hydrophilic

MIT Biology Hypertextbook: Chemistry Review

1.5 Hydrophobic Interactions Nonpolar molecules cannot form H-bonds with H2O, and are therefore insoluble in H2O. These molecules are known as hydrophobic (water hating), as opposed to water loving hydrophilic molecules which can form H-bonds with H2O. Hydrophobic molecules tend to aggregate together in avoidance of H2O molecules; hydrophobic interactions are clearly demonstrated when you put an oil drop on water. This attraction/repulsion is known as the hydrophobic (fear of water) force. To understand the energetics driving this interaction, visualize the H2O molecules surrounding a "dissolved" molecule attempting to form the greatest number of hydrogen bonds with each other. The best energetic solution involves forcing all of the nonpolar molecules together, thus reducing the total surface area that breaks up the H2O H-bond matrix.

1.1 Membrane Structure and Composition

into the hydrophilic environment. The membrane is approximately 5 nm thick.

To do so required the hydrophilic head

Membrane Transport Problem Answers

ends of the protein are hydrophilic and it is quite thermodynamically

Lipids

The lipids we'll be studying are phospholipids, the primary components of cellular membranes. Phospholipids are amphipathic; that is, they are both hydrophilic and hydrophobic. The "head" of a lipid moleule is negatively charged phosphate group and the two

phosphate groups facing out into the hydrophilic environment. There are

Membrane Proteins

hydrophilic and one hydrophobic . A hydrophilic domain (consisting of

hydrophilic amino acids) at the N-terminus is poking out in the

plasma membrane, and a hydrophilic domain at the C-terminus protrudes

attached to their hydrophilic domains that protrude into the extracellular

becomes apparent that hydrophilic domains (i.e. having hydrophilic amino

domains inserted into the plasma membrane separated by hydrophilic

Membrane Transport Mechanisms

cell. In fact, this hole can be a relatively hydrophilic environment if

hydrophilic side chains from the membrane-spanning chains surrounding