MCB 181R Exam 1

• Biogenic synthesis refers to the spontaneous generation of new molecular structures through chemical reactions under suitable environmental conditions.
• Microfilament

  Subunit: Actin Monomers
• Microtubules

  Subunit: a and d tubulin dimers
• Intermediate filaments

  Subunit: Diverse range of proteins
• It also plays a role in intracellular transport, cell division, and movement.
• The cytoskeleton is composed of three types of protein fibers: microfilaments, intermediate filaments, and microtubules.
• Actin filaments are involved in muscle contraction and cell motility.
• Actin monomers are subunits that make up microfilaments.
• Diverse range of proteins make up intermediate filaments.
• a and d tubulin dimers are subunits that make up microtubules.
• Cilia and flagella are made up of microtubule structures that move cells or fluids.
• What types of molecules can do simple diffusion across a cell membrane?

  small, nonpolar
• What type of transport involves using energy to build up an electrochemical gradient, and then using that electrochemical gradient to move another substance against its own concentration gradient?

  Secondary Active Transport
• A substrate crosses the cell membrane by traveling through a carrier protein, moving down its concentration gradient. What type of transport is this?

  Facilitated diffusion
• Which cell membrane composition is most likely at low temps?

  long tails
• The term phospholipid can best be described as

  A nonpolar lipid molecule that is made Amphipatic by the addition of a phosphate.
• When liquid H2O freezes, the solid ice that is formed

  is less dense
• cell membrane (plasma membrane)

  separates the contents of the cell from its environment
• nucleus

  houses the DNA of the cell