Biological Molecules Flashcards
1
Q
What’s a monomer
A
Small basic mollecular unit that can form a polymer
2
Q
What’s a polymer
A
Large complex molecule composed of many repeated monomers
3
Q
monomer and polymer
Link between evolution
A
dna is made from same components, idea that we evolved from the same biochemistry
4
Q
What’s a condensation reaction
A
Joining monomers together by a covalent bond - releasing water
5
Q
What’s a hydrolysis reaction
A
Breaking down a polymer by the addition of water
6
Q
Carbon atoms readily form bonds together forming a
A
Backbone, where other carbons can be attached
7
Q
General formula of monosaccharides
A
CnH2nOn
8
Q
3 examples of monosaccharides
A
Glucose, galactose, fructose
9
Q
Difference between alpha and beta glucose
A
Alpha has the hydroxyl group below carbon 1
10
Q
Alpha and beta glucose are …. Of eachother
A
Isomers
11
Q
How do you recognise galactose
A
Similar to beta glucose
The hydroxyl group from carbon 4 is above not below
12
Q
How do you recognise fructose
A
Pentagon shape
13
Q
What’s a reducing sugar
A
Sugar that con donate electrons to another chemical
14
Q
What’s benidicts solution
A
Alkane solution of copper II sulphate
15
Q
Why does benidicts solution form a red precipitate when a reducing sugar is present
A
Copper II is reduced to Copper I oxide
16
Q
A glucose + fructose
A
Sucrose
17
Q
A glucose + A glucose
A
Maltose
18
Q
A glucose + galactose
A
Lactose
19
Q
How do we detect non deducting sugars
A
Need to be hydrolysed into its monosaccharides
20
Q
Method for testing non reducing sugars
A
- After benidicts test
- Add 2cm3 of liquid food to Hcl and heat in water bath
- Slowly add hydrocarbonate to neutralise the hcl and test with ph paper to test when it’s alkaline
- Retest with benidicts
21
Q
What 3 polysaccharides are used for?
A
Starch - storage
Glycogen - storage
Cellulose - structural
22
Q
Test for starch
A
- 2cm3 of sample into spotting tile
- Add 2 drops of iodine
Positive = orange —> blue/black
23
Q
Where is glycogen found and stored
A
Animals + bacteria
In muscles and liver
24
Q
Glycogen main features (4)
A
Insoluble - doesn’t affect water potential, doesn’t diffuse out of cells
Compact - large storage in small space
More highly branched then starch - enzymes react simultaneously to release glucose for resp as it’s needed for animals as they have a high metabolic rate
Alpha 1,4 and 1,6 glucosidic bonds
25
What’s cellulose made from
Beta glucose
26
Structure of cellulose
Beta glucose 1,4 glycosidic bonds
Every other glucose is rotated 180°
Long straight unbranched chains
Chains become linked by hydrogen bonds to form microfibrils
These stack to form fibrils
27
Importance of cellulose
Prevents cells bursting by creating an inwards pressure, leaving plant cells turgid ( swollen ) so they can provide the maximum surface area for photosynthesis
28
4 stages of protein production
Monomer of amino acids
Di peptide = 2 amino acids joined by a peptide link
Monomer = polypeptide
One or more polypeptides = protein
29
3 parts of amino acids and group names
NH2 - amine group
R - variable group
COOH - carboxyl group
30
If there are 30 amino acids how many peptide bonds and H2Os will there be
29
31
Primary structure of a protein
The sequence of amino acids determined by DNA
32
Secondary structure of proteins
The linked amino acids have NH and COO groups the H is + and the O is -, they attract eachother and form weak hydrogen bonds and 3D structures
Alpha helix
Beta pleated sheets
33
Tertiary structure of proteins
The 3D structures can be folded to give more complex shapes. The bonds are determined by the primary structure
Bonds:
Disulphide bridges- strong not easy broken
Ionic bonds - formed between carboxyl and amino
Hydrogen - easily broken
34
Quaternary structure of proteins
Large proteins often form complex molecules with multiple polypeptide chains
35
Test for proteins
1. Sample of solution unit equal amounts of sodium hydroxide solution
2. Add few drops of copper II sulphate and mix gently
Positive = blue—> purple
36
What’s covalent bonding
Atoms share a pair of electrons
37
What’s ionic bonding
Opposite charges attract each other ( weaker then covalent )
38
What’s a hydrogen bond
When electrons in a molecule are not evenly spread out so one side is more negatively charged. This molecule is said to be polarised, the neg of one molecule attracts pos of another to form a weak electrostatic bonds
39
What is the process of making polymers
Polymerisation
40
What’s condensation and hydrolysis reactions
Condens - joining of monomers to form polymers
Hydrolysis - separating of polymers to form monomers
41
What’s metabolism
All the chemical processes that takes place in living organisms collectively
42
What’s avogadros constant
6.022 x 10^23
43
What’s a molar solution
One mole of solute in each litre
44
2 formations of starch
Amylopectin
Amylose
45
Features of amylopectin (5)
Alpha 1,4 1,6 glycosidic bonds
Insoluble - don’t affect water potential
Compact - large storage in small space
Hydrolysed into glucose —> ATP for resp
Branched - enzymes react simultaneously
46
Features of amylose (4)
Alpha 1,4 glycosidic bonds
Insoluble - don’t affect water potential
Compact - large storage in small space
47
Structure for all starch
Arranged in a helix where the OH groups are pointing inwards to form hydrogen bonds
48
what do lipids contain
carbon, hydrogen , oxygen
49
properties of lipids ( 2 )
insoluble in water
solubkle in organic solvents
50
the 4 roles of lipids
source of energy - when oxidised they produce more the twice the energy of carbs and produce valuable water
waterproofing - insoluble in water eg: waxy cuticle in plants to conserve water
insulation - poor conductor, electrical insulator for myelin sheath around nerve cells
protection - protects delicate organs
51
how is a triglyceride fromed
condensation reaction between 1 glycerol and 3 fatty acids
52
formula for glycerol and fatty acids
glycerol
CH2OH
CHOH
CHOH
CH2OH
fatty acid
COOHR
53
how do triglycerides vary (3)
the variable group R
if its saturated ( single )
if its unsaturated ( double )
54
properties of saturated triglycerides
solid at room temp ( fats )
higher boiling point
compact = dense
55
properties of unsaturated triglycerides
liquid at room temp ( oils )
lower boiing point
non compact = less dense
56
properties of triglycerides ( 2 )
insoluble - dont affect water potential
high ratio of energy, stored in 'carbon-hydrogen' bonds
57
what is the bond between fatty acid and glycerol and how many water produced
ester
3
58
what is phospholipids made up of
1 glycerol
2 fatty acids
1 phosphate group
59
what happens to phospholipids in water
they form two layer sheets called bilayers
60
what happens to the phosphate head and fatty acid tail in water
phosphate head - outside as its hydrophilic and makes hydrigen bonds with the water
fatty acid tail - inside as its hydrophobic
61
what are the properties of phospholipids
- polar molecules form a bilayer to make a barrier
- phosphate heads help to hold at the surface of cell membranes
62
emulsion test practical method
1. add a sample of ethanol to the food, as ethanol dissolves lipids and mix
2. add to water and shake again
3. if its milky its positive for lipids
63
What’s an enzyme
Globular protein with a specific shape determined by tertiary structure, biological catalyst , speeds up rate of reaction, decreases activation energy, without being used up
64
What’s needed for an enzyme to work
- enough collisions
- enough energy to react
- enough energy to break bonds
65
Induced fit method
1. Substrate of a disaccharide joined by glycosidic bond
2. Enzyme molds around the substrate to make a conformational change due to the enzyme being complimentary
3. The binding of the substrate and enzyme, at the enzymes active site, creating an enzyme substrate complex, putting the stress on bonds. Breaking substrate into products
66
How do you measure the rate of enzyme activity
- how fast products are made
- how fast substrates are broken down
67
How does the affect of PH affects enzyme activity
- denatures on both side
- height at optimum PH
68
How does concentration of substrate affect enzyme activity
- ROR rises
- Gets to point of saturation where all enzymes are occupied and substrate increase doesn’t affect ROR
69
How does concentration of enzyme affect enzyme reaction
Liner measure as long as there is sufficient substrate,
point of saturation is all substrate is used up
70
How does temperature affect enzyme activity
Lower temp = fewer successful collision due to less activation energy
Optimum = more enzyme substrate complex
Above - denature, more collisions but shape no longer complimentary
71
What’s non competitive inhibition - does increasing substrate affect
- Where the inhibitor goes in the allosteric site
- changes shape of active site
- increasing substrate doesn’t affect inhibitor
72
What’s competitive inhibition - will increasing substrate affect
- inhibitor occupies active site
- increases substrate decreases affect of inhibitor
73
DNA + RNA
What are individual units of DNA called
Nucleotides
74
DNA + RNA
Structure of a nucleotide and the differences for DNA + RNA
Phosphate group
Nitrogenous base
Pentose sugar
DNA = Deoxyribose sugar
RNA = Ribose sugar
75
DNA + RNA
How do nucleotides join together
Via a condensation reaction between
Carbon 3 and a phosphate group
76
DNA + RNA
What bond is created via nucleotides and what does that create
Phosphodiester bond forms a sugar phosphate backbone
77
DNA + RNA
What are the 2 ends of DNA called and why is this important
5’ = five prime
3’ = three prime
DNA is a double helix, one strand goes in the opposite direction
78
DNA + RNA
What are the pairs of bases, number of H bonds
Adenine + Thymine = 2 H bonds
Guanine + Cytosine = 3 H bonds
In RNA = Adenine + Uracil
79
DNA + RNA
What bases are pyrimidine and which are purine
Pyrimidine= thymine and cytosine
Purine = adenine and guanine
80
DNA + RNA
Functions of DNA: sugar phosphate backbone
- Protects bases and bonds from chemical and thermal damages
- provides strength
81
DNA + RNA
Functions of DNA: complimentary base pairings
- A-T or A-U
- C-G
They allow accurate copying during DNA replication of protein synthesis
82
DNA + RNA
Functions of DNA: hydrogen bonds
Many = stability
C-G = strong due to 3
Easily broken to allow for DNA replication semi conservatively
83
DNA + RNA
Functions of DNA: Large Molecules
Stores large amounts of genetic info
84
DNA + RNA
Functions of DNA: sequence of bases
- confirms overall geno/phenotype
- 3 bases code for an amino acid
85
DNA + RNA
Functions of DNA: Helix
Compact
86
DNA + RNA
Functions of DNA: double stranded
Replication can be made semi conservatively
87
DNA + RNA
3 types of RNA
- messenger RNA
- Ribosomal RNA
- Transfer RNA
88
DNA + RNA
Stage 1/4 of DNA replication
1. DNA unzips by the enzyme HELICATE breaking H bonds
89
DNA + RNA
DNA replication stage 2/4
2. Free floating nucleotides from nucleus join by complimentary base pairings
90
DNA + RNA
DNA replication stage 3/4
3. DNA polymerase forms sugar phosphate backbone via a phosphodiester bond and a condensation reaction, hydrogen bonds form between bases with no enzyme needed
ATP activatesb
91
DNA + RNA
DNA replication stage 4/4
They are now semi conservative with one strand being OG and one new
92
DNA + RNA - Evidence for semi conservative replication
Why did they do the experiment
Needed a way to tell the old strand from the new strand
93
DNA + RNA - Evidence for semi conservative replication
What did they use
- use bacteria for DNA = easy to grow
- use different isotopes of nitrogen in the nitrogenous base - N15 and N14
94
DNA + RNA - Evidence for semi conservative replication
Process used to separate weight
Centrifucation
95
DNA + RNA - Evidence for semi conservative replication
What were the options
Semi conservative - one strand each
Conservative - the same in each
Dispersive - mixture in each
96
DNA + RNA - Evidence for semi conservative replication
How did they conclude it wasn’t conservative
They proved it was half as heavy when adding N14
97
DNA + RNA - Evidence for semi conservative replication
How did they conclude it wasn’t conservative
They proved it was half as heavy when adding N14
98
ATP
What’s the real name for ATP
Adenosine trisulphate
99
ATP
What is it
Phosphorylated nucleotide
100
ATP
What’s the structure
Adenine
Ribose
3 phosphate
101
ATP
Method of hydrolysis of ATP
Add ATP hydrolase = enzyme
Leaving ATP + inorganic phosphate
And energy
102
ATP
How does energy get released from hydrolysis of ATP
Breaking bonds changes chemical potential energy and energy is released from phosphate bond
103
ATP
What happens to the energy
Can be coupled to energy requiring reactions
104
ATP
Examples of energy requiring reactions
Active transport
Muscle contraction
Protein synthesis
DNA replication
105
ATP
What’s ATP phosphorylation and what’s the method
The IP released can be used to phospholrate other compounds
Gives the phosphate = molecule more reactive, lowers activation energy
106
ATP
What’s ATP phosphorylation used for example
Used for glucose during the start of respiration ( glycolysis)
107
ATP
Process of ATP synthesis
ATP is re synthesised by condensation of ADP and PI via an enzyme called ATP synthase
Using energy from respiration, stored in phosphate bond
108
ATP
Properties of ATP ( 5 )
- small amounts of energy realised each time
- soluble = can be transported around the cell
- Easy hydrolysed = energy
- can phosphorlyate = transfer phosphate to another molecule
- can’t pass out of cell = immediate supply of energy
109
ATP
Where is it made and what in
Respiration = mitochondria
Photosynthesis = chloroplasts
110
INORGANIC IONS
what are the 7 ions
Iron
Phosphate
Hydrogen
Calcium
Nitrate
Magnesium
Sodium
111
INORGANIC IONS
what do iron ions do
Found in haemoglobin to transport oxygen
112
INORGANIC IONS
what do phosphate ions do
forms structural components of DNA and phospholipids
Affects water potential
113
INORGANIC IONS
what do sodium ions do
Transmission of nerve impulses
Affects water potential
114
INORGANIC IONS
what do calcium ions do
important structural component in teeth and bones
115
INORGANIC IONS
what do hydrogen ions do
important for determining PH of a solution
116
INORGANIC IONS
what do magnesium ions do
chlorophylll contains this - needs for photosynthesis
117
INORGANIC IONS
what do nitrate ions do
sourches of nitrogen can be used to make proteins
118
WATER
Importance of H bonds
- H = is positive
- O = is negative
Water is dipolar
Water is attracted to eachother and can each make 4 other bonds
119
WATER
7 properties of water
Metabolite
Solvent
High SHC
Large latent heat
Cohesive
Hight surface tension
Dense when frozen
120
WATER
Importance of being a metabolite
Metabolite in many reaction - condensation and hydrolysis, water is used or produced
Eg: reactant in photosynthesis
121
WATER
What the importance of being a solvent
Due to being polar, substances can dissolve in it, this is important as it speeds up chemical reactions
Eg: good transportation of ions in blood
122
WATER
What’s the importance of having high specific heat capacity
Lots of energy needed to raise temp by 1 degrees due to having many H bonds
Acts as a temperature buffer
EG:
Good for equatic habitats = stable environment
123
WATER
What’s the importance of large latent heat of vaporisation
Lots of energy needed to change state
Has a cooling affect = no thermal damage
124
WATER
What’s the importance of being cohesive
Makes H bonds with eachother and things around it ( adhesive )
Eg: waiter can travel up xylem in unbroken columns
125
WATER
What’s the importance of being cohesive
Makes H bonds with eachother and things around it ( adhesive )
Eg: waiter can travel up xylem in unbroken columns
126
WATER
What’s the importance of having high surface tension
This is because it’s cohesive - when water meets air
Eg: water surface is good habitat for pond skaters
127
WATER
What’s the importance of water being more dense when frozen
Makes it a good insulator
Eg: in a lake, when the surface freezes it insulates water below so it doesn’t freeze
