2.1.2 biological molecules Flashcards
what is a monomer
a single repeating unit that can join with others to form polymers
what is a condensation reaction
making a polymer out of monomers
what is a hydrolysis reaction
breaking down polymers into monomers
what type of molecule is water
a polar molecule (hydrogen is partially positive and oxygen is partially negative) with unevenly distributed charges
what is cohesion
water molecules attracted to eachother
what is adhesion
water molecules attracted to other molecules
what is capillary action
adhesion and cohesion allow water to move up a capillary against gravity
what are the properties of water
high boiling point (strong H bonds)
ice is less dense
universal solvent
what do monosaccharides make and what type of reaction is it
polysaccharides with glycosidic bonds
condensation
what is the difference between alpha glucose and beta glucose
alpha glucose has H above the OH on both sides
beta glucose has OH above the H on the right and the H above the OH on the left
what are the hexose sugars
glucose
galactose
fructose
what is the pentose sugar
ribose
what are the triose sugars
aldose
ketose
what is the disaccharide sucrose made of
glucose + fructose
what is the disaccharide lactose made of
galactose + glucose
what is the disaccharide maltose made of
a glucose + a glucose
what elements are carbohydrates made of
CHO
what are the two types of starch
amylopectin and amylose
describe amylopectin
a glucose
1-4 and 1-6 glycosidic bonds
branched
describe amylose
a glucose
1-4 glycosidic bond
unbranched and coiled
soluble in water
describe glycogen
a glucose
1-4 and 1-6 glycosidic bonds
very branched
compact
large surface area for release of glucose
describe cellulose
b glucose (rotated 180° from eachother)
1-4 glycosidic bond
unbranched
many hydrogen bonds (strong)
what elements are lipids made from
CHO
what are lipids soluble in
organic substances only (e.g. alcohol)
what is a saturated lipid
no carbon-carbon double bonds
only found in animals
what is an unsaturated lipid
contains carbon-carbon double bonds
only found in plants
weak intermolecular forces
what is a triglyceride
1 glycerol + 3 saturated or unsaturated fatty acids joined by ester bonds
energy reserves in plants and animals
how are triglycerides different to phospholipids
1 fatty acid is replaced with a phosphate group
what elements are proteins made from
CHON
what are amino acids and what do they make
monomers that make proteins using peptide bonds
what is an R group
a group in an amino acid specific to the protein
what is a primary structure
order of amino acids in a protein
what bonds are in the primary structure
peptide
what is a secondary structure
shape taken by primary structure (either alpha helix or beta-pleated sheet)
what bonds are in the secondary structure
peptide and hydrogen
what is a tertiary structure
3D shape of protein
what bonds are in the tertiary structure
peptide, hydrogen, disulphide and ionic
what is a quarternary structure
how polypeptide chains fit to make a protein
what are the properties of a globular protein
compact, spherical, soluble
what is a conjugated protein
a protein containing a non-protein prosthetic group
what are examples of globular proteins
insulin = regulates blood glucose levels (2 polypeptide chains joined by disulphide bonds)
haemoglobin = transports O2 around the body as it binds to the haem group (4 polypeptide chains, 2 alpha, 2 beta)
what are the properties of a fibrous protein
strong, insoluble, no tertiary structure
what are the examples of fibrous proteins
collagen = connective tissue that provides support as it is flexible in low stress and stiff in high stress)
keratin = strengthens hair and nails (more bonds means less flexible)
elastin = walls of vessels
what elements make up nucleotides
CHONP
what do nucleotides make and what type of reaction is it
nucleic acids using phosphodiester bonds
condensation
what are the components of a nucleotide
phosphate group
pentose deoxyribose sugar
nitrogenous base
what are the nitrogenous bases
adenine
guanine
thymine
cytosine
what do we use chromatography for
analysis of substances by separation
how do we calculate the Rf value
distance moved by solute/distance moved by solvent
what is colorimetry used for
concentration determination
what do we use to test for starch and what is a positive result
iodine
blue/black colour change
what do we use to test for lipids and what is a positive result
ethanol emulsion
cloudy emulsion
what do we use to test for proteins and what is a positive result
biuret test
lilac colour change
what do we use to test for reducing sugars and what is a positive result
benedicts reagent
brick-red precipitate/green-red colour change
what do we use to test for non-reducing sugars
acid hydrolysis using HCl and NaHCO3 powder
brick-red precipitate/green-red colour change
