Biological Molecules Flashcards
Alpha and beta glucose are isomers of each other- describe the difference between their structures..
H above OH= alpha
OH above H= beta
Draw!!!
Monomer
The simplest unit, or repeating unit of a polymer
Polymer
Long-chain molecules made out of sub units (monomers)
Macromolecule
A large complex molecule
Monosaccharide
The simplest units of carbohydrates and simplest form of sugar
Disaccharide
Sugars made out of two monosaccharides, joined together with a glycosidic bond
Polysaccharides
Subunits of monosaccharides that are joined together with condensation reactions
Condensation reactions-formation of the glycosidic bond
A glycosidic bond is created when two or more monosaccharides join together
Condensation reaction causes the two hydroxyl groups (OH-) to align, dropping a water molecule and joining the molecules
What is a hydrolysis reaction?
The opposite to a condensation reaction-causes the breakage of glycosidic bonds
Involves the addition of water to cause the components to complete the molecules with the missing H20 and therefore separate
Characteristics and uses of polysaccharides
Range from highly branched to linear
Notable polysaccharides- starch (made up of amylose and amylopectin), glycogen and cellulose
Used for the storage of short chain molecules, allowing the body to have reserves of useful molecules e.g. Glucose stored as polysaccharide glycogen, making it inert until it is required
Characteristics and uses of Triglycerides
Acid+ alcohol = ester
Triglycerides are chemically bonded tri esters of fatty acids and glycerol
Formed by combining three fatty acid molecules with glycerol
Provided ur body with energy but most importantly to store energy from protein, fats and carbohydrates
Characteristics and uses of phospholipids
They are dipolar- heads are hydrophilic and tails hydrophobic
Used in the body to create phospholipid bilayers- fundamental feature of cell membranes
Amino acids
Monomers from which all proteins are made
20 different amino acids
Each have a amine group (NH2) and and a carboxylic acid (COOH) at the other end
R group is what differentiates each 20 amino acids
Peptide bond
Amino acids combine through another form of condensation reaction to create a peptide bond
NH2 looses a H molecule and COOH looses a hydroxyl (OH)
Remaining link made up of C=O and N-H ( this is the peptide bond)
Organisation of protein catagories
Primary
Secondary
Tertiary
Quaternary
Primary structure of proteins
The number sequence and type of amino acids that make up a polypeptide chain
Secondary structure of a protein
If the structure of a polypeptide chain is an alpha helix, beta sheet, or both
Tertiary structure of a protein
This is a protein with a 3D globular shape, established through the formation of various bonds between non adjacent amino acids
Quaternary structure of a protein
When a protein consists of two or more polypeptide subunits
Haemoglobin- example of globular protein
Consist of four polypeptide chains- two alpha and two beta
Each is associated with a heam group containing iron
Each molecule is almost a spherical shape
Aids it’s function as iron combines reversible with oxygen
Collagen- example of a structural protein
Consists of long polypeptide chains, each associated with each other to form a triple helix structure
Helix is covalently bonded side to side-makes protein flexible strong against pulling forces and does not stretch
Characteristics of water
Dipolar molecule- oxygen has slight negative charge and hydrogen has slight positive charge
These charges result in weak forces of attraction between adjacent molecules- called hydrogen bonding
Why is hydrogen bonding in water significant?
Water acts as a solvent to substances that are hydrophilic as they can dissolve and create a solution
High specific heat capacity- large amount of energy needed to increase temperature- useful for organisms to maintain stable body temp
High latent heat of vaporisation- large amount of every needed to break bonds and change state- again helpful to maintain body temp
Structure of glycogen
Similar to amylopectin but more highly branched due to 1,6 glycosidic bonds between alpha-glucose molecules forming frequently
Structure of cellulose
A polymer of beta glucose
It is a structural polysaccharide found in cell walls
Long chain of cellulose molecules form bundles knows as microfibrils- become cellulose fibres
Held together with hydrogen bonding
