C

• Enzyme


  Proteins acting as catalysts, made by living cells to speed up biochemical reactions, where the enzyme converts substrates into products
• Catalyst


  A substance that increases the rate of a chemical reaction but is not changed by the reaction
• Rate of reaction


  The speed at which a chemical reaction occurs
• Substrate


  The substance that an enzyme interacts with to create a product
• Product


  The substance formed as a result of a chemical reaction
• Metabolism


  All the chemical reactions that occur in living organisms, both intracellular and extracellular
• Intracellular


  Reactions that happen inside of the cells
• Extracellular


  Reactions that happen outside of the cells, for example digestion
• Enzymes


  • They are specific, and each enzyme catalyses one specific reaction or group of reactions
  • Because of enzyme specificity, living organisms have to produce many different enzymes
• Catabolism


  Reactions that break down larger molecules into smaller ones, for example digestion of food
• Hydrolysis reaction


  The reactions that occur during digestion, used to deconstruct polymers into monomers
• Anabolism


  Reactions that build up smaller molecules into larger ones, they require energy, for example photosynthesis. Macromolecules are produced from monomers using ATP. They are condensation reactions
• Condensation reaction


  A reaction where water is produced as a by-product
• Active site


  The specific region on the surface of the enzyme where the substrate binds to so that the reaction can be catalysed. The shape of the active site is specific so only certain substrates can bind to it
• Induced fit hypothesis


  When the substrate binds to the active site, the interaction causes them both to change and both their bond angles and bond lengths are altered, chaining the three-dimensional molecular shapes of the substrate and the active site
• Enzyme-substrate complex


  The temporary association between the enzyme and its substrate during a chemical reaction, where the enzyme binds to the substrate at the active site
• If the temperature increases in a liquid


  The rate of the substrate-active site collision will increase since it leads to a faster molecular motion
• Substrate concentration


  The amount of substrate present in a chemical reaction
• Denaturation


  When changes occur to an enzyme, such as the protein structure being altered by temperature, or chemicals, the enzyme no longer works as a catalyst. When the changes cannot be reversed the enzyme is denatured
• Enzyme activity


  How well an enzyme works in catalysing a chemical reaction
• Optimum


  A specific temperature or pH-value where the enzyme activity is the highest. Each enzyme has their own specific different optimums
• pH


  A measure of the concentration of hydrogen ions, a low pH means high concentration of hydrogen ions. Determines whether a substance is basic or acidic
• Polarity


  A molecule having a positive and a negative pole
• Amino acids


  The building blocks of proteins. Consists of one amine group, a carboxyl group, and a side chain
• Transition state


  A state that the chemical reaction needs to reach before it can be converted into a product. Energy is required for this; it is called activation energy and is used to break bonds in substrate molecules
• Activation energy


  The energy required to reach the transition state. It is used to break bonds in substrate molecules
• Independent variable


  The factor that is being investigated; they are varied to see what the effect is
• Dependent variable


  The result of the experiment, the factor that is being measured. The independent variable affects the dependent variable
• Controlled variable


  Factors that must be kept constant in an experiment so that they don't affect the results
• Adenosine triphosphate (ATP)


  A molecule used by cells as a source of energy
• Adenine


  A component of ATP, a nitrogenous base
• Ribose


  A sugar molecule found in the structure of ATP
• Phosphate, Pi


  A chemical group essential for ATP structure and function
• Nucleotide


  The building block of nucleic acids, like DNA and RNA, consisting of a nitrogenous base, a sugar, and a phosphate group
• Water soluble


  Able to dissolve in water
• Synthesis


  The process of combining simpler substances to form more complex ones
• Anabolic reaction


  A metabolic process that builds larger molecules from smaller ones, requiring energy
• Endothermic reaction


  A chemical reaction that absorbs heat from its surroundings
• Condensation reaction


  A chemical reaction in which two molecules combine to form a larger molecule with the elimination of water
• Active transport


  The movement of molecules across a cell membrane against their concentration gradient, requiring energy