Comparing Cells & Viruses

Virus: Structure

What is a Virus?

Have you ever had the flu? A cold? Chicken pox? If so, you have had a virus.
A VIRUS is a nonliving particle made of proteins, nucleic acids, and (sometimes) lipids.
Viruses are considered to be nonliving because they do not have the ability to reproduce on their own. They must be inside a host cell in order to reproduce.

Viruses differ widely in terms of size and structure. However, all viruses are much smaller than the cells they infect. Most viruses are so small they can be seen only with the aid of a powerful electron microscope.

Multiple Select

Observe the structure of the viruses pictured.

As you look from virus to virus, which structural components do all the viruses have in common.

[check all that apply]

• genetic material

• capsid

• cell membrane

• core

• cytoplasm

Virus: Structure

As you can see, all the viruses show some type of genetic material, either DNA or RNA, and a CAPSID or protein coat, surrounding the virus.
The capsid has three functions:

1. It protects the virus.

2. It contains special sites on its surface that allow the virus to attach to a host cell.

3. It provides proteins that enable the virus to penetrate the host cell membrane.

Labelling

Study the picture of a virus.

Label the virus by dragging the labels to the appropriate structure.

Drag labels to their correct position on the image

CAPSID

DNA or RNA

SURFACE PROTEIN

Virus: Structure

Viruses Compared to Eukaryotic Cells

Viruses are different from living cells.
Two eukaryotic cells - one a plant cell and the other an animal cell - are shown.
Eukaryotic cells contain membrane-bound organelles, such as a nucleus. 

Categorize

Options (12)

nucleus

chloroplasts

cell membranes

DNA or RNA

nucleoid

Capsid

plasma cell membrane

Compare and contrast typical structures found in viruses and eukaryotic (plant & animal) cells by organizing these options into the right categories.

Eukaryotic cell

Virus

Both cells & viruses

Prokaryote cell