module 2-biological molecules Flashcards
water
atoms have slightly negative and slightly positive electronegativity, interact + and -
properties of water
high boiling point
freezes-ice, less dense, ice floats=cohesive, so can draw up water
solvent
medium for chemical reactions
good transport medium
coolant-mantain temperatures
forms on surfaces of ponds/lakes=insulating layer.
carbohydrates
single unit=monosaacharide, many of these=polysaacharides.
glucose
hexose monosaccharide
can be alpha or beta
polar and soluble in water.
alpha or beta?
OH on left side inverted
galacose+glucose
lactose.
2 alpha react
both OH react, form covalent bond-GLYCODSIC BOND, condensation reaction as water is a product. forms MALTOSE. 1-4 glycodsic bond
amylopepticin
1-4, and 1-6 glycodsic bonds.
branced structure=faster glucose release
amylose
alpha glucose molecules
twists to form helix, stabilised by h2 bonding
more compact, less soluble
glycogen
excess glucose in animals
insoluble.
highly branched and coiled=makes very compact
hydrolysis
releases glucose.
requires addition of water.
celluose
beta molecules turned upside, cannot coil or branch.
h2 bonding with microfibrils, join to make macrofibrils
=strong
=insoluble
bednict test
reducing sugar
1)place in boiling tube
2)add equal amount of bendict reagent
3)beat mixture
4)green-yellow-red
non reuducing
boiled with dilute hydrochloric acid
starch
ioodine test for potassium iodide.
yellow to purple/black
lipids
non polar molecules
macromolecules made from repeating units
Triglycerides
combine one glycorel with 3 fatty acids
glycerol=alcohol-OH
fatty acid=carboxyl group, and has hydrocarbon tail
both glycerol and triglyceride have OH
leading to formation of 3 water molecules, bonds=ester bonds
