Biological Molecules Flashcards
1
Q
Carbohydrates
A
Made of carbon hydrogen oxygen
Mostly made by plants
Important energy resource
2
Q
Positive Benedict’s
A
Blue to red
3
Q
Starch -iodine
A
Brown to blue black
4
Q
General carb formula
A
(Ch2o)n
5
Q
Fructose symbols
A
C6h12o6
6
Q
Monosaccharides
A
Consist of one sugar unit where number of carbon atoms can very
Glucose fructose ribose
(Ch20)n
Soluble in water
Often taste sweet
7
Q
Ribose formula
A
C5h10o6
8
Q
Cellulose
A
Beta
1,4 glycosidic bonds
Plants
Structural ridigty ,prevents burst and maintains turgid
Unbeanched chains linked together
9
Q
Disaccharide
A
Consist of 2 monosaccharides connected by a glycosidic bond formed by a condensation reaction where a water molecule was lost
Lactose sucrose maltose
10
Q
Monomer +monomer
A
Disaccharide
Water molecule removed by condensation reaction
11
Q
Maltose
A
Glucose + glucose
12
Q
Starch
A
Alpha
1,6
1,4 glycosidic bond
Formed by condensation reactions
Branched and h branched chains
Found in plants seeds and storage organs
Energy storage
Large and insoluble
Iodine
13
Q
Sucrose
A
Glucose +fructose
14
Q
Polymer
A
Large complex molecules composed of long chains of monomers joined together
15
Q
Unbranded chains
A
Linked together by ma h h binds adding to strength microfibriks join together to form fibres adding more strength
Microfiibrriks join together to form fibres adding more strength
16
Q
Adaptions of being large and insoluble
A
No diffusion out of cells
Compact a lot can be stored in snakkk space
Branched many ends for enzymes to start hydrolysis
17
Q
Polysaccharide
A
Chains of ma h sugar units can be straight or branched
Glycogen cellulose starch
18
Q
Example of monomers
A
Glucose
Amino acids
19
Q
Lactose
A
Glucose + galactose
20
Q
Monomer
A
Small basic molecule units
21
Q
Glycogen
A
Alpha
Glycosidic bonds formed by condensation reactions
Branched
Animals fungi bacteria
Storage polymer and hydrolysed to release glusocse for resp
Large and insoluble
22
Q
Why does sucrose need to be broken down.
A
To become a reducing sugar
23
Q
What carb has 1!6 glycosidic bind
A
Amylopectin
24
Q
Why add ethanol to lipids
A
To dissolve it
25
Polar (charged substances )
Soluble in water
26
Lipids
Contain carbin hydrogen and oxygen
Insoluble in water
Soluble in all and acetone (organic solvents )
27
Role of lipids
High in energy
When oxided t provide twice the energy and also release water
Excessive dietary fat intake which is associated with obesity ,diabetes,cancer
Saturated fat found in dietary products and animal fats lead to fatty plaques in arteries
In cell membrane
Phospholipids contribute to flexibility of membranes
Solubilise fat for so,unless vitamins
Protection in kidneys
Insulation for respiration and maintain 37 for chem reaction
Waterproof
Insoluble I. Water does not dissolve in cytoplasm
28
Triglycerides
Most common lipids in food
Compromised of 1 glycerol man’s 3 fatty acid molecule joined by ester bond via condensation reaction
29
Fatty acids
Long hydrocarbo. Chain which a carboxy group
No c-c double bonds
Mini unsaturated or poly unsaturated
Nature depends on which fatty acids are present
30
Structure of triglycerides
High ratio of energy storing carbon-hydrogen bonds to carbin atoms
Good storage molecule
Release water darn oxidised due to high ratio of hydrogen and oxygen and therefore provide an important source of water fir organisms in dry desserts
31
Phospholipid
One of fatty acids molecules is replaced with a phosphate molecule
Made of hydrophilic head and hydrophobic tail
Polar molecule as two ends behave different
32
Importance of hydrogen bonds
1)cross links between chains
2)forms microfibrillis
3)hydrogen bonds strong in large numbers
33
Polymer
Large molecules consisting of large numbers of repeating units connected by covalent bonds
34
Monomer
Small my,wake that maybe come chemically bonded to other monomers to form a polymer
35
Amino acid =
Minomer
36
Polypeptide
Polymer
37
Types of r groups
Hydrophilic
Hydrophobic
38
Hydrophilic
Polar -acid or basic
39
Hydrophobic
Non polar
Acid and basic r group will attract each other
Hydrophobic group and will attract each other
40
What type of bind does carb have
Glycosidic
41
What type of bind does a lipid have
Ester
42
What type of bind does protein have
Peptied
43
Why are hydrogen binds important in cellulose molecules
Give add strength and make mucrofibrrikis which join together to form fibres
Cross links in chains of hydrogens
Strong in large numbers
44
Why spiral shape in hydrogen is important
Compact occupies small space and highly packed
45
What is a. Unsaturated fatty acid
It has one or more double carbin carbin bind
2 carbind with one hyrigrgen
46
How many molecules in triglycerides
4
47
Large and insoluble
Compact
Occupy small space
Branched ends
No diffusion out of cells
48
What bind is formed in a condensation reaction
Glycosidic bond
49
Hydrolysis
When water is added to a disaccharide under suitable conditions it breaks the glycosidic bond releasing the monosaccharides
50
Cellulose is a
Polysaccharide
51
Polysaccharide
Polymers formed by combining together many monosaccharides molecules which are joined by glycosidic bonds that were formed by condensation reactions .
52
How is Starch suited
Insoluble - doesn’t affect water potential so water is not drawn in to cells by osmosis
Large and insoluble - it doesn’t diffuse out of cells
Compact-so a lot of it can be stored un a small space
53
Glycogen adaptions
Insoluble -does not rent to draw water into the cells by osmosis
Does not diffuse out of cells
Compact sores in small space
54
How is cellulose adapted
Straight unbranched chains
Beta glusocse
Hydrogen bonds form cross links between adjacent chains strength
Molecules grouped to form microfibriklis
55
Role of lipids
1)source of energy
2)waterproofing
3)insulation
4)protection
56
Source of energy
When oxidised lipids provide 2x the energy as the same mass of carbohydrates and release valuable water
57
Waterproofing
Lipids are insoluble in water therefore useful as waterproofing
Both plants and waxy lipid cuticles that conserve water
58
Protection
Fat us often stored around delicate organs such as kidneys
59
Triglycerides
Three fatty acids combined with glycerol
Each fatty acid forms an ester bind with glycerol in condensation reactions
60
Saturated fatty acids
All carbon atoms are linked to the maximum possible number of hydrogen atoms
61
Phospholipids
Hydrophobic tail - orients itself away from water but mixes rweadily with fat
Hydrophilic head interacts with water but not with fat
62
Polar meaning
Molecules that have two ends that behave differently
63
primary structure
the sequence of amino acids in the polypeptide chain
detrmines shape and function
peptide bond
64
what makes dipeptide bonds
condesnation reaction
65
2 amino acids
dipeptide more than two amino acids =polypeptied formed by condesnationreactions
66
what determines sequence of amino acids
DNA base sequence of the gene that codes for the polypeptide in nucleus by transcription.
67
secondary structure
strings of amino acids twist to form either an alpha helix of a beta plated sheet
peptide and hydrogen bonds formed
68
alpha helix
69
tertiary structure
fold to form a 3d shape
chemical bonds and hydrophobic interactions between r groups maintains shape
some r groups are polar meaning they are hydrophillic and attract to other polar r groups
non-polar r groups are hydrophobic and face inside the protein
ionic bonds if r groups are charges and disulphate bonds
70
in a tertiar structure what shape does polypeptide form
a 3d structure
71
types of bond in tertiary structure of protein
1)disulphide bridges -strong covalent bonds and not easily broken
2)ionic bonds
3)hydrogen bonds
72
disulphide bridges -
strong covalent bonds and not easily broken
73
ionic bonds
ionic bonds weaker than disulphide bonds and easily broken by change in PH
74
hydrogen bonds
hydrogen bonds -numerous but easiy broken especially by high temperatures
75
quzternary strucutre
determines by several polypeptide chains combining to form a big protein
76
conjugated protrin
a non protein molecule added
eg-haemoglobin contains an iron group
77
explain how the primary structure of an enzyme determines its three dimensional shape and properties
1)primary structure isnthe sequwnce of amino acids in a polypeptide chain
2)determining positiin of the bonds and active site hape
3)complimentary
78
globular proteins
fold into compact spherical shape
usually soluble
carry out metabolic functions
-quaternary
79
examples of globular protiens
enzymes
haemoglobin
antibodies
80
fibrous proteins
form long parallel chains crosslinked for stabiliity
they are usually inoluble and have structural functions
81
examples of fibrous proteins
keratin
collagen
biotin
82
collagen
-primary strcutre is unbranched polypeptide chains
-secondary structure polypeptied chain very tightly wound
-lots of glycine-helps close packing
-found in tendonds
-not souble
polymer of amino acid
83
Amino acid groups
1)amino group
2)carboxyl group
3)hydrogen group
4)hydrogen atom
5)r group
84
Amino acid definition
Basic monomer units which combine to make up a polymer called a polypeptide
85
Formation of peptide bond
Amino acid monomers combine
Removal of water molecule in condensation reaction
Broken by hydrolysis to give two Camino acids
86
Primary structure of proteins
Series of condensations many amino monomers join in polymerisation
Creating polypeptide sequence of amino acids in a polypeptide chains forms the primary structure of any protein
Determined by dna
Determines shape and function
87
What can a change in amino acid sequence do
Change in shape of a protein and may stop carrying out its function
Protein show especifc to its function
88
Secondary structure
Of proteins
NH pos and -c=o groups neg
Readily form weak bonds -h2 bonds
Long peptide chain twisted into 3d shape
Alpha helix
89
More on ionic bonds
Formed between any carboxyl and amino groups that are not involved in forming peptide bonds
Weaker than disulphide binds
Easily broken due to change in ph
90
Ina tertiary structure what makes protein distinctive
3d shape
How functions
Be recognised by other molecules
Interact with molecules in a specific. Way
91
Quaternary structure
Individual polypeptide chains linked in various ways
Non protein-prosthetic groups
92
why is solid water less dense than liquid water
because of hydrogen bonds
93
why is water dipolar
pair of shared electrons in the oh bonds are more attracted to the oxygen atom
therefore uneven dsutrubution of charge
oxygen-neg
hydrogen-pos
therefore dipolar
94
why is water polar
electrons are attracted more strongly to the oxygen than the two hydrogens
95
why polar is useful
excellent solvent
useful for transport of substance
reactions happen much faster in aqueous solution
96
water properties
-a high specific heat capacity
because of hydrogen bonds
-takes a lot of energy to change the temp which reduces the dramatic changes that would affect enzymes
-aquatic animals
-high latent heat of vaporisation
-because of hydrogen bonds
-lots of energy required to evaporate the water so it has a cooling effect like sweating for animal cells and transpiration of plants
-cohesion between molecule
-hydrogen bonds
-creates surface tension providing a habitat
for small insects
-key to transports n the xylem
-adhesion because of hy2 bonds
-involved in transport in the xylem
-water has a solid for that floats because of hydrogen bonds where ice is less dense than water and this produces ice caps with produce a habitat eg.polar bears
97
importance of water to living orgsnisms
1)to breakdown complex molecules by hydrolysis
2)chemical reactions take place in the aqueous medium
3)reactant for photosynthesis
98
water being a solvent
1)gases scubas oxygen and carbon dioxide
2)wastes such as urea and ammonia
3)inorganic ions and small hydrophilic molecules such as amino acids ,monosaccharides and atp
99
incompressibility of water
-much less distance between the molecules in liquid than in a gas
-provide support for the hydrolystatic skeleton of animals such as earthworms and give turgor pressure in plants
100
maximum density of water at 4 degrees
-most liquids contract on cooling reaching maximum density at their freezing point
-water reaches max density at 4 degrees
-ice formed is less dense than the cold water so it floats on top and insulates the water below it. lakes rarely freeze solid and the aqautic life can survive freezing temps.
101
Isomers
Organic molecules that have the same chemical formula but different structural formula; [1 mark]
102
how cellulose gives cotton strength
The many hydrogen bonds found between the parallel chains of microfibrils; [1 mark]
Cellulose fibres and other molecules (eg. lignin) found in the cell wall form a matrix; [1 mark]
103
When Benedict’s reagent is mixed with sucrose solution there is...
No colour change BECAUSE sucrose is a non-reducing / not a reducing sugar
104
two similarities between glycogen and starch
Both are made of the same monomer, alpha/∝ glucose
Both are branched molecules
Both contain 1,4 glycosidic bonds and 1,6 glycosidic bonds
105
two differences between glycogen and starch
Starch is made up of amylose and amylopectin polysaccharides
Glycogen is more highly branched than starch (amylopectin)
Glycogen has more terminal ends than starch
106
The reaction that converts glucose into starch
Is a condensation reaction
That forms glycosidic bonds (between monomers
Chains are formed with 1-4 links/bonds
Branches are formed with 1-6 links/bonds
Water is produced (as a by-product)
107
explain one reason why peas use starch for storage rather than glucose
Starch is insoluble SO does not affect water potential / has no osmotic effect / cannot leave the cell
Starch has a coiled/helical/spiral structure SO can fit many molecules into a small area / compact / tightly packed
108
chemical formula of maltose
C12H22O11
109
saturated fatty acids have the least amount of oxygen
110
what bonds to primary structure have
polypeptide bonds
111
secondary structure bonds
hydrogen bonds
112
tertiary bonds
disulphide
ionic
113
conditions for a reaction to occurf
1)reactants must collide with suffient energy to alter the arrange meant of the atoms
2) The free energy of the products must be less than of the substrate
3)many reactions require an initial amount of energy to start. the minimum about of energy needed is the activation energy.
reactants energy must be more than the products
114
anabolic
requires energy
115
catabolic
releases energy
116
activation energy
-the energy of products must be lower than that of the substrates
-subsgtarte molecules must collide with sufficient energy to start the reaction
-enzymes lower the activation energy by stretching or pushing molecules
117
explain how the 3d structure of proteins enable enzymes to preform their function as biological catalyst
1)tertiary structure-of the protein provides an active site on the surface of the molecule
2)the complimentary substrate molecule fits into the active site forming enzyme substrate complex
3)products form released from the active site having the enzyme unchanged and ready to combine with more substrate molecules .
118
the induced fit model
-two advantages compared to lock and key
-it explains how enzymes may exhibit broad specifity eg.bonding to variety of lipids
-it explains how catalysts may occur where conformational change stresses bonds in the substrate increasing reactivity
119
describe the induced fit model of enzymes action and how an enzyme acts a catalyst
induced model shows broad specificity and the active site is relaxed which allows it to modify so its complimentary to the substrate as bonds break down to distort the shape of the active site an forms enzyme substrate complexes reducing activation energy
1)substrate binds to the active site
2)active site changes shape
120
Enzymes
Globular proteins that act as a biological, catalytic
Speed up reaction
121
anabolic reactions
building for complex molecules from simpler ones by drawing two or more substrates into the active site forming bonds between them and realising a single product
eg.protein synthesis and photosynthesis
122
catabolic reaction
involve the break down of complex molecules into simpler products which happens when a single substrate is drawn into the active site and broken apart into two or more distinct molecules
123
metabolism
sum of all the chemical reactions
eg.hydrolysis
124
catalyst
a substance that speeds up reactions without changing the products
125
metabolic pathway
sequence of enzymes controlled reactions
126
specificity
only able to catalyst specific reactions
127
substrate
the molecules the enzymes works on
128
product
molecules produced by enzymes
129
enzymes bringing substrate molecules together
anabolic reactions
130
enzymes being a globular structure
active site has a specific shape due to tertiary structure of protein
a change in shape of the protein affects shape of active site and the function of the enzyme
131
how would you measure the effect of an enzyme
-compare uncatalysed rate with catalysed
-enzymes can increase rate by a factor of between 10^8 to 10^26
132
enzyme binds to the substrate to form an enzyme substrate complex
133
factors affecting enzymes
-temperature,
pH,
enzyme concentration, substrate concentration,
134
what is rate of enzyme action dependent on
number os substrate molecules present
135
rate of reaction levels off
max rate of reaction (max) reaches saturation point as all active sites are occupied
136
some active sites free at lower substrate concentrations
137
why enzyme conc levels off
max rate of reaction (max) reaches saturation point as all substrate are occupied
138
thermophilic bacteria
have enzymes with optimum temp of 85 degrees
139
pepsin ph
2
140
tripsin ph
7/8
141
why ph affects proteins
ph affects fermentation of h bonds and sulphur bridges in protein and so affects shape
change in ph also alters the charges on the amino acid that make up the active site substrate complex cannot form.
142
name the part of the pancreatic cell that forms the inactive form of trypsin
ribosomes
143
suggest the advantage of producing trypsin in an active form of molecules
it doesn't digest/break down protein in the cells - good that trypsin inactive in the pancreas so tissue is not destroyed
144
