Chapter 1

?
  • Created by: Kittykiah
  • Created on: 17-03-19 18:41
What is covalent bonding?
When atoms share a pair of elections in their outter shells. Forms a more stable compound called a molecule due to the outter shell being filled.
1 of 93
What is ionic bonding?
When ions with opposite charges attract (electrostatic attraction.) These bonds are weaker than covalent bonds.
2 of 93
What is hydrogen bonding?
When electrons are unevenly distributed (polar molecule) Postive of one attracts to the negative of another (electrostatic attraction) however the intermolecular bonds aren’t weak.
3 of 93
What is the order of strength between the bonds? (Strongest first)
Covalent, ionic, hydrogen.
4 of 93
What is a condensation reaction?
The formation of polymers by subtracting a waterbed molecule (formed)
5 of 93
What is hydrolysis?
The addition of a water molecule breaking a polymer chain into monomers.
6 of 93
Define metabolism
All the chemical processes that take place in living organisms.
7 of 93
What are monosaccharides?
Soluble, sweet sugar
8 of 93
What are disaccharides?
Two monosaccharides joined together by a condensation reaction.
9 of 93
What two monosaccharides form maltose?
Glucose + glucose
10 of 93
What two monosaccharides form sucrose?
Glucose + fructose
11 of 93
What two monosaccharides form lactose?
Glucose + galactose
12 of 93
What bond is created when a condensation reaction joins two monosaccharides?
Glycosidic bond.
13 of 93
when a disaccharide is made what is the extra product?
water
14 of 93
What test is used to test for reducing sugars?
Benedicts / copper (2) sulphate
15 of 93
What happens to the solution if reducing sugars are present?
A red precipitate is formed of copper (1) sulphate. This will now be insoluble
16 of 93
Exam Q: how would you test for a reducing sugar?
Mark 1- add Benedicts solution, Mark 2- heat in a water bath, Mark 3- If present it will turn from blue to a red precipitate.
17 of 93
Why is copper (2) sulphate reduced?
A transfer of electrons.
18 of 93
Describe the structure of alpha glucose
The OH is on the bottom. C-O at the top with CH2OH coming off the C and C-C at the bottom
19 of 93
What’s the general formular of monosaccharides?
(CH2O)n n can be any number from 3 to 7
20 of 93
What’s the formular of glucose?
C6H12O6
21 of 93
How do you test for non-reducing sugars?
Must do this to break down the disaccharide into its monosaccharide. First add hydrochloric acid to break the bonds then use sodium hydrogen carbonate to neutralise it (litmus paper can be used to test) then add benedicts solution.
22 of 93
Why does it need to be neutralised?
Because the hydrochloric acid makes it acidic and benedicts can not test acidic solutions. (As it’s alkali)
23 of 93
What disaccharide is an exception and can be detected by the benedicts test straight away?
Maltose
24 of 93
What are the 3 polysaccharides?
Starch, glycogen and cellulose
25 of 93
What’s the test for starch?
Add iodine solution (If starch is present it will go from yellow to blue-black.
26 of 93
How is starch Amylose ideal for storage?
Coiled structure so it’s compact
27 of 93
Features of Amylose
Coiled, unbranched, 1-4 glycosidic linkages
28 of 93
Features of Amylopectin
1-6 glycosidic linkages, branched chains,
29 of 93
How is Amylopectin good for quick release of energy?
Able to break off glucose, easily hydrolysed ready for respiration
30 of 93
Why is it good that starch is insoluble?
Does not draw in water by osmosis (doesn’t affect water potential)
31 of 93
Why is it good that it is large + insoluble?
It does not diffuse out of cells.
32 of 93
What glucose units is starch made of?
Alpha glucose
33 of 93
What glucose units is glycogen made of?
Alpha
34 of 93
Where is glycogen found?
In the liver and muscles (stored)
35 of 93
Features of glycogen
1-6 glycosidic linkages, branches
36 of 93
Why is it good that it’s insoluble?
Does not draw water into the cells by osmosis + does not diffuse out of the cells
37 of 93
Why is it good that it’s compact?
More can be stored in a small place
38 of 93
Why is there more branching than starch?
We need it more readily because we respire more due to having a higher metabolic rate and being more active. Can be broken down more rapidly (hydrolysed)
39 of 93
What glucose units isn’t cellulose made from?
Beta glucose
40 of 93
What is the structure of cellulose?
Rotated 180 degrees each time. (Unbranded and straight running parrallel)
41 of 93
How are cross linkages made in cellulose?
Adjacent chains join using hydrogen bonding
42 of 93
How do the cross linkages make a strong cell wall?
Due to a massive number of the bonds it strengthens It.
43 of 93
What is cellulose made of?
Microfibrils and fibres. (= more strength)
44 of 93
What does cellulose prevent?
The cell wall from bursting under water pressure - osmosis (as they are rigid and turgid)
45 of 93
How does the cell walls being turgid help photosynthesis?
Maximises surface area
46 of 93
What polysaccharides are only found in plants?
Starch and cellulose
47 of 93
What polysaccharide is only found in animals? (+Bacteria)
Glycogen
48 of 93
what elements are present in carbohydrates?
hydrogen, oxygen and carbon
49 of 93
what are the roles of lipids?
source of energy, waterproofing, insulation, protection
50 of 93
how are lipids good at waterproofing?
they are insoluble in water
51 of 93
how are lipids good for insulation?
fats are slow conductors of heat and when stored help retain body heat.
52 of 93
how is fat good at protection?
its often stored around delicate organs like the kidneys.
53 of 93
how are lipids a good source of energy?
When oxidised they provide x2 as much as carbohydrates and release valuable water.
54 of 93
what are triglycerides made up of?
3 fatty acids and 1 glycerol.
55 of 93
how do they form?
each fatty acid forms an ester bond with the glycerol in a condensation reaction.
56 of 93
whats the structure of a fatty acid?
the variation comes the fatty acids but they all have a -COOH group and a hydrocarbon chain
57 of 93
what is meant by a saturated fatty acid?
having no carbon double bonds (if there is its saturated, either mono or poly.)
58 of 93
how are triglycerides good for energy storage?
they have a low mass to energy ratio so more can be stored in a smaller volume, they are large,non-polar and insoluble so osmosis is not affected in cells.
59 of 93
what makes up a phospholipid?
2 fatty acids, 1 phosphate, 1 glycerol
60 of 93
what does hydrophobic mean and which part of the phospholipid is?
it means that it repels water - the 'tail' being the fatty acid
61 of 93
what does hydrophilic mean and which part is?
it means it attracts water - the 'head' being the phosphate (gets closer to the cytoplasm and the extracellular fluid.)
62 of 93
how does the tail being hydrophobic help the cell membrane structure?
as it is trying to get away from the cytoplasm inside and the extracellular fluid it stays in the middle. (as they are both water based)
63 of 93
what does it mean that phospholipids are polar?
they position themselves in water so that the heads are as close as possible and tails as far away as possible.
64 of 93
what is the test for lipids?
emulsion test- ethanol an an equal amount of water, if fats are present then a milky-white emulsion will form on the top
65 of 93
what forms a polypeptide?
amino acids joining together
66 of 93
what bond is formed when the condensation reaction occurs?
peptide bonds
67 of 93
whats the structure of an amino acid and how do they vary
NH2 (amino group) on the left, a C in the middle with a H bellow it and the R group above it (variable group) there are 20 different amino acids, COOH (carboxyl) on the right.
68 of 93
what process breaks down proteins? (hydrolysis)
digestion
69 of 93
describe the primary structure of proteins
the sequence of amino acids in the polypeptide chain, determined by dna genes.
70 of 93
how is the primary structure important to the end protein?
the shape and therefore function is determined by this. a mutation/simple change in the sequence can change the protein.
71 of 93
describe the secondary structure
the chain coils due to hydrogen bonding into alpha helix folds and beta pleated sheets.
72 of 93
describe the tertiary structue
coiling and folding done further: hydrogen bonding, ionic bonding and disulfide bridges between the cysteine. sulfur bonding together)
73 of 93
describe the quaternary structure
this is only for proteins needing to bond multiple polypeptide chains or a prosthetic group.
74 of 93
what does a conjugated protein mean?
there is no prosthetic group
75 of 93
what is the test for proteins?
the biuret test: first add sodium hydroxide to make the solution alkali then copper (2) sulphate. purple if present blue if not.
76 of 93
how are fibrous proteins structured?
in parallel polypeptide chains held together by cross-links, from long, rope-like fibers with high tensile strength + insoluble.
77 of 93
what is the structure of a globular protein?
spherical shape caused by tightly folded polypeptide chains. (so that hydrophobic groups are on the inside while hydrophilic on the outside therefore soluble in water.)
78 of 93
how do enzymes speed up reactions?
they catalyse it by lowering the activation energy.
79 of 93
Exam Q: describe the induced fit model (2 Marks)
mark 1- enzyme and substrate collide randomly, mark 2- first not complementary but then changes shape to bind. forms and enzyme-substrate complex
80 of 93
how does the increase in heat to the optimum affect enzyme action?
increases kinetic energy, increased collisions, more enzyme-substrate complexes formed
81 of 93
how does too much heat affect enzyme activity?
break the teritary bonds, enzyme shape changes/ can even denature so the active site is no longer complementary to the substrate
82 of 93
what does the ph refer to?
the amount of H+ ions in a solution
83 of 93
what happens when the ph goes above or bellow the optimum?
changes the side group charges what create the active site so the enzyme denatures. this is because it affects the tertiary structure.
84 of 93
how do you calculate the ph?
-Log[concentration] = 1x10 ^-ph
85 of 93
where does a competitive inhibitor bind?
the active site (reversible)
86 of 93
where does a non-competitive inhibitor bind?
attaches to any part (alloseric site) (irreversible) as it changes the shape
87 of 93
how to end product inhibitors work?
when the amount of end product is high it binds non-competitively to an enzyme blocking further production of its self and when the amount falls the inhibitor ends and pathway restarts.
88 of 93
why are end product inhibitors important?
they regulate metabolic pathways
89 of 93
how does enzyme concentration effect the rate of reaction?
more enzymes mean quicker rate of reaction because more substrates can bind at the same time (able to repeat procedure on more than one active site)
90 of 93
what happens when there are extra enzymes than substrates?
as the optimum has been met it will not increase the rate of reaction because there are already enough active sites to accommodate all the available substrate molecules. (would be flat on a graph)
91 of 93
how does the substrate concentration effect rate of reaction?
increases when substrate concentration increases as then the enzymes can work at full capacity.
92 of 93
what happens when the substrate concentration goes above the optimum?
on a graph i will go flat as there will not be enough enzymes to fit all the substrates.
93 of 93

Other cards in this set

Card 2

Front

What is ionic bonding?

Back

When ions with opposite charges attract (electrostatic attraction.) These bonds are weaker than covalent bonds.

Card 3

Front

What is hydrogen bonding?

Back

Preview of the front of card 3

Card 4

Front

What is the order of strength between the bonds? (Strongest first)

Back

Preview of the front of card 4

Card 5

Front

What is a condensation reaction?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biological molecules resources »