Tuesday, 9 May 2017

How greasy are your chips? - By Elena Haro

 In this experiment Elena studied and compared the grease in different brands of potato chips or crisps. She used different bags of crisps, a rolling pin, plastic bags and wax paper.
She weighed the same amount of crisps and put each serving in a plastic bag. She rolled over them several times with the rolling pin making sure they were totally pulverized. She then placed each serving on a piece of wax paper and placed the wax paper on top of a piece of graph paper, After this she counted the number of squares that became translucent from the grease. Onlythe squares that were half full or more were counted. The squares that were less than half full were disregarded. Elena recorded the number of squares covered in grease and compared the different  brands. 





Monday, 24 April 2017

Biomolecules

BIOMOLECULES
They are the building blocks of life. Biomolecules make up cells and perform important functions in living things. They are mainly composed of carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus.
ORGANIC BIOMOLECULES ARE EXCLUSIVE TO LIVING THINGS, they are large molecules made up of many atoms.
CARBOHYDRATES
They are the most abundant, they are made up of saccharides or sugars, for example glucose or fructose.
Function: They are responsible for storing and transporting energy. However, others are structural components, e.g. cellulose.
Examples:
Sucrose – it is a disaccharide (made up of two sugars, glucose and fructose).
Cellulose-it is a polysaccharide, made up of many sugars, it is responsible for the cell wall structure of plants.
Starch (almidón)- it is a polysaccharide, responsible for storing energy. Pasta and rice contain starch.
LIPIDS (FATS)
Lipids are insoluble in water and difficult to digest. They perform many functions in living things.
Examples:
Fats and oils- they store energy.
Phospholipids-are the fundamental structure of cell membranes.
Steroids- They act as sexual hormones or vitamin D.
Waxes (ceras) – are produced by animals and plants as protection.
Lipids release a lot more energy than carbohydrates once digested.

PROTEINS
 These are macromolecules (large molecules) with very complex structures, made up of chains of smaller molecules called aminoacids.
Functions:
Their functions are very varied.
-They give structure to cells, e.g. collagen in the skin.
-They transport substances around the body e.g. haemoglobin transports oxygen in the red blood cells.
- They regulate chemical reactions e.g. enzymes
- They protect our body from bacteria and other microorganisms e.g. antibodies



NUCLEIC ACIDS
 These are also macromolecules, they are formed by the union of smaller molecules, nucleotides. Nucleic acids make up the genetic material of cells, that is the DNA or RNA.
EXAMPLES:
-         Deoxyribonucleic acid or DNA: it is found in the cell nucleus and makes up the chromosomes. It stores the information necessary for the functioning of the cell. It contains hereditary information.
-         Ribonucleic acid or RNA:  It is found in the cytoplasm. It participates in the synthesis of proteins.
INORGANIC BIOMOLECULES
THEY ARE NOT EXCLUSIVE TO LIVING THINGS. They are small molecules made up of very few atoms.
-Water: it is the most abundant substance in living beings. It makes up about 65% of your body. It is present in tissues, organs, blood and even in your teeth. It is used to carry out all the chemical reactions. It is also needed to transport substances and to regulate the body temperature.
-Mineral salts form the solid structure of living beings, such as skeletons, nails, horns, beaks etc. Mineral salts are also involved in chemical reactions and they are necessary for the transmission of nervous impulses.
Activity
Proteins are formed by chains of 20 different aminoacids.
a)    Imagine that proteins were made up of only two different amino acids called aa1 and aa2. Write the possible kinds of proteins combining the amino acids in a chain of three. For example aa1 + aa1 + aa1
b)    Changing one amino acid in a chain can produce
c)     a completely different protein. Do you think this fact is related to the wide variety of living things on Earth?









Monday, 20 March 2017

Newborn Baby Grey Kangaroo - Attenborough - Life of Mammals - BBC



  Marsupials are mammals that don't have a developed placenta. Marsupials have a very short gestation period and the joey is born in an essentially fetal state. These complete their development inside the mother's pouch. Once in the pouch the embryo climbs up their mother's body in search of a mammary gland to feed on. Some species of joeys stay in the pouch for upto a year or until the next joey is born. This fascinating video will show you how the undeveloped embryo is born and how it lives in th pouch. Kangaroos and koalas are marsupials as well as rat kangaroos and possums.

Monday, 16 January 2017

EXAM DATES

These are the exam dates for the second term:

- 6th February - E2A,B,C
- 8th February - E1B,C,D;F
- 10th February - E1A,E
- 15th February - E2D
- 16th February - E2E,F
- 8th March - E1B,C,D,F
- 10th March - E1A, E



Tuesday, 20 December 2016

Insects around the world - By Francisco Lemos

Francisco showed his amazing collection of insects at the Science Fair. It took him some time to find a suitable stand to display his collection on and eventually managed to recycle a stand from a hairdresser.


In the class, we coverd the stand with card and made individual labels with the names of all the insects. Francisco's knowledge not only includes the name of each of the species, but also the geographical areas they inhabit, the group or orders they belong to and many other physical features.
The collection included a variety of arthropods, like insects, arachnids and myriapods.







Solar Hot Dog Cooker - By Manuel Rodríguez


The Sun is a wonderful and free source of energy. It is there, just waiting to be used. It's a clean and very powerful source of energy. Spain is a particularly sunny country and learning how to benefit from the Sun's energy and using it in our interest is no doubt a way of reducing the use of other energy sources.
 In .this project we built a simple solar hot dog cooker for use on a sunny day. This project demonstrates how easy it is to make use of the Sun's energy.


 This hot dog cooker uses a reflective parabola. A parabola is a symmetric curve, that resembles the letter `u´. The focus is a point in the parabola, above the vertex, that is, it lies along the axis of symmetry.



 If we cover the parabola with a highly reflective material, such as, aluminium foil, it will act as a mirror and reflect the rays of light. The parabola is shaped so that it collects the Sun rays and focuses them at one point, This central point is called the focus. This point accumulates a lot of energy and is the most active point in the parabola. If we place the sausage along the focus, there is enough energy to cook it in a few minutes on a hot day.

 Manuel cooked various sausages this way at the Science Fair. He made the solar hot dog cooker by cutting a parabola out of a shoe box. First, he drew the parabola on graph paper using the formula y=ax2  and used it as a template .Then he covered the box with aluminium paper. He used two long scraps of cardboard to build supports for a skewer. He calculated the focus and placed a long wooden skewer at the focal point with a sausaged poked on it and left it in the Sun. Shortly after, the sasauge was perfectly cooked!

  

Friday, 18 November 2016

ESO 1 - FIRST TERM EXAM CONTENT

For the first term exam you must revise and study:
Unit 1 - The Earth in the Universe
Unit 2 - The Water Planet.

It's important to read carefully through the units and it's a good idea to underline the important parts (with a pencil). Try to think about what we have insisted on and repeated in the class.
It's also a good idea to read through the activities we he have done, the exam questions will be similar!