Biological Molecules Flashcards
What is a monomer?
the basic subunit that joins to form larger molecules such as monosaccharides, amino acids, and nucleotides
What is a polymer?
a molecule made of long chains of a repeating subunit
What is a macromolecule?
a giant molecule such as polysaccharides, proteins, and nucleic acids
What is a carbohydrate?
sugars made of carbon, hydrogen and oxygen with the general formula Cx(H2O)n
What is a monosaccharide?
a single molecule of sugar
What is a disaccharide?
two monosaccharides joined by a glycosidic bond
What is a polysaccharide?
long chains of monosaccharides joined by glycosidic bonds
What is glucose?
the most common hexose sugar, which is used as energy in aerobic respiration and as a building block
What is alpha glucose?
an isotope of glucose in which the hydroxyl group OH on the first carbon is positioned below the ring structure
What is beta glucose?
an isotope of glucose in which the hydroxyl group OH on the first carbon is positioned above the ring structure
What is the bond between carbohydrates?
the glycosidic bond, C-O-C
How is the bond between carbohydrates formed?
by condensation, the removal of a water molecule
What are some common disaccharides?
- sucrose, a glucose + b fructose, linkage
- maltose, a glucose + a glucose
- lactose, glucose + galactose
What are some common polysaccharides?
- starch
- glycogen
- cellulose
- amylose
- amylopectin
What are some common monosaccharides?
- hexoses (glucose, fructose, galactose)
- pentoses (ribose, deoxyribose)
- trioses
How is the bond between carbohydrates broken?
by hydrolysis, the addition of a water molecule
What is amylose?
a very long, unbranched polymer of 1, 4-linked a glucose that forms helices
What is amylopectin?
a shorter, branched polymer of a glucose, where the straight chains form 1, 4 linkages, and the branches form 1, 6 linkages
What is starch?
the storage macromolecule found in plant cell chloroplasts, made of a mixture of amylose and amylopectin
What is glycogen?
the storage molecule found in animal cells, a polymer of 1, 4 and 1, 6-linked a glucose similar in structure to amylopectin, but more complexly branched and therefore tightly packed in granules
What is cellulose?
the structural component in plant cell walls, a polymer of 1, 4-linked b glucose, each molecule of which is rotated 180° to the next
crosslink to form microfibrils, which form fibres
these form insoluble fibres with high tensile strength
What is a lipid?
an insoluble molecule characterised by a bond between an alcohol and a fatty acid, commonly known as fats and oils