Question { 5742 }

what is lineweaver burk equation?explain it?

Answer

he plot provides a useful graphical method for analysis of
the Michaelis–Menten equation:


Taking the reciprocal gives


where V is the reaction velocity (the reaction rate), Km is
the Michaelis–Menten constant, Vmax is the maximum reaction
velocity, and [S] is the substrate concentration

use: The Lineweaver–Burk plot was widely used to
determine important terms in enzyme kinetics, such as Km and
Vmax, before the wide availability of powerful computers and
non-linear regression software. As the y-intercept of such a
graph is equivalent to the inverse of Vmax; the x-intercept
of the graph represents −1/Km. It also gives a quick, visual
impression of the different forms of enzyme inhibition.
The double reciprocal plot distorts the error structure of
the data, and it is therefore unreliable for the
determination of enzyme kinetic parameters. Although it is
still used for representation of kinetic data,[2] non-linear
regression or alternative linear forms of the Michaelis–
Menten equation such as the Hanes-Woolf plot or Eadie–
Hofstee plot are generally used for the calculation of
parameters.[3]
When used for determining the type of enzyme inhibition, the
Lineweaver–Burk plot can distinguish competitive, non-
competitive and uncompetitive inhibitors. Competitive
inhibitors have the same y-intercept as uninhibited enzyme
(since Vmax is unaffected by competitive inhibitors the
inverse of Vmax also doesn't change) but there are different
slopes and x-intercepts between the two data sets. Non-
competitive inhibition produces plots with the same x-
intercept as uninhibited enzyme (Km is unaffected) but
different slopes and y-intercepts. Uncompetitive inhibition
causes different intercepts on both the y- and x-axes but
the same slope

problem:The Lineweaver–Burk plot is classically used in
older texts, but is prone to error, as the y-axis takes the
reciprocal of the rate of reaction – in turn increasing any
small errors in measurement. Also, most points on the plot
are found far to the right of the y-axis (due to limiting
solubility not allowing for large values of [S] and hence no
small values for 1/[S]), calling for a large extrapolation
back to obtain x- and y-intercepts.

Question { 9292 }

what is the abbreviation of CTF-FTB?

Answer

CTF-connective tissue factor.
There are three major types of muscle fiber. These are classified by how fast they contract or twitch. These are called
Slow twitch (ST):h are characterized by having a good deal of myoglobin and mitochondria. They are weaker than the other types, but are made to work without tiring for a very long time. Your heart is the absolute winner for slow twitch fiber, since it never stops working. (It does rest between beats, which is why cardiovascualr training is good for it -- your resting heart rate will drop, thereby giving your heart more of a break.) Other place you find slow twitch fibers are in the calf, neck and the quadriceps (thigh) muscle.
Fast twitch A (FTA) which has fairly short endurance lasting about 2 - 3 minutes and is designed to give great speed. This has larger nerves so it can fire faster and supplies about 5 times the amount of power that ST fibers do. This is dominant in the abs, triceps and hamstrings.
Fast twitch B (FTB) This is designed for bursts of power. It fatigues very quickly -- within a few seconds. These have typically 10 times the strength of slow twitch fiber.

Both types of fast twitch fiber have much in common and things that apply to both will use the abbreviation of FT.
You were born with whatever mixture you were born with, and you cannot grow different fibers, just thicken the ones you've got. Normally, young athletes should be evaluated for various events to see exactly what mix they have. For instance, one person might have a bit more fast twitch fiber in his or her quadriceps than another and therefore have an edge as a sprinter. While you cannot change the composition, you can alter some of the properties, such as making fast twitch fiber grow more mitochondria and therefore increase its endurance