Ch.5 The Structure and Function of Large Biological Molecules Flashcards
Macromolecules
A giant molecule formed by the joining of smaller molecules, usually by a dehydration reaction (ex: proteins)
Polymer
A long molecule consisting of many similar or identical building blocks linked by covalent bonds
Monomers
The subunit that serves as the building block of a polymer (some have functions of their own)
Enzymes
Specialized macromolecules that speed up chemical reactions
Dehydration Reaction
A reaction in which two molecules are covalently bonded to each other with the loss of a water molecule
Hydrolysis
Reverse of the dehydration reaction; bond between monomers is broken by the addition of a water molecule
Carbohydrates
Include sugars and polymers of sugars
What are the simplest carbohydrates?
Monosaccharides
Disaccharides
Double sugars consisting of two monosaccharides joined by a covalent bond
What are carbohydrate macromolecules?
Polymers called polysaccharides, which are composed of many sugar-building blocks
What are types of monosaccharides?
Glyceraldelcyde, ribose, glucose, galactose, and fructose
What are types of disaccharides?
Sucrose, lactose, and matose
Sucrose
Glucose + fructose
Lactose
Galactose + glucose
Matose
Glucose + glucose
What are types of polysaccharides?
Starch, glycogen, and cellulose
Monosaccharides
The simplest carbohydrate active alone or serving as a monomer for disaccharides and polysaccharides
What is the most common monosaccharide that is of central importance to the chemistry of life?
Glucose (C6H12O6)
What do monosaccharide molecular formulas typically have?
Some multiple of CH2O
What does the location of the carbonyl group in sugar affect?
Whether a sugar is either an aldose or ketose
What is typically the size of the carbon skeletons of sugars?
Ranges from three to seven carbons
Aldoses (aldehyde sugars)
Carbonyl group at the end of the carbon skeleton
Ketoses (ketone sugars)
Carbonyl group within the carbon skeleton
Trioses
Three carbon sugars (ex: glyceraldehyde)
Pentoses
Five carbon sugars (ex: ribose)
Hexoses
Six carbon sugars (ex: glucose)
Polysaccharides
Macromolecules, polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages
Function of polysaccharides
Some serve as storage material, others as building material for structures that protect the cell
How do plants and animals store sugar for later use?
In the form of storage polysaccharides
What is the architecture and function of a polysaccharide determined by?
Its sugar monomers and the position of the glycosidic linkages
Starch
A polymer of glucose monomers that plants store as granules within cellular structures known as plastids
What does starch represent?
Stored energy because the glucose it is made up of is a major cellular fuel
Glycogen
A polymer of glucose that is like amylopectin but more extensively branched (stored by animals)
Where do vertebrates store glycogen?
Mainly in liver and muscle cells
Cellulose
A major component of the tough walls that enclose plant cells