module 1; biological molecules Flashcards
Define the term Monomer
Monomers are smaller units from which larger molecules are made
Define the term Polymer
Polymers are molecules made from a large no.of monomers joined together in a chain
Give examples of Monomers
1. Glucose
2. Amino acids
3. Nucleotide**
Give examples of Polymers
1. Starch
2. Cellulose
3. Glycogen
4. Protein
5. DNA & RNA
What is a Condensation reaction?
It’s a reaction that joins 2 molecules, creating a chemical bond and forms water as a by-product
What is a Hydrolysis reaction?
Breaks a chemical bond between 2 molecules using water
give examples of monosaccharides
- glucose
- fructose
- galactose
give examples of disaccharides and their monomers
- sucrose = glucose + fructose
- maltose = glucose + glucose
- lactose = glucose + galactose
draw a an alpha~glucose & beta~glucose monomer
alpha - OH group on C1 is at the bottom
beta - OH group on C2 is at the top
define the term isomer
isomers are molecules with the same molecular formula but have different structures
give examples of polysaccharides and where they are found
- starch - found in plants (cells e.g. chloroplasts)
- cellulose - found in plants (cell wall)
- glycogen - found in animals (muscle & liver cells)
describe the structure & function of starch
starch forms both amylose & amylopectin
store of alpha~glucose
- amylose
1,4 glyco bonds
unbranched helix - is compact so can fit a lot of glucose in a small space - amylopectin
1,4 & 1,6 glyco bonds
branched molecule - increases SA for rapid hydrolysis back to glucose
both are insoluble = won’t affect water potential
describe the structure & function of cellulose
beta~glucose monomers
1,4 & 1,6 glyco bonds
structure strength for cell wall
polymer forms long, straight chains held in parallel by many H bonds forming microfibrils
many H bonds = collective strength
insoluble = won’t affect water potential
describe the structure & function of glycogen
alpha~glucose
1,4 glyco bonds
store of glucose
highly branched molecule
branched = increased SA for rapid hydrolysis back to glucose
insoluble = won’t affect water potential
how are triglycerides formed?
by a condensation reaction between 1 molecule of glycerol & 3 molecules of fatty acids
what is the difference between a saturated & unsaturated fatty acid
a saturated fatty acid only has single bonds between carbons whereas unsaturated fatty acids have at least 1 double bond between carbons
what are the properties of triglycerides?
- energy storage - large ratio of energy storing C-H bonds = lots of energy stored in molecule
- high ratio of H to O atoms - acts as metabolic water source = can release water when oxidised (essential for animals like camels)
- don’t affect water potentials & osmosis - as they are large & hydrophobic = so they are insoluble in water
- low mass - a lot can be stored without increasing mass & preventing movement
how are phospholipids formed?
by 2 condensation reactions, 2 fatty acids bond to a glycerol resulting in 2 ester bonds
what are the properties of phospholipids?
- hydrophobic head - due to -ve charge on phosphate group
- attracts water & repels fats - as it’s charged
- hydrophobic tail repels water & mixes with fats - as it’s not charged
- 2 charged regions = polar
how is the phospholipid bilayer formed?
in water phospholipids are positioned in a way that the heads are exposed but the tails are not which forms bilayer
what are the monomers that form proteins called?
amino acids
draw the structure of an amino acid
(NH3) - (R)-(C)-(H) - (O)=(C)-OH
what do 2 monomers of proteins form & name the reaction that occurs
a condensation reaction occurs which joins 2 amino acids to one another by forming a peptide bond
how are proteins formed?
a series of condensation reactions occur which form a peptide bond between each amino acid forming a chain