1
Q
What is a monomer?
A
Small basic molecular units that join together to make polymers
2
Q
What type of molecule is DNA and RNA
A
Protein molecule
3
Q
What monomer is DNA and RNA made from
A
Nucleotides
4
Q
What are the bonds that connect monomers in DNA and RNA
A
Phosphodiester bonds
5
Q
What type of molecule is cellulose, starch and glycogen?
A
Carbohydrate
6
Q
What type of molecule is insulin
A
Protein molecule
7
Q
What monomer is cellulose, starch and glycogen made up of?
A
Monosaccharides
8
Q
What bonds connect monomers in cellulose?
A
Covalent bonds
9
Q
What bonds connect monomers in starch?
A
Glycosidic bonds
10
Q
What bonds connect monomers in glycogen?
A
Glycosidic bonds
11
Q
What are polymers?
A
Large complex molecules composed of long chains of monomers joined together
12
Q
What are monosaccharides?
A
Sugars that are composed of only 1 type of sugar eg:glucose. Theses cant be hydrolysed to give a simple sugar
13
Q
What is the difference between the structure of alpha glucose and beta glucose?
A
The 2 types of glucose have 2 groups that are bonded to carbon reversed- the H and OH
In Alpha the hydrogen is Above, ands in Beta the hydrogen is Below
14
Q
What are disaccharides?
A
2 monosaccharides joined together
15
Q
What is a condensation reaction? What happens during a condensation reaction of 2 alpha glucose molecules?
A
Reaction that joins monomers with a covalent bond. The product of H2O is produced and a glycosidic bond forms
16
Q
What 2 monosaccharides are sucrose made from?
A
Glucose and fructose
17
Q
What 2 monosaccharides are maltose made from?
A
Glucose and glucose
18
Q
What 2 monosaccharides are lactose made from?
A
Glucose and galactose
19
Q
What is a glycosidic bond?
A
A bond that joins 2 or more monosaccharides together
20
Q
What is an ionic bond?
A
A bond that involves donation and acceptance of electrons. This occurs between a metal and a non metal
21
Q
What is hydrolysis
A
A reaction that splits molecules using water
22
Q
What is the main bodily use for glucose?
A
Respiration
23
Q
What is a polysaccharide?
A
Many monosaccharides joined together
24
Q
What organism is starch found in and which specific location of the organism is it found in?
A
Starch is found in the seeds and tubers of plants
25
What specific monomer makes up starch?
Alpha glucose
26
Is starch branched? Is it straight or helical?
Starch is not branched and is helical
27
What organism is glycogen found in? What part of the organism is it found in?
Glycogen is found in the liver and muscle of animals
28
What specific monomer makes up glycogen
Alpha glucose
29
Is glycogen branched? Is it straight or helical?
Glycogen is branched and it is straight
30
What organism is cellulose found in and what part of the organism is it found in?
Cellulose is found in the cell walls of plant cells
31
What specific monomer makes up cellulose?
Beta glucose
32
Is cellulose branched? Is it straight or helical?
Cellulose is not branched and is straight
33
Why is it important for starch and glycogen to be helical, insoluble and large?
. Being helical allows them to be compact and store lots of glucose in a small space
. Being insoluble ensures no osmotic effect
. Being large ensures the polysaccharide cant move out of the cell
34
Why is being branched important for glycogen?
So it can be rapidly hydrolysed to release glucose for respiration- this is important as animals are very active so they need a lot of energy quick
35
How does cellulose provide structural strength?
They have hydrogen bonds between chains which gives them strength
36
What are 2 examples of a lipid?
Triglycerides, phospholipids
37
What are the components of a triglyceride?
Made up of 3 fatty acids and 1 glycerol. Has long tails of hydrocarbons
38
What are the properties of triglycerides?
. Hydrophobic as the fatty acids repell water
. The tail makes lipids Insoluble in water
. It don't affect water potential of the cell
. Fatty acids are non polar
39
What is the biological function of triglycerides
. It is a store of energy- fatty acids contain lots of energy in bonds
. Thermal insulation
. Metabolic water
. Buoyancy - it can float
40
What is the difference between saturated and unsaturated fatty acids?
Saturated fatty acids don't have double bonds between carbon atoms, it is saturated with hydrogen.
. unsaturated fatty acids do have a double bond between carbons, causing the chain to kink
41
What are the components of phospholipids?
. Hydrophilic head
. Phosphate in the head
. Hydrophobic tail
. 1 glycorol
. 2 fatty acids
42
What are the properties of phospholipids?
. Phosphate head is hydrophilic and polar and attracted to water
. Fatty acids are non polar and hydrophobic
.fatty acids repell water
43
What are the biological functions of phospholipids?
Cell membranes - controlls what goes in and out of the cell
44
What are the similarities between triglyceride and phospholipids?
. Both have a hydrophobic tail of fatty acids that repell water
. Both have saturated and unsaturated fats
. Both have 1 glycorol
. Both contain hydromolecules
Both contain ester bonds
45
What are the differences between triglycerides and phospholipids?
. Phospholipids have 2 fatty acids, triglycerides have 3
. Phospholipids has a hydrophilic head, triglyceride doesn't
. Phospholipids have a phosphate making it hydrophilic, triglyceride doesn't
46
What are the components of an amino acid?
. Amino group (basic)
. Carboxyl group (acidic)
. R group
47
How many levels of protien structure are there and what are they?
There are 4 levels:
. Primary
. Secondary
. Tertiary
. Quaternary
48
Describe the primary structure of a protien
. Is a chain of amino acids held together by peptide bonds
. Is a polypeptide
49
Describe the secondary structure of a protien
Have hydrogen bonds in alpha helix and pleated sheet to hold the structure in place
50
Describe the tertiary structure of a protien
. Contain alpha helix and pleated sheets
. This is further folding where the whole chain and secondary structure folds into a specific 3D shape
. Has peptide bonds
. Has ionic bonds between ionised R groups
. Disulphide bonds between R groups containing SH groups
. Has hydrogen bonds
51
Describe the quaternary structure of a protein
Has more that one polypeptide chain which makes it a quaternary protein. It is held together by hydrogen bonds between the chains
52
What is activation energy?
The mount if energy needed for a reaction to take place
53
What is a catalyst?
Something that speeds up the rate of a reaction without being used up
54
What is an active site
A region on the enzyme that binds to a substance during a reaction
55
What is complementary?
When the enzyme and substrate have a specific shape that fits into each other
56
What is specific
Clearly defined or identified
57
What is denaturation
When an enzyme breaks up and stops working
58
What is an enzyme
A biological molecule. It is a catalyst that speeds up the rate of a reaction without being used up, by lowering the amount of activation energy needed in order for that reaction to occur
59
What is a substrate
The substance on which an enzyme acts
60
What is an enzyme-substrate complex
A temporary molecule formed when the substrate binds to the active site of an enzyme
61
What is a buffer
A solution which resists changes in the PH where acid or alkali can s added to it
62
What is kinetic energy?
The energy an object has which causes movement
63
What is an intracellular enzyme
An enzyme that works in a cell
64
What is an extracellular enzyme?
An enzyme that works outside a cell
65
How do enzymes speed up the rate of a reaction?
By lowering the amount of activation energy needed inorder for it to occur
66
Explain lock and key theory
The enzymes active site and substrate have a complimentary shape to each other. The substrate binds to the active site and the enzyme then breaks the substrate down into products
67
Explain the induced fit model
The enzymes active site and substrate is not complementary to each other so the active site moulds in order for the substrate to fit into it. The enzyme then breaks the substrate down into products
68
Explain how tempurature affects enzyme action
. As tempurature increases, enzyme activity increases because the particles have more kinetic energy, therfore they move more which causes more collisions between enzyme and substrate.
At some point the tempurature reaches its optimum which is when enzyme activity is at its highest
. If tempurature increases above the optimum, enzyme activity begins to fall as less Collins occur between enzyme and substrate, due to enzymes denaturing
69
What is PH a measure of?
PH is a measure of hydrogen ions in a solution
70
How does PH affect enzyme activity?
Enzymes work best at an optimum pH. Enzymes have diferent optimum pH. Changes in pH affect the charges on the amino acids in enzymes and extreme changes in pH can cause ionic bonds to break. This causes the tertiary structure of the protien to change, making the enzyme no longer complimentary to the substrate so enzyme activity will decrease.
71
How does substrate concentration affect enzyme activity
. Low substrate concentration means not all active sites are occupied to enzyme activity is low
. Saturation point: all enzymes are occupied
. Beyond saturation point: substrate concentration is high so all active sites are occupied and there are spare substrates
72
How do competitive inhibitors effect enzyme activity
The inhibitor has a similar shape to the substrate which is complimentary to the enzymes active sight. The inhibitor binds to the active sight of the enzyme, preventing the substrate from binding so less enzyme substrate complexes are made, lowering enzyme activity
73
Explain how non competitive inhibitors affect enzyme action
Non comperptive inhibitors bind to the alosteric sight of the enzyme. This changes the tertiary structure of the enzyme, so the enzymes active sight changes, making it no longer complementary to the substrate. No more enzyme substrate complexes are made so enzyme activity decreases
74
Investigating enzyme practicle
75
Info on DNA
. Full name is deoxirobose nucleic acid
. Sugar: deoxyribose
. Bases: adeneine, cytosine, guanine, thymine
. Number of strands: 2 linked strands
. Number of types: only 1 type
. Location: nucleus
. Function: contains instructions needed for an organism to develop, survive and reproduce and codes for proteins
76
Info on RNA
. Full name is ribonucleic acid
. Sugar: ribose
. Bases: adeneine, cytosine, guanine, uracil
. Number of strands: one strand
. Number of types: 3 type - mRNA, tRNA, rRNA
. Location: cytoplasm, nucleus, ribsomes
. Function: to react protien via translation, carry genetic code from the nucleus to the ribosomes. Brings amino acids to ribosomes (tRNA), component of ribosomes (rRNA)
77
Explain how DNA replication occurs
. DNA stands are split by an enzyme called DNA helicase
. After split, each strand becomes a template
. Nucleotides complementary to the strands then join together. This then creates 4 seperate DNA chains. 2 chains are joined together the the enzyme DNA polymerase to create 2 seperate DNA molecules
78
What is needed for DNA replication to occur?
ATP
79
Which direction can DNA be synthesised in
In a 5' to 3' direction (in vivo)
80
In which direction does the DNA stand move down the template strand?
In a 3' to 5' direction
81
How did meselson and stahl prove the semi conservation model?
Meselson and stahl (1958) grew the. bacteria escherichiacoli with diferent isotopes of nitrogen. The bacteria was exposed to N15 for several generations until it was exposed to lighter N14. Scientists could then distinguish there diferent densities by cetrefuging them. After doing this N15 was lower in the tube than N14 as N15 is heavier.
82
What are the properties of water and why are they significant?
. important metabolite - it can be a reactant or a product
. high latent heat of vapourisation - lots of heat energy can evaporate. This is used for sweating to cool the body
. acts as a tempurature buffer - has a high specific heat capacity (energy needed to raise temp of 1kg of substance by 1°C) so has little effect on large bodies of water --> water in cell dissolved in cytoplasm so cell is not distrupted so enzymes are not denatured.
. Is cohesive - tenancy of molecules to stick together. This is needed in plants as it allows water to move up the plant. Also needed for surface tension
83
What is ATP made up of?
Adeneine, ribose and 3 phosphates
84
Why is ATP necessary
It is necessary as cells can't ge there energy directly from glucose, so in respiration, energy is released from glucose is used to make atp and then molecules of atp provide energy for chemical reactions in cells
85
What are some reactions and processes that require atp?
. DNA replication
. Cell divison
. Active transport
. Muscle contraction
.protien synthesis
. Photosynthesis
86
How is ATP synthesised and broke down
. Atp is synthesised from adp and inorganic phosphate.
. Adp is a molecule containing adeniene, ribose and 2 phosphates.
. This is turned into atp by joining a third phosphate to it.
. During this energy is released.
. Energy is stored in the phosphate bond. When this energy is needed by the cell, atp is broken back down into adp and inorganic phosphate energy is released by the phosphate bond and is used by the cell
. Is a hydrolysis reaction
. Used enzyme hydrolase to go from atp to adp
. Uses enzyme synthase to go from adp to atp
87
What is the formula and function of hydrogen ions
Formula: H+
Function: affects the PH of substances (more H+ ions rhat OH- ions in a solution makes and acid). It is also I portant for photosynthesis that occur in the thylakoid membranes in chloroplasts and respiration that occur in the inner membrane of mitochondria. It is also used to make atp in aerobic respiration
88
What is the formula and function of sodium ions
Formula: Na+
Function:
. important for generation nerve impulses for muscle contraction
. for regulating fluid balance in the body
. important for movement of glucose into the blood
89
What is the formula and function of iron ions
Formula: Fe2+
Function: associated with heamaglobin which is made up of 4 polypeptide chains with Fe2+ I the centre. The Fe2+ binds with oxygen. When oxygen is bound Fe2+ becomes Fe3+
90
What is the formula and function of phosphate ions
Formula: 3-
PO
4
Fuction:
. involved in photosynthesis and respiration reactions.
. Needed for synthesis of many biological molecules such as nucleotides (such as atp) phospholipids and calcium phosphate which strengthens bones
Biology Alevel
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