Plasma Membrane

Three of the four macromolecules are found embedded within or are on the plasma membrane. Which macromolecule is not a major component of the plasma membrane?

Nucleic acids

1. These molecules form the framework of the plasma membrane; they associate to form two sheets.

2. To which of the four macromolecules does this molecule belong?

3. What term is used to communicate that the structure is two sheets?

4. Is the portion of the molecule facing the interstitial fluid or the cytosol polar or nonpolar?

5. What is the name of the portion of the molecule that forms the inner structure of the plasma membrane? (Hint: this should the name of the portion of the molecule as given in Chapter 2. See Table 2.4)

1. phospholipids

2. Lipids

3. Phospholipid bilayer

4. polar

5. Fatty acid tails

1. This molecule is responsible for providing strength to the membrane and stabilizing it against temperature changes:

2. To which of the four macromolecules does this molecule belong?

3. Is this a polar or nonpolar molecule?

4. Would it be found among the heads of the phospholipid or the fatty acid tails of the phospholipid?

1. Cholesterol

2. Lipids

3. nonpolar

4. Fatty acid tails

1. What is the term used to refer to the coating of sugar that is important for cell-to-cell recognition?

 

2. What two molecules make up this structure?

3. What does the prefix “glyco-” refer to?

4. Consider the name and using Fig 4.5 to help you, which part of the molecule would be integral in the membrane?

1. Glycocalyx

 

2. Glycoproteins glycolipids

3. sugar

4. protein

in the plasma membrane, the proteins that are dispersed within the lipids make up about half of the plasma membrane by weight (p109). The functions of these proteins are critical for cell function.

1. What is the general term for proteins that are embedded within and extend all the way across the plasma membrane? I

2. What is the general term for proteins that are not embedded, but are found on the external or internal surface of the plasma membrane?

1. Integral proteins

2. Peripheral proteins

These proteins catalyze reactions at the external or internal membrane surface:

Enzymes

These proteins are used by the cells in the immune system to distinguish between self and non-self:

Identity marker

These proteins provide a passage for polar and charged molecules to enter or leave the cell:

Channel proteins

These proteins move molecules into or out of the cell against their concentration gradients using energy:

pumps

These proteins provide a site on the internal surface of the membrane where microtubules, microfilaments, and intermediate filaments can attach:

anchoring site

These proteins allow cells to stick together:

Cell-adhesion proteins

These proteins bind molecules to signal some function within the cell or membrane:

Cell surface receptors

These proteins move molecules into or out of the cell with their concentration gradients:

Carrier proteins