CAIE Biology IGCSE Biological Molecules Definitions PDF
Document Details
CAIE
Tags
Summary
This document provides definitions for different biological molecules, including amino acids, carbohydrates, and lipids. It is likely supplementary material to be used in an IGCSE Biology course. The document does not appear to be a past paper, but rather a collection of definitions.
Full Transcript
Definitions and Concepts for CAIE Biology IGCSE Topic 4: Biological Molecules Definitions in bold are for supplement only Amino acids - Small molecules from which proteins are synthesised. Benedict’s test - A chemical test used to test for reducing...
Definitions and Concepts for CAIE Biology IGCSE Topic 4: Biological Molecules Definitions in bold are for supplement only Amino acids - Small molecules from which proteins are synthesised. Benedict’s test - A chemical test used to test for reducing sugars that produces a different colour based on the amount of reducing sugar present. Biuret test - A chemical test that produces a purple colour in the presence of protein. Carbohydrate - A large molecule that is synthesised from simple sugars. Cellulose - A type of carbohydrate made from many glucose molecules joined together. It is the main component of the cell wall in plants. Complementary base pairing - Describes how cross-links form between complementary base pairs. A pairs with T and C pairs with G. DCPIP test - A chemical test for vitamin C. Upon the addition of DCPIP, a colour change from blue to colourless indicates a positive test. DNA - A double-stranded polymer of nucleotides, wound to form a double helix, that carries the genetic code. Emulsion test - A chemical test that produces a cloudy emulsion when performed on lipids. Fats - Lipids that are solid at room temperature. Fatty acids - Small molecules from which fats are synthesised (along with glycerol). A molecule of fat contains three fatty acid molecules. Glucose - A small molecule from which many carbohydrates (e.g. glycogen, starch, cellulose) are synthesised. Glycerol - A component of fat molecules. Glycogen - A type of carbohydrate made from many glucose molecules joined together. It serves as an energy store in animals. Iodine test - A chemical test that produces a blue/black colour when iodine solution is added to a sample containing starch. Lipids - A group of large molecules that are synthesised from fatty acids and glycerol. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Nucleotides - The monomers of DNA consisting of a five-carbon sugar, a phosphate group and one of four chemical bases (A, T, C, G) attached to the sugar. Oils - Lipids that are liquid at room temperature. Protein - A large molecule that is synthesised from amino acids. Solvent - A substance which other solutes are dissolved in e.g. water. Starch - A type of carbohydrate made from many glucose molecules joined together. It serves as an energy store in plants. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc
