1 Cells and Membrane Structure Free Online FlashCards

What does cell theory state about the composition of living organisms?

All living organisms consist of one or more cells.

What is the cell’s role in the organization of living things?

The cell is the basic unit of structure and function in living things.

According to cell theory, where do new cells come from?

New cells arise from preexisting cells.

Which four components are shared by all cells?

All cells have a plasma membrane, cytoplasm, DNA, and ribosomes.

Where is DNA located in a prokaryotic cell?

In prokaryotic cells, DNA is in a nucleoid region that is not enclosed by a nuclear membrane.

What internal structures distinguish eukaryotic cells?

Eukaryotic cells have a membrane-enclosed nucleus and membrane-bound organelles.

What is the basic framework of the plasma membrane?

A phospholipid bilayer: two layers of phospholipids arranged tail-to-tail.

How are phospholipids oriented in a membrane bilayer?

The hydrophilic heads face the watery fluids inside and outside the cell; the hydrophobic tails point inward, away from water.

What does amphipathic mean for a phospholipid?

It has both a water-attracting hydrophilic region and a water-avoiding hydrophobic region.

What makes the membrane fluid in the fluid mosaic model?

Many membrane lipids and proteins can move sideways within the membrane, making it flexible and dynamic.

What do membrane proteins contribute to membranes?

Membrane proteins give membranes many of their specific properties and functions.

How can membrane carbohydrate chains help cells?

Carbohydrate chains attached to some membrane lipids and proteins can help cells interact and be recognized.