- Created by: Laura Dewhurst
- Created on: 27-04-15 12:34
What Is Chemistry?
Material chemistry: plastics, metal, etc
Biochemistry: chemistry of living things
Sensory neurochemistry: music
Pharmacology: psychoactive drugs
Alcohol: beer and wine
Food: proteins, fats, carbohydrates
Animals in Chemistry
Cone Snail: most venomous animal
Platypus: venomous (neurotoxins)
Sharks: fancy blood
Life Processes in Chemistry
Reproduction: hormones and pheromones
Movement: actin and myosin
Basic Life Processes
Elements are 'pure' substances, which can't be broken down any further by conventional processes.
The existing elements can be combined to make all the other stuff that exists.
Elements consist of atoms, which are made of particles: protons, neutrons and electrons.
Elements in Living Things
Most living things contain similar elements: this is because we all share the same evolutionary origin.
This is useful: it allows animals to eat plants, and other animals, to gain energy and material to grow.
Life on Earth
Mainly contains carbon, nitrogen, oxygen and hydrogen.
These probably came from space as meteorites and bits of comets.
Other elements important to living things: phosphates to make ATP for energy, and calcium for bones and shells.
Atomic number: number of protons
Mass number: number of protons and neutrons
The number of protons defines what an element is.
Isotopes: elements with different numbers of neutrons.
Radioisotopes: radioactive isotopes
Extra neutrons make the atom unstable.
Over time it can change into a different element by radioactive decay.
Radiocarbon Dating & Labelling
Can be used to measure the age of ancient carbon-containing materials, such as wood and bones.
After death, the amount of carbon 14 decays at a known rate: measuring the amount of carbon 14 left can help estimate the age: it works for things between 10,000 and 60,000 years old.
Radioactive isotopes can also be used to investigate physiological processes in living things.
Atoms and Electrons
Atoms use electrons to make compounds.
It is the interchanging or sharing of electrons which lets atoms join together and make compounds.
Electron shells: the negatively charged electrons are arranged in layers around the nucleus of protons and neutrons.
These aren't actual physical layers, they are more like energy levels.
2 electrons go into the first shell, 8 in the second, 8 in the third...
Full electron shells = stability
Elements are arranged so the columns indicate outer number of electrons and therefore similar properties.
E.g. all of the group 1 metals are very radioactive