Category Archives: respiration

Week 3: Biochemical Processes

living_cells

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The biological cell is not the static, neat drawing you find in text books, but a dynamic, differentiated, three-dimensional, living unit with many specialised processes occurring simultaneously. You should already know the basic structure and function of the cell, including the main organelles. This animated video shows some of the inner life of a cell – can you identify the cell membrane, embedded proteins and ribosomes? Over the next fortnight you will need to better understand the following biochemical cellular processes:

Cellular Respiration by Video Conference from GTAC

mitochondria_respiration

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Today our Year 12 students had the opportunity to work with Fran and Catherine from the Gene Technology Access Centre to learn more about cellular respiration. They participated in a 90 minute Polycom session using models and interacting with experts to gain insight into how cells respire and how research into this biochemical pathway may lead to the development of treatments for cancer. It is a wonderful opportunity for small, rural and isolated schools to be able to connect with this world-class educational centre, without the expense and inconvenience of long travel times, permission slips, risk-assessment forms and arranging buses or train tickets. On Monday we will participate in another GTAC session: “The Many Colours of Photosynthesis”. Students’ comments included:

“The experiment that was demonstrated was something we couldn’t do at school, so it was good to learn how that was done and analyse the data.” – Kiri

“The slideshow and worksheets were clear and informative, allowing us to understand and visualize the process of respiration”. – Che

“It was all really good, especially knowing what is important for the exam”. – Stephanie

What do bread and ginger beer have in common?

They are both made with yeast (Saccharomyces cerevisiae) – a living organism that produces ethyl alcohol and carbon dioxide when allowed to grow in suitable conditions. This is an example of anaerobic respiration, or fermentation, which produces a small amount of energy (ATP) compared to aerobic respiration. An animation of the process of ATP production during fermentation is here.

In bread making, the carbon dioxide gas is captured in a gluten matrix produced by working the flour together with water into a dough. When the dough is baked, the yeast is killed, the small amount of alcohol evaporates and the carbon dioxide produces a light, fluffy loaf of bread. More about the science of bread making here.

When making beer, sugar is added to ‘feed’ the yeast and carbon dioxide bubbles are produced, along with a small amount of alcohol (less than 0.5% in the bottle we will produce). The lemon juice and ginger added to homemade ginger beer is for taste.