Tag: Cells

What Students Want to Know About Cells

Cell Day 2014

During a live online chat dubbed “Cell Day,” scientists at NIGMS recently fielded questions about the cell and careers in research from middle and high school students across the country. Here’s a sampling of the questions and answers, some of which have been edited for clarity or length.

What color are cells?
While cells with lots of iron, like red blood cells, may be red, usually cells are colorless.

How many different types of cells can be found inside the human body?
There are about 200 cell types and a few trillion total cells in the human body. That does not include bacteria, fungi and mites that live on the body.

Is it possible to have too many or not enough cells?
The answer depends on cell type. For example, within the immune system, there are many examples of diseases that are caused by too many or not enough cells. When too many immune cells accumulate, patients get very large spleens and lymph nodes. When too few immune cells develop, patients have difficulty fighting infections.

How fast does it take for a cell to produce two daughter cells?
Some cells, for example bacterial ones, can produce daughter cells very fast when nutrients are available. The doubling time for E. coli bacteria is 20 minutes. Other cells in the human body take hours or days or even years to divide.

Do skin cells stretch or multiply when you gain weight?
The size of cells is tightly regulated and maintained so they do not stretch much. As the surface area of the body increases with weight gain, the number of skin cells increases.

Why do cells self-destruct?
The term for cellular self-destruction is “apoptosis” or “programmed cell death.” Apoptosis is very important for normal development of humans and other animals as it ensures that we do not have too many cells and that “unhealthy” cells can be eliminated without causing harm to the surrounding cells. For instance, did you know that human embryos have webbing between their fingers and toes (just like ducks!)? Apoptosis eliminates the cells that form the web so that you are born with toes and fingers.

In what field is there a need for new scientists?
I would say that there is a need for scientists who can work at the interface between the biological and biomedical sciences and the data sciences. Knowing sophisticated mathematics and having computer skills to address questions like ‘what does this biomedical data tell us about particular diseases’ is still a challenge.

What is a scientist’s daily work day like? Is all of your time spent in a lab testing or like in an office throwing ideas around?
There are lots of different kinds of jobs a scientist can have. Many work in labs where they get to do experiments AND throw ideas around. Working in a lab is a lot of fun—you learn things about the world that no one has known before (how cool is that?). Other important jobs that scientists can do include writing about science as a journalist, helping other scientists patent new technologies they invent as a patent agent or lawyer, or working on important scientific policy issues for the government or other organizations.

Capitalizing on Cellular Conversations

Fat cells
Fat cells such as these listen for incoming signals like FGF21, which tells them to burn more fat. Credit: David Gregory and Debbie Marshall. All rights reserved by Wellcome Images.

Living things are chatty creatures. Even when they’re not making actual sounds, organisms constantly communicate using chemical signals that course through their systems. In multicellular organisms like people, brain cells might call, “I’m in trouble!” signaling others to help mount a protective response. Single-celled organisms like bacteria may broadcast, “We have to stick together to survive!” so they can coordinate certain activities that they can’t carry out solo. In addition to sending out signals, cells have to receive information. To help them do this, they use molecular “ears” called receptors on their surfaces. When a chemical messenger attaches to a receptor, it tells the cell what’s going on and causes a response.

Scientists are following the dialogue, learning how cell signals affect health and disease. They’re also starting to take part in the cellular conversations, inserting their own comments with the goal of developing therapies that set a diseased system right.

Continue reading this new Inside Life Science article

Cool Images: Holiday Season Cells

Yeast cells deficient in zinc and the Tsa1 protein have protein tangles. Credit: Colin MacDiarmid and David Eide, University of Wisconsin-Madison.

Yeast cells deficient in zinc and the Tsa1 protein have protein tangles. Credit: Colin MacDiarmid and David Eide, University of Wisconsin-Madison.

Just in time for the holidays, we’ve wrapped up a few red and green cellular images from basic research studies. In this snapshot, we see a group of yeast cells that are deficient in zinc, a metal that plays a key role in creating and maintaining protein shape. The cells also lack a protein called Tsa1, which normally keeps proteins from sticking together. Green areas highlight protein tangles caused by the double deficiency. Red outlines the cells. Protein clumping plays a role in many human diseases, including Parkinson’s and Alzheimer’s, so knowledge of why it happens—and what prevents it in healthy cells—could aid the development of treatments.

See more festive images!