D) Ca₂+ cyc le d ur ing ac tiva tion an d re lax atio n o f s ke leta l m us cle
E) The breakdown and synthesis of glycogen with each contraction

Question 5

Which of the follo win g ra nk m eta bo lic p ath wa ys correctly in terms of their rate of ATP regeneration?

A) Oxidative phosphorylation > glycolysis > creatine phosphokinase
B) Glycolysis>oxidative phosphorylation > creatine phosphokinase
C) Creatine phosphokinase> glycolysis > oxidative phosphorylation
D) C re atin e p ho sp ho kin as e > ox ida tive ph os ph or ylatio n > glyc olys is
E) Glycolysis > creatine phosphokinase > oxidative phosphorylation

Question 6

Slow twitch muscle fibers

A) Are Typ e I fibers
B) Are Type IIa fibers
C) Develop m ore force than fas t twitch m uscle fibers
D) Have m ore glycogen than fast-twitch fibers
E) Have the h ighest rate of glycogen lolysis am ong m uscle fibers

Question 7

W hen the intensity of exercise Increases

A) The duty cycle Increases
B) The rest period to recovery metabolic reserves gets shorter
C) Glycolytic flux Increases
D) Glycogenolysis Increases
E) All of the above

Question 8

Creatine phosphate and creatine phosphokinase

A) Co m pris e th e fas test w ay to reg en erat e AT P in w ork ing m us cle
B) M ak e u p o ne of t he ste ps of g lyco lysis
D) R eg ula te g lyco ge no lysis
E) R eg ula te g luc on eo ge ne sis
F) Are intermediates in the ETC

Question 9

In the Cori cycle, blood lactic acid is converted to glucose in the

A) Slow twitch mu scle fibers
B) Oxidative m uscle fibers
C) Intestines
D) Liver
E) Lungs

Question 10

The m ost rapid regeneration of ATP during muscle contraction is provided by

A) Creatine phosphokinase
B) Myokinase
C) G lyco lysis
D) TC A cycle from carbohydrate precu rsors
E) Oxidative phosphorylation

Question 11

The so ur ce ca pa ble of p ro vid ing the gre ate st a m ou nt o f en er gy fo r A T P r eg en er atio n is

A) Cre atine p hos pha te
B) G lyco lysis
C) G luc on eo ge ne sis
D) G lyco ge no lysis
E) Oxidative phosphorylation

Question 12

The total amount of ATP used in an exercise

A) Increases with intensity of exercise
B) Increases with blood pH
C) Increases with the duration of exercise
D) Is independent of body mass
E) Both A and C are correct

Question 13

Sources of fuel for muscle energy include

A) Blood glucose
B) Muscle glycogen
C) Liver glycogen through blood glucose
D) Blood lipids
E) All of the above

Question 14

Type I m uscle fibers are

A) Fa st tw itch fat igu ab le
B) Fa st tw itch , inte rm ed iate fat igu ab le
C) Fast twitch, fatigue-resistant
D) Slo w tw itch , fa tigu ab le
E) Slow twitch, fatigue-resistant

Question 15

The "anaerobic threshold" refers to the

A) W ork load th at ca n be con duc ted w hile ho lding o ne's brea th
B) The oxygen tension in the blood that mak es one breathe
C) The w ork load at w hich blo od lactic acid con cen tratio ns beg in to rise p recip itou sly
D) T he ox yge n te ns ion tha t ca us es blo od lac tic a cid to r ise pre cip itou sly
E) Oxygen content below wh ich mitochondr ia fail to produce ATP

Question 16

The m yokinase reaction con verts

A) Glucose-1-phosphate to glucose and ATP
B) Fructose-1,6 bisphophate to fructose-1-phosphate and ATP
C) 2 ADP to AT P an d AM P
D) ADP and Pi to ATP
E) Ac tin a nd AT P to ph os ph or ylate d a ctin and ADP

Question 17

Fatigue in intense, short-duration exercise is thought to be due to

A) Increased cytoplasmic [Pi] and acidosis (decreased pH)
B) Depletion of glycogen stores
C) Depletion of creatine phosphate
D) Increased AMP
E) Neuro m uscular junction failure

Question 18

Fa tigue in long d uratio n, lowe r intens ity exerc ise is th oug ht to be due to

A) Increased cytoplasmic [Pi] and acidosis (decreased pH)
B) Depletion of glycogen stores
C) Depletion of creatine phosphate
D) Increased AMP
E) Neuro m uscular junction failure

Question 19

"An aero bic m etab olism " refe rs to m etab olic pa thwa ys that

A) Are cond ucted at atm osphe ric pressure
B) Ar e c on du cte d w itho ut a ir
C) Do not require oxygen
D) Are inhibited by oxygen
E) Take place in an anoxic environment

Question 20

The gre ate st p ar t of AT P h ydr olys is d ur ing ac tiva tion of m us cle co ntr ac tion is produced by

A) SERCA1 pump
B) Na, K-ATPase
C) Acto-myosin ATPase
D) M itoc ho nd ria l F0F1 ATPase
E) Glucokinase

Question 21

Diabetics must pay attention to the amount of exercise they get because

A) Ex er cis e Decreas es glyc og en olys is
B) Ex ce ris e Decreas es lipo lysis
C) Exercise Increases blood glucose
D) Ex ercis e ha s an insu lin-like effe ct o n m us cle
E) Exercise antagonizes insulin action