Lucas part 5 Flashcards
what is work
Energy used to move an object by applying force (F) over a distance (d).
W= F x D
UNIT FOR WORK
joules or newton meters (Nm)
Work occurs only if there is ____ in the direction of the force.
movement
why is pushing a box that doesn’t move NOT considered work
bc the box doesnt move in the direction it is pushed in
What kind of contraction are you performing while holding a plank? Are you doing work?
isometric, no because there’s no movement when holding a plank
in words, what is power
the rate at which work is done or energy is used.
what is the formula for power
P = w/t = (fxd)/t = f x v
because v = d/t, therefore f/1 x d/t = f x v
v for shortening velocity
unit for power is in
watts
what’s the relationship between force and velocity
as force increase, velocity decreases
in words, what’s the relationship between power and velocity (explain the power velocity curve), and force too
at high force and low velocity, power is low because there’s high force but low velocity and it’s not balanced
Example: heavy objects move very slow, weightlifters
at low force and high velocity, power is low because there’s low force and high velocity and it’s not balanced
Example: a small ball moving very fast
power peaks at intermediate force and velocity.
Example: cycling, sprinting, rowing
systems used to generate ATP
Phosphocreatine
Glycolysis-Lactic Acid
Oxidative Phosphorylation
formula for phosphocreatine system
Cr−Pi+ADP→Cr+ATP
creatine plus ADP and Pi forms Creatine and ATP
is the phosphocreatine system fast or slow in atp production
fast, 4 mol atp/min
why is the phospho creatine system short lived
only provides energy for 5-8 seconds
what does the Glycolysis-Lactic Acid System do
converts glucose to pyruvate and makes atp
what is the speed of the Glycolysis-Lactic Acid System
moderate 2.5 atp/min
does the Glycolysis-Lactic Acid System support high intensity activities
yes, at < 70% max effort
the glycolysis lactid acid system produces ____ as a byproduct, which may affect muscle performance.
lactic acid
what does the oxidative phsophorylation process do
Aerobic process using oxygen, glucose, and fatty acids to make atp
is the oxidative phsophorylation system fast or slow
slow but efficient 1 mol atp/min
what is the best system to make atp with for long term acitvity, low intensity
oxidative phosphorylation, < 70% max effort
what is the fuel source for the first 5-10 minutes for oxidative phosphorylation
muscle glycogen
what is the fuel source for 2-4 hours for oxidative phosphorylation
blood glucose and fatty acids
3 types of muscle fibers
SO (Slow oxidative)
FOG (fast oxidative glyoclytic)
FG (fast glycolytic)
what is the speed for SO, FOG, and FG in that order
SO: slow
FOG: fast
FG: fast
metabolism for SO, FOG, and FG
SO: aerobic (oxidative)
FOG: mainly aerobic, some anaerobic (glycolytic)
FG: anaerobic (glycolytic)
fatigue resistance for SO, FOG, and FG
SO: high resistance
FOG: moderate resistance
FG: low resistance
applications for SO, FOG, and FG
SO: endurance activities (long-term), marathon running
FOG: middle distance (sustained power)
FG: sprints or weightlifting (short bursts of power)
what is the mitochondria and blood supply for SO FOG and FG
SO: high mitochondria, high blood supply, red myoglobin
FOG: medium mitochondria, medium blood supply, pink myoglobin
FG: low mitochondria, low blood supply, white myoglobin
whats the relationship between the SO, FOG, and FG and the force-power-velocity relationship
SO: narrower force and power curve
FOG: wider force and wider power curve
FG: in the middle
glycogen stores for SO, FOG and FG
SO: low
FOG: medium
FG: high
Max power for SO, FOG, and FG
SO: good
FOG: high
FG: very high
what is the max efficiency in the human muscle in percent
25%
Remaining energy from muscles is often lost as heat (e.g., from ____).
Calcium pumps
Isometric contractions (e.g., holding a plank) are energetically ____ because no mechanical work is done. (efficient or inefficient)
inefficient
Malignant Hyperthermia: cause mutations in calcium channels (e.g., DHPRs, RyRs) that lead to ____
constant Ca²⁺ release.
what are some symptoms of malignant hyperthemia (that causes constant release of calcium…)
Overheating, excessive energy use, muscle rigidity.
3 things endurance training increases
mitochondria, capillary density, muscle glycogen storage
strength training increases 2 things
myofibirls, phosphocreatine/ATP stores
2 types of fiber separated in fish
red fibres (oxidative): for steady swimming
white fibres (glycolytic): for fast bursts of energy
while other vertebrates have (mixed or separated) fibers?
mixed
You are riding a bike. On flat ground, your muscle was producing peak power. If you go on an incline, then what happens?
Is your leg moving slower or faster than before?
Is your muscle shortening slower or faster?
Is your muscle producing as much force as before?
How does power change?
Is your leg moving slower or faster than before?
Slower. Climbing a hill increases resistance, which reduces the velocity of your leg movements.
Is your muscle shortening slower or faster?
Slower. Muscle shortening velocity decreases as more force is required to push against the hill’s resistance.
Is your muscle producing as much force as before?
More force. Overcoming the incline requires greater force, even though velocity decreases.
How does power change?
Power depends on both force and velocity:
P=F×v
As velocity decreases and force increases, you may fall below peak power because muscles operate most efficiently at an intermediate velocity.
A muscle fiber has enough ATP for ~3 seconds of activity at max power. Additional energy must come from other sources:
phosphocreatin, oxidative phsophorylation, glycolysis
Why do muscles get warm during use?
During muscle activity, not all ATP energy is used for mechanical work (~25% max efficiency). The rest is released as heat.
ATP-consuming processes like the Ca²⁺ pumps (in the sarcoplasmic reticulum) and cross-bridge cycling generate thermal energy.
