Topic 1 - Biological Molecules Flashcards
(63 cards)
Covalent Bond
Type of chemical bond in which two atoms share a pair of
electrons.
Ionic Bond
A bond between a positive ion which has lost an electron(s)
and a negative ion which has gained an electron(s)
Hydrogen Bond
Chemical bond formed between the positive charge on a
hydrogen atom and the negative charge on another atom of
an adjacent molecule
Polar Molecule
A molecule which has a partially positive charge in one part
of the molecule and completely negative charge in another
part (a dipole)
Monomer
One of many small molecules that combine together to form
a polymer
Polymer
Large molecule made up of many repeating smaller
molecules (monomers).
Polymerisation
The process of making a polymer
Condensation
Chemical process in which two molecules combine to form a
more complex one with the elimination of a simple
substance, usually water. Many biological polymers (e.g.
polysaccharides, polypeptides) are formed by condensation.
Hydrolysis
The breaking down of large molecules into smaller ones by
the addition of water molecules.
Metabolism
All the chemical processes that take place in living
organisms.
Carbohydrate
Compounds made from carbon, hydrogen and oxygen. Either
monosaccharides, disaccharides and polysaccharides.
Monosaccharide
A single sugar e.g. glucose
Organic Molecule
Molecules containing carbon that can be found in living
things; four classes are carbohydrates, proteins (chain of
amino acids), lipids, and nucleic acids
Disaccharide
Made up of two sugar units that are formed by a
condensation reaction. Monosaccharides are joined by a
glycosidic bond.
Polysaccharide
Made of many sugar units that are formed by a condensation
reaction. Monosaccharides are joined by a glycosidic bond.
Hexose sugar
A sugar made up of 6 carbons.
Glucose
C6H12O6 – a single sugar which is used in respiration.
Reducing Sugar
A sugar that serves as a reducing agent. All monosaccharides are reducing sugars along with some
disaccharides.
Benedict’s reagent
Blue solution which is used to test for reducing and nonreducing sugars.
Reducing sugar test
Heat solution with Benedict’s reagent to test for reducing
sugars. If it goes brick red then a reducing sugar is present.
Glycosidic bond
Bond between sugar molecules in disaccharides and
polysaccharides.
Non-reducing sugar
A sugar which cannot serve as a reducing agent. An example
is sucrose.
Non-reducing sugar test
Following a negative reducing sugars test. Heat the solution
with HCl to hydrolyse the non-reducing sugar into it’s
monosaccharides. Then perform the Benedict’s test again. If
you get a positive result after hydrolysis then a non-reducing
sugar is present.
Starch
A polysaccharide found in plant cells made up of alphaglucose – comprised of amylose (alpha-1,4 glyosidic bonds)
and amylopectin (alpha-1,4- and alpha-1,6-glyosidic bonds).