5.0 Introduction

Question 1

What is the structure of cell membranes?

Answer 1

composed of lipids, proteins, and carbohydrates

Question 2

What is the plasma membrane?

Answer 2

a selective barrier that controls the movement of molecules between the inside and outside of the cell

Question 3

Describe the internal organization of cells.

Answer 3

cells can be classified as prokaryotes or eukaryotes, which differ in their degree of internal compartmentalization

Question 4

What is the endomembrane system?

Answer 4

an interconnected system of membranes that defines spaces in the cell, synthesizes important molecules, and traffics and sorts these molecules in and out of the cell

Question 5

What do mitochondria and chloroplasts both do?

Answer 5

they are organelles that harness energy, and likely evolved from free-living prokaryotes

Question 6

What is the cell theory?

Answer 6

• all organisms are made up of cells
• cells are the fundamental unit of life
• cells come from preexisting cells

there is no life without cells, and cells are the smallest units of life

Question 7

What led to the development of the cell theory?

Answer 7

cells differ in size and shape, but they share many features