biological molecules Flashcards
what is a monomer
repeating units that join together to form polymers
what is a polymer
chains of many repeating units/ monomers
what is a condensation reaction
joining 2 monomers together by creating a chemical bond and removing water
what is a hydrolysis reaction
splitting up of polymers by breaking a glycosidic chemical bond by adding water
what type of bond is formed between 2 monosaccharides
glycosidic
what type of energy do simple sugars provide
short term energy release
what type of energy does complex carbohydrates provide
long term energy release
functions of carbohydrates
provide structure in plant cell walls
provide energy
regulates blood glucose
what are the monomers of carbohydrates
monosaccharides
what are the 3 main monosaccharides
glucose, fructose, galactose
what elements are carbohydrates made up of
carbon hydrogen oxygen
glucose + glucose —>
maltose
glucose + fructose —>
sucrose
glucose + galactose —>
lactose
what is the equation of a condensation reaction
monosaccharide + monosaccharide —> polysaccharide + water
what is the polymer starch made up of
repeating units of glucose
what is the equasion for a hydrolysis reaction
polysaccharide + water —> monosaccharide + monosaccharide
what do lipids do in living things
part of a cell membrane and provides insulation and energy
what does starch do
breaks down into glucose for energy
what are monosaccharides
single sugars
examples of monosaccharides
glucose fructose galactose
what polymer is made up of repeating units of alpha glucose
starch and glycogen
example of disaccharides
lactose sucrose maltose
what is the main function of starch
long term slow energy release
why is it helpful for starch to be insoluble
so osmosis can’t take place as cells would rupture without. cell membrane in high concentration
why is it helpful for starch to be coiled
more glucose molecules fits into a smaller space as its compact
what is an isomer
molecules with the same molecular formula but different structures
what are the 2 isomers of glucose
alpha and beta
what is the difference between alpha and beta glucose
the OH is below on the alpha glucose but on beta it is above
why can alpha glucose easily form polysaccharides
by condensation reactions and the OH is next to another one on the next monosaccharide
polymer of alpha glucose
starch and glycogen
polymer of beta glucose
cellulose
what is another name for starch
amylose
what are the features of starch
helical/ coiled structure
large
too big to escape cell membranes
compact
insoluble
many branches
what does glucose turn into in the liver
glycogen
what is glycogen
polymer of alpha glucose, stores energy in animals
features of glycogen
not coiled
has tons of branches for faster energy release
many ends
insoluble
similarities between starch and glycogen
starch and glycogen are both:
insoluble
branched
polysaccharides- alpha glucose
made up of carbon hydrogen and oxygen
long term energy stores
differences between starch and glycogen
glycogen isn’t coiled but starch is
glycogen has more branches than starch
glycogen is produced in animals but starch is in plants
why is it harder for beta glucose to form polymers than alpha glucose
one molecule needs to rotate upside down to have 2 OH’s next to eachother
why does each monomer of beta glucose need to be flipped
the H and OH are flipped so every other monomer must be flipped too, this gives strength for plant cell walls
what are the features of cellulose
unbranched chains called fibrils
chains don’t coil
strong intermolecular forces due to length (hydrogen bonds)
hard to seperate
strong and rigid
what are the structural similarities between starch and cellulose
both have glycosidic bonds
both are made up of carbon hydrogen and oxygen
both are poly saccharides of glucose
what are the structural differences between starch and cellulose
starch has branched ends whereas cellulose is unbranched chains
starch doesn’t have hydrogen bonds but cellulose does
starch is a polymer of alpha glucose, cellulose is a polymer of beta glucose
starch is helical, cellulose is straight
examples of polysaccharides
starch cellulose glycogen
examples of polysaccharides
starch cellulose glycogen
what are carbs proteins and nucleic acids examples of
polymers
what colour does benefits turn when testing for reducing sugar
blue > brick red
what colour does iodine turn when testing for starch
orange > blue/ black
what type of test is the starch test
qualitative (present or absent not a set number)
what is the function of a lipid
insulation
surround and protect organs
energy source
hormones
what is the structure of a triglyceride
1 glycerol molecule and 3 fatty acid molecules
what is the long hydrocarbon chain split into
acid group and R group
if lipids contain less oxygen than carbohydrates what does that lead to
less energy produced by lipids
what are the 2 groups of fatty acids
saturated
unsaturated
what does saturated mean
full of hydrogen
what does unsaturated mean
fewer hydrogen molecules and have atleast 1 double carbon bond
what is the structure of a lipid
contains fatty acids and glycerol
what type of bond forms in a triglyceride
ester bond
formation of spherical triglyceride droplets
hydrophobic fatty acids point inwards to avoid water and hydrophilic glycerols point outwards to attract water and form a circle
what are phospholipids made of
a phosphate ion and 2 fatty acid chains
what structure does a phospholipid make
a phosphate ion forms a strongly hydrophilic head and the tails are hydrophobic as they are uncharged
what form does phospholipids naturally form
a bilayer
what are the similarities between triglycerides and phospholipids
have fatty acids
made of c, h and o
form ester bonds
hydrophobic + philic
made by condensation
what are the differences between triglycerides and phospholipids
P has phosphorus, T doesnt
T have 3 fatty acids, P has 2
T form monolayer/ droplet, P forms a bilayer
what is the test for lipids
emulsion test
describe the emulsion test
add sample to test tube
add ethanol then equal amounts of water
(to dissolve fats then form a layer of lipids)
shake vigorously- white emulsion forms
name 3 organelles found in some bacterial cells
slime capsule
plasmid
flagellum
how many fatty acids are in a triglyceride
3
what organelle produces triglycerides
SER
structural difference between starch and cellulose
OH group is different
starch - A
cellulose- B
adaptations of cellulose for plant cells
straight fibrils with hydrogen bonds-
makes them strong and rigid for cell wall structure
unsaturated
contain a double c=c bond
why can’t triglycerides form a bilayer but phospholipids can
P- are equally hydrophilic and phobic and attract water
T- are mainly hydrophobic and form a droplet to keep water away as much as possible
why are triglycerides mainly hydrophobic
triglyceride head is smaller than the tails so hydrophobic is dominant
what elements are in all amino acids
nitrogen, oxygen, carbon, hydrogen
give examples of a protein
enzymes
some hormones
antibodies
what is the monomer of a protein
amino acid
what 3 groups make up an amino acid
amino acid group
R/ variable group
carboxylic acid group
what is the equation for a dipeptide formation
amino acid + amino acid = dipeptide + water
how is a dipeptide and bond formed
by a condensation reaction between 2 amino acids, 1 H2O molecule is removed and a peptide bond is formed between the monomers
2 ways in which all peptides are similar
have a carboxylic acid group
have an amino acid group
1 difference between all dipeptides
different variable group
what does the variable group of an amino acid determine
shape of a protein
by the amino acids it’s made of, and chemical bonds
what is a protein made up of
more than 1 polypeptide
what is determined by the shape of a protein
its function
name the 4 factors that affect protein structure
primary
secondary
tertiary
quaternary
describe what is the primary structure
determined by the sequence of amino acids that are joined by peptide bonds
describe what is the secondary structure
H atoms of amino acids join to O atoms of other amino acids and form hydrogen bonds
causing the polypeptide to fold
creates alpha helix and beta sheet
describe what the tertiary structure is
R groups of amino acids interact to form ionic bonds (due to + and - charges), hydrogen bonds and disulfide bridges,
these bonds cause the polypeptide to form 3D shapes
describe what the quaternary structure is
polypeptides interact with other polypeptides and form proteins
what is the definition of an enzyme
biological catalysts which speeds up the rate of reaction by lowering activation energy without being used up
what are the limitations of enzymes
denature in high temperatures and ph, low temperatures cause the enzyme to work slower as they have less kinetic energy
what is the main function of an enzyme
hydrolysis of larger molecules into smaller molecules
how does the induced fit model of an enzyme work
enzymes active site and substrate shape isn’t complimentary at first
once binded= enzyme substrate complex
and active site changes shape to be complimentary to the substrate
forces substrate to bend and put a strain on the bonds
lowers activation energy= substrate is easier to break apart into products
how does high/ low pH affect rate of reaction in enzymes
active site changes shape and denatures so it’s not complimentary
less enzyme substrate complexes are formed
slow rate of reaction
how does high temperature affect rate of reaction in enzymes
active site denatures and is no longer complimentary
less enzyme substrate complexes are formed
slow rate of reaction
how does low temperature affect rate of reaction in enzymes
active site doesn’t denature but slows down due to less kinetic energy
slow rate of reaction
how does low temperature affect rate of reaction in enzymes
active site doesn’t denature but slows down due to less kinetic energy
slow rate of reaction
how does enzyme concentration affect rate of reaction
substrate complex is limited
high concentration= more collisions
more enzyme substrate complexes
slower rate of reaction
how is ATP synthesised (equasion)
ADP + Pi -> ATP + H2O
how does substrate concentration affect rate of reaction
high= more collisions more enzyme substrate complexes
eventually rate slows down as enzyme concentration is a limiting factor
how does competitive inhibitors affect the rate of reaction
inhibitor binds to the enzymes active site so the substrate can’t bind to the enzyme, less enzyme substrate complexes
slows rate of reaction as less substrates are broken down
how does a non competitive inhibitor affect rate of reaction
bonds to an area away from the active site- (allosteric site) so the active site changes shape, less enzyme substrate complexes, slower rate of reaction
how do you calculate rate of reaction
1/ mean(time taken)
how do you calculate overall rate of reaction
total volume of product cm3/ total time taken s
how does rate of reaction change over time
decreases and starts to slow down as there are less enzyme substrate complexes and collisions as the concentrations of enzymes and substrates decrease
how do you calculate instantaneous rate of reaction
draw a tangent and calculate gradient
change in y/ change in x
what is the test for proteins
buiret test
buiret reagent= sodium hydroxide+ copper sulfate
positive= purple
negative= blue
how is ATP synthesised
created in a condensation reaction during respiration and photosynthesis using a ATP synthase enzyme, ADP + Pi
how many ATP molecules are produced for each molecule of glucose breaking down
33
what is the equation for breaking down ATP
ATP + H2O > ADP + Pi
how is ATP broken down
ATP is hydrolysed - bonds break to release energy - when energy is required, by the enzyme ATP hydrolase
what does adding a phosphate ion do to something
make it more likely to do chemical reactions to change is shape and make it change shape to be complimentary
name and describe what is the process to produce energy
respiration- break down glucose using oxygen to produce energy, water and carbon dioxide forming an ATP molecule
what is the structure of ATP
3 phosphate ions
ribose pentose sugar
nitrogenous base A
give 2 ways the hydrolysis of ATP is used in cells
provide energy
make substances more reactive
where do non competitive inhibitors bind to enzymes
allosteric site away from the active site
what shapes do polypeptides fold into in the secondary structure
alpha helix
beta sheet
where is dna found in a eukaryote and prokaryote
eukaryote- nucleus
prokaryote- plasmid and circular dna
RNA has an extra what?
base ( U )
what is dna made from
nucleotides
wheee can dna be found in a virus
capsid
what does dna do
code for a sequence of amino acids - polypeptides
what is the structure of a nucleotide
1 phosphate ion
deoxyribose pentose sugar
nitrogenous base ATCG
what are the differences between a nucleotide and ATP molecule
ATP has 3 phosphate ions, N has 1
ATP is always the adenine base, N can be any
ATP has ribose, N has deoxyribose
what are the similarities between ATP and nucleotide molecules
same pentose sugar
have a nitrogenous base
contain a phosphate ion
what is the condensation reaction for nucleotides
mononucleotide + mononucleotide > polynucleotide + water
what is the name of the bond that forms between sugar and phosphate
phosphodiester bond ( phosphorous , 2 oxygen , carbon )
what is complimentary base pairing
c + g
a + t
what is one molecule of dna made up from
2 polynucleotide strands joined by hydrogen bonds between nitrogenous bases
how is dna a polymer
made up of many repeating nucleotides
describe semi conservative DNA replication
- parental dna gets copies
- strand splits, hydrogen bonds break by “dna helicase” enzyme
- free floating nucleotides line against complimentary bases, form hydrogen bonds
- nucleotides join to complimentary bases, for phosphodiester bonds by “dna polymerase”
- 2 dna molecules formed, identical to parental dna
what does semi conservative mean
keeping half of the dna as a template
what does dna helicase do
break down hydrogen bonds to seperate dna strands
what does dna polymerase do
forms phosphodiester bonds during a condensation reaction, removing a water molecule and joining 2 complimentary base pairings
where are free nucleotides found in the cell
nucleus
what is the substrate and product of dna helicase
substrate- dna molecule
product- 2 seperate dna strands
when does dna replication occur
interphase
what elements are found in all nucleotides
h, c, o, n, p
how long does it take for 1 piece of dna to replicate
1 hour
what biological molecule is RNA
a polynucleotide
what is the functions of RNA
transfer genetic information during protein synthesis
forms part of a ribosome
structure of RNA
phosphate ion
ribose pentose sugar
nitrogenous base EXCEPT thymine
uracil
name the 4 nitrogenous bases of RNA
adenine
cytosine
guanine
uracil
how is DNA and RNA similar
both have:
phosphate ion
pentose sugar
nitrogenous bases
phosphodiester bonds
how is DNA and RNA different
DNA has no oxygen, RNA has oxygen
DNA contains thymine, RNA doesn’t
DNA is double stranded, RNA is single stranded
DNA has paired bases, RNA doesn’t
DNA has no uracil, RNA has uracil
what sugar is found in dna
deoxyribose
what are the key properties of water
metabolite in chemical reactions
solvent
high specific heat capacity
high latent heat
cohesive
why is water being a metabolite a key property?
it is used in chemical reactions such as condensation/ hydrolysis
why is water being a solvent a key property?
it’s a solvent for polar molecules so reactions can occur, charged molecules dissolve
why does water have a high specific heat capacity
takes a lot of energy to break hydrogen honds
why is water having a high specific heat capacity a key property
allows temperature buffering so it stays at the same temeperature, enzymes don’t denature
why does water having a high latent heat of evaporation a key property
allows cooling through evaporation
why is cohesion of water important
produces surface tension for small organisms so they can float
what are all of the properties of water a result of
hydrogen bonds
what is the formula of a hydrogen ion
H+
what is the formula of a iron ion
Fe 2+
what is the formula of a sodium ion
Na+
what is the formula of a phosphate ion
Po4 3-
what is the formula of a calcium ion
Ca2+
what is the role of hydrogen
controls Ph in fluids
used in respiration and photosynthesis
what is the importance of hydrogen
affects enzyme controlled reactions by controlling ph
what is the role of iron
bonds oxygen to red blood cells using haemoglobin
what do the importance of iron
haemoglobin transports oxygen around the body and reach cells for aerobic respiration
what is the importance of sodium
allows glucose to get to cells for respiration
what is the role of sodium
involved in the process of glucose from food to blood
what is the role of phosphate
forms sugar phosphate backbone in dna
phospholipids
atp
dna
rna
what is the importance of phosphate in phospholipids
forms cell membrane
what is the importance of phosphate in atp
energy release
what is the importance of phosphate in dna
holds genetic information, codes for sequence of amino acids
what is the role of calcium
stimulates muscle contraction
what is the importance of calcium
movement by muscle contraction
what is an ion
charged particle formed by losing or gaining an electron
how is maltose produced
condensation reaction between 2 glucose molecules by removing 1 water molecule
how is sucrose produced
condensation reaction between 1 glucose and 1 fructose molecule by removing 1 water molecule
how is lactose produced
condensation reaction between 1 glucose and 1 galactose molecule by removing 1 water molecule
what is the main property of all inorganic ions
don’t contain carbon atoms and found in cytoplasm
why is glucose dissolvable in water
contains many hydroxyl groups which are polar so they can form hydrogen bonds with water molecules
