LESSON 5.1: Cell Transport & Homeostasis: Cell Structures Involved in Cell Transport

LESSON 5.1: Cell Transport & Homeostasis: Cell Structures Involved in Cell Transport

Name: ______Period: _____

LESSON 5.1: Cell Transport & Homeostasis: Cell Structures Involved in Cell Transport


1.Function of the plasma membrane:

  1. ______
  2. ______
  3. ______

2.Selective permeability______

  1. Most important substance that passes through = ______

WHY??? ______

3.Why is it important for inorganic ions, like sodium (Na+), potassium (K+), calcium (Ca2+), and chlorine (Cl-) to be able to pass through the plasma membrane? ______

4.What is the function of oxygen? ______

5.What do hormones do? ______

The Phospholipid Bilayer

Two layers of phospholipids; hydrophobic, or water-hating, interior (tails) and hydrophilic, or water-loving, exterior (heads)

Proteins embedded within it have a variety of functions

6.Hydrophobic molecules are ______, easily cross; if small enough

7.Hydrophilic molecules are ______, need help to cross; usually through embedded proteins

Proteins Embedded in the Plasma Membrane

8.What types of embedded membrane proteins are not involved in transport? ______

9.What types of embedded membrane proteins are involved in transport? ______

10.In the picture below label the peripheral proteins and the integral proteins…

Integral proteins types…

11.______allow ions, polar molecules to cross

  1. Types of transport proteins:
  2. Channel proteins  hydrophilic channel

Give examples of two molecules that can pass through channel proteins below:



What is the special name given to channel proteins that allow water to pass through them? ______

What type of channel protein open and closes in response to a stimulus allowing certain types of ions to cross the membrane? ______

  1. Carrier proteins  hold molecules and change shape as they pass them through

Give an example of a carrier protein: ______

Cytoplasm’s Role in Intracellular Transport

12.What do the enzymes in cytoplasm do? ______

13.What function do the salts carry out? ______

14.What is the purpose of cytoplasmic streaming? ______

Role of Cytoskeleton in the Cytoplasm

15.How many different types of threadlike structures make up the cytoskeleton? ______

16.Which of the structures from question 15 above are involved in intracellular cell transport? ______

17.______ composed of protein called actin; act like tracks within cells for myosin molecules

18.______ tracks for vesicle intracellular transport

The Endomembrane System in Eukaryotic Cells

19.What is the function of the endomembrane system? ______

20.Which organelles in cells make-up the endomembrane system? ______

21.When the organelles of the endomembrane system are not directly connected, how do they transport materials between them? ______

22.Where do the vesicles come from that are sending materials? ______

23.What do vesicles fuse with? ______

The Endoplasmic Reticulum (ER)

24.What types of molecules are transported by the ER? ______

25.Which types of ER forms vesicles to transport these molecules? ______

26.What organelle do these vesicles usually travel to next in the endomembrane system? ______

The Golgi Apparatus

Processes proteins and prepares them for use both inside and outside the cell.

Receives proteins from the ER that have been transported in vesicles, then packages and labels them; sending them on to their next destinations in another set of vesicles.

Golgi is also involved in the transport of lipids around the cell.


27.What do vesicles store and transport? ______

28.What organelles do they pinch off of? ______

Lysosomes and Endosomes

29.What organelle do lysosomes bud off of? ______

30.What is the main function of lysosomes? ______

31.What are pathogens? ______

32.What organelle do endosomes bud off of? ______

33.What is the main function of endosomes? ______

34.What do we call vesicles that are larger than 100 nanometers? ______

Special Transport Structure in Plant Cells

35.What are plasmodesmata? ______

36.Why are plasmodesmata needed in plant cells? ______

37.Label the following organelles of the endomembrane system on the picture below: endoplasmic reticulum, Golgi, vesicle, endosome, lysosome, and nuclear envelope.

Homeostasis and Cell Function

38.What do homeostatic mechanisms do? ______

39.What can happen to a cell if homeostatic regulation fails? ______


40.Review all we have learned in this lesson, by looking over your notes on the copy of the textbook given to you. On the back of this page summarize in your own words the topics covered and how they aid in cell transport and the maintenance of cell homeostasis. You should write a minimum of 3-4 paragraphs and include the following topics: plasma membrane’s role, role of membrane proteins, roles of cytoplasm and cytoskeleton, function and components of endomembrane system, special structure of plant cells that aid in transport against barriers, and how all these things help cells maintain homeostasis. This assignment is worth 15 points.