Skip to main content
Ch. 3 - Cell Structure and Function
Bauman - Microbiology with Diseases by Taxonomy 6th Edition
Bauman6th EditionMicrobiology with Diseases by TaxonomyISBN: 9780134832302Not the one you use?Change textbook
Chapter 3, Problem 4

The term fluid mosaic has been used in describing the cytoplasmic membrane. How does each word of that phrase accurately describe our current understanding of a cell membrane?

Verified step by step guidance
1
Understand the term 'fluid mosaic' by breaking it into two parts: 'fluid' and 'mosaic'.
The word 'fluid' refers to the dynamic and flexible nature of the membrane, meaning that the lipid bilayer is not rigid but allows lateral movement of lipids and proteins within the layer.
The word 'mosaic' describes the membrane's composition, which is made up of various molecules such as phospholipids, proteins, and carbohydrates arranged in a patchwork or mosaic pattern.
Explain how the fluidity allows the membrane to adapt, self-heal, and enable the movement of membrane proteins that perform different functions like transport, signaling, and enzymatic activity.
Describe how the mosaic nature reflects the diversity of components embedded in or attached to the membrane, contributing to its selective permeability and functional complexity.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Fluidity of the Membrane

The term 'fluid' refers to the dynamic nature of the lipid bilayer, where phospholipids and proteins can move laterally within the layer. This fluidity allows the membrane to be flexible, self-healing, and enables the movement of membrane proteins essential for cell function.
Recommended video:
Guided course
02:10
Biological Membranes

Mosaic Structure

'Mosaic' describes the patchwork arrangement of various proteins embedded in or attached to the lipid bilayer. These proteins serve diverse roles such as transport, signaling, and structural support, creating a complex and heterogeneous membrane composition.
Recommended video:
Guided course
04:41
Discovering the Structure of DNA

Phospholipid Bilayer Composition

The cytoplasmic membrane is primarily composed of a bilayer of phospholipids, with hydrophilic heads facing outward and hydrophobic tails inward. This arrangement forms a selective barrier that regulates the passage of substances in and out of the cell.
Recommended video:
Guided course
04:05
Phospholipids
Related Practice
Textbook Question

A "9 + 2" arrangement of microtubules is seen in __________ .


a. archaeal flagella

b. bacterial flagella

c. eukaryotic flagella

d. all prokaryotic flagella

1557
views
Textbook Question

Which of the following is not a function of a glycocalyx?


a. It forms pseudopods for faster mobility of an organism.

b. It can protect a bacterial cell from drying out.

c. It hides a bacterial cell from other cells.

d. It allows a bacterium to stick to a host.

1267
views
Textbook Question

A scientist who is studying passive movement of chemicals across the cytoplasmic membrane of Salmonella enterica serotype Typhi measures the rate at which two chemicals diffuse into a cell as a function of external concentration. The results are shown in the following figure. Chemical A diffuses into the cell more rapidly than does B at lower external concentrations, but the rate levels off as the external concentration increases. The rate of diffusion of chemical B continues to increase as the external concentration increases.


a. How can you explain the differences in the diffusion rates of chemicals A and B?

b. Why does the diffusion rate of chemical A taper off?

c. How could the cell increase the diffusion rate of chemical A?

d. How could the cell increase the diffusion rate of chemical B?

1310
views
Textbook Question

Which of the following is most associated with diffusion?


a. Symports

b. Antiports

c. Carrier proteins

d. Endocytosis

1297
views
Textbook Question

Which of the following is not associated with prokaryotic organisms?


a. Nucleoid

b. Glycocalyx

c. Cilia

d. Circular DNA

914
views
Textbook Question

A local newspaper writer has contacted you, an educated microbiology student from a respected college. He wants to obtain scientific information for an article he is writing about “life” and poses the following query: “What is the difference between a living thing and a nonliving thing?” Knowing that he will edit your material to fit the article, give an intelligent, scientific response.

1350
views