Growth Factors - Online Tutor, Practice Problems & Exam Prep

Growth Factors

In this video, we're going to begin our lesson on growth factors. Some microbes require growth factors from the environment that they cannot synthesize on their own. Growth factors can be defined as biological substances that promote cellular growth. Prestigious organisms are organisms that have complex nutritional requirements. In other words, prestigious organisms require many growth factors. If we take a look at our image down below, notice on the left-hand side, these little yellow circles that you see represent growth factors that a cell would obtain from its environment. The growth factor can bind to a specific growth factor receptor found in the membrane of the cell. When the growth factor binds to the growth factor receptor, it triggers a cascade of events inside the cell that ultimately leads to the cellular response. That cellular response is cell division, allowing the cell to divide and grow. Thus, the name "growth factors" leading to cellular growth. Again, a prestigious organism is an organism that has complex nutritional requirements and requires many different growth factors. Notice here we're showing you a prestigious organism saying, "I need tons of these growth factors." This concludes our brief introduction to growth factors. We'll be able to get some practice applying these concepts moving forward. I'll see you all in our next video.

Small organic molecules that must be provided to bacteria for them to grow are called:

• A. Minerals.
• B. Growth factors.
• C. Water.
• D. Vitamins.

Some microorganisms are difficult to culture because they require very specific growth factors to flourish. For example, Neisseria gonorrhoeae is difficult to culture because it requires blood, hemoglobin, many amino acids and many vitamins to grow. Neisseria gonorrhoeae, is an example of what type of organism?

• A. A halophilic organism.
• B. A photoheterotrophic organism.
• C. A fastidious organism.
• D. A facultative anaerobic organism.