Biological Molecules Flashcards
What are the 5 main biological molecules that living organisms are made up of
carbohydrates
lipids
protein
DNA/RNA
water
What are the 2 types of carbohydrates
simple carbohydrates
complex carbohydrates
What are the 2 types of carbohydrates
simple carbohydrates
complex carbohydrates
What are monomers
individual units that makes a polymer
what are polymers
many repeating units of monomers
What are carbohydrate monomers called?
monosaccharides
what is a dissacharide
two monosaccharides
what is a polysaccharide
multiple monosaccharides
What is a condensation reaction
a reaction that makes up bonds
a glycosidic bond forms between the two monosaccharides as a molecule of water is released
what is a hydrolysis reaction
a reaction that breaks down bonds(water is taken in)
Name 4 types of monosaccharides
alpha glucose
beta glucose
galactose
fructose
which monosaccharides are examples of reducing sugars
all of them
Name 3 disaccharides
maltose(alpha glucose and alpha glucose)
lactose(alpha glucose and galactose)
sucrose(alpha glucose and fructose)
Which disaccharides are examples of reducing sugars?
maltose and lactose
Name 3 polysaccharides
starch(multiple alpha glucose)
glycogen(multiple alpha glucose)
cellulose(multiple beta glucose)
What does the alpha glucose structure look like
what does the beta glucose structure look like
what does the galactose structure look like
How does a condensation reaction change the structure of a monosaccharide
What things do you need to know about starch
-energy store found in plant cells in the form of grains
-a polysaccharide of alpha glucose joined via condensation reactions to form glycosidic bonds
-includes alpha 1,4 and 1,6 glycosidic bonds
describe the structure of starch
-large
-insoluble
-alpha helix shape
-branched
explain how the structure of starch aids it’s function
large-won’t diffuse out of cells
insoluble-osmotically inactive
alpha helix shape-compact energy store
branched-rapidly release alpha glucose when needed
what things do you need to know about glycogen
-it’s a polysaccharide of many alpha glucose joined via condensation reaction to form glycosidic bonds
-it’s an energy store in the form of granules in cytoplasm
-has alpha 1,4 glycosidic bonds and many more alpha 1,6 glycosidic bonds compared to starch
describe the structure of glycogen
-large
-insoluble
-alpha helix shape
-branched
explain how the structure of glycogen aids it’s function
large-won’t diffuse out of cells
insoluble-osmotically inactive
alpha helix shape-compact energy store
branched-rapidly release alpha glucose when needed
What things do you need to know about cellulose
-it’s a polysaccharide of many beta glucose molecules joined through condensation reactions to form beta 1,4 glycocidic bonds
-it’s used to make cell walls
-every other beta glucose is inverted
Describe the structure of cellulose
Made from beta- glucose
Parallel chains can form hydrogen bond “cross links”
cellulose can form microfibrals which join to form fibres
Explain how the structure of cellulose aids its function
Allows long straight chains to form
Adds strength to the cell wall
Adds strength
Finish the sentence:
A reducing sugar is able to…
…lose an electron and give it to another compound
What do we use to test for reducing sugars
We test for reducing sugars by giving them something to reduce:Benedict’s reagant
How do we test for reducing sugars?
-Add benedict’s solution
-Heat it up
-Colour change from blue-red to
Why does a substance containing a reducing sugar go from blue to red?
Benedict’s contains Cu2+ ions in the form of copper(II) sulfate
When the Cu2+ ions gain an electron(from a reducing sugar), they become Cu+ ions in the form of red (I) oxide
What are the possible results of the benedict’s test?
Blue- negative (no concentration)
Green- very low
Yellow- low
Orange- moderate
Red- high (high concentration)
How do we test for non reducing sugars?
-Get a negative benedict’s test
-Boil with HCl to hydrolyse non reducing sugar
-Neutralise HCl using NaOH
-Add benedict’s
-Heat
-Colour change from blue- red
How do we test for starch?
Add iodine
Colour change should be orange-dark blue/ black
How does a colorimeter that gives an absorbance reading work?
There’s a light source which the solution inside a test tube absorbs. There’s a light receptor on the other side of the test tube which absorbs the light they comes out of the test tube. The higher the value, the more light is being absorbed/blocked. 0=dilute, 1=max concentration
How does a colorimeter that gives a transmission reading work?
Same as absorbance reading but the higher the number, the more light can pass through so 0=max concentration and 1=dilute
What are the steps to identify an unknown glucose solution?
Pour unknown glucose solution into a beaker and leave to the side
step 1. have 5 known glucose concentrations in beakers (0mol dm-3 to 100mol dm-3)
step 2.perform a benedict’s test(lowest concentration will be blue, highest cone i’ll be red)
step 3. perform colorimetry to identify absorbance
step 4. perform a calibration curve with concentration on x and absorbance on y(straight line)
step 5.perform benedict’s and colorimetry on unknown sample+identify absorbance
step6. read off graph to identify concentration of unknown solution
What are lipids
They are biological molecules that are used for:
energy store
insulation(thermal, electrical-myelin sheaths cover nerves)
water proofing(waxy cuticle)
protection(heart, kidneys)
What are the two types of lipids
triglycerides
phospolipids
What are triglycerides
consists of fats(solids at room temp) and oils(liquid at room temp)
they are not polymers as they are not made of many repeating units of monomers
What is the general structure of triglycerides
What is the chemical structure of tryglicerides
How does a glycerol molecule bond with the 3 fatty acid molecules to form a triglyceride?
They bond through a condensation reaction (where water is lost) to form an ester bond
Describe the features of a triglyceride
-insoluble
-low mass to energy ratio
-high ratio of hydrogen atoms to oxygen atoms
-high ratio of energy storing C-H bonds
Explain how the features of a triglyceride aids its function
-osmotically inactive
-don’t have to carry a heavy energy store
-water can be released during breakdown
-energy dense molecule
What is a phospholipid
A major component of cell membranes
What’s the general structure of a phospholipid
What does a phospholipid consist of?
A phosphate molecule
2 fatty acids
A glycerol molecule
In the general structure of a phospholipid, a phosphate molecule and glycerol molecule are usually called what?
a phosphate ‘head’
In the general structure of a phospholipid, the fatty acids are usually called what
the fatty acid ‘tails’
Is the phosphate ‘head’ polar or non polar
polar
There are delta positive and delta negative regions and the electrons are unevenly distributed so therefore, the polar head is hydrophilic(attracted to water)
Is the fatty acid tails polar or non polar and why?
They are non polar
The electrons are spread out evenly so the non polar tails are hydrophobic
What is an amphipathic molecule?
A molecule with polar and non polar regions can. This property is essential for form a phospholipid bilayer(2 layers-a double membrane)
How do phospholipid layers react in water
The tails of the layers point inwards, towards each other so the hydrophilic head can interact with the water and the hydrophobic tails avoid the water
What is the chemical structure of phospholipids
What is the chemical structure of phospholipids
Describe and explain the functions of phospholipids
hydrophobic/hydrophilic regions-allows phospholipid bilayer formation
glycolipids can form-allows for cell recognition
What are the functions of proteins
Structural-collagen(connected tissues), keratin(hair,nails,horns)
Involved in signalling-hormones(insulin and FSH
Catalysts-enzymes that speed up a reaction
Transport-haemoglobin transports oxygen
What is the name of a protein monomer?
amino acid
What is the name of a protein dimer ?
dipeptide
What is the name of a protein polymer?
polypeptide
What is the chemical structure of an amino acid
How many different amino acids are there and what is the relationship with them all?
20
They all have the same ‘general structure’. Only the ‘R’ group changes
What is the chemical structure for a dipeptide(formation)
Proteins are the only molecules that don’t have condensation reactions between carboxyl groups!!
Exam Q: How does dipeptide form?
A condensation reaction occurs between the carboxyl group of one amino acid and amine group of the other
How many levels of polypeptide structure are there?
4
What happens in the first level of polypeptide formation?
The sequence of amino acids are formed. This is determined by your ur genes.
What happens in the 2nd level of polypeptide formation?
The initial folding of a polypeptide into an alpha-helix or beta-pleated sheet due to hydrogen bonding
What happens in the 3rd level of polypeptide formation?
Further folding of polypeptide into a 3D shape held together by more hydrogen bonds(disulfide bonds and ionic bonds)
What is a disulfide bond?
The strongest type of bond that holds proteins together
What is an ionic bond
A bond that occurs between C=0(carboxy) and N-H(amine) groups
What happens in the 4th level of polypeptide formation?
Multiple polypeptides bonded together
e.g haemoglobin
What happens in the 5th(extra)level of polypeptide formation?
Prosthetic group
Non-protein based molecule that aids function
e.g. iron is needed for haemoglobin to carry oxygen
Exam Q:Describe how the secondary structure of a polypeptide is produced by bonds between amino acids
Polypeptides are folded into alpha helix or beta pleated sheets due to hydrogen bonding between C=O and N-H groups
Exam Q: Explain how two proteins have the same number and type of amino acids but different tertiary structures
Different sequence of amino acids leads to hydrogen/ionic/disulfide bonds forming in different places, resulting in 3D shapes being different
What is an enzyme?
A protein catalyst that lowers activation energy without being used up
What are the 2 types of enzyme action?
-catabolic(breaking down) reaction
-anabolic(building up) reaction
What does activation energy mean
it is the amount of kinetic energy needed for a reaction to occur
How do enzymes work in a catabolic reaction?
An enzyme works by forming an “enzyme-substrate complex” which strains bonds, lowering the activation energy.
How do enzymes work in an anabolic reaction?
They work by bringing substrates closer together. This lowers the activation energy needed for the reaction to take place.
Explain the induced fit model of enzyme action
-Before the reaction, enzyme action is not complimentary to substrate.
-The shape of active site changes as enzyme-substrate complex forms
-This stresses bonds or brings substrates closer together
-Lowering activation energy
Explain the first stage of the progress of reaction graph
-Initially there’s lots of the substrate and empty active sites
-So there are many E-S complexes that can form
-So the reaction starts off fast
Explain the first stage of the progress of reaction graph
-Initially there’s lots of the substrate and empty active sites
-So there are many E-S complexes that can form
-So the reaction starts off fast
Explain the second stage of the progress of reaction graph
-There’s less substrate, so more product
-So it’s more difficult for E-S complexes to form
-So the reaction slows
Explain the second stage of the progress of reaction graph
-There’s less substrate, so more product
-So it’s more difficult for E-S complexes to form
-So the reaction slows
Explain the third stage of the progress of reaction graph
-There’s no more substrate
-So no E-S complexes can form
-So the reaction stops
Explain the third stage of the progress of reaction graph
-There’s no more substrate
-So no E-S complexes can form
-So the reaction stops
How can you calculate the mean rate of reaction?
amount of product formed/time taken to form product
Explain how this progress of reaction graph shows the effect of temperature on ROR
Enzymes have more Ek at 37 degrees C so more E-S complexes form which leads to a faster reaction(steeper line, earlier plateau)
Explain how this ROR graph shows the effect of temperature on ROR
1.As temperature increases, the rate increases due to more Ek
2.Optimum temp- where the most E-S complexes form
3.As temp increases, rate decreases due to enzymes being denatured(tertiary-3D- structure of enzyme active site changes so no E-S complexes form)
What is an acid?
A compound that releases hydrogen ions(H+) when in solution
What is an alkali?
A compound that releases hydroxyl ions (OH-) when in solution
Explain how this progress of reaction graph shows the effect of temperature on ROR
-At pH2, the increases number of H+ ions are attracted to amino acids of enzymes
-Ionic/hydrogen bonds of tertiary structure are disrupted
-Active site of enzymes denature
Explain how this progress of reaction graph shows the effect of pH on ROR
-At pH2, the increases number of H+ ions are attracted to amino acids of enzymes
-Ionic/hydrogen bonds of tertiary structure are disrupted
-Active site of enzymes denature
Explain how this ROR graph shows the effect of pH on ROR
1.active site denatures so no E-A complexes form
2.Optimum pH
3.Active site denatures so no E-S complexes can form
Explain how this ROR graph shows the effect of pH on ROR
1.active site denatures so no E-A complexes form
2.Optimum pH
3.Active site denatures so no E-S complexes can form
Explain how this progress of reaction graph shows the effect of enzyme concentration on ROR
-At 2M, the reaction is faster because there’s more enzymes so more E-S complexes
Explain how this ROR graph shows the effect of enzyme concentration on ROR
-As enzyme concentration increases, rate also increases in direct proportion
-Because more E-S complexes can form
-Rate is only limited by the amount of substrate
Explain how this progress of reaction graph shows the effect of substrate concentration on ROR
-For the 2M substrate, the reaction is faster
-More substrate means more E-S complexes
Explain how this progress of reaction graph shows the effect of substrate concentration on ROR
-For the 2M substrate, the reaction is faster
-More substrate means more E-S complexes
Explain how this ROR graph shows the effect of substrate concentration on ROR
-As substrate concentration increases, rate also increases in direct proportion
-Because more E-S complexes can form
-Rate is only limited by the amount of enzyme
What are proteins?
Polymers made from many amino acids joined by peptide bonds
what do enzyme inhibitors do
they slow down enzyme catalysed reactions
what are the two types of enzyme inhibitors
competitive inhibitors
non competitive inhibitors
what are competitive inhibitors
molecules with a similar shape to a substrate
they bind to active sites and prevent enzyme- substrate complexes forming
how do competitive inhibitors work
•Reaction slows as
•C. I. binds to active site
•Prevents E-S complexes
how can we increase the rate of product formation
by adding more substrate
the additional substrate will outcompete the inhibitor
what is a non competitive inhibitor
•Molecules that attach to a binding site on an enzyme – NOT the active site (allosteric binding site)
•This changes the 3⁰ of the active site permanently.
•No longer complementary.
•No E-S complexes can form.
how do non competitive inhibitors work
•Reaction slows and does not complete.
•NCI binds to allosteric binding site.
•A.S. changes shape (permanently)
•No E-S complexes form.
how can we increase the rate of product formation
You CAN’T increase the rate of product formation by adding more substrate.
The enzymes are out of action. The only way to overcome this is to add more enzyme.
what is digestion
the hydrolysis of large, insoluble food molecules into small, soluble food molecules that can be absorbed into the blood
what do the salivary glands do
release salivary amylase enzymes
what does the stomach do
if produced HCl and protease enzymes. And physically churns food
what does the liver do
produces bile
what does the gall bladder do
stores/releases bile into ileum
what does the ileum do
absorbs products of food digestion into the blood
what does the large intestine do
absorbs water
what do the teeth do
physically break down food into smaller pieces
what does the oesophagus do
carries food to the stomach
what does the pancreas do
produces pancreatic amylase, proteases and lipase
what do the rectum and anus do
rectum stores faeces
faecus exits via anus
what is the enzyme for starch
pancreatic/salivary amylase
what is the product of the digestion of starch
maltose
where is the product of the digestion of starch made
salivary glands, pancreas
where does the enzyme of starch act?
mouth
ileum
what bonds are broken when starch is digested
alpha 1-4 and 1-6 glycosidic bonds
what is the enzyme for maltose
maltase
what is the product of the digestion of maltose
2 alpha glucose
where is the product of the digestion of maltose made
ileum lining
where does the enzyme of maltose act?
ileum
what bonds are broken when maltose is digested
alpha 1-4 glycosidic bond
what is the enzyme for sucrose
sucrase
what is the product of the digestion of sucrose
alpha glucose, fructose
where is the product of the digestion of sucrose made
ileum lining
where does the enzyme of sucrose act?
ileum
what is the enzyme for lactose
lactase
what is the product of the digestion of lactose
alpha glucose
galactose
where is the product of the digestion of lactose made
ileum lining
where does the enzyme of lactose act?
ileum
what is the enzyme for proteins
endopeptidase
what is the product of the digestion of proteins
smaller peptides
where is the product of the digestion of proteins made
stomach, pancreas
where does the enzyme of protein act
ileum
stomach
what bonds are broken when protein is digested
peptide
what is another enzyme for proteins
exopeptidase
what is another product of the digestion of proteins
amino acids,
dipeptides
where is the product of the digestion of proteins made
pancreas, stomach
where does the enzyme of protein act
ileum
stomach
what bonds are broken when protein is digested
peptide
what is the enzyme for dipeptides
dipeptidase
what is the product of the digestion of dipeptides
amino acids
where is the product of the digestion of proteins made
ileum lining
where does the enzyme of dipeptides act
ileum
what bonds are broken when dipeptides are digested
peptide
what is the enzyme for lipids
lipase
what is the product of the digestion of lipids
2 fatty acids
monoglyceride
where is the product of the digestion of lipids made
ileum lining
pancreas
where does the enzyme of lipids act
ileum
what bonds are broken when lipids are digested
ester
how are lipids digested
bile salts emulsify the fat globules into micelles (smaller lipid droplets)associated with bile salts. this means that they have a larger surface area for faster lipase action
lipase then digests these droplets into micelles containing monoglycerides and fatty acids in bile
what are the advantages of micelle formation
droplets increase surface areas (for lipase/enzyme action)
so faster hydrolysis/ digestion of triglycerides/ lipids
micelles carry fatty acids and glycerol/ monoglycerides to/through membrane/ to inestinal epidermal cell
describe the structure of the ileum
walls are folded into villi
walls are 1 cell thick
epithelial cells have microvilli
many capillaries
muscle in villi
explain how the structure of the ileum aids function
larger SA for faster absorption
short diffusion distance=faster absorption
larger SA for faster absorption
Rich blood supply maintains diffusion gradient
maintain diffusion gradient by moving contents of lumen
how are monosaccharides abosorbed
sodium is removed (from epithelial cells) by active transport via sodium potassium carrier protein into blood, maintaining low concentration of sodium(in epithelial cells); Glucose moves into blood via carrier protein by facilitated diffusion.
how are lipids absorbed
fatty acids and glycerol are non polar
enter epithelial cells via simple diffusion
travel to smooth ER
tryglicerides are formed
then travel to golgi for processing
what is the role of the golgi in lipid absorption
golgi apparatus modifies/ processes triglycerides.
it combines triglycerides with proteins
forms vesicles
what is DNA made of?
a double stranded helix structure, containing a sugar phosphate backbone with nitrogen-containing organic base pairs in the centre
What is the structure of a nucleotide?
a strand of DNA or RNA is a polynucleotide made up from joined mononucleotides
individual nucleotides are made from 3 components, what are they?
a phosphate group
a pentose sugar
an organic base
which components are known as the backbone?
phosphate group
pentose sugar
In a DNA mononucleotide, the organic base can either be…
adenine
thymine
cytosine
guanine
In a DNA mononucleotide, what is the pentose sugar ?
it is always deoxyribose
In an RNA mononucleotide, the organic base can either be…
adenine
uracil
cytosine
guanine
In an RNA mononucleotide, what is the pentose sugar ?
it is always ribose
Exam style question:
Give two ways in which the nucleotides in DNA are different from the nucleotides in RNA
RNA contains ribose whereas DNA contains deoxyribose
RNA contains Uracil whereas DNA contains thymine
What bonds are the 2 strands of a DNA molecule joined by?
hydrogen bonds
What bonds are adjacent nucleotides joined by?
phosphodiester bonds
Base pairings are…?
specific. we say the these bases are complementary to each other
What are the base pairings in DNA?
adenine-thymine
cytosine-guanine
Explain how the organic bases help to stabilise the structure of DNA
-The phosphodiester backbone protects the more chemically reactive bases inside the double helix
-As there are more hydrogen bond between C-G, DNA molecules with a greater proportion of C-G pairings are more stable
-There are additional forces between base pairs that hold the molecule. This is called base stacking
What is the DNA structure and function?
-phosphodiester backbone-prevents bases reacting with environment
-long molecule-stores a lot of info
-double helix structure- makes DNA compact
-Weak hydrogen bonds join base pairs- easily broken for DNA replication
-Double stranded-allows replication from template strand
-Base sequence- allows info to be stored
-‘Base stacking’- makes DNA stable
when does DNA replication happen?
during interphase of the cell cycle
What 4 things are needed for DNA replication?
-DNA molecule to be replicated
-Free DNA nucleotides
-DNA helicase enzyme
-DNA polymerase enzyme
How does DNA polymerase act?
It acts in a 5’ - 3’ direction
How does DNA polymerase act?
It acts in a 5’ - 3’ direction
Exam Tech: Explain how DNA is replicated
- strands separate/H-bonds break
- DNA helicase(involved);
- Both strands act as templates
- Free nucleotides attracted
- H-bonds reform
- Complementary/specific base pairing /AT and GC;
- DNA polymerase joins nucleotides via phosphodiester bonds
- Semi-conservative replication/ new DNA molecules contain one old strand and one new strand
What’s the Meselton and Stahl experiment?
Stage 1:
Grow E-coli bacteria in agar containing ‘heavy’ isomers of nitrogen
Stage 2:
Allow 15N bacteria to undergo one cell division
Stage 3:
Allow 14N and 15N bacteria to undergo one cell division
What is energy used for ?
Active transport, muscle contraction, protein synthesis, phosphorylation
How is energy used for active transport?
Used any named method( glucose absorption, ion uptake at roots)
How is energy used for active transport?
Used any named method( glucose absorption, ion uptake at roots)
How is energy used for muscle contraction?
For movement
How is energy used for muscle contraction?
For movement
How is energy used for protein synthesis?
For growth and repair
How is energy used for a phosphorylation ?
Making molecules more reactive by lowering their activation energy
What does the energy from respiration take the form of?
A nucleotide called Adenosine Triphosphate (ATP)
What’s the ATP structure?
How is energy released?
-The bonds between the outer phosphate groups in ATP are unstable so have a low activation energy
-A single hydrolysis reaction can remove a phosphate. The phosphate can form bonds with other molecules- which releases energy(phosphorylation)
Describe the ATP to ADP reaction
The ATP->ADP reaction is a hydrolysis reaction. It is catalysed by the enzyme ATP hydrolase
What is the equation for the hydrolysis of ATP?
ATP+H20->ADP+Pi+E
How is ATP synthesised?
The enzyme ATP synthase catalyses a condensation reaction to join a phosphate to ADP to form ATP(phosphorylation)
How is ATP synthesised?
The enzyme ATP synthase catalyses a condensation reaction to join a phosphate to ADP to form ATP(phosphorylation)
What is the reaction to synthesise ATP?
ADP+Pi+E->ATP+H20
What is the reaction to synthesise ATP?
ADP+Pi+E->ATP+H20
Where does the energy for ATP synthesis come from?
light
respiration
What are some pros/advantages of ATP?
1.releases energy in small/manageable amounts
2.broken down in a one step reaction
3.it phosphorelates to lower the activation energy needed for biological molecules to react
4.rapidly reformed
5.soluble-most biological reactions take place in solution - cytoplasm
What are the cons/disadvantages of ATP?
ATP cannot be moved from cell to cell / stores because it is so reactive
What kind of energy source is ATP?
immediate
Compare the characteristics of ATP and carbs/lipids
ATP
-small quantities present within mitochondria of cells
-rapidly reformed
-energy released in small, suitable amounts
-single hydrolysis reaction to break down
-can not be stored
-soluble
Carbs/Lipids
-large quantities present as fat/glycogen
-slower to form
-energy released in larger, less soluble amount
-many reactions required to release energy from a glucose molecule
-can be stored
-glycogen/fat insoluble
Describe water
It is 2 hydrogen atoms covalently bonded to 1 oxygen atom
Electrons have uneven distribution
We describe water as being a polar molecule
What are hydrogen bonds?
-They form between polar molecules containing hydrogen
-They do not result in a permanent structure, bonds break and reform as water molecules move around
What are the properties of water that make it good for the cytoplasm?
-polarity means it can act as a good solvent(chemical reactions happen faster in solutions)
-reactive(can be used in hydrolysis reactions)
What are the properties of water that are due to hydrogen bonding?
-high specific heat capacity
-high latent heat of vaporisation
-cohesive
-adhesive
-transparent
-variable density
Why is polarity a useful property of water?
polarity=good solvent
The + and - ions in ionic compounds are more attracted to the polar molecule than each other. This causes them to dissociate and dissolve.
Chemical reactions can happen faster in solution-more collisions
Why is having a high specific heat capacity a useful property of water?
SHC is the energy required to increase 1kg of water by 1 degrees celsius
The SHC of water is 4148 J/Kg which is high due to many H-bonds which need lots of energy to overcome
This makes water a good temperature buffer.Enzymes are protected against denaturing.
Why is having a high specific heat capacity a useful property of water?
SHC is the energy required to increase 1kg of water by 1 degrees celsius
The SHC of water is 4148 J/Kg which is high due to many H-bonds which need lots of energy to overcome
This makes water a good temperature buffer.Enzymes are protected against denaturing.
Why is having a high latent heat of vaporisation a useful property of water?
LHV is the energy required to vaporise 1kg of Makes water useful for sweat. It can transfer a lot of thermal energy away from the body.
Why are cohesion and adhesion useful properties of water?
H-bonds =cohesion/adhesion of water in xylem. Allows a continuous movement of water up xylem.
Cohesion leads to surface tension. Allows organisms to escape predators/ find prey.
What are the main ions in biology?
iron, phosphate, nitrate, hydrogen, calcium, magnesium
What do iron, nitrate and hydrogen ions do?
iron-involved in haemoglobin structure. Allows oxygen to bind
phosphate-involved in phospholipids, ATP, DNA/RNA
hydrogen-involved in photosynthesis and respiration
What do calcium and magnesium ions do?
calcium-involved in muscle contraction
magnesium-involved in making chlorophyll
