Biological Molecules Flashcards
what makes up polysaccharides/nucleotides
monosaccharides
what makes proteins
amino acids
what makes lipids
fatty acids and glycerol
what makes maltose
a glu + a glu
what makes lactose
b glu + galactose
what makes sucrose
a glu + fructose
describe monosaccharides (4) hexoses and pentoses
sugars
dissolve easily
hexoses = glucose/fructose/galactose
pentoses = ribose/deoxyribose
what does alpha glucose look like
OH group on right is on the top, switch around
what does beta glucose look like
OH group on the bottom, no switch around
function of monosaccharides
source of energy in respiration - C-H = release of energy
make larger molecules - glucose makes starch/glycogen/cellulose,
glucose bonds
glycosidic bonds
what is the proces of breaking apart disacchardes
hydrolysis
joining monosaccharides to form glycosidic bonds
condensation
describe polysaccharides
many monosaccharides + glycosidic bonds
not sugars
glucose converted into polysaccharides (glycogen/starch)
properties of polysaccharides as storage (4)
dissolves easily
osmotic properties
reactive
can be converted back
what are the four polysaccharides
amylose
amylopectin
starch
cellulose
describe amylose (5)
condensation of a-glucose 1,4 linked chains are curved helical structure compact molecule
describe amylopectin
condensation from a-glucose
1,4 + 1,6 linked
branched
describe starch/glycogen
amylose + amylopectin
describe cellulose cell wall (4)
polymer of b-glucose
rotate every 180 degrees
weak hydrogen bonds BUT many = strong
slow rate of breakdown
describe in detail how fibres are formed and properties of cell wall (4)
60-70 cellulose molecules cross linked to form microfibrils to form fibres in bundles
high tensile strength
withstand large pressure from osmosis
permeable
difference between glycogen and amylopectin
glycogen more branched
describe fatty acids (3)
unsaturated - double bonds
mono/poly saturated
plants = unsaturated
how to form an ester
alcohol + acid
describe triglyceride
fats and oils
glycerol + fatty acid → glyceride
glycerol = 3OH
three hydrophobic tails = insoluble
ratio of oxygen: carbon of triglycerides compared to carbohydrates
lower ratio
function of triglycerides (3)
energy reserves
insulator
oxidised into water
describe phospholipids (4)
triglyceride - one fatty acid + phosphate group
soluble
phosphate group is hydrophilic
makes up phospholipid bilayer
how many amino acids are present
20
definitio of primary structure of proteins
sequence of amino acids in a straight chain
definition secondary structure of proteins
regular order of amino acids due to hydrogen bonds
a helix/b pleated sheets
describe a helix and b pleated sheets
shape due to hydrogen bonding between -CO- and -NH-
looser shape caused by hydrogen bonding - broken by pH and temp.
definition of tertiary structure of protein
folding and coiling of chain due to interactions between R groups
example of tertiary structures
lysozyme/myoglobin/haemoglobin
bonds in tertiary structure
hydrogen bonds
disulfide bonds
ionic bonds
weak hydrophobic interactions
definition of quarternary structure
protein molecule made of two or more polypeptides
describe properties of globular proteins (4)
spherical
water soluble
prosthetic group
hydrophilic outside, hydrophobic inside
example of globular protein
haemoglobin
describe properties of fibrous protein (2)
structural protein
insoluble
example of fibrous protein + description (5)
collagen three polypeptides hydrogen bonds hold triple helix cross links make fibrils - fibres high tensile strength
describe properties of water (7)
solvent transport medium high specific capacity high latent heat of vaporisation ice is less dense than liquid high surface tension and cohesion water is reagent
