Thursday, 30 April 2015

TAL Biology field trip to Denmark


The TAL Biology and Geography students went to Fanø in Denmark in March to carry out the coursework part of the A2 syllabus.

After landing in Billund (home of Legoland, which sadly we didn’t have time to visit), a short journey by taxi took us to the ferry port for a 10 minute trip to the island of Fanø. Here we were met by the Danish teachers that help us with the field trip, and they cooked up a large meal for everyone once we’d settled in to the apartments.


During the following days the students carried out their coursework on a variety of topics – lichen coverage on bunker walls, anthill frequency on salt marshes and heather distribution in relation to soil pH were some of the investigations carried out. The students were very hard-working – many of them worked late into the night on soil testing! The final evening was the now famous quiz night, where the students were given a series of questions by Jeppe, our Danish guide, about their time on Fanø. The winners got a packet of flødeboller, and the chance to laugh at the team that answered the question “how many times a day is the Wadden Sea flooded?” with “every 10 minutes”, as they ate their prize.





We returned by taxi to Billund, arriving back in London late in the evening, tired but happy at another successful trip. Many thanks to Mrs De Silva for coming along and providing support to everyone!

The photos are from Charlotte - thank you!

Thursday, 26 February 2015

Rubisco

Ribulose bisphosphate carboxylase (rubisco): where would we be without this protein?


It does look like a large tangle of spaghetti hiding 8 French flags, but it's also essential in the Calvin-Benson cycle.

Plants fix carbon dioxide (from the air usually) by attaching it to a 5-carbon molecule called ribulose-1,5-bisphosphate (thankfully abbreviated to RuBP). The 1-carbon CO2 and the 5-carbon RuBP forms two molecules of the 3-carbon molecule 3-phosphoglyceric acid (3-PGA). This is the first stage of the previously mentioned Calvin-Benson cycle. The 3-PGA goes on to be made into all the things a plant needs.

So what has all this got to do with the big ball of green pasta?

Rubisco is the enzyme that catalyses the combination of RuBP and CO2. No rubisco, no photosynthetic products, and so no life as we know it on planet Earth.

However, this isn't its only claim to fame; it's also the most abundant protein on the planet. In the average plant leaf, the chloroplasts (where all the above reactions take place) contain about half of the total protein content of the leaf. And about half of the protein content of a chloroplast is rubisco! This means that about a quarter of the protein in a leaf is rubisco.

Leaves form an essential part of the diets of animals (including us), and protein from the leaves is digested to amino acids, so animal proteins can be made. And guess which protein supplied you with a very large proportion of your building blocks...?

Wednesday, 28 January 2015

Serenade the Sun

It's amazing what a ball of mostly iron will do if you shine a light at it for four billion years.

'Dawn sun worship' by Philip Alexander


We've finished our course content in TAL biology so today we were looking back with the theme of light. This year is the UN International Year of Light and our Sun is the reason we are here: From what you ate today and how you traveled to where you are, to how life survived long enough for humans to evolve. We found eight biological processes that respond to light...

Plants:
  • Phototropism - When shoots grow towards the light, and roots away.
  • Photosynthesis - Nature's solar panel: converting light energy into sugar since the first oceans.
  • Phytochromes - Pigments that control when a plant flowers or a seed germinates.
  • Etiolation - More a response to the absence of light, when plants stretch under a rock.
Humans:
  • Iris reflex - Controls the amount of light that enters the eye.
  • Sight - The obvious one: Perceiving light rays as images.
  • Tanning - Pigmentation of the skin.
  • Vitamin D - Amazingly we can make a vitamin in our skin!
Add more in the comments!

Wednesday, 21 January 2015

The longest neurone in the human body is one of the peripheral neurones in the leg, travelling from the base of the spine to the foot - over 1 metre in some people!
Running this a close second is the neurone from the motor cortex to the lower part of the spine...

These are single cells, with highly specialised axons that span huge distances for their size. The question now is: how long could they get? If they grow proportional to a person's height, are they capable of indefinite growth if given sufficient nutrients?

Over a metre long and not visible to the naked eye...


(http://diamidinophenylindolee.tumblr.com/post/59584066686/single-neuron-under-the-electron-microscope)