B2- enzymes

proteins, catalysts and enzymes

• protein molecules are made of long chains of amino acids
• the chains form specific shapes depending on its function
• they can be; tissues, hormones, antibodies or catalysts
• a catalyst is a substance that provides an alternate route to the activation energy which speeds up the reaction and isn't used up
• chemical reactions in a cell are controlled by proteins called enzymes- these are biological enzymes which speed up reactions
• the shape of the enzyme is called the active site and the other molecules can be fit into that shape
• the substrate can be held in the active site, connected to another molecule or broken down
• enzymes can: build bigger molecules from smaller ones e.g. starch from glucose
• convert one molecule into another e.g. a type of sugar into another one
• break down large molecules into smaller ones e.g. in digestive system

factors affecting enzyme action

• heat- the hotter the temp the more energy the molecules have so the more frequent the collisions BUT if it gets too hot…