Homework 2

Discussion: Energy for Life / Energy Reactions and Processes

In your primary post, please write a response of at least 125 words  to one (1) of the following three (3) bulleted options. In addition,  please make a substantive reply to a fellow student on any topic.

Discussion Topic 1. The phytoplankton that brought Earth to life.  Review the video (Johnson, 2014) about the "phytoplankton that brought  Earth to life" from the link given below, or from the link in the  Instructor's Insights area. In this clip, which is under 5 minutes in  length, Penny Chisholm discusses a tiny phytoplankton called  Prochlorococcus. Based on that video, please address the following:

• (a) What is the importance of Prochlorococcus for life on the planet Earth, both historically and in the present day?
   
• (b) Explain what the known geographic variations in  Prochlorococcus tell us about relationships between organisms and their  environments.
   

Discussion Topic 2. Characteristics of ATP.  If you choose this topic for your primary post, you must base your post  on the instructor's video about ATP (Cox, 2015). The video can be found  in the Instructor Insights area.

• (a) Describe two or more characteristics of ATP, covered in the video.
   
• (b) Explain how these characteristics are functionally important for the cell.
   
• Please note that I am looking for specific points that are covered in the video, so material gleaned from Wikipedia or other sources may not meet the requirements.
   

Discussion Topic 3. Chemosynthesis in the Giant Tubeworm.  The Giant Tubeworm (Riftia pachyptila) is an animal that lives on the  floor of the ocean, near hydrothermal vents that release very hot,  chemical-rich water. Like all organisms Riftia pachyptila needs energy  to go on living. It has a unique source of energy, and a unique way of  harvesting the energy (Deep Marine Sciences, 2015; JKM12988, 2016;  Kusek, 2007).

• (a) Describe how Riftia pachyptila get its energy.
   
• (b) Discuss how this relates to this week’s lessons.
   

References

Cox, J. F. (2015). Four minutes about ATP. [video clip]. Please see "Instructor's Insights" area for Week 3.

Deep Marine Scenes. (2013). Facts: Giant Tube Worms. [Video]. Retrieved from https://www.youtube.com/watch? v=IddCPTnmj4Q

JKM12988. (2016, December 5). Giant Tube Worms and symbiotic bacteria. [Video]. Retrieved from https://www.youtube.com/watch?v=dg6ZewBTRj8&t=6s

Johnson, R. (2014, March 5) The phytoplankton that brought Earth to  life. PBS Newshour. Public Broadcasting System. Retrieved from http://video.pbs.org/video/2365193451/

Kusek, K. M. (2007, January 12). Deep-sea tubeworms get versatile 'inside' help. Oceanus Magazine. Retrieved from http://www.whoi.edu/oceanus/feature/deep-sea-tubeworms-get-versatile-inside-help