Biological Molecules Flashcards
(130 cards)
1
Q
What is a monomer?
A
One of many small molecules that join to form a larger one
2
Q
What is a polymer?
A
Large molecule made of small repeating units
3
Q
What is a condensation reaction?
A
When 2 molecules join together and eliminate water
4
Q
What is hydrolysis reaction?
A
When 2 molecules are split by the addition of water
5
Q
What are carbohydrates made of and their function?
A
C,H,O
main source of energy for organisms
6
Q
What are lipids made of and their function?
A
C,H
serve to store energy and provide thermal insulation to plants and animals
7
Q
What are nucleic acids made of and what is their function?
A
H,O,N,C,P
to store and transmit genetic information
8
Q
What are proteins made of and their function?
A
N,C,H,O
To catalyse reactions, store and transfer smaller molecules and ion, to move muscles and to defend body against disease
9
Q
What is the bond between carbohydrates?
A
Glyosidic
10
Q
What are the bonds between proteins?
A
Peptides
11
Q
What are the bonds between lipids?
A
Ester
12
Q
What are the bonds between nucleotides in DNA
A
Phosphodiester
13
Q
What type of reactions do proteins, carbohydrates, lipids and DNA use to help form a polymer
A
Condensation
14
Q
What are monosaccharides?
A
-Soluble, sweet tasting substances -with general formula (CH2O)n
-n=1-7
15
Q
What is the formula for
Triose
Tetrose
Pentose
Hexose
Heptose
A
Triose-c3h6
Tetrose-c4h8c4
Pentose-c5h10c5
Hexose- c6h12c6
Heptose- c7h14c7
16
Q
What are the 3 monosaccharides that have the formula: C6H12C6?
A
Glucose, fractose, galactose
17
Q
What is the structure of glucose?
A
Draw +check
18
Q
Difference between alpha and beta glucose?
A
The C1 is reversed.
Alpha= H—-C—-OH
Beta= OH—-C—-H
19
Q
What is an isomer?
A
Molecules which the same molecular formula as each other, but with atoms connected to each other in a different way
20
Q
Glucose+glucose=
A
Maltose
21
Q
Glucose+fructose=
A
Sucrose
22
Q
Glucose+galactose=
A
Lactose
23
Q
What’s a polysaccharide?
A
is a long-chain carbohydrate made up of smaller carbohydrates called monosaccharides
24
Q
How is starch bonded?
A
With alpha glycosidic bonds
25
What are the 2 main forms of starch?
Amylase and amylopectin
26
What is the structure of amylase?
-formed of alpha-glycosidic bonds between neighbouring 1’ and 4’ carbons of glucose molecules.
-unbranched
27
What is the structure of amylopectin?
-branched
-1-4 alpha glycosidic bonds
-also contains 1-6 glycosidic bonds every 24-30 glucose units
-this causes the branching
28
Relate the structure of starch and glycogen to its function
- starch is insoluble and will not move via osmosis into/ out of cells
- it does not diffuse out of cells
- COMPACT MOLECULES- a lot can be stored in a small space
- when hydrolysed- it is is broken down to alpha glucose
-branched form has many ends, each of which can be acted on by many enzymes to help quickly release glucose monomers
29
Extra structures of glycogen?
-More branched
-Main carb in animals is in liver and muscles
-Doesn’t store as much as starch
-More branches as this allows to be acted on by more enzymes, therefore, easily broken down by glucose
- useful because animals have a higher metabolic requirement
30
Structure of cellulose?
glycosidic bonds
Beta glucose 1,4
• condensation reaction
-every other monomer is inverted
So the top row of fibre can join to the bottom row with hydrogen bonds
.this provides strength as they turn to fibrils
31
Why are the parallel chains important in cellulose?
- they contain microfibrils
- these give cellulose immense strength, it stops plant cell bursting when full of water (osmosis)- TURGOR PRESSURE
-microfibrils have ‘H’ bonds
32
Monomer and function of glycogen?
Monomer - alpha glucose
Function- glucose storage
33
What is the monomer and function of starch?
Monomer- glucose
Function- glucose storage
34
Monomer and function of cellulose?
Monomer- beta glucose
Function- cell wall formation in plants, provides with structural support and resists tugor pressure
35
What type of sugars are monosaccharides and polysaccharides?
Reducing
36
What are reducing sugars?
Sugar that donates electrons to another chemical
37
What are non- reducing sugars?
Do not change the colour of Benedict’s as they don’t reduce CU2+ ions
E.g disaccharides, sucrose
38
Why is a water bath better than a bunsen burner? During the Benedict’s test
Because it heats up at a constant speed and is easier to take control and monitor
39
How can you change the Benedict’s test from qualitative to quantitative data?
Using a colorimeter- this can determine the concentration in a solution
40
Similarity and differences between lactulose and lactose?
Both are bonded by glycosidic bonds
However,
lactulose= fructose+ galactose
Lactose= glucose+ galactose
41
Functions of proteins?
- acting as enzymes
- growth and maintenance
- structural support
-hormones
42
What are proteins?
polymers (polypeptides) made of monomers called amino acids
43
What is an amino acids structure?
- a central carbon at bonded to an anime group - NH2
- a carboxylic acid group- COOH
- an H atom
- 4th group is a variable R group
44
What are essential amino acids?
Can’t be synthesised by the body
45
What are the non essential amino acids?
Body can produce
E.g glutamine can be formed by processes such as transmission in the liver
46
what can amino acids be used for?
Nucleotide bases, neurotransmissitters, coenzymes, hormones
47
Two amino acids= dipeptide
How is this formed?
By condensation reaction- eliminates water
48
What is the primary structure of protein?
The particular amino acids and the sequence in which they are joined.
Determines the final shape of protein
49
What is the secondary structure of protein?
Can be alpha helix’s or beta sheets and are bonded by hydrogen
Alpha helix= vulnerable to changes in pH and temp
50
What is the tertiary structure?
3-dimensional coiling of the secondary structure to form a precise, compact shape, stabilised by H bonds, ionic bonds, disulphide bonds and hydrophobic interactions
51
What is the quaternary structure of proteins?
Many proteins are composed of one or more polypeptide chains. Polypeptides are often known as subunits.
Eg. Haemoglobin, microtubules
52
Does the primary structure have
Peptide
Hydrogen
Disulphide
Ionic
Hydrophobic interactions… bonds
Peptide bonds
53
Does the secondary structure have
Peptide
Hydrogen
Disulphide
Ionic
Hydrophobic interactions… bonds
Peptide
Hydrogen- only between amino and carboxyl groups
54
Does the tertiary structure have
Peptide
Hydrogen
Disulphide
Ionic
Hydrophobic interactions… bonds
Peptide
Hydrogen- R groups, amino acid and carboxyl groups
Disulphide
Ionic
Hydrophobic interactions
55
Properties of lipids?
-Contain C,H,O2
-proportion of carbon to oxygen and hydrogen is smaller than carbohydrates
-insoluble in water—->non polar
-soluble in organic solvents e.g. alcohols and acetone
56
Roles of lipids?
-contribute to flexibility of cell membranes
-source of energy
- water proofing
-insulation
-protection
57
What is a triglyceride made of?
3 fatty acids
1 glycerol
58
What are saturated fats?
Have no double bonds between carbons
59
What are mono saturated fats?
Have a single double bonded carbon
60
What are polyunsaturated fats?
Have many double bonds between carbons
61
What are the differences between saturated and unsaturated fats?
Saturated-
Solid at room temp
Increases level of bad cholesterol
Low density lipoprotein clogs arteries
Unsaturated-
Liquid at room temp
Increases levels of good cholesterol
High density lipoprotein grabs LDL and escorts it to liver, breakdowns and removed
62
What are lipoproteins?
Triglycerides+ protein+ cholesterol
63
What is LDL and HDL?
LDL- low protein, high cholesterol
HDL- high protein, low cholesterol
64
Function of LDL?
-deliver cholesterols to cells for membranes/ synthesis of steroid hormones
-cells take up cholesterol by receptor mediated endocytisis
65
What is cell signalling?
-LDL binds to specific LDL receptor and internalised in an endocytic vesicle
-receptors are recycled to cell surface, while hydrolysis reaction in the endolysosome releases cholesterol for use in cell
66
What are triglycerides?
-huge no. Of energy rich C-H bonds, great for energy source
-low mass: energy- more energy stored in smaller place
-non polar- insoluble so no osmotic effect
-high H:O- when oxidised, fats release water (good for desert animals)
67
What are phospholipids made of?
2 fatty acids + 1 phosphate molecule bound to glycerol
68
In a phospholipid.. what part is hydrophobic and hydrophilic?
Fatty acids repel water- hydrophobic
Phosphate molecules attract water - hydrophilic
Phospholipids are POLAR molecules- 2 ends that behave differently
69
What do phospholipids do?
Make cell membranes
Form important cell signalling receptors
70
What is the lock and key method?
The enzyme having the perfect shape of active site so the substrate can fit directly into it
71
What is the induced fit model?
When a part of the substrate binds to the enzyme, which then alters the shape of the active site to be complementary to the substrate. This creates a enzyme substrate complex which lowers activation energy
72
What is catabolism and anabolism ?
Catabolism release energy stored in the chemical bonds, whereas anabolism uses simple molecules to build complex substances using energy
73
Enzymes are globular proteins. What are globular proteins?
-hydrophobic groups in the centre
-hydrophilic groups on the outside
74
What is the enzyme substrate complex?
Active site that has a complementary substrate so it can bind
ESC stabilises the transition state of reaction, lowering AE
75
What do the R groups in the active site bind to?
They bind to the substrate via hydrogen or ionic bonds
Stabilises and ensures specificity
76
How does the shape of a protein get determined?
Monomers join to form a primary structure of a protein by amino acids forming a chain of poly peptide, using peptide bonds, which determine the shape of the protein using a specific sequence
77
How does pH affect enzymes?
Enzymes work best at pH 7
Above or below optimum pH can change the ionisation of R groups and can therefore break ionic bonds in tertiary structure, affects binding of substrate and eventually it denatures
78
What is pH?
-measure of hydrogen ion conc
- higher H+ conc, lower pH
-because of charge, H+ can interfere with hydrogen and ionic bonds holding tertiary structure together
79
How does temp affect enzymes?
-low temps= kinetic energy is too low so very few collisions between enzyme and substrate
-high temp= denture
80
What is a competitive inhibitor?
Similar to shape of substrate and competes for active site
81
What is a non competitive inhibitor?
Bind to another site and distorts enzymes tertiary structure (active site)
82
How can a non competitive inhibitor reduce the rate of an enzyme?
Binds to another site and distorts tertiary structure shape, including active site and decreases ROR. enzyme substrate complex won’t be made as no complementary binding
83
What is the structure of ATP?
Adenine (nitrogenous base)
ribose (Penrose sugar)
3 phosphate groups with high energy bonds
Adenine+ribose = adenosine
84
What is the universal currency of energy?
ATP
85
Why do cells need ATP?
Cells can’t get energy directly from glucose, so in respiration, energy released from glucose is used to make ATP
86
What is ATP synthesis?
ADP—-> ATP
87
What does ATP stand for?
Adenosine triphosphate
88
Describe how ATP molecule is formed from its component molecules?
-made from nucleotide base adenine is formed with a ribose sugar and 3 phosphate groups, by condensation reaction
89
Structure of DNA?
Double helix made of 2 polymer strands linked by hydrogen bonds between pairs
Phosphodiester backbone
90
What are the names of the four bases: A,T,C,G
A- adenine
T- thymine
C-cytosine
G-guanine
91
Which bases are triple and double bonds?
A and T are double
C and G are triple
92
Purine?
Double ringed structure
Adenine, guanine
93
Pyrimidine?
Single ring structure
Cytosine, thymine, uracil
94
How is a nucleotide structured?
-Phosphate acids attaches to Pentose sugar with ester bond
-Pentose sugar attaches to organic base with glycosidic bond
-has 4 bases bonded to carbon 1 of deoxyribose
-phosphate group is covantly bonded at carbon 5
95
How are polynucleotide strands built?
Condensation reactions forming covalent phosphodiester bonds in which the phosphate of one nucleotide forms a bond between carbon 5 of one sugar and carbon 3 of next
96
What is base: thymine replaced with in the RNA
Uracil
97
Differences between DNA and RNA
DNA- double stranded, deoxyribose, bigger than RNA, template to be transcript , hereditary model
RNA- single stranded, ribose, tRNA, mRNA, translated into a protein
98
How long is the human genome?
3.2 billion long, 20,000 genes
99
Steps of DNA replication
1) 2 strands of DNA separates as hydrogen bonds break between bases
2) free nucleotides bind to comp. bases
3) DNA polymerase, joins up free nucleotides to form daughter strand. Does this by forming phosphodiester bonds between nucleotides- double helix
4) dna polymerase continues until 2 new strands
100
how can ATP be re-synthesized?
ATP can be re synthesised in condensation reaction between ADP and phosphate
catalysed by ATP synthase
101
what kind of molecule is water?
polar
102
how is water shown as a polar molecule in models?
triangular model with oxygen at the point
the electrons (negative) are more concentrated around oxygen than hydrogen
103
why is water a polar molecule?
because the charge is not evenly distributed
104
what molecule is water when its a SOLVENT
dipolar
105
what does dipolar mean?
charged parts of water molecules are attracted to charged ions in polar substances
106
water as a coolant has a very strong......
attraction between water molecules, so water can be a very effective coolant because it has high latent heat of vaporization.
107
what does water having a high latent heat of vaporization?
takes a lot of heat/ energy to overcome forces of attraction between water molecules that'll change state of matter.
108
water has a high specific heat capacity. What does this mean?
needs a lot of energy to raise temp of 1kg by 1 degree
109
water as an insulator..
when ice forms, the ice insulates the water below along aquatic organisms to survive.
110
how does water have high surface tension?
air interface,
the cohesive forces between water molecules act in an inward direction giving water high surface tension
111
what does high surface tension of water mean for organisms
small organisms can land on water and move about on it.
112
water molecules are very -------- sticking together because of --------- bonds
cohesive
hydrogen
113
examples when water has been used for transport, because it is cohesive
transport of ions in solution xylem of plants
transport of soluble products of digestion in blood of animals
114
how is water used as a reagent?
metabolic reacions, espc, hydrolysis
photosyn
115
What does the bladder do in water controls
Stores urine
116
What does the kidneys do in water controls
Regulates water content and filters blood
117
What does the renal vein do in water controls
Carries deoxygenated blood away from kidneys
118
What does the renal artery do in water controls
Carries oxygenates blood to kidneys
119
What does the ureter do in water controls
Carries urine from kidneys to bladders
120
What does the urethra do in water controls
Carries urine to outside of ur body
121
Stage 1 of Function of kidneys
1)
FILTRATION -blood under high pressure of nephron which adds ultrafiltration of the blood, small molecules filtered out and pass into nephron tubules (inc. urea, water, ions, glucose), however molecules such as blood proteins, are too big to fit through capillary wall and remain in blood
122
Stage 2 of functions in kidneys
SELECTIVE REABSORPTION
kidneys selectively reabsorb molecules which body need back in bloodstream: glucose, water, mineral ions
123
Hypotonic
Water conc is higher outside
124
Isotonic
Water conc same both sides
125
Hypertonic
Water conc low outside
126
If body has little water in it..
-hyperthalmus detects low blood water conc
-pituitary glands produce more ADH
-kidney reabsorbs more water into blood
-less vol of urine produced
127
If body has too much water in it…
-hypothalamus detects high blood water conc
-pituitary gland produces less ADH
-kidney reabsorbs less water into blood
-high vol of urine produced
128
Stage 3 of functions of kidneys
FORMATION OF URINE
Molecules which are not selectively reabsorbed continue through nephron tubule as urine
129
What features of ATP makes a good energy store
High energy bonds between 3 phosphate molecules and when they’re broken they release high amounts of energy
130
Process of semi conservative replication
-Original culture was N15 so created N15 band only
-culture moved to N14 environment
-newly replicated strands would contain N14 and original parent strand (N15)
-further generations: N14 in all new strands and N15 in orginal parent strand so it’s N14/14 and N14/15
