2.2 bio molecules Flashcards
to learn
1
Q
define a condensation reaction
A
a reaction when two molecules join with the removal of water
2
Q
define hydrogen bond
A
a weak interaction that can occur where a negative polar atom bonds to a polar posiive hydrogen atom
3
Q
define hydrolysis reaction
A
reaction that occurs when a molecule is split with the addition of water
4
Q
define a monomer
A
a small molecule which binds to many other identical monomers
5
Q
define a polymer
A
a large molecule made from many monomers
6
Q
how many electrons in hydrogens outer shell?
A
one electron, only has one electron
7
Q
how many hydrogens can carbond bind with?
A
carbon can bind with 4 hydrogens
8
Q
what reactions join and split monomers and polymers?
A
conndensation and hydrolysis
9
Q
what charge is hydrogen?
A
hydrogen is polar
slightly positive
10
Q
which elements are in carbohydrates?
A
C, H, O
11
Q
which elements are in proteins?
A
C, H, O, N, S
12
Q
Which elements are in nucleic acids?
A
C, H, O, N, P
13
Q
what is the monomer of a carbohydrate?
A
monosaccharides
14
Q
wha is the polymer of carbohydrates?
A
polysaccharides
15
Q
what is the monomer of proteins?
A
amino acids
16
Q
what is the polymer of proteins?
A
polypeptides and proteins
17
Q
what is the monomer of nucleic acid?
A
nucleotides
18
Q
what is the polymer of nucleic acid?
A
DNA and RNA
19
Q
how are H and O bonded together in water?
A
two hydrogens are covalently bonded to the oxygen
20
Q
why is water polar?
A
because oxygen has more positive protons in its nucleus so it exerts a stronger attraction for the shared electrons.
this makes the oxygen become slightly negative
hydrogens become slightly positive
21
Q
why is a hydrogen bond weaker than a covalent bond?
A
covalents bonds share electrons which requires more energy to bresk
22
Q
why is it beneficial for water to be liquid at room temperature?
A
-provides a habitat for living things in rivers lakes and seas
-form a major component of the tissues in living organisms
-provide a reaction medium for chemical reactions
-provide an effective transport medium
23
Q
at what temperature does water get less dense?
A
4-0
24
Q
what is beneficial about ice being less dense than water?
A
-aquatic organisms have a stable environment for the winter
-bodies of water are insulated. ice layer reduces rate of heat loss
25
an example of an ionic solute?
sodium chloride
26
an example of a covalent solute?
glucose
27
why is water a good solvent?
water is polar
solute is polar
positive and negatives part of water and solute are attracted
water clusters aound the charged parts and keeps them seperated,
they then dissolve and a solution is formed
28
what is beneficial about water being a good solvent?
-molecules and ions can move around and react together
-cytoplasm is 70% water
-molecules and ions can be transported in organisms whilst dissolved in water
29
why does the surface of a water droplet look spherical?
because hydrogen bonds between the molecules pull them together
30
what is beneficial about water being cohesive?
-insects can walk on water
-columns of water in plant vascular tissue are pulled up the xylem tissue together from roots
31
what is specific heat capacity?
the amount of energy needed to change 1kg by 1 degree
32
what is beneficial about water having a high specific heat capacity?
-water doesnt heat up or cool down very easily so aquatc organisms have a stable environment
-organisms need a stable temperature for enzyme controlled reactions to happen properly
33
what is latent heat of vaporisation?
the energy needed for it to change state without changing the temperature
34
what is water's latent heat of vaporisation like?
it is high
water is held together by hydrogen bonds
a larger amount of enegy neeeded to make it evaporate
35
define a glycosidic bond
a bond formed between 2 monosaccharides by a hydrolysis reaction
36
what are the three functions of carbohydrates?
-source of energy
-energy store
-structural units e.g cellulose
37
a monosaccharides soluble in water?
yes
38
when are monosaccharides insoluble?
in non-polar solvents
39
what is the backbone of a monosaccharide?
single-bonded carbon atoms with one double-bonded to an oxygen
(forms a carboxyl group)
40
what type of sugar is maltose and lactose?
reducing sugars
41
what type of sugar is surcrose?
nom-reducing sugar
42
what is maltose made of?
alpha and alpha glucose
43
what is sucrose made of?
alpha glucose and fructose
44
what makes up lactose?
beta and alpha glucose
45
what makes up cellobiose?
beta and beta glucose
46
what does beta and alpha glucose make?
lactose
47
what does beta and beta glucose make?
cellobiose
48
what do alpha glucose and fructose make?
sucrose
49
what does alpha and alpha glucose make?
maltose
50
what bond holds together disaccharides?
glycosidic bonds from a condensation reaction
51
how is cellobiose obtained?
hydrolysis of cellulose (polysaccharide)
52
whats the molecular formula of alpha and beta glucose?
C6 H12 O6
53
whats the role of alpha glucose?
-energy source
-energy stores
-component of starch and glycogen
54
whats the role of beta glucose?
-energy source
-provides structural support
-component of cellulose which helps support plant cell walls
55
why type of sugar is glcose?
hexose
56
what is the molecular formula for ribose?
C5 H10 O5
57
What is the molecular formula for deoxyribose?
C5 H10 O4
58
what is the role of ribose in the body?
component of RNA, ATP and NAD
59
what is the role of deoxyribose in the body?
component of DNA
60
what type of sugar is (deoxy)ribose?
Pentose
61
what is a homopolysaccharide?
A polysaccharide made solely of one kind of monosaccharide
62
what is a heteropolysaccharide?
a polysaccharide made of more than one monosaccharide
63
an example of a homopolysaccharide?
starch
64
an example of a heteropolysaccharide?
hyaluronic acid
65
is amylose branched?
no
66
is amylopectin branched?
yes
67
is glycogen branched?
yes
68
where do you find amylose and amylopectin?
in plants
69
where do you find glycogen?
in humans
70
where are the glycosidic bonds in amylose?
between carbon 1-4
71
what shape is amylose?
amylose is coiled in a spiral shape.
H bonds holding the spiral in place
hydroxyl groups on C2 inside the coil make it less soluble and allow H bonds to maintain the shape
72
in amylopectin, where are the glycosidic bonds?
1-4
1-6
73
what shape is amylopectin?
coiled into a spiral shape
branches emerging from the spiral
74
where are the glycosidic bonds in glycogen?
carbons
1-4
1-6
75
How often is amylopectin branched?
Every 25th unit
76
How often is glycogen branched?
Every 10th unit
77
Is cellulose soluble?
No, it is insoluble
78
What is cellulose like?
Tough, insoluble and fibrous
79
What is cellulose made from?
A homosaccharide of beta glucose
80
How is cellulose bonded?
Every other beta glucose is rotated 180°
1-4 glycosidic bond
81
How is cellulose bonded?
Every other beta glucose is rotated 180°
1-4 glycosidic bond
82
Why is cellulose not spiralled?
Because every other molecule is upside down
83
How can hydrogen bonds be formed between different chains in cellulose?
Because the hydroxyl group on carbon 2 sticks out
Enabling hydrogen bonds to be formed between chains
84
How many cellulose chains makes a micro fibril?
60-70 cellulose chains
85
How big in diameter are micro fibrils?
10-30nm in diameter
86
How many micro fibrils make a macro fibrils?
up to 400 microfibrils
Which are embedded in pectins to form plant cell walls
87
What makes the cellulose cell walls stronger?
Macrofibrils are embedded in pectins to form the wall
Macrofibrils run in all directions criss-cross for extra strength
88
What makes the cellulose cell walls stronger?
Macrofibrils are embedded in pectins to form the wall
Macrofibrils run in all directions criss-cross for extra strength
89
Are cellulose cell walls permeable?
Yes they’re fully permeable
Space between the macrofibrils for water and mineral ions
90
Are cellulose cell walls permeable?
Yes they’re fully permeable
Space between the macrofibrils for water and mineral ions
91
In a cellulose cell wall, what makes it water proof?
Cutin and suberin
92
What is a bacterial cell wall made out of?
Peptidoglycan
93
What are insect and crustacean exoskeletons made of?
Chitin
94
What’s the difference between cellulose and chitin?
Chitin has an avetylamino group on carbon 2 rather than hydroxyl
95
Define lipids
A group of substances that are soluble in ethanol
Insoluble in water
Tryglyceride, two fatty acids, one phosphate group
96
Define lipids
A group of substances that are soluble in ethanol
Insoluble in water
Tryglycerides, phospholipids, glycolipids and cholesterol
97
Define a macromolecule
A very large, organic molecule
98
Define phospholipid
A molecule consisting of glycerol,two fatty acids and one phosphate group
99
Why are lipids insoluble in water?
As they are not polar
So they don’t attract water molecules
100
What are the three most important lipids in living things?
Phospholipids, triglycerides and steroids
101
Is lipid a macromolecule?
Yes
102
What are triglycerides made of?
Glycerol and fatty acids
103
How many carbons atoms are in glycerol?
3 carbon atoms
104
What does glycerol look like?
H H H
| | |
H—C—C—C—H
| | |
OH OH OH
105
Define amino acids
Monomers of all proteins
all amino acids have the same basic structure
106
Define peptide bond
A bond formed when two amino acids are joined by a condensation reaction
107
When would you find a peptide bond?
When two amino acids are joined together by a condensation reaction
108
What elements are in amino acids?
Carbon
Hydrogen
Oxygen
Nitrogen
Some have sulfur
109
What does every proteinogenic amino acid have?
An amino group
-NH2
A carboxyl group
-COOH
110
What bonds hold amino acids together?
Joined together by covalent bonds called peptide bonds
111
Which enzymes catalyse the making and breaking of peptide bonds?
Protease during digestion
112
Define the primary structure of a protein?
The sequence of amino acids found in a molecule
113
What is the quaternary structure?
Protein structure when a protein consists of more than one polypeptide chain
For example insulin
114
What is the secondary structure?
The coiling or folding of an amino acid chain, which arises often as a result of hydrogen bond formation between different parts of the chain.
The main forms of secondary structure as the helix and the pleated sheet
115
What is their tertiary structure?
The overall three dimensional shape of a protein molecule
116
What is the function of a protein determined by?
It’s structure determines the function of a protein
117
How many amino acids are there?
20
118
What do you call the sequence of amino acids in a protein chain?
The primary structure
119
Chains of amino acids are not straight but twists into a shape called the …?
Secondary structure
120
What is a b pleated sheet?
When an amino acid chain folds over on itself
121
What is an a helix?
It has 36 amino acids per 10 turns of the helix
122
What’s holds a B pleated sheet together?
The hydrogen bonds between the -NH group of one amino acid and -CO group of another four places ahead of its chain
123
Why does a presence of sugars at a low concentration show up as green in a Benedict’s test?
Benedict’s solution contains Cu 2+ ions
Not many of them are reduced to Cu+ ions
Less precipitate is formed
Makes it green
124
What’s the difference between a reducing sugar and non-reducing sugar?
Reducing sugars donate an electron
Nonreducing sugars don’t do that
125
Why is it important for animals that glycogen is more branched than amylopectin?
Allows animals to access glucose quicker for faster respiration
126
Why is it important that the OH group on C2 of glucose is on the inside of the amylose spiral?
Makes it less soluble
127
What are the advantages of a polysaccharide being branched?
More compact
More ends for glucose molecules to be hydrolysed
Ready for respiration
128
What percentage of starch is amylopectin?
70%
129
What bond forms between glycerol and fatty acids?
Ester bond
130
How do you make a triglyceride?
One glycerol and three fatty acids
131
What group do fatty acids belong to?
(-COOH) carboxylic acids
132
Are triglycerides soluble?
No they’re insoluble
133
What is a Micelle?
Insoluble droplets in cells with tails inwards and heads outwards
Can be transported through the cells aqueous environment
134
What is a molecule that is both hydrophilic and hydrophobic?
Amphipathic
135
An example of an amphipathic molecule?
Phospholipid
136
What’s the permeability of a membrane like?
Selectively permeable
Only small non polar molecules can move through
137
What must be present for a fatty acid to be considered unsaturated?
Double covalent bond (carbon)
138
Where is cholesterol produced?
Primarily in the liver and in intestines
139
What does cholesterol do in membranes?
Provides stability
Increases fluidity when cold
Decreases when hot
140
Do lipids dissolve in ethanol?
Yes
141
Describe the emulsion test- test for lipids?
-Lipids dissolve in ethanol because ethanol has a non polar ethyl group
-the dissolved lipid is added to pure water
-the lipid is insoluble in water and a white cloudy emulsion forms on the surface
142
Two reasons why triglycerides are used as energy storage molecules?
Insoluble in water
Energy dense - double of a carbohydrate
143
What is in the basic structure of an amino acid?
Amine group
Carboxy group
144
What is the smallest amino acid and why is it the smallest?
Glycine
It’s R group is a hydrogen atom
145
Why is the amino acid cysteine important?
A disulfide bond firms between the R groups of two cysteine molecules, forming the strongest covalent bond
146
How many different amino acids are found in cells?
20
147
How many non essential amino acids are there that our bodies can make from other amino acids?
5
148
How many essential amino acids are there that we eat?
9
149
How many amino acids are conditionally essential
6, only needed when an infant or a growing child
150
What is an amphoteric molecule?
A molecule that has acidic and alkaline properties
151
Why can amino acids be a buffer?
-Amine group gains H+ ions and decreases in acidity
-carboxyl group loses H+ ions and increases in acidity
152
What bond joins two amino acids?
Peptide bonds
153
Explain why amino acids have some properties of a pH buffer?
Carboxyl group can donate a hydrogen ion and act like acid while amine group can receive a hydrogen ion like a base.
Resists large pH change
154
Explain why amino acids have some properties of a pH buffer?
Carboxyl group can donate a hydrogen ion and act like acid while amine group can receive a hydrogen ion like a base.
Resists large pH change
