Chapter 4 - Biological Molecules Flashcards
what are carbohydrates?
substances that include sugars, starch and cellulose; they contain carbon, oxygen and hydrogen
what are sugars?
carbohydrates that have relatively small molecules; they are soluble in water and taste sweet
what is glucose?
a sugar that is used in respiration to release energy
what is glycogen?
a carbohydrate that is used as an energy store in animal cells
what is starch?
a carbohydrate that is used as an energy store in plant cells
what is iodine solution?
a solution of iodine in potassium iodide; it is oragne-brown and turns blue-black when mixed with starch
what is benedict’s solution?
a blue liquid that turns orange-red when heated with reducing sugar
what are reducing sugars?
sugars such as glucose which turn Benedict’s solution orange-red when heated together
what are fats?
lipids that are solid at room temperature
what are oils?
lipids that are liquid at room temperature
what are lipids?
substances containing carbon, hydrogen and oxygen; they are insoluble in water and are used as energy stores in organisms
what is emulsion?
a liquid containing two substances that don’t fully mix; one of them forms tiny droplets dispersed throughout the other
what is protein?
a substance whose molecules are made of many different amino acids linked together; each different protein has a different sequence of amino acid
what is amino acid?
a substance with molecules containing carbon, hydrogen, oxygen and nitrogen; there are 20 different amino acids found in organisms
what are antibodies?
molecules secreted by white blood cells which bind to pathogens and help to destroy them
what are pathogens?
microorganisms that cause diseases such as bacteria
what is keratin?
the protein that forms hair
what is a biuret reagent?
a blue solution that turns purple when mixed with amino acids or proteins
what is DCPIP?
a purple liquid that becomes colourless when mixed with vitamin C
what are nucleotides?
molecules that are linked together into long chains to make up a DNA molecule
what is a base?
one of the components of DNA; there are four bases A, C, G and T and their sequence determines the proteins that are made in the cell
what does the concept of complementary bae pairing mean?
its the way in which the bases of the two strands of DNA pair up; A always with T and C with G
