Biological Molecules

• The biochemistry of life is shared across all organisms, this is indirect evidence of evolution.
• What are the four main types of organic molecules?

  Carbohydrates, lipids, proteins and nucleic acids
• What elements are in all of the molecules of life?

  Carbon, hydrogen and oxygen
• All organisms use the same nucleic acids as genetic material, use the same 20 amino acids to build proteins and use lipids and carbohydrates as energy stores and to make up their cell membranes and walls. These similarities give support for the theory that all animals and plants share the same common ancestor.
• What are monomers?

  Singular units from which larger molecules are made through the process of polymerisation
• What are some examples of monomers?

  Monosaccharides, amino acids and nucleotides
• What are polymers?

  Large molecules made from lots of repeating units (monomers) joined together.
• What are some examples of polymers?

  Starch, glycogen and DNA
• What is a condensation reaction?

  A reaction that joins two monomers together with the formation of a covalent bond, and involves the elimination of a water molecule.
• What is a hydrolysis reaction?

  A reaction that breaks the covalent bond between two monomers and involves the use of a water molecule
• What are the monomers for carbohydrates?

  Monosaccharides
• What are the monomers for proteins?

  Amino acids
• What are the monomers for nucleic acids?

  Nucleotides
• What is the covalent bond type formed in carbohydrates?

  Glycosidic bond
• What is the covalent bond type formed in proteins?

  Peptide bond
• What is the covalent bond type formed in nucleic acids?

  Phosphodiester bonds
• What is the polymer made from carbohydrate monomers?

  Polysaccharides
• What is the polymer made from protein monomers?

  Polypeptides
• What is the polymer made from nucleic acid monomers?

  Polynucleotides
• What are some polymer examples for carbohydrates?

  Glycogen, cellulose and starch
• What are some polymer examples for proteins?

  Enzymes, antibodies, channel proteins and haemoglobin
• What are some polymer examples of nucleic acids?

  Deoxyribonucleic acid and Ribonucleic acid
• What are monosaccharides?

  Individual sugar molecules (monomers) that make up larger molecules such as disaccharides and polysaccharides.
• What are the two types of sugar molecules?

  Pentose and hexose sugars
• What is a hexose sugar?

  A sugar that contains six carbon atoms
• What is a pentose sugar?

  A sugar molecule that contains five carbon atoms
• What are dissacharides?

  Carbohydrates that are formed when two monosaccharides join through a condensation reaction, forming a glycosidic bond between the two OH groups
• What is a polysaccharide?

  A complex carbohydrate that is formed when more than two monosaccharides are joined together by a condensation reaction, they can be broken down by hydrolysis back into their monomers.
• Polysaccharides can be formed from glucose monomers that are joined by either 1-4 or 1-6 glycosidic bonds, referring to the carbon number of the two molecules that have joined to form the bond.
• What is a 1-4 glycosidic bond?

  Where the glycosidic bond is formed between the first and the fourth carbon, they make long and unbranched chains
• What type of glycosidic bond is shown here?

  A 1-4 glycosidic bond

  
• What is a 1-6 glycosidic bond?

  Where the glycosidic bond is formed between the first and the sixth carbon, making long and branched chains.
• What type of glycosidic bond is shown here?

  A 1-6 glycosidic bond

  
• What is a reducing sugar?

  A reducing sugar is a carbohydrate that can donate electrons to another chemical, typically through a chemical reaction called a reduction, thus being known as reducing agents
• What is a non-reducing sugar?

  A carbohydrate that do not donate electrons to other molecules in chemical reactions
• Reducing sugars are all monosaccharides and some disaccharides
• Non-reducing sugars are never monosaccharides but some disaccharides
• What are some examples of monosaccharides?

  Glucose, galactose and fructose
• What type of sugar is glucose?

  A hexose sugar, meaning that it contains six carbon atoms.
• How many isomers does glucose have?

  Two