AQA A Level Biology - Biological Molecules with correct answers

M=At ... What are biological molecules? Molecules made and used by living organisms e.g. Carbohydrates, Proteins, Lipids, DNA, ATP, Water, Inorganic Ions 00:03 01:36 What is a covalent bond? A chemical bond formed when atoms share electrons in their outer shell - creates a more stable compound What is a hydrogen bond? Negative region of one polarised molecule and positively charged region of another attract - weak electrostatic bond is formed What is a polar molecule? A molecule in which the (electrons) are unevenly distributed What is an ionic bond? The electrostatic attraction when ions with opposite charges (positive and negative) attract one another - weaker than covalent bonds Monomers Small molecules that can link together to form long chains Polymers Long chains of monomer sub-units Polymerisation A chemical reaction joining monomers in long chains to form a polymer. The monomers of a polymer are usually based on ...? Carbon Two examples of industrially produced polymers? Polyethene and Polyesters Three examples of polymers made naturally by living organisms? Polysaccharides, Polynucleotides and Polypeptides Basic sub-unit of a polysaccharide? Monosaccharides (or a single sugar) e.g glucose Basic sub-unit of a polynucleotide? Mononucleotide How are polypeptides formed? Linking together peptides that have amino acids as their basic sub-units (condensation reaction) Condensation reaction In polymerisation, each time a new sub-unit is attached a molecule of water is formed. Examples of condensation reactions? Polypeptide from amino acids. Polysaccharide starch from monosaccharide glucose. Hydrolysis reaction A chemical reaction that breaks apart a larger molecule by adding a molecule of water.