Biological Molecules 1 Flashcards
(139 cards)
1
Q
Define monomers and polymers and what is the process called when monomers form polymers
A
Monomers - Small, basic molecular unit
Polymers - large, complex molecules made from long chains of monomers bonded together
2
Q
Give some example of monomers
A
Monosaccharides
Amino acids
Nucleotides
3
Q
Define condensation reaction
Define hydrolysis reaction
A
Condensation reaction- Monomers join together to produce a polymer and water
Hydrolysis reaction- Use water to break down a polymer into monomers
4
Q
Glucose + Glucose -> —— + water
A
Maltose
5
Q
What conditions are needed for hydrolysis reaction
A
Enzyme(catalyse reactions)
Optimum pH levels
Optimum temperature
6
Q
Why are Hydrogen bonds not in biomolecules
What are polar molecules
A
Hydrogen bonds are weak
Molecules with a partial charge due to uneven distribution of electrons in the atom
7
Q
Ionic bond and covalent bond
Does or doesn’t dissolve in water
A
Ionic bond does dissolve in water
Covalent bond doesn’t dissolve in water
8
Q
What properties of a molecule is affected by the bond type
A
Boiling point
Melting point
Malleability
Solubility
9
Q
What is the polymers of glucose amino acid and nucleotide
A
Starch Cellulose Glycogen
Protein
DNA RNA
10
Q
What 3 elements do all carbohydrates contain?
Name 3 types of carbohydrates
Give 3 examples of each one
A
Carbon Hydrogen Oxygen
Monosaccharides Disaccharides Polysaccharides
Monosaccharides: Glucose, Fructose, Galactose
Disaccharides: Sucrose, Maltose, Lactose
Polysaccharides: Starch, Cellulose, Glycogen
11
Q
What is found in all 3 Polysaccharides
A
Glucose
12
Q
What does ATP and ADP stand for
A
Adenosine Triphosphate
Adenosine Diphosphate
13
Q
Why is ATP a derivative of a nucleotide
A
It is also made of a sugar, base and Phosphorus
14
Q
What is the Phosphate, base and sugar in ATP
A
Phosphate-Triphosphate
Sugar: Ribose/Pentose
Base: Adenine
15
Q
What is the word equation for aerobic respiration and where does the energy come from
A
Oxygen + Glucose -> Carbon dioxide + water + Energy(ATP)
Energy comes from bonds in glucose
16
Q
What is the reaction when ATP releases energy
what is the word equation
What enzyme is needed
A
Hydrolysis
ATP + H2O -> ADP + Pi + Energy
ATP hydrolase
17
Q
What is the reaction for the resynthesis of ATP
What is the word equation
What enzyme is needed
Where does this process take place
A
Condensation
ADP + Pi -> ATP
ATP synthase
Takes place during photosynthesis or respiration
18
Q
What is the word for adding phosphorus and removing phosphorus
A
Phosphorylation
Dephosphorylation
19
Q
What are the 3 ways ATP is synthesised
A
Oxidative phosphorylation (aerobic respiration in plant and animal cells)
Photophosphorylation (Photosynthesis in chlorophyll)
Substrate level phosphorylation (free phosphorus + ADP in plant/animal cell)
20
Q
Give a few examples of the role of ATP in biological systems
A
Active transport(movement against the concentration gradient)
Protein synthesis
Muscle contraction(requires energy for the filaments to work)
Metabolic processes(build macromolecules)
Secretion(required to form lysosomes)
Activating molecules(Phosphate released from the hydrolysis of ATP can be used to activate other key biological molecules)
21
Q
Why does ATP have a short term energy supply
A
-Weak bonds between Phosphate group
-Energy is released in a single step (adding water)
-Releases less energy compared to glucose
22
Q
What is the function of ATP and why is it important for metabolic reactions in cells
A
An immediate source of energy for biological processes
Metabolic reactions in cells must have a constant, steady supply of ATP
23
Q
Why are Phosphate groups inorganic
A
They do not contain any carbon atoms
24
Q
Why is ATP an immediate source of energy
A
Only one bond needs to be hydrolysed to release energy
25
What is phosphorylation and give an example
The inorganic Phosphate released during the hydrolysis of ATP can be bonded onto different Compounds to make them more reactive
This happens to glucose ar the start of respiration to make it more reactive
26
What makes ATP a suitable immediate source of energy(explain properties)
-ATP releases energy in small, manageable amounts so no energy is wasted(cells do not heat from wasted hear energy and cells are less likely to run out of resources. Glucose would release large amounts of energy which results in wasted energy)
-Small and soluble so easily transported around the cell(can dissolve in cytoplasm, common with glucose)
-Only one bond needs to be hydrolysed to release energy(Glucose needs several bonds to be broken to release all its energy)
-It can transfer energy to another molecule by transferring one of its Phosphate groups(can able phosphorylation, glucose can't as it doesn't have any Phosphate groups)
-ATP can't pass out of the cell so the cell always has an immediate supply of energy, cell can run out of glucose
27
Compare the strength of the bond between covalent and ionic
What is the electrostatic attraction between opposite charged ions called
Covalent- more stable molecule formed
Ionic- weaker than covalent bonds
Ionic bond
28
What are 5 examples of biomolecules
Nucleic acids
Polysaccharides
Lipids
Proteins
Water
29
Describe Hydrogen, covalent and ionic bonds
HYDROGEN: Electrons tend to position at one side which causes molecule to become polarised. Negatively charged region attracts positively charged region of another molecule. Individually, these bonds are weak but collectively become important forces to define the molecules properties
COVALENT: Shared pair of electrons. Filled outer shell of electrons for both atoms. More stable molecule is formed
IONIC: Oppositely charged ions attract eachother. Electrostatic attraction between them is known as the ionic bond. Weaker than covalent bonds
30
Where does initial energy come from
-The sun
-Photosynthesis occurs in plants where carbon dioxide and water react to release oxygen and glucose
-Respiration occurs where glucose is oxidised to make ATP
31
Why are --------- bonds are broken in ATP easily
Phosphodiester bonds
They have a low activation energy
32
What can the Phosphate bring produced in the hydrolysis of ATP be used for
To phosphorylate compounds by binding on to them to make them more reactive
To provide energy to energy requiring cellular reactions
33
Why is ATP not a good long term source of energy
Easily be hydrolysed into ADP
Fats and Carbohydrates are better stores of long term energy(glycogen and starch)
34
Glucose is an isomer
Define isomer
Same molecular formula but a different structure
35
Glucose is an isomer
Define isomer
Same molecular formula but a different structure
36
Samsung notes (glucose)
Yay
37
What is a molar solution
1 mole is in a litre of solvent
38
Name two lipids and describe their structures
TRIGLYCERIDES: 1 Glycerol and 3 fatty acids
PHOSPHOLIPIDS: 1 glycerol, 2 fatty acids, 1 Phosphate group
39
What is the reaction that forms Triglycerides and Phospholipids and what bonds are formed and what molecule is also formed
Condensation reaction
Ester bond
Water molecules
40
Define Saturated fatty acids and Unsaturated fatty acids
The hydrocarbons chain only has single bonds between carbons
The hydrocarbon chain consists of atleast one double bond between carbons
41
What are the 4 properties of Triglyceride and explain them
ENERGY STORAGE Large ratio of energy storing carbon Hydrogen bonds compared to the number of carbon atoms
METABOLIC WATER SOURCE High ratio of Hydrogen to oxygen atoms, triglycerides can be oxidised to release water
INSOLUBLE IN WATER Large and hydrophobic and do not affect water potentials and osmosis
LOW MASS Lots can be stored without increasing the mass by a lot and preventing movement
42
Describe the emulsion test for lipids
Dissolve the sample in ethanol
Add Distilled water
Lipid is present if a white emulsion forms
43
Describe the fatty acid and Phosphate in phospholipids and how they react to water
What is this type of molecule called
Fatty acids are hydrophobic and repel water because they have no charge, but it reacts with lipids
Phosphates are hydrophilic and attract water because its charged
Amphipatic
44
Why are phospholipids polar molecules
They have 2 charged regions
45
Describe how phospholipids are positioned in water
Heads (phosphate) is exposed to water and tails are not(fatty acid)
46
What are the functions of Proteins
Structure
Immunological functions(antibodies)
Catalytic functions(enzymes)
Signalling/Identification(antigens)
47
Name the 3 groups in an amino acid monomer
Amino group
Variable group (R group)
Carboxyl group
48
What molecule is formed when 2 amino acids react together
What bond is formed
Dipeptide
Peptide bond
49
What is the bond formed between glucose
Glycosidic
50
What method should you use to seperate the different amino acids
Chromatography
51
Explain the 4 structures of Proteins in all 4 stages
PRIMARY STRUCTURE : The order of amino acids in the polypeptide chain(Peptide bonds holds all the amino acids together in the polypeptide chain)
SECONDARY STRUCTURE : The sequence of amino acids causes parts of protein molecule to bend into an alpha helix or fold into beta pleated sheets (Hydrogen bonds hold together the secondary structure - Hydrogen bonds form between the C=O groups of the carboxyl group (especially O) of one amino acid and the H in the amino group of another amino acid
TERTIARY STRUCTURE : The further folding of the secondary structure to form a unique 3D shape, 3D structure is held in place by ionic, Hydrogen and disulfide bonds(The ionic and disulfide bonds form betweeb R groups of different amino acids)(Disulphide bonds only occur if there is an amino acid with a sulfur in its R group)
QUARTERNARY STRUCTURE : A protein made up of more than 1 polypeptide chain
52
What happnes when a protein is denatured
The bonds that hold the tertiary and secondary structure in shape are broken and the unique 3D shape is lost
53
What conditions denature a protein
-Too high temperature(Too much kinetic energy)
-Too high/low pH (Too many H+ or OH-)
54
Why is the primary structure of a protein very important
If one amino acid in the sequence is different, it will cause the ionic/hydrogen/ disulfide bond to form in a differnt location, this results in a different 3D shape, this changes the shape of the active site(enzyme will not function)
55
What happens if carrier proteins are denatured
Their binding site changes shape so the molecules are no longer complementary and cannot be transported across membranes
56
What does biuret solution contain
Sodium hydroxide and Copper II
57
What structure are enzymes and what kind of proteins are they
Tertiary structure
Globular proteins
58
Sucrose + water ->
Lactose + Water ->
Maltose + Water ->
Sucrose + water -> Glucose + Fructose
Lactose + Water -> Glucose +Galactose
Maltose + Water -> Glucose + Glucose
59
Why does the acitive site of an enzyme have a specific, unique shape
Due to the specific folding and bonding in the tertiary structure of the protein
Unique 3D structure determines the shape of the active site.
60
What are the 2 models of enzyme action
Lock and key model
Induced fit model
61
Explain the lock and key model
The enzyme active site is a fixed shape and random collisions cause the substrate to collide and attach fk the enzyme which forms an enzyme substrate complex
-The substrate then distorts which lowers the activation energy - products are released - enzymes active site is empty - enzyme can be reused
62
Explain the induced fit model
Enzyme's active site is induced (chnages shape slightly) to mould around the substrate - puts strain on bonds in substrate and weakens them - lowers activation energy - products are removed -> active site returns to original shape
63
What factors affect enzyme action
Temperature
pH level
Enzyme concentration
Substrate concentration
Inhibitors
64
Explain temperature in rate of reaction
-If the temperature is low, there is not enough kinetic energy for successful collisions between enzyme and substrate
-As the temperature increases, the kinetic energy increases so more frequent, successful collisions betweeb enzyme and substrate so rate of reacrion increases
-When the temperature is too high, the enzymes denatured and active sites chnage shape as the bond holding together the amino acids in the fixed, 3D tertiary structure are broken so enzyme substrate complexes can't form
65
Explain pH in rate of reaction
-If the pH is too high(too many hydroxide ions) or too low (too many Hydrogen ions), this will Interfere with the charges in the amino acids in the active site and breaks down the bonds holding together the amino acids in the tertiary structure, active site chnages shape and enzyme denatured so less enzyme substrate complexes form
66
Explain substrate concentration in rate of reaction
-At low substrate concentration, the rate of reaction is low so substrate concentration is the limiting factor as there are few successful collisions between the enzyme and substrate so less enzyme substrate complexes form
-As the substrate concentration increases, the frequency of collisions between the enzyme and substrate increases do the rate of reaction increases
- When you keep increases the substrate concentration, the rate of reactions starts to become constant as the enzyme active sites are Saturated(new limiting factor is enzyme concnetration)
67
Explain enzyme concentration in rate of reaction
-At low enzyme concentration, the rate of reaction is low as enzyme active sites are saturated, so enzyme concentration is the limiting factor
-As the enzyme concentration increases, there are more frequent and successful collisions between the enzyme and substrate, so the rate of reaction increases
-As enzyme concentration increases, rate of reaction stays constant as substrates are used up so no collisions between enzyme and substrate and now enzyme substrate complexes form
68
EQ: Describe bow the structure of a protein depends on the amino acids it contains
- Structure is determined by position of amino acid
- Primary structure is sequence kf amino acids
-Secondary structure is formed by Hydrogen bonding
-Tertiary structure is formed by interactions
-Creates active sites in enzymes
-Quarternary structure contains more than one polypeptide chain
69
Describe the structure of proteins
Polymer of amino acids
Joined by peptide bonds
Formed by condensation
Primary structure is order of amino acids
Secondary structure is folding of polypeptide chain due to Hydrogen bonding
Tertiary structure is 3D folding due to Hydrogen bonds and ionic bonds
Quarterbary structure is two or more polypeptide chains
70
EQ Describe how proteins are digested in the human gut
Hydrolysis of peptide bonds
Endopeptidases break polypeptide into smaller peptide chains
Exopeptidases remove terminal amino acids
Dipeptidases break down dipeptides into amino acids
71
What do inhibitors do
What are two types of inhibitors and explain them
They prevent the formation of enzyme substrate complexes
Competitive inhibitor: Inhibitors has a similar shape to substrate. Inhibitors can bind to active site. Enzyme substrate complex unable to form.
Non competitive inhibitors: Inhibitor binds to enzyme away from the active site. Forces the active site to change shape. Substrate can no longer bind to active site. Enzyme substrate complexes do not form
72
Biomolecules Samsung notes
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73
MONOSACCHARIDES
Explain fructose, glucose, galactose
Fructose: Sugar found naturally in fruits vegetables and honey
Glucose: Main sugar used for respiration. Absorbed and transported in bloodstream to cells
Galactose: Mainly in our diet as part of Lactose dissacharide
74
How can you differentiate alpha glucose and beta glucose
In alpha glucose, the hydroxyl group is below Carbon 1
In beta glucose, the hydroxyl group is above Carbon 1
75
STARCH
Monomers?
Bonds between monomers?
Function?
Location?
Structure?
Explanation of how the structure leads to the function?
MONOMERS: Alpha glucose
BONDS BETWEEN MONOMERS: 1-4 glycosidic bonds in amylase, 1-4 and 1-6 glycosidic bonds in amylopectin
FUNCTION: Insoluble store of glucose
LOCATION: Plant cells(e.g. starch grains in chloroplast)
STRUCTURE: Amylase is a long, unbranched chain that forms a helix
Amylopectin is a branched molecule
EXPLANATION OF HOW THE STRUCTURE LEADS TO THE FUNCTION
Forms a helix that is compact so it can fit a lot of glucose in a small space
Branched structure which increases surface area for rapid hydrolysis back into glucose
Insoluble so doesn't affect water potential
76
GLYCOGEN
Monomers?
Bonds between monomers?
Function?
Location?
Structure?
Explanation of how the structure leads to the function?
MONOMERS: Alpha glucose
BONDS BETWEEN MONOMERS: 1-4 and 1-6 glycosidic bonds(more 1-6 glycosidic bonds than amylopectin)
FUNCTION: Insoluble store of glucose
LOCATION: In liver and muscle cells in animals
STRUCTURE: Highly branched molecule
EXPLANATION OF HOW THE STRUCTURE LEADS TO THE FUNCTION
Branched structure increases surface area for rapid hydrolysis back to glucose
Insoluble so won't affect water potential
77
What reaction forms polysaccharides
Condensation reaction
78
CELULLOSE
Monomers?
Bonds between monomers?
Function?
Location?
Structure?
Explanation of how the structure leads to the function?
Beta glucose
1-4 glyscosidic bonds
Structural strength for cell walls
Plants in cell wall
Polymers form long, straight, unbranched chains. Chains are parallel to eachother and are held together by Hydrogen bonds which form cross links between adjacent chains, this forms fibrils. Subsequent beta glucoses are rotated by 180°
Many Hydrogen bonds provide collective strength
Insoluble so does not affect water potential
79
Explain how cellulose molcules are adapted for their function in plants cells
- Long unbranched straight chains provide rigidity that is required to support the plant
- Hydrogen bonds form cross links between adjacent and chains which provides strength
-Cellulose has high tensile strength
-Cellulose fibres provide extra strength to the cell walls
80
Describe the test for starch
Add iodine
If the solution changes colour from orange to blue-black, starch is present
81
Name some reducing sugars
Glucose, Fructose, Galactose, Lactose, Maltose
82
Name some non reducing sugars
Sucrose
83
Describe the test for reducing sugars
Add benedicts solution and hear in a Waterbath
Colour change from blue to green/yellow/brick red
84
In the Benedicts test, what do the colours green, yellow and brick red indicate
GREEN: Low concentration of non/reducing sugars
YELLOW: Moderate concentration of non/reducing sugars
BRICK RED: High concentration of non/reducing sugars
85
In a benedicts test, why does the colour change at the top of the solution first?
Convection currents cause hotter particles in the solution to rise to the top. They have lots of kinetic energy, so they have lots of successful collisions so the reaction is faster and colour chnage happens first at the top
86
Explain the test for non reducing sugars
Add acid to the non reducing sugar and boil it
Cool the solution and then alkali to neutralise it
Add benedicts solution and heat in a water bath
If there is a colour chnage from blue to green/yellow/brick red, ----- conc of non reducing sugars are present
87
When testing for non reducing sugars, why do you add acid and then why do you neutralise it with alkali
Acid hydrolysis - Hydrolysis of the glycosidic bonds in sucrose releasing glucose and fructose
Benedicts test doesn't work in acidic conditions
88
What is the explanation for how reducing sugars make a colour change observable
When a reducing sugar is tested, the reducing sugar is oxidised and the benedicts solution is reduced as the reducing sugar loses an electron so Cu²+ can form Cu+ which forms a red precipitate
89
Why do non reducing sugars not show a colour change
In non reducing sugars, the reducing group is involved in the glycosidic bonds in sucrose so sucrose can't lose an electron so Cu²+ does not form Cu+ ions
90
What is a carbohydrate
A molecule formed from one or more monosaccharides
91
What is a disaccharide
A molecule formed by the condensation of two monosaccharides
92
What is Maltose, sucrose and lactose
A disaccharide formed by the condensation of a glucose molecule and a .... molecule
93
What is a polysaccharide
A molecule formed by the condensation of many monosaccharide units
94
What does DNA stand for
Deoxyribonucleic acid
95
What js the function of DNA
Codes for the sequence of amino acids in the primary structure of a protein which determines the 3D structure and function of a protein
96
What is the structure of DNA
Double helix structure
97
What are the 3 parts that makes up the nucleotide in DNA
Phosphate
Deoxyribose
Nitrogenous base
98
What are the 4 nitrogenous bases in DNA (complementary base pairs)
Adenine - Thymine
Guanine - Cytosine
99
Condensation reactions between the deoxyribose sugar and Phosphate in DNA nucleotide form ...
Define this blank
Phosphodiester bonds
Strong covalent bonds that ensure the genetic code isn't broken down
100
What makes the sugar Phosphate backbone in DNA very strong
Phosphodiester bonds between the deoxyribose sugar and Phosphate
101
In DNA, Hydrogen bonds only form between...
How mamy Hydrogen bonds does Cytosine and Guanine form?
How many Hydrogen bonds does Adenine and Thymine form?
Why is this complementary base pair important
Complementary base pairs
3
2
To help maintain the order of the genetic code when DNA replicates
102
In DNA, pyrine bases always pair with pyrimidine bases
Name the pyrine bases and number of rings
Name the pyrimidine bases and number of rings
Name the pyrine bases and number of rings - Adenine + Guanine + 2 rings
Name the pyrimidine bases and number of rings - Cytosine + Thymine + 1 ring
103
Explain how the structure of DNA relates to its functions
-Stable structure due to sugar Phosphate backbone (covalent bonds) and the double helix
-Double stranded so replication can occur using one strand as a template
-Weak Hydrogen bonds for easy unwinding of the two strands in a double helix during replication
-Large moelcule so carries lots of information
-Complementary base pairing allows identical copies to be made
104
What are the 3 parts in the nucleotide of an RNA
Ribose, nitrogenous base, Phosphate
105
What are the nitrogenous bases in RNA(complementary base pairs)
Adenine - Uracil
Guanine- Cytosine
106
In comparison to DNA, RNA is...
A shorter polynucleotide chain and is single stranded
107
What is the function of RNA
Copy and transfer the genetic code from DNA in tbe nucleus to Ribosomes
108
Before a cell divides, what has to happen to DNA
It has to replicate
109
Why is the process of DNA replication semiconservative
Each time DNA divides, each of the two DNA moelecules made contain half the original strand of DNA
110
Explain the process of DNA replication
1) Dna helicase breaks the Hydrogen bonds between the complementary base pairs between the two strands in the double helix
2) This causes the DNA double helix to unwind
3) Each of the two strands acts as a template for free nucleotides to assemble along the strand according to their complementary base pairs by DNA polymerase
4) DNA polymerase joing together adjacent nucleotides through condensation reactions
5) DNA replication is semiconservative as each of the two DNA molecules produced contain half the original strands of DNA
111
What are the two distinctive ends nucleic acids have
What does this refer to
What does each end bind to
5' and 3'
This refers to the 5th and 3rd carbon on the sugar
5' end binds to a Phosphate
3' end binds to a hydroxyl group
112
What kind of enzyme is DNA polymerase
Why is it a .... enzyme
Unidirectional enzyme
It reads the template DNA from 3' to 5' direction but makes the new strand from the 5' to the 3' direction
113
What does DNA polymerase catalyse
DNA polymerase catalyses the formation of phosphodiester bonds in the sugar Phosphate backbone
114
In DNA replication, how does Hydrogen bonds form
Hydrogen bonds form naturally, no enzyme is needed
115
What is the role of DNA ligase in DNA replication
DNA ligase joins fragments together to form a continuous strand
116
What two people discovered the double helix structure of DNA and who were they helped by and how
What was their hypothesis
Watson and Crick (helped by Rosalind Franklin's research on xray diffraction)
Hypothesis: DNA must replicate conservatively or semiconservatively
117
Who did an experiment that proved DNA replication must be semiconservative, and how did they do this
Meselson and Stahl did an experiment which involved growing bacteria in mediums containing 2 different isotopes, 14N and 15N
118
How did DNA form is Meselson and Stahl's experiment
Bacteria (E coli) takes in Nitrogen isotopes to make nitrogenous bases which can make new DNA molecules
119
In Meselson and Stahl's experiment, how did they work put what DNA was present
Explain the result for both isotopes
DNA samples were spun in a centrifuge to confirm their density
15N will settle lower down as it is more dense
14N will settle higher up as it is less dense
120
In Meselson and Stahl's experiment, what was the order of each medium and the percentage outcome of each DNA molecule produced
15N (15N 15N 100%)
14N (15N 14N 100%)
14N (15N 14N 50% + 14N 14N 50%)
121
Why is water a polar molecule
Where does the Hydrogen bond form in a water molecule
Uneven disturbution of electrons so oxygen has a greater share of electrons. Oxygen has a partial negative charge and Hydrogen has a partial positive charge
Hydrogen bond forms between fhe Hydrogen in a water moelcule and an oxygen in another water molecule
122
What are the 5 key properties of water
Metabolite
Solvent
High specific heat capacity
High latent heat of vaporisation
Cohesion
123
KEY PROPERTIES OF WATER
Explain metabolite
Involved in many reactions such as hydrolysis and condensation (90% of plasma is wafer and Cytoplasm contains a lot of water)
124
Do polar or non polar substances dissolve in water
Polar
125
KEY PROPERTIES OF WATER
Explain solvent
-Dissolves many substances which allows substances to be transported
-Partially positively charged Hydrogen ions attract negative ions and partially negatively charges oxygen ions attracts positive ions xausing them to seperate(dissolve)
126
KEY PROPERTIES OF WATER
Explain high specific heat capacity
Amount of energy required to increase the temperature of 1kg of a substance by 1°C
-A lot of energy is required to increase temperature of water as some of the energy is used to break Hydrogen bonds between water molecules
-Acts as a buffer against temperature change so internal temp of organisms should remain relatively constant despite the outside temp
Enzymes don't denture or reduce in activity
127
KEY PROPERTIES OF WATER
Explain high latent heat of vaporisation
-A lot of energy is required to convert water from a liquid to gas as energy is needed to break Hydrogen bonds between water molecules
-Has a cooling effect on organisms as water absorbs a lot of hear before it turns into water vapour so a lot of heat is removed from organism (Plants - transpiration)
128
KEY PROPERTIES OF WATER
Explain cohesion
Water molecules 'sticking' together by Hydrogen bonds
-When water molecules move up the xylem in a plant through transpiration, it moves as a continuous column, easier to draw up a column rather than individual molecules
-Also provides surface tension on water allowing smaller organisms to settle on it, providing hem a habitat away from predators within water
129
INORGANIC ION
Define ion
Define inorganic ion
Ion is an atom that has an electrical charge
Inorganic ion is an ion that doesn't contain carbon
130
Where can inorganic ions be found
In solution in Cytoplasm and bodily Fluids
131
What are 5 inorganic ions
Hydrogen ions
Potassium ions
Sodium ions
Phosphate ions
Iron ions
132
What is the importance of Hydrogen ions
-Concentration of Hydrogen ions determines the pH, the higher the concentration of Hydrogen ions, the lower the pH(acidic) and this affects enzyme activity
-ATP synthesis in mitochondria during respiration, proton gradient is formed to release energy
133
In mitochondria, where is there a high and low concentration of Hydrogen ions
High in membrane
Low in matrix
134
What is the importance of potassium ions
Crucial to heart function and skeletal and smooth muscle contraction
135
What is the importance of sodium ions
Glucose and amino acids are absorbed in the small intestine by cotransport with sodium ions
136
What is the importance of potassium and sodium ions
Important in the nervous system and communication between neurones
137
What is the improtance of Phosphate ions
Combines with calcium to form calcium Phosphate(rigidity of bones)
138
What are the two isotopes of iron
Fe²+ and Fe³+
139
What is the importance of iron ions
Fe²+ binds to oxygen so haemoglobin binds to oxygen and transports it to cells
