Exam II Flashcards
anaerobic ATP synthesis
glycolysis
aerobic ATP synthesis
Kreb’s cycle
per molecule of glucose, each Kreb’s cycle yields:
8 NADH
2 FADH2
2 ATP
concentrations of citrate synthase (CS) and malate dehydrogenase (MDH) are indicative of what?
enzyme concentrations can indicate a tissue’s ability to synthesize ATP
redox balance in e- transport chain
ratio of reduced/oxidized NAD+/ NADH & FAD+/FADH2
role of metabolic water in e- transport chain
keeps the cycle going by passing e-
NADH produces ____ ATP from ATP synthase
~2.5
FADH2 produces _____ ATP from ATP synthase
~2 ATP
coupling
-links e- transport to oxidative phosphorylation
coupling is loose, which means ATP production is usually around 30 as opposed to a theoretical 38
-coupling is considered “tight” when the P/O ratio is high
uncoupling protein #1 (UCP1)
- maintains redox balance
- some animals use this to produce heat
-provides a path for protons to diffuse from the intermembrane space to the mitochondrial matrix without ATP synthesis
normoxic
normal O2 concentration
hypoxic
below 10% O2 concentration
anoxic
0% O2 concentration
LDH isozyme in pyruvate—> lactate
LDHm
LDH isozyme in lactate–> pyruvate
LDHh
beta oxidation
lipid metabolism
gluconeogenesis
pyruvate—> glucose
expensive, uses ~6 ATP
Glyconeogenesis
pyruvate—> glycogen
excess lactate is transferred to
the heart and/or the liver (Cori cycle)
muscle fiber (cell) types vary in
metabolism
slow oxidative muscles (SO)
-red/slow twitch
-300 ATP/sec
-aerobic metabolism
-lots of myoglobin, mitochondria, and capillaries
-small diameter
-slow to fatigue, low power
fast glycolytic muscles (FG)
-white/fast-twitch
-600 ATP/sec
-anaerobic
-lots of power output
-less myoglobin, mitochondria, and capillaries
-quicker to fatigue
fast oxidative glycolytic muscles (FOG)
-intermediate between FG+SO
-600 ATP/sec
the power of muscles is dependent on
enzymes in myosin heads
muscle contraction
Ca++ binds to troponin
muscle relaxation
Ca++ ATPase pumps release Ca++
typical locomotion muscles are composed of
90% myofibrils
10% sarcoplasmic reticulum, mitochondria, and glycogen
composition of rattlesnake shaker muscles
30% myofibrils
26% sarcoplasmic reticulum
17% glycogen
26% mitochondria
-they can contract ~90 times/sec
synchronus flight muscles in insects
neural input and muscle action potentials are evoked with each muscle contraction
asynchronous flight muscles in insects
-the muscle contracts more than once per nerve impulse
-very sensitive to stretching and can be activated with no action potential
-demands more mitochondria but are very efficient
synchronus muscle mechanism
- elevator muscles pull wings up
- depressor muscles pull wings down
asynchronous muscle mechanism
- Vertical muscles pull on the roof of the thorax, causing the wings to rise. The thorax widens and lengthens, and stretches the longitudinal muscles.
- Longitudinal muscles pull on the anterior and posterior ends of the thorax, causing the wings to lower. The thorax narrows and shortens, and stretches the vertical muscles.
O2 deficit
difference between theoretical O2 demand and actual O2 uptake
excess post-exercise O2 consumption (EPOC)
-the difference between theoretical O2 demand and actual O2 uptake at the end
-not well understood why it occurs, independent of LDH
-can be described as “heavy breathing” after exercise
pay-as-you-go-phase
making ATP as you use it as O2 supply levels out
in order for muscle contraction to occur, ____ must bind to ____
Ca++, troponin (TN)
ATP synthase
permeable to protons and that couples the motive energy of the diffusing protons to the synthesis of ATP from ADP
P/O ratio
-the number of ATP molecules formed per atom of oxygen reduced to water
-electrons that pass the entire length of the electron transport chain from NADH to oxygen
a cell is in redox balance for NAD if……
it can convert NADH back to NAD as fast as NAD is being converted to NADH
anaerobic glycolysis
the entire sequence of reactions that converts glucose to lactic acid
steady-state mechanism
-the cell remains essentially constant in its levels of ATP and of the precursors and by-products of ATP production
-maintains homeostasis
-theoretically free of intrinsic limitations
*usually aerobic ATP production
-resting state, such as sitting and reading
non-steady state mechanism
-depletes supplies, accumulates products, or otherwise alters the conditions of its own operation at rates fast enough that the mechanism is self-limiting/self-terminating
-cannot persist for a long duration of time
*usually anaerobic ATP production
-active, such as running a race
steady-state criterion (4)
- produces ATP as fast as it is used
- uses raw materials no faster than they are replenished
- chemical by-products are voided as fast as they are made
- does not cause other changes in cell function that progress to the point of disrupting cell function
role of phosphagens in ATP production
synthesized by use of high energy phosphate bonds taken from ATP and later donate phosphate bonds to ADP to form ATP
what is the most abundant phosphagen in invertebrates?
arginine phosphate
what is the most abundant phosphagen in vertebrates?
creatine phosphate, high concentration in resting muscle
muscle cells often have enhanced O2 stores because…
they contain myoglobin, which bind to O2 molecules in high concentrations
muscle fatigue
exercise-induced reduction in a muscle’s ability to generate peak forces and maintain power output
what is necessary for muscles that yield a high speed (hypothetically)?
- fast myosin
- weak troponin
- lots of SR + pumps
- lots of mitochondria
- lots of capillaries: O2 to mitochondria +glycogen
maximal exercise
a given individual in a particular state of training is capable of a certain maximal rate of O2 consumption
submaximal exercise
exercise that requires less than the maximum rate of O2 consumption
supramaximal exercise
exercise that requires more than an individual’s maximum rate of O2 consumption
supramaximal exercise transition phase
-demands ATP at a greater rate than can ever be supplied by steady-state aerobic catabolism
-the pay-as-you-go phase is never reached
-anaerobic glycolysis must continue to be tapped for ATP as long as the exercise continues; this causes increasing O2 deficit and lactic acid buildup
light submaximal exercise transition phase
-transition phases occur at the start and end
-no lactate produced
-replenish O2 and phosphagen stores
heavy submaximal exercise transition phase
lactate accumulates at the start and is metabolized at the end (EPOC)
with increasing duration of exercise, ATP production shifts from _____ to ______
anaerobic to aerobic
composition of fish muscle
-SO muscle makes up ~10% or less of the total trunk muscle; never exceeds 25%
-SO muscle is used for slow, steady cruising
-the majority of the trunk is made up of FG-like fibers
-FG fibers are used for bursts of high-speed swimming and is prone to fatigue
O. princeps
high altitude, CO