Crystals: discover their beauty and how we can use them in biology, in the year of crystallography!

Introduction
Biology lecture hopefully used for CBS 2014
Useful information
Kit List: 

Ripple tank (Gordon reckons this will be easy to build)
Obstructions to create the correct waves...

Marshmellows
Cocktail sticks

100 2p coins

4 identical wolly animals
4 different identical wolly animals
4 more different identical wolly animals
A few sticks to make a unit cell
A tape measure with an arrow on the end of it

Building blocks (like the ones from cantilever bridge)

Laser pointer
Slits through which to break the light to make pritty diffraction pattern.

2 Demonstrators pretending to be a membrane transporter

Web camera with a shutter speed of a couple of seconds, or normal web camera with software that does that.

Some way of growing crystals... PBS??? NaCl???

Explanation
Explanation: 

Overview

This is a very exciting talk. Hopefully. Probably. Well, maybe. Possibly. Potentially. Anyway, this is all about trying to make crystallography appear fun, exciting, and wonderful. Thus this is what this talk is about. It is essentially a nice meander through how to do X-ray crystallography...

In the beginning

So then – welcome everyone, say your name, and thank the demonstrators for helping you throughout the talk. So then, let us begin.

This talk is all about three words, and these are the only things I would like you to remember. Protein X-ray crystallography. I am fully expecting you to not have any clue what they are. I am going to take each word, and tell you all about it, as it is one of the most amazing and incredible part of science

Proteins

Before I begin – let us first consider this. ~What do you find in a city? Anyone – hands up. Excellent. No you don’t find a UFO in a city normally, but nice try. Yes. Here are a list of examples – buildings, taxis, police cars, police stations, etc… Now let us take two examples – a taxi and a police station – what do you find in a taxi? (Ask around). Talk about steering wheel, brake, boot etc… Then what do you find in a police station (Again ask around)? Smoke detector, prison cells, doors etc…

So your body is just like this city. It has a huge number of things in it – and these are called cells – just like the taxis and the buildings. Now inside your cells there are a huge number of things that do stuff. Like the smoke detector – and these are proteins. They are very very small, but we want to know what they look like. Take a picture of the insides of a smoke detector – get to know what it looks like.

Just trying to take a photo. That is all.

Leads on to getting everyone to imagine they are proteins. I want to take a picture of you on this web camera – I want everyone to be as still as possible – 3,2,1,cheese. – What did you all do – you all froze in place – which is great because the web camera had a very slow shutter speed – it took in light for a whole 2/3 seconds. Now let us do it again – keep completely still, but this time, I want everyone to do jazz hands. Picture. Look – the hands are really blurred. In fact protein, when left in water, like it normally is inside you, is like you running around really, really fast all over the room, and when we take a picture of it using this technique, leads to a big blur. We want to freeze it in place, and this leads to us crystallising it.

What are crystals? See these beautiful examples above – which is what you automatically think of. Very beautiful. So what exactly are they? Repeat of a very small repeating unit in a very ordered way. It is a small unit repeating in a very ordered way.

So then, how do we build a crystal – it is just a repeat of lots of small building blocks. I want one brave volunteer to come down and build a tower from these wooden blocks – so then these blocks represent one unit of a crystal, and in a crystal they just repeat and repeat. So then, with these nice large blocks, build a tower. Go. Look how nice that is – a perfect tower. Give a huge round of applause.

Now then, it is time to get a demonstrator to build a tower as well – years of university training for this one moment. OK, I want you to build a tower out of (mass unveiling) these rubber ducks. Go. Watch him fail. Some things crystallise a lot easier than other things. Now we can add things to the solution to help them crystallise. For example, if we put the rubber ducks into these boxes, then they can now be stacked, and so now crystallise. This is what we do to proteins – they are essentially rubber ducks, and we add things to help them crystallise.

Why do we want to get them to crystallise – it freezes them in place. Right – everybody one hand with their neighbour – now try to do jazz hands without letting go. It is a lot more difficult, isn’t it? Now imagine you were joined together with a huge number of other people. Very difficult to do jazz hands. Thus we get a crystal which freezes them – so persuades them to stand still

How do we get a nice crystal? The important thing about building a crystal is that it takes time. Like writing this talk. In order for it to be nicely ordered. Imagine packing away to go on holiday. If you do it in two minutes – suitcase is a huge mess, whereas if you spend all day doing it, it is far more likely to be neat and nicely ordered – well hopefully…

Why does ordering the crystal matter – well, if I go over here to this OHP – I can explain why. Switch on an OHP. Look at this – it looks like a fuzzy circle doesn’t it. This is because all of these OHP sheets are disordered. If I now order them all – hey presto, get a triangle. Therefore having a nice ordered structure is important. If you get a horrible mess, cannot tell much from it.

So finally I come to the X-Ray Part of this talk… What is an X-Ray? Well, it is a special type of light, actually – you all know what light is – it can be thought of as a wave. However, there are other types of light as well, ranging from radio waves, to microwaves – warms up your food. It is what controls your TV (IR), and what is harmful from the sun. X-Rays, though are the most common place.

They are all a wave – possibly use a slinky, but no RA yet.

What is an X-ray – well you all know the hospital use – look at bones. Here we are looking at what is absorbed, and what isn’t. However, in protein X-Ray crystallography, we are interested in a very different thing – what is diffracted. Now to explain what happens we have this ripple tank here, happily chugging along – bringin up and down a plunger. Up, down, up down – look at the waves. This is an awesome model for light – it too is a wave that goes up and down. Now, do you see the pattern? What do you think happens when I put a block in it. – Get a very different picture now – the waves spread out from this point – get a pattern – called a diffraction pattern actually. Now look how it changes if I open up the second hole – get a very different pattern now. Same happens here with light.

Now I see some not sure faces in the audience – so I will now demonstrate this with light – I have in my hand a tiny grid – not as tiny as the proteins, but still really tiny, and I have two lasers – a red one and a green one. I am now going to shine it against the wall – see one single beam. Now if I put an EM grid in front of it – what happens? Wow – get a diffraction pattern – isn’t that exciting – it is just a series of dots though. Can we tell what this actually looks like in real life though – the answer is yes we can – use a lens – just like in a camera – this will then bring back our image of the light shining through the holes in this metal grid.

Now the question is – why don’t we just shine a laser on to the crystal – the answer is that it doesn’t quite work – look here – let me now change this to a green laser (was red) – so this is moving in the spectrum towards X-rays – notice how all the dots change position – how far apart the dots are depend both on how big the grid is, and on the light. Proteins are really, really close together, so we have to use X-rays.

Next question then – we use X-rays, why can we not use a lens like in a camera to get a pretty picture of the protein – answer – because there is no lens good enough. However we can do it mathematically – if we knew everything from these dots – we could work it out.

Now to get from these dots to nice pretty picture of a protein still takes a lot of work, and a lot of PhD students and software, but we will ignore that for now. We get a nice pretty picture of a protein, such as this one – hoorah. Now this is a very special protein called haemoglobin – what it does is that it carries oxygen round the entire body – like a taxi service. We get a nice picture, which looks like this.

However, there is a condition in which the protein is deformed – sickle cell anaemia – it is like having a taxi where you have forgotten to put in the back seats, so it carries oxygen less well. Totally changes the shape of a red blood cell – e.g. if you look at the crystal shown below, you get the following fluffy red blood cells- you can have a look on the way out

Finally, I am going to grow a crystal on the way out. Most crystals take a very long time to grow. However, occasionally, you can get very rapid crystallisation. Here is a solution of sodium acetate solution (brought in by demonstrator from next door). It is currently liquid – put it under the camera. Now if I add this small crystal – so as to add as a starting point for the tower of crystallisation – look it becomes a full crystal.

Thank you for listening – thank you for our funding bodies – and thank you to our demonstrators. On your way out – you can look at these crystals or these cells. Hope you have a pleasant day!

Risk Assessment
Date risk assesment last checked: 
Fri, 02/02/2018
Risk assesment checked by: 
Miffles
Date risk assesment double checked: 
Wed, 07/02/2018
Risk assesment double-checked by: 
Sarah
Risk Assessment: 

Ripple Tank

DESCRIPTION Perspex tray of water, with a ripple generator at one end creating the waves. Different blocks to put over it to create the wave pattern afterwards as well. Light above, and then a sheet of paper underneath on to which a camera is pointed.
RISKS
  1. Water spilling on to the floor causing slip hazard
  2. Water near electrical light
  3. Moving parts of the ripple creating device
  4. Wet blocks which form the wave guides
ACTION TO BE TAKEN TO MINIMISE RISKS
  1. Ensure that the water in the ripple chamber is not too deep
  2. Electrical items to be turned off at mains in event of nearby spillage
  3. Ensure that any blocks are placed on tissue/paper towels after leaving the device
  4. Make sure that no children get too close to the ripple making part of the machine
ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
  1. Wipe up any spills. Turn off electrical equipment if near that.
  2. Call First Aider in event of injury
  3. For any injuries from getting fingers inside motors, immediately turn off machine and call First Aider
  4. Call First Aider
Creating a crystal representation from marshmallows and cocktail sticks
DESCRIPTION People have 8 marshmallows, put them together in a cube (alternating white and pink) to model a NaCl unit cell.
RISKS
  1. Allergies to the marshmallows.
  2. Cocktail sticks may be used to poke other audience members/themselves
ACTION TO BE TAKEN TO MINIMISE RISKS
  1. Ensure that ingredients are clearly displayed. Ask for volunteers without allergies.
  2. Tell people who are looking after younger people to supervise them when they have the cocktail sticks, bin all cocktail sticks after demonstration.
ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
  1. For allergies, Call a first aider.
  2. For any injuries from cocktail sticks, call first aider.

Building blocks demo:

DESCRIPTION Get people to build a perfect tower in either 5 seconds, 30 seconds or 3 minutes, showing why it takes time to build the perfect crystal
RISKS
  1. Risk of stubbing fingers on blocks
  2. Dropping blocks on toes
  3. Risk of splinters from wooden blocks
ACTION TO BE TAKEN TO MINIMISE RISKS
  1. Warn volunteers to be careful when building their towers
  2. Ensure blocks are not liable to fall on to floor.
  3. Visual check of wooden blocks before hand to volunteers to ensure no splinters
ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
  1. In the unlikely event of injury from wooden blocks, call First Aider in event of injury.
  2. Any splinters in fingers - call first aider.

Laser pointer demo:

DESCRIPTION Laser pointer shining through different grids - diffraction pattern on the wall
RISKS
  1. Light shining into audience or presenters eyes.
ACTION TO BE TAKEN TO MINIMISE RISKS
  1. Shine light away from the wall. Ensure that there is also no reflections which would lead to it being shined into people's eyes
ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
  1. Immediately turn off laser. Call first aider if there is any persistent problem.

Crystal Growing:

DESCRIPTION Grow crystal in front of audiences eyes
RISKS
  1. Solution splashing on to floor (slip hazard), or into people's eyes (stinging sensation)
  2. Burns from lamp heating up
  3. Electrical equipment (lamp and camera) near to water (sodium acetate solution)
ACTION TO BE TAKEN TO MINIMISE RISKS
  • Do not overfill container with solution when pouring. Discourage audience members from getting too close or touching solution.
  • Do not touch hot lamp, switch off after demonstration to allow it to cool.
  • Use a tray to catch spills, mop up any spills before they reach electrical equipment, and demonstrator to take care to avoid splashing of solution onto electrical equipment.
  • Ensure presenter is aware of position of camera and lamp.
  • ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
  • Call first aider in case of injury.
  • Web camera:

    DESCRIPTION Take a picture of an audience with a slow shutter speed
    RISKS
    1. People not wanting picture to be taken
    ACTION TO BE TAKEN TO MINIMISE RISKS
    1. Any images taken will be immediately destroyed.
    ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
      -

    Coin tossing:

    DESCRIPTION Every single person gets a 2p coin. Then everyone stands up. Toss coin. If you are a head, stay standing, if you are a tail, sit down.
    RISKS
    1. People tossing the coin and it hitting someone, causing injury
    ACTION TO BE TAKEN TO MINIMISE RISKS
    1. Warn people that there only needs to be a little flick up into the air.
    ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
    1. Check if anyone hit by a coin. Call first aider in case of injury.

    Protein demonstration:

    DESCRIPTION Two CHaOS people pretending to be a protein, whilst the lecturer walks through them.
    RISKS
    1. Injury to the lecturer or CHaOS people
    ACTION TO BE TAKEN TO MINIMISE RISKS
  • Ensure that the action is well rehearsed.
  • ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
  • Call first aider in case of injury.
  • Demonstration of the Patterson Map

    DESCRIPTION Uses wooly animals as a visual aid
    RISKS
  • Animals falling on floor, acting as a slip hazard
  • ACTION TO BE TAKEN TO MINIMISE RISKS
  • Ensure animals are not on the edge of the table when demonstrating, and pick up any which fall promptly.
  • ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
  • Call first aider in case of injury.
  • FULL SIZED BINOMIAL DISTRIBUTION MODEL

    DESCRIPTION Nice demonstration of forming a binomial distribution, which is vital for all likelihood based methods
    RISKS
    1. Balls been released over the floor.
    2. Model smashing on floor.
    ACTION TO BE TAKEN TO MINIMISE RISKS
    1. Ensure balls are not released over the floor
    2. Ensure that model is well away from the edge of the table and stable, so it cannot fall over and shatter
    ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
    1. Collect any balls that have been released. Call first aider in event of injury.
    1. Sweep up any broken parts of the model. Call first aider in event of injury.

    HANDWARMER DEMONSTRATION

    DESCRIPTION Demonstration showing how handwarmers crystallise instantaneously
    RISKS
    1. The bag may burst open
    ACTION TO BE TAKEN TO MINIMISE RISKS
    1. Ensure that you do not press the bag too tightly
    ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
      Wash hands. Clear up any area covered by contents of the handwarmer.

    CRYSTALS

    DESCRIPTION Crystals to be shown and passed around
    RISKS
  • Possible choke hazard for small children with small crystals
  • Dropping crystals could cause injury.
  • Crystals could be sharp and cause cut injury
  • ACTION TO BE TAKEN TO MINIMISE RISKS
  • Do not pass round any very small crystals, or pass them round in sealed container.
  • Warn audience to handle crystals carefully
  • Ensure no sharp edges before passing them round (and using a sealed container if so)
  • Ensure all crystals collected back
  • ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
  • Call a first aider
  • If child chokes on crystal, call first aider, and advise parents to take them to A&E.
  • AUDIENCE JAZZ HANDS

    DESCRIPTION Whole audience jazz hands, freely and with one hand on neighbour, to show protein dynamics
    RISKS
  • Overzealous movement or pushing causing injury by hitting neighbour/seats
  • ACTION TO BE TAKEN TO MINIMISE RISKS
  • Encourage sensible behaviour and stop demonstration if getting out of hand
  • ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
  • Call a first aider in case of injury
  • RUBBER DUCKS TOWER BUILDING

    DESCRIPTION CHaOS demonstrator to attempt to build tower out of rubber ducks
    RISKS
  • Trip hazard from falling rubber ducks
  • ACTION TO BE TAKEN TO MINIMISE RISKS
  • Clear away rubber ducks after demonstration
  • ACTION TO BE TAKEN IN THE EVENT OF AN ACCIDENT
  • Call a first aider in case of injury
  • This experiment contains mains electrical parts, see separate risk assessment.
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