Once a DNA fragment has been isolated or produced (see the last article), the next step is often to produce many copies of it. One common way to do this is to use the polymerase chain reaction, which is a fairly simple process that can be automated. In this article we will look in detail... Continue Reading →
In the last article, we ended transcription with a strand of messenger RNA (mRNA) ready to leave the nucleus and travel to the ribosomes. The ribosomes are where translation happens - the next step in protein synthesis. Translation Translation begins with the mRNA strand settling between the two subunits of the ribosome. Each three base... Continue Reading →
Transcription is the first stage of protein synthesis. It transcribes a DNA sequence into a messenger RNA (mRNA) sequence. In eukaryotic cells, DNA is found in the nucleus so that is where transcription occurs. In prokaryotic cells it happens in the cytoplasm because the DNA is not contained in a nucleus. In this article will... Continue Reading →
Last week we looked at glucose and disaccharides, which are simple carbohydrates. However, many carbohydrate molecules are made up of long chains of monosaccharides joined together to form polysaccharides. Today we will look at polysaccharides made from glucose. We saw in the last article that to form the disaccharide maltose, two glucose molecules are joined... Continue Reading →
Glucose is a really important carbohydrate for living organisms because it is a reactant in respiration. It is a monosaccharide - a single sugar monomer that can be used to build other types of carbohydrates called polysaccharides. We will cover polymers of glucose in a separate article - today we will look at the structure... Continue Reading →
Water is extremely important to living organisms. Not only is it needed internally, but also externally as part of the environment - some organisms live in it. It is also a reactant in photosynthesis, so contributes to the oxygen in the atmosphere. In short, water is essential for life as we know it. Structure of... Continue Reading →
Today we are looking at adenosine triphosphate, often just abbreviated to ATP because as with most scientific terms, it's a bit of a mouthful. This molecule is very important in providing a quick source of energy for processes in cells. Let's have a closer look at its structure and function. Structure of ATP ATP is... Continue Reading →
Lipids are a particular interest of mine as my PhD was based on fat metabolism. They have important functions in the body, and can be both friend and foe. Fatty Acids Fatty acids all have the same basic structure, but have a variable R group which is a long hydrocarbon chain. If there are no... Continue Reading →
Amino acids are the building blocks of proteins. In this series we have already seen how nucleotides are the monomers joined together to make polynucleotide chains in DNA and RNA. Similarly, in proteins, amino acids are the monomers joined together to make polypeptide chains. Structure Firstly, let's look at the structure of an amino acid.... Continue Reading →
