Examples of H-band in the following topics:
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- Within the A-band is a region known as
the H-band, which is the region not superimposed by actin myofilaments.
- Within the H-band is the M-line, which is composed of myosin myofilaments and
titin molecules crosslinked by myomesin.
- At the level of the sliding
filament model, expansion and contraction only occurs within the I and H-bands.
- During contraction myosin ratchets along actin myofilaments compressing the I and H bands.
- During stretching this tension is release and the I and H bands expand.
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- By changing the pH of the solution, you can change the charge state of the solute.
- The pH of an aqueous solution can affect the solubility of the solute.
- As it migrates through a gradient of increasing pH, however, the protein's overall charge will decrease until the protein reaches the pH region that corresponds to its pI.
- The proteins become focused into sharp stationary bands with each protein positioned at a point in the pH gradient corresponding to its pI.
- Describe the effect of pH on the solubility of a particular molecule.
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- A carboxyl group (COOH) is a functional group consisting of a carbonyl group (C=O) with a hydroxyl group (O-H) attached to the same carbon atom.
- Carboxylic acids are characterized as weak acids, meaning that they do not fully dissociate to produce H+ cations in a neutral aqueous solution.
- Carboxylic acids can be characterized by IR spectroscopy; they exhibit a sharp band associated with vibration of the C-O bond between 1680 and 1725 cm-1.
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- Since most organic compounds have C-H bonds, a useful rule is that absorption in the 2850 to 3000 cm-1 is due to sp3 C-H stretching; whereas, absorption above 3000 cm-1 is from sp2 C-H stretching or sp2 C-H stretching if it is near 3300 cm-1.
- Standard abbreviations (str = strong, wk = weak, brd = broad & shp = sharp) are used to describe the absorption bands.
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- According to band theory, a conductor is simply a material that has its valence band and conduction band overlapping, allowing electrons to flow through the material with minimal applied voltage.
- In solid-state physics, the band structure of a solid describes those ranges of energy, called energy bands, that an electron within the solid may have ("allowed bands") and ranges of energy called band gaps ("forbidden bands"), which it may not have.
- Band theory models the behavior of electrons in solids by postulating the existence of energy bands.
- On the left, a conductor (described as a metal here) has its empty bands and filled bands overlapping, allowing excited electrons to flow through the empty band with little push (voltage).
- Apply the concept of band theory to explain the behavior of conductors.
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- Compounds having absorption bands in the visible or near ultraviolet spectrum may be electronically excited to such a degree that weak covalent bonds undergo homolysis.
- Each horizontal row of data is normalized to 1º C–H (1.0), but there are also large differences between rows.
- Thus the rate of reaction of 1º C–H with Cl• is a thousand times faster than with Br•.
- However, the less reactive bromine atom shows much greater selectivity in discriminating between 1º, 2º and 3º C–H groups.
- The exceptional facility with which S–H and Sn–H react with alkyl radicals makes thiophenol and trialkyltin hydrides excellent radical quenching agents, when present in excess.
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- The energy (ΔE) required to effect the electron promotion is therefore less, and the wavelength that provides this energy is increased correspondingly (remember λ = h • c/ΔE ).
- Benzene exhibits very strong light absorption near 180 nm (ε > 65,000) , weaker absorption at 200 nm (ε = 8,000) and a group of much weaker bands at 254 nm (ε = 240).
- The added conjugation in naphthalene, anthracene and tetracene causes bathochromic shifts of these absorption bands, as displayed in the chart on the left below.
- All the absorptions do not shift by the same amount, so for anthracene (green shaded box) and tetracene (blue shaded box) the weak absorption is obscured by stronger bands that have experienced a greater red shift.
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- Most of the states with low energy (closer to the nucleus) are occupied, up to a particular band called the valence band.
- In semiconductors, only a few electrons exist in the conduction band just above the valence band, and an insulator has almost no free electrons.
- Semiconductors and insulators are further distinguished by the relative band gap.
- In semiconductors, the band gap is small, allowing electrons to populate the conduction band.
- As the energy in the system increases, electrons leave the valence band and enter the conduction band.
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- IR (infrared) spectra for esters feature an intense, sharp band in the range 1730–1750 cm−1 assigned to νC=O, or vibration of the C=O bond.
- The C-H bonds adjacent to the carbonyl are weakly acidic, but undergo deprotonation with strong bases.
- In this diagram, the red part of the molecule represents the portion formerly attributed to ethanol (minus a H), and the green part of the molecule represents the ethanoic acid portion (minus an OH).
- Esterification is a form of dehydration synthesis, so the H and OH components are removed as water.
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- $\displaystyle \int_0^h \left ( p + \rho v^2 \right ) dz = \frac{1}{2} \rho g h^2 + \rho v^2 h.$
- $\displaystyle v_1 h_1 = v_2 h_2, v_1^2 h_1 + \frac{1}{2} g h_1^2= v_2^2 h_2 + \frac{1}{2} g h_2^2.$
- $\displaystyle v_1^2 = \frac{1}{2} g \frac{h_2}{h_1} \left ( h_1 + h_2 \right ), v_2^2 = \frac{1}{2} g \frac{h_1}{h_2} \left ( h_1 + h_2 \right ).$
- $\displaystyle q_1 - q_2 = g j \frac{\left (h_1^2 + h_2^2 \right ) (h_2 - h_1)}{4 h_1 h_2}. $
- \sqrt{g h_1}$ and $v_2 > \sqrt{g h_2}$.