1.1 Biological Molecules Flashcards
What is an inorganic ion?
What are they also called?
what are they needed for?
Something that has 1 or fewer carbon atoms.
often called minerals.
To survive
What is an organic ion?
Molecules that have 2 or more carbon atoms.
What is a macronutrient?
(example)
it is something needed in small concentrations
(magnesium/iron)
What is a micronutrient?
(example)
needed in minute concentrations
(copper/zinc)
what is the biological importance of magnesium?
-Important when making chlorophyll
-Essential for photosynthesis to make glucose
What happens if there is no chlorophyll?
The leaves will be yellow, (chlorosis)
What is the process of having less magnesium?
less magnesium-less photosynthesis-less glucose-less respiration-less ATP (energy) - less growth - DEATH OF PLANT
What do mammals need magnesium for?
Needed for their bones
What is the importance of iron?
iron is a component of haemoglobin (found in red blood cells)
What is haemoglobin needed for?
To transport oxygen
what does a lack of iron cause?
Anaemia
What are the symptoms of Anaemia?
-faint
-fatigue
-dizziness
What causes dizziness?
-less oxygen transported around the body,
- so less aerobic respiration,
-so less ATP
What is the importance of calcium?
(animals)
Important for structure in the bones and teeth of mammals. calcium hardens bones and teeth due to ossification.
what is the importance of calcium in plants?
component of plant cell walls
What is the importance of phosphate?
3 examples…
used for making nucleiotides (ATP/ DNA/ RNA)
part of phospholipids found in biological membranes
hardens bones
what are metabolic reactions
reactions that happen in cells
what is anabolism?
examples
- Building molecules up
(production of starch/glucose, DNA replication, protein synthesis)
What is catabolism?
examples
Breaking molecules down
(digestion of food decomposition)
what is a polymer?
when molecules are joined together in a repeating fashion. It is a larger more complex molecule.
what are all living organisms made from?
5 biological molecules
What are the five biological molecules?
-protein
-water
-carbohydrates
-nucleic acids
-lipids
does protein have monomer/polymer
yes
what’s the general name of the monomer of a protein?
amino acid
what’s the general name of the polymer of a protein?
polypeptide
what bonds to proteins have?
They have peptide bonds
does water have monomers and polymers?
No
is water a monomer or a polymer?
isn’t really a monomer or a polymer
does carbohydrates have monomer/polymers
yes
what’s the general name of the monomer of carbohydrates?
monosaccharide
what’s the general name of the polymer of carbohydrates?
polysaccharide
what bonds do carbohydrates have?
glycosidic bonds
do nucleic acid have monomers/polymers?
yes
what’s the general name of the monomer of nucleic acid?
nucleotide
what’s the name of the polymer of nucleic acid?
polynucleotide
name some nucleotides
ATP, DNA & RNA
Explain the structure of water.
- 2 hydrogen atoms strongly covalently bonded to one oxygen atom
- small in size
- polar/dipole
explain bonds and charges within water
-hydrogen shares a pair of electrons with the oxygen\not shared equally
what does polar mean?
- an unequal distribution of charge
- oxygen is slightly negative, hydrogen slightly positive
what does delta mean?
slightly
what does dipole mean?
overall there is no charge
what are the hydrogen bonds in water responsible for
many of the properties of water
what causes a hydrogen bond to form?
the uneven distribution of charge allows a hydrogen bond to form. it forms between the hydrogen atom of one water molecule and the oxygen atom of another water molecule.
what is the strength of hydrogen bonds?
Individually they are weak but because there are so many of them within water make the structure of water very strong.
what does water to water form?
why
A cohesive force
strong attraction due to hydrogen bonding.
what does water to a polar ion form?
creates an adhesive force.
what do forces of cohesion and adhesion help?
(in a plant)
- forces of cohesion and adhesion help water travel up the xylem vessel of the stem of plants.
what do water droplets form?
what causes this
form spheres
(cohesion between water molecules)
what causes high surface tension in water?
due to cohesion forces (hydrogen bonds) which also causes the ‘skin’ where the water meets the air.
what can the surface of the water behave like?
what do molecules on the surface do?
Behave like an elastic sheet due to cohesion.
they pull strongly together as they are not affected by the molecules above them.
What is the importance of water having a high surface tension?
- some animals (pond skaters) can walk on water.
- A habitat can be produced on top of the water
what is the property of latent heat?
why does this happen
a great deal of heat energy is needed to change water from a liquid to a vapour. because there are many hydrogen bonds.
what is needed to break hydrogen bonds?
Lots of energy
what does water have in terms of latent heat?
high latent heat of evaporation so when changing from water to vapour it absorbs a large amount of heat energy.
what is the importance/function of having high latent heat?
The evaporation of water (sweating) takes away energy from the skin and causes the cooling effect.
why does water have high specific heat capacity?
because there are many hydrogen bonds, a large amount of heat energy is needed to raise the temperature of water.
what is the importance/function of water having a high specific heat capacity?
(internal temperature)
allows the cell to maintain a relatively stable internal temperature & stops enzymes denaturing because a large amount of heat energy is needed to raise a cells temperature.
what is the importance/function of water having a high specific heat capacity?
(environmental temperature)
prevents fluctuation in the water temperature. provides a thermostatically stable environment for aquatic organisms
When is water used as a reactant?
In photosynthesis and hydrolysis reactions
what is a hydrolysis reaction?
the insertion of water
what is a condensation reaction?
the removal of water
why is water a universal solvent?
because it is polar
what does it mean in terms of water being a universal solvent?
-dissolves lots of different solutes
-effect solvent as it can form hydrogen bonds with ions (NaCl)
what does the positive end of the water molecule attract?
negative ion
what does the negative end of the water molecule attract?
positive ion
what do water molecules do?
(ions)
they surround ions and then they dissolve
what is the importance/function of water being a universal solvent?
- chemical reactions can happen
- makes transport inside living things easier
- act as a transport medium carrying dissolved molecules
what are some examples of dissolved molecules in water?
(animals/plants)
- blood in animals
- water transports minerals ions in the xylem
what is denser, ice or water?
ice is less dense than water so will float on top.
why is water less dense when frozen?
Because the distance between water molecules increases. held in a lattice structure with hydrogen bonds.
what is the difference between ice and water in terms of density?
water- molecules are closer, higher density
ice- water molecules are much more spread out, lattice, lower density
what is the importance/function of the density of water?
ice forms an insulating layer in top of water which prevents it all from freezing. the liquid beneath the ice has a higher temperature than the air above it.
what does the density of water mean for the living organisms?
organisms living in a pond that is covered in ice will still survive. They won’t freeze
what is the colour of water?
colourless which makes it transparent to light
what is the importance of water being colourless?
sunlight can reach plants at the bottom of the water. photosynthesis can occur
why is phosphorus required?
to synthesise phospholipids/nucleotides/ ATP/DNA/RNA
why is sulphur required?
to synthesise some amino acids/ methionine/ cysteine/ proteins
water is metabolite, what does this mean?
metabolite is a molecule that takes part in metabolic reactions. this is a biochemical reaction that takes place inside cells in order to keep them alive.
when is water a key metabolite>
in condensation and hydrolysis reactions.
what do carbohydrates contain?
carbon, hydrogen, oxygen
are they organic ?
yes because there are more than one carbon
what are carbohydrates made up of?
chains of individual monomer components joined together to form a polymer.
what is a monomer?
single repeating units of a polymer
what is carbohydrates monomer?
monosaccharide
2 monosaccharides ?
disaccharides
3 or more monosaccharides?
polysaccharides
properties of monosaccharides?
-sweet
- organic
- soluble molecules
-building blocks for other larger carbohydrate
what’s the general formula of monosaccharides?
(CH20)n
how many carbon atoms do the following have?
TRIOSE/PENTOSE/HEXOSE
- three
- five
- six
function of triose?
example of one…..
important in metabolism. triose sugars are intermediate in the reactions of respiration and Photosynthesis
(glyceraldehyde)
function of pentose
example…..
molecules of nucleic acids such as DNA,RNA,ATP
(ribose/deoxyribose)
function of hexose
example…
(glucose) it is a source of energy in respiration. C-H and C-C bonds are broken to release energy. this energy is transferred to make adenosine triphosphate (ATP)
what is an isomer?
they have the same chemical formula and the same number of atoms but the atoms are arranged differently.
what are the isomers of glucose?
how do you know which is which
alpha(H above/ OH below) and beta (H below/ OH above)
which glucose can be broken down in respiration?
only alpha glucose because only enzymes which git its shape are present.
condensation reaction?
removing water, formation of glycosidic bond by the removal of water
hydrolysis reaction?
breaking of glycosidic bond by the addition of water.
what’s a disaccharide?
two monosaccharides bonded with the formation of a glycosidic bond and the removal of water
explain the formation of a hexose disaccharide
-glycosidic bonds between carbon one on one monosaccharides and carbon four on another
-the hydroxyl group (-OH) on each monosaccharide aligns
-each glycosidic bond = one molecule of water removed
-oxygen atom left to join the two monosaccharides together
-1-4 Glycosidic bond is formed
what are the monomers in maltose?
what’s the use for it in living organisms?
alpha glucose + alpha glucose
found in germinating seeds
what are the monomers in sucrose?
use in living organisms
alpha glucose + fructose
A product of photosynthesis which is transported into the phloem
What are the monomers in lactose?
use in living organisms
alpha glucose + galactose
Found in mammals milk
What is a reducing sugar
A reducing sugar is a sugar that can donate an electron to another chemical
examples of reducing sugar
-all monosaccharides (glucose/fructose/galactose)
- some disaccharides maltose
- Not sucrose
Reducing sugar test
-Add Benedicts reagent to the sample HEAT
-if reducing sugar is present colour change from blue to brick red
-if the reducing sugar is not present the colour remains blue
Why is the Benedict’s test semi quantitive method
Because it indicates presence or absence of glucose as well as the relative concentration of different solutions however you can’t give it a value
How do you test a non-reducing sugar
It must be broken down into its monosaccharide components by hydrolysis (can then be tested as a reducing sugar)
Non-reducing sugar test
-Add Benedict’s, heat
-if colour is blue add hydrochloric acid and heat to hydrolyse glycosidic bonds
-add sodium hydroxide to neutralise solution (test with litmus paper)
-add Benedict’s, heat
- if a non-reducing sugar is present blue to brick red
- if a non-reducing sugar is not present, colour will remain blue
What does a biosensor do
Gives an accurate measurement of sugar present
what’s a polysaccharide?
polymers of many monosaccharides all joined by condensation reactions, via glycosidic bonds.
what’s the general formula of a polysaccharide?
(C6H10O5)n
what is polymerisation?
process of bonding many monomers by condensation reactions to form one large molecule
general properties of polysaccharides?
-often folded/can be branched
- are not sugar
- not sweet, cannot be crystalised
-insoluble
- compact molecules
- carry lots of energy
polysaccharide property
(glucose)
how is water drawn into the cell avoided?
-is the main source of energy in a cell and has to be store (cannot be left as a monosaccharide)
-soluble in water, would increase the concentration of the cell so would draw water into the cell by osmosis.
- glucose is converted into a storage product (polysaccharide)
why is it important that polysaccharides are insoluble?
means the cell is osmotically stable.
stops the cell from bursting
why can’t polysaccharides difuse out of cells?
they’re too big
what are the storage polysaccharides?
starch/glycogen
structure polysaccharides?
cellulose/chitin
what is starch?
-a storage polysaccharide
-found in plants as small grains/seeds
- energy source in plants
function of starch?
main source of glucose in plants
structure of starch?
mixture of 2 polymers (a glucose monosaccharides)
bonded together in 2 different ways forms…..
(starch)
amylose and amylopectin
amylose propeties
- long linear
- unbranched chain of a glucose
- coiled shape wound tight into a coil (v good energy store)
- 1-4 glycosidic bonds
why is amylose not very good for releasing energy?
as it only has 2 ends where the reactions can happen for energy to be released
amylopectin properties
-long branched chain of a glucose
- 1-4/1-6 glycosidic bonds formed by condensation reactions
why can glucose be released quickly in amylopectin
because it’s branched so lots of ends where glucose can be released from
what are the characteristics that make starch a good energy store
-insoluble and so don’t draw water into/ or out of the cell by osmosis
- compact
- when hydrolysed, forms monosaccharides of alpha glucose, easily transported/used in respiration
important properties of starch
(3)
- insoluble in water
- osmotically stable
- good energy store
is the starch test quantitive/ qualative?
qualative
explain the starch test…
- Add iodine
- if starch is present, colour change from brown-black
- if starch isn’t present, colour will remain the same
what is glycogen?
main storage product in animal, looks like amylopectin (highly branched)
where is glycogen stored?
stored in the liver/ skeletal muscle
what’s the difference between glycogen and amylopectin?
more side branches, means stored glucose can be released quickly
what are the bonds in glycogen>
1-4 glycosidic
what does glycogen being highly branched mean?
means it’s easier to hydrolyse glycosidic bonds and releases glucose.
very good for energy release
where is cellulose found?
found in plant cellulose cell walls
what is cellulose made up of?
Made up of repeating units of B glucose
held by 1-4 glycosidic bonds
every other B glucose rotates 180 degrees so that OH line up so H2O can be removed and glycosidic bonds form
what does cellulose rotating 180 degrees allow?
allows hydrogen bonds to form between chains of beta glucose (cross links)
what do lots of chains of cellulose joined together form
microfibrils
explain structure of cellulose in terms of bonds etc..
- hydrogen bonds between the chains
- makes cellulose strong
- important for cell wall structure
- stops plant cells from bursting when water enters
what is chitin?
similar to cellulose but for animals
what does chitin form?
forms the exoskeletons of insects and fungi cell walls
properties of chitin
- strong
- lightweight
- waterproof
what happens that’s difference than cellulose
some OH groups are replaced by nitrogen containing acetylamine groups
- monomers in each chains are rotated 180
- h bonds form between chains of chitin (cross links)
- forms microfibrils
what makes cellulose strong
the numerous hydrogen bonds
most common type of lipid
triglycerides
how are triglycerides formed
by 3 condensation reaction between glycerol and fatty acids.
structure of a triglyceride
3 fatty acids
1 glycerol
insoluble
form an ester bonds
how can triglycerides differ
length of the fatty acid chain (no of carbons)\
whether they’re saturated/ unsaturated
what is atherosclerosis
heart disease caused by fatty deposits (atheroma) in the coronary arteries
explain what saturated fats contain and what they do
they contain low density lipoproteins
these build up and restrict blood flow
explain what unsaturated fatty acids contain and what they do
make more high density lipoprotein
these are good because they carry LDLs to the liver for disposal
uses of triglycerides
(when oxidised)
- triglycerides release more energy for use in respiration than an equal mass of carbohydrate lipids
other uses of triglycerides
-protection around important organs
- produce lots of metabolic water when oxidised (important for camels)
- stored under skin/ important for insulation
- component of cell membrane
- waterproofing
what’s an ester bond
an oxygen atom joining two atoms, one of which Is a carbon atom attached by a double bonds to another oxygen atom
what do lipoproteins travel around the body in
the bloodstream
atherosclerosis
=?
disease
atheroma
=?
fatty deposits
what makes a phospholipid different to a triglyceride
one of the fatty acid molecules is replaced by a phosphate group
explain the structure of a phospholipid
phosphate head which is hydrophilic
and a fatty acid tail which is hydrophobic
adaptation of a phospholipid
the phospholipid bilayer
where are phospholipids found
found in cell membranes
what is the non protein part of haemoglobin contain
a ham group which contains iron
what is glucose
the main energy source for most cell
main form in which carbohydrates are transported around the body of animals
function of monosaccharides
- a source of energy in respiration
- building blocks for large molecules
- intermediate in reactions
- used to make nucleotides
lipids in terms of water
they are insoluble in water but soluble in organic solvents such as ethanol
what are the chemical properties of lipids
non-polar molecules
insoluble in water but dissolve in organic solvents
fats are solid at room temp whereas oils are liquid
what are waxes
similar to fats and oils but also contain alcohol
they’re insoluble and are important in organisms such as insects where the waxy cuticle cuts down water loss and to reduce transpiration
what is the emulsion test for lipids
ethanol is added to the sample, test tube is shaken.
if a lipids is present the solution will go to a milky white precipitate
what bonds are in proteins
hydrogen
disulphide
ionic
hydrophobic/hydrophillic interactions
four protein structures
primary
secondary
tertiary
quaternary
definition of primary structure
sequence of amino acids in a polypeptide
only link by peptide bonds
what is the secondary structure
shape that the polypeptide chain forms as a result of hydrogen bonding.
alpha helix (helical/spiral)
b pelted sheets (flat sheets/ zig zag shape)
tertiary structure
formed by the bending and twisting of the polypeptide helix into a compacted structure. this gives the molecules its 3D shape.
shape is maintained by disulphide, ionic and H bonds
quaternary structure
combination of 2 or more polypeptide chains in tertiary form
larger more complex molecules
example of a globular protein
haemoglobin
function of globular protein
enzymes
antibodies
plasma proteins
hormones
globular proteins
spherical molecules
soluble in water
explain how globular proteins are structured
bended and twisted so the hydrophobic molecules are in the middle, hydrophilic on the outside
example of a fibrous protein
collagen
fibrous protein
perform structural functions
secondary structure
consists of polypeptides in parallel chains/sheets with numerous cross linkages to form fibres (keratin in hair)
insoluble in water, strong and tough
what does collagen do
provides tough properties needed in tendons. a single fibre consists of 3 polypeptide chains twisted around each other like a rope
test for proteins
- add Biuret Reagant and blue coupe (II) sulphate and sodium hydroxide to the solution
shake it
what is the result of the protein test
solution will turn purple in the presence of peptide bonds (protein)
more purple solution
more peptide bonds
