Covalent Bonds in Polymers A covalent bond is the sharing of two or more electrons between two atoms The electrons can be shared equally forming a nonpolar covalent bond or unequally (where an atom...
Biological Molecules: Key Terms The key molecules that are required to build structures that enable organisms to function are: Carbohydrates Proteins Lipids Nucleic Acids Water The key biological m...
Testing for Non-Reducing Sugars Sugars can be classified as reducing or non-reducing; this classification is dependent on their ability to donate electrons (a reducing sugar that is able to donate ...
The Benedict's Test for Reducing Sugars Method Add Benedict's reagent (which is blue as it contains copper (II) sulfate ions) to a sample solution in a test tube It is important that an excess of B...
Testing for Key Biological Molecules There are a number of tests that can be carried out quickly and easily in a lab to determine if a sample contains one of the key biological molecules (carbohydr...
Key Features of Viruses Viruses are non-cellular infectious particles that straddle the boundary between ‘living’ and ‘non-living’ They are relatively simple in structure; much smaller than prokary...
Structural Features of Typical Prokaryotic Cells Animal and plant cells are types of eukaryotic cells, whereas bacteria are a type of prokaryote Prokaryotes have a cellular structure distinct from ...
The Vital Role of ATP All organisms require a constant supply of energy to maintain their cells and stay alive This energy is required: In anabolic reactions – building larger molecules from smalle...
Electron Micrographs: Animal Cells TEM electron micrograph of an animal cell showing key features Exam Tip You should be able to describe and interpret photomicrographs, electron micrographs and dr...
Calculating Actual Size When investigating the size of organisms and biological structures you will use a microscope of a specific magnification to produce an image Photomicrographs are images obta...
Resolution & Magnification Magnification Magnification is how many times bigger the image of a specimen observed is in compared to the actual (real-life) size of the specimen A light microscope...
Eyepiece Graticules & Stage Micrometers An eyepiece graticule and stage micrometer are used to measure the size of the object when viewed under a microscope Each microscope can vary slightly so...
