biological molecules Flashcards
name 4 monosaccharides
-alpha glucose
-beta glucose
-galactose
fructose
what bond is formed when a disaccharide is formed
glycosidic and a condensation reaction forms to bond the monosaccharides.
name 3 disaccharides
-maltose
-lactose
-sucrose
how is maltose formed
glycosidic bond formed from a condensation reaction joined by a 1-4 glycosidic bond between 2x alpha glucose molecules.
how is sucrose formed
an alpha glucose and fructose
name the 4 polysaccharides
-chitin.
-glycogen
-cellulose
-starch
what polysaccharide stores glucose in plants and contains amylose and amylopectin
starch
what is amylose
a polysaccharide with coiled chains of a-glucose and are 1-4 glycogen bonds and takes longer to separate.
why is amylopectine different from amylose
amylopectine has 1-4 and 1-6 glycosidic bonds and are strands not coiled connected to form branches so more easily seperated.in plants amylopectine consists of about 70-80 of starch.
why is starch insoluble
does not affect water potential of cells.
what is glycogen
energy store in animals made of only a glucose and is highly branched for easier break down.
what is cellulose
straight chains of b-glucose with no branches held with 1-4 bonds . Are able to form many hydrogen bonds between )H groups of ajacent chains-produces micro fibrils which group to form macro fibrils and group to form cellulose fiber.
what does chitin consist of
made of structural b-glucose whcih is rotated like in cellulose and some of the 0H groups are replaced with an amino acid. Cross linkage between these adjacent chains gives structural benefits
what can chitin also be referred to as
mucopolysaccharide because contains amino acids.
in triglycerides how is the fatty acids and glycerol bonded
3-condensation reactions forming 3 ester bonds.
why are tiglycerides not polymers
they are not made of repeating small units of the same molecule.
what are the differences between saturated and unsaturated fats
saturated fats are solid at room temp with no double bonds and are most animal fats.more hydrogen atoms in hydrocarbon tale-has a straighter looking structure. unsaturated fats are liquid at room temp with double bonds and most plant fats. fewer hydrogen atoms in hydrocarbon tale.
describe a feature of phospholipids
head is hydrophilic wheras the tales are hydrophobic usually joined by a glycerol molecule
the phosphate moleule is joined to glycerol by waht bonds
phosphate ester bond forming a water molecule.
what happens with phospholipds in water
hydrogens dissociate from phosphoric acid giving the acid a negative charge creating a hydrophilic head as water is polar.
use of phospholipds
important for all membranes and they can move around each other so keep the fluidity and keep the membrane stable.
what is the role of the bilayer
control of substances in and out.
-electrical insulation e.g mylein sheath. due to its partial permeability.
-thermal insulation.
-only small non-polar molecules can pass e.g oxygen
role of lipids
-energy store
-hibernation
-in seeds
-electrical insulation.
-thermal insulation
-organ protection
-structure of plasma mem.
-waterproofing
-buoyancy
what does high cholesterol cause
raises low density liipoproteins and atherosclerosis
what are amino acids made up of
basic group (amine /amino group) an acidic group (carboxyll), a hydrpgen atom and a residual/variable group.
how is a dipeptide formed
peptide bonds between two carboxyll groups through condensation reactions
what is the name given to the process of bonding to form polymers
polymerisation
what is a secondary protein
the sequence of amino acids causes some amino acids to bend into a-helix shapes or fold into b-peated sheets . Hydrogen atoms bond but in large number s they provide strength.
what bonds are tertiary structures held with
disulphide,ionic and hydrogen
why does the protein molecule bend and twist in tertiary structures
to achieve max stability at lowest energy state.
what quaternary protein has magnesium as its prosthetic group
chlorophyll
what are globular proteins
3D folding in tertiary or Quaternary proteins resulting in a spherical shape
what are fiborous proteins
long rope like shapes made of secondary and primary proteins
fibrous proteins:
polypeptide chains form long twisted strands held together.
-seconday protein
-stable.
-insoluble
-structural e.g keratin
globular:
-polypeptide chains roll up into a spherical shape.
-unstable
-soluble
-metabolic e.g enzymes, antibodies or hormones.
what does keratin consist of
2x a-helices twisted together.
what does collagen consist of
3x a-helices twisted tightly together held with hydrogen bonds e.g ligaments
