Search results
The polar heads contact the fluid inside and outside of the cell. The phosphate group is negatively charged, making the head polar and hydrophilic—or “water loving.” A hydrophilic molecule (or region of a molecule) is one that is attracted to water.
Consider substances that can easily diffuse through the lipid bilayer of the cell membrane, such as the gases oxygen (O 2) and carbon dioxide (CO 2). These small, fat soluble gasses and other small lipid soluble molecules can dissolve in the membrane and enter or exit the cell following their concentration gradient.
Specify the chemical properties of water. The smallest, most fundamental material components of the human body are chemical elements. All of the elements found in the human body—elements that include phosphorus, carbon, sodium, and calcium, to name a few—originated in stars.
Molecules with polar covalent bonds have “poles”—regions of weakly positive and negative charge—and have a triangular three-dimensional shape. An atom of oxygen and two atoms of hydrogen form water molecules by means of polar covalent bonds.
The structure of the lipid bilayer allows only small, non-polar substances such as oxygen and carbon dioxide to pass through the cell membrane, down their concentration gradient, by simple diffusion.
14 sie 2020 · Define chemical bonding, molecules, salts, and compounds; and list 3 types of chemical bonds important for the study of human physiology; Define ionic bonds and describe how they form, and define salts; Define covalent bonds and describe how they form, and differentiate between the two types of covalent bond
1 sty 2005 · Some molecules (e.g., oxygen, carbon dioxide, and water) can easily cross the plasma membrane, whereas other substances (e.g., large molecules and ions) must move through the protein channels.
