Question

briefly explain each of the following terms. give examples and/or structures where appropriate. three sentences max.

steady-state assumption

bohr effect

hemiacetal

amphiphile

integral membrane protein

competitive inhibitor

kcat

GPI-linked protein

Answer 1

1) steady state approximationSets the rate of change of a reaction intermediate in a reaction mechanism to zero.
steady state situation in which all state variables are constant in spite of ongoing processes that strive to change them.

2) Bohr effect - the decrease in the oxygen affinity of a respiratory pigment (such as hemoglobin) in response to decreased blood pH resulting from increased carbon dioxide concentration in the blood

3) Hemiacetal - any of a class of compounds characterized by the grouping C(OH)(OR) where R is an alkyl group and usually formed as intermediates in the preparation of acetals from aldehydes or ketones.

4) Amphiphile - Amphiphiles are molecules containing a nonpolar hydrophobic region and a polar hydrophilic region will self-assemble in aqueous solution to form distinct structures such as micelles, vesicles, and tubules.

5) IMP - Integral proteins are the proteins of the cell membrane which are completely embedded in the bilayer of phospholipids and have hydrophilic and hydrophobic regions.
The region touching the hydrophobic tails are ought to be hydrophobic region where as the region of the protein exposed to the watery environment are the hydrophilic regions.

6) In competitive inhibition, an inhibitor molecule is similar enough to a substrate that it can bind to the enzyme’s active site to stop it from binding to the substrate. It “competes” with the substrate to bind to the enzyme.

7) Kcat, or k2 or turnover number (they all mean the same thing) is a measure of how many substrates one (1) enzyme can convert into a product per second. Vmax is simply Kcat times the enzyme concentration.

8) Glycosylphosphatidylinositol (GPI)-anchored proteins are a class of membrane proteins containing a soluble protein attached by a conserved posttranslational glycolipid modification, the GPI anchor, to the external leaflet of the plasma membrane. The GPI anchor is highly conserved among species and during evolution and GPI-APs play a wide variety of physiological roles, as enzymes, cell surface antigens, signalling receptors, cell adhesion, and migration molecules.