Chapter 2

Question 1

What is the plasma membrane? What are its functions?

Answer 1

The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells

The basic function is to protect the cell from its surroundings - consisted of a phospholipid bilayer with embedded proteins

Question 2

Where in the prokaryotic cell is DNA found? How is it organized?

Answer 2

Remember: prokaryotic cells do not have a nucleus

It is found in a coiled loop floating in the cytoplasm in a region called the nucleoid

Arranged in a simple circle

Question 3

Nuclear pore complex

Answer 3

A large octangonally symmetrical, cylindrical, structure formed of many different proteins

Question 4

Nuclear pore

Answer 4

The path for the assisted exchange of large molecules such as proteins and RNA molecules with the cytoplasm- small molecules just pass through

Question 5

Nuclear localization signal

Answer 5

An amino acid sequence that tags a protein for import into the cell nucleus by nuclear transport