unit 1 Flashcards
1
Q
what are organisms made of?
A
proteins carbohydrates lipids water nuclei acid
2
Q
polymer
A
large complex molecules composed of chains of monomers joined together
3
Q
monomers
A
small basic molecular units that form a polymer
4
Q
condensation reaction
A
forming a chemical bond between monomers by releasing a molecule of water
5
Q
hydrolysis reaction
A
breaking the chemical bonds between monomers by addition of molecule of water
6
Q
3 types of carbohydrates
A
disaccharides, monosaccharides, polysaccharides
7
Q
monosaccharides
A
form disaccharides general formula (CH2O)n simple sugars small molecules in water and taste sweet
8
Q
isomers
A
molecules with the same molecular formula but different structural formula
9
Q
2 types of glucose
A
beta glucose (OH before H) alpha glucose (H before OH)
10
Q
glucose + glucose= ?
A
?= maltose
11
Q
glucose + ? = sucrose
A
?= fructose
12
Q
glucose + ? = lactose
A
?= galactose
13
Q
polysaccharides
A
large complex molecules known as polymers they are formed when large number of monosaccharides link via glycosidic bonds
14
Q
3 types of polysaccharides
A
starch
glycogen
cellulose
15
Q
starch
A
alpha glucose
1-4 and 1-6 glycosidic bonds
16
Q
glycogen
A
alpha glucose
1-4 and 1-6 glycosidic bonds
found in animals
17
Q
cellulose
A
beta glucose
1-4 glycosidic bonds
found in plants
18
Q
what are monosaccharide glucoses the main source of and for what
A
main source of energy for aerobic respiration
19
Q
lipids
A
made up of C, H and O
contain proportionally less oxygen
not polymers
20
Q
triglycerides are made of what?
A
3 fatty acids + glycerol
21
Q
phospholipids are made of what?
A
2 fatty acids + glycerol + phosphate group
22
Q
what is the structure of glycerol?
A
H
|
H- C -OH
|
H- C -OH
|
H- C -OH
|
H
23
Q
what do fatty acids consist of?
A
carboxylic acid group COOH
long hydrocarbon chain (R)
a methyl group CH3
24
Q
do saturated fatty acids have a double bond?
A
no
25
what is monounsaturated?
one double bond between carbon atoms
26
what is polyunsaturated?
more than one double bond between carbon atoms
27
what does a C=C present do in fatty acids?
introduces “kinks” to the hydrocarbon chain (its tilted)
28
what can unsaturated fatty acids be?
cis and trans
29
what is cis?
hydrogen atoms are on the same side of a double bond
H H
\ /
C=C
30
trans
hydrogen atoms are on opposite sides of a double bond
```
H
\
C=C
\
H
```
31
how are molecules joined together in triglycerides?
through condensation, water is lost each time a bond is made
32
what is the link between each fatty acid and glycerol molecule called
an ester bond
33
properties of fatty acids
```
non polar (no uneven distribution of charge)
this means they do not interact with water (hydrophobic)
insoluble
```
34
properties of phospholipids
phosphate head is hydrophilic/ polar head (uneven distribution of charge) soluble
fatty acid tail is hydrophobic/ non polar tail and is insoluble
35
emulsion test
- add few drops of liquid food sample to dry test tube
- add 2cm^3 ethanol and shake it thoroughly
- add 2cm^3 of deionised water
- make observations
- layer of cloudy white forms at top
36
2 amino acids bonded
dipeptide
37
many amino acids bonded
polypeptide
38
what do amino acids differ in/ have in common
all have NH^2 and COOh and H they differ in R group
39
what are dipeptide made by
condensation reaction
40
what bond does a dipeptide have and between what
peptide bond between COOH and NH^3 group
41
enzymes
biological catalyst that speed up chemical reactions in living things but do not change/ get used up in process
42
intercellular
in cells
43
extracellular
outside cells
44
cellular level
respiration
45
whole organism
digestion
46
what are enzymes example of globular or fibrous?
globular in their tertiary structure
47
what do the tertiary determine
the shape of active site
48
induced fit model
- AS not complementary to substrate
- substrate binds to AS and the shape of it changes slightly as well as the substrate a little and then it goes back to its normal shape
49
factors affecting enzyme structure
high temp and high pH above or below optimum these all cause denaturing of enzymes
50
denaturing
- when the tertiary structure of enzymes are damaged causing a change in the shape of the AS and enzymes can no longer catalyse a reaction
51
enzymes and activation energy
lower the activation energy of the reaction so they allow reactions to take place at lower temperature
52
activational energy
minimum amount of energy required to take place
53
breakdown
when substrate changes shape to fit the AS of enzymes- bonds are bent so less energy needed to break them
54
synthesis
when 2 or more substrate held together in AS repulsion between substrates is reduced so less energy needed to fork bonds
55
rules
- substrate needs to be complementary to AS
| - substrate must collide with the sufficient energy for reaction to happen
56
calculate the rate of enzyme- catalysed reaction
product formed or substance breakdown/ time
57
what 4 things affect enzyme activity
pH
substrate conc
enzyme conc
temp
58
temperature
- molecules get more kinetic energy moving faster
| - means more frequent collisions between substrate and AS
59
competitive inhibitors
binds to AS of enzyme
60
non competitive inhibitor
binds to enzyme at a site which is not the AS
61
competitive inhibitors
compete with substrate and have a similar shape to the substrate and can be overcome by increasing sun conc
62
non competitive inhibitors
causes AS to change shape to substrate and can no longer bind
63
pH
either side of optimum causes enzymes to denature as H+ and OH- ions cause change of charge on amino acids in ASA
- causes H binds and ionic bonds to break and changes tertiary structure
64
substrate conc
linear increase at first then more frequent collisions between enzyme AS and substrate, enzymes saturated- every AS already occupied
65
enzyme conc
increases enzyme activity linear increase frequency of collisions
66
biuret test for enzymes
- add few drops of sodium hydroxide (alkali)
- add a few drops of copper (II) sulfate
+ purple colour
- remains blue
67
primary structure
sequence of amino acids in the polypeptide chain and has a peptide bond
68
secondary structure
formation of alpha helix or beta pleated sheet
| hydrogen bonds between N-H and C=O group on amino acids still has a peptide bond
69
tertiary structure
3D structure
IONIC BONDS- between + and - amino acids
DISULPHIDE BONDS- between cysteine amino acids close together (as they contain S)- covalent bond between 2 sulfur atoms
HYDROGEN BONDS- between N-H and C=O groups on amino acids
polypeptide bonds examples of covalent
70
quaternary structure
when 2 or more polypeptide chains join together, sometimes with an inorganic component to form a protein
71
amylose
- found in plants
- unbranched chain
- alpha glucose
- angle of bonds cause a helical shape held in place by hydrogen bonds
72
amylose function helical structure
compact so large amount of glucose in a small place in cell
73
amylopectin
- found in plants
- alpha glucose
- long branched chain
- due to 1-6 glycosidic bond
74
amylopectin functions
branches allow enzymes (amylose) to access glycosidic bonds so glucose is easily released
75
glycogen structures
- found in animals
- alpha glucose
- long branched chain
- 1-6 glycosidic bond occurs every 8-10 glucose molecule
76
glycogen function
- more branched = more storage for glucose
| - released quicker and enzymes have easier access to glycosidic bonds
77
cellulose structures
- found in plants
- beta glucose
- long unbranched straight chain
- every other beta glucose unit rotated 180 degrees
- H bonds form between OH adjacent parallel chains
78
cellulose function
- microfibrals form cellulose fibrils
| - many layer of fibrils make up cell walls they are permeable because fibrils have gaps
79
testing for starch
add iodine dissolved in potassium iodide solution to sample
| + browny orange to blue black
80
reducing sugar test
-add blue benedicts reagent to sample
-heat in water bath thats been brought to boil
+ brick orange
- stays blue
81
nonreducing sugar test
-carry out reducing sugar test then heat new sample with dilute hydrogencarbonate
-then heat sample with benedicts reagent in water bath
+ brick red percipitate
- blue
82
meaning of non reducing sugars
sugars such as sucrose that are not readily reduced in another substance
83
reducing sugars
sugars such as glucose and fructose that readily lose electrons to another substance
