A chemical reaction involves reactants turning into products. You can tell when a reaction has happened because there will be production (or sometimes absorption) of energy; usually in the form of heat but sometimes light & sound too. There may also be a change of colour but this doesn’t always happen. The end products will …
Continue reading Rates Of Reaction…
Work done by Dr Nikola Koepke (formerly from Oxford University but now at Zurich Universtory) looked at the remains of skeletons from the 8th century BC until the 18th century AD and used changes in people’s heights over this period as a measure of how well fed they were. The study combined biology and archaeology …
Continue reading What Have The Romans Ever Done For Us…
More definitions and links to Twig Prep videos as a companion to Words (Chem. Ed.) Respiration – whilst dictionaries and encyclopaedia will define this as ‘supplying the cells with oxygen’ we always use it in the sense of “the process within all living cells that releases energy from food molecules (usually glucose)” aerobic – aerobic …
Continue reading Words, Words, Words (Bio. Ed.)…
Apologies – this has ended up being a long read. Don’t feel you have to do it all in one. I will post separate pieces on much of this in the future. This might be a useful page to refer back to in the future. Graphics like this annoy me slightly. The information is good …
Continue reading Food Groups…
Some of you will know that cows are my favourite animals so you can imagine how delighted I was to see a headline a few years ago in the Telegraph… “McDonald’s launches study into flatulent cows used in its burgers” This seems to include several of my favourite scientific themes; namely cows, the scientific method, food and burping (eructation). What …
Continue reading Cows – Nature’s Most Noble Beasts…
If you look at the word carbohydrate you can probably work out what elements it must be made from. The letters ate at the end of a compound indicate that there is oxygen built into the molecule. Examples would be copper sulfate (copper, sulfur & oxygen) or calcium carbonate (calcium, carbon & oxygen). Carbohydrate does …
Continue reading Carbohydrate…
I go on about amino acids a lot. Sorry about that! If you click here you will be logged into Focus eLearning (come straight back!), then if you click here you will be taken to a nice page about how the digestive enzyme pepsin breaks a protein molecule in your food down into individual amino …
Continue reading Tryptophan…
I have often mentioned the importance of nitrogen (in the form of nitrate) to the growth of plants. It gets mentioned pretty regularly in the questions after several posts and when I wrote about crop circles, Fritz Haber and Norman Borlaug. Plant nutrients often appear as part of exam questions so please forgive me if …
Continue reading Plant Nutrients Part One…
A catalyst is a substance that enables (or speeds up) a chemical reaction without itself being altered by that reaction. Catalysts, therefore, are not used up as they influence a reaction. Enzymes are biological catalysts – in other words catalysts that operate within living things. The names of enzymes are usually made by putting -ase …
Continue reading Biological Catalysts…
This post assumes that you have read That Is Like, So Unfair about what makes a fair test. When you are asked to comment on why a particular step is taken in an experiment it is tempting to answer, “To make it a fair test” without really thinking it through carefully. There are two other …
Continue reading Accurate & Precise…
