Unit 4 AOS 2 Flashcards
1
Q
What is food needed for in the body
A
energy, growth, regulating body processes
2
Q
What are the major food groups needed for the body
A
proteins, carbohydrates, fats and oils, vitamins and minerals
3
Q
What are proteins needed for
A
growth, repair, immunity, transport of molecules,
4
Q
Examples of what proteins are used for
A
hormones, enzymes, cellular structures (e.g. cell membrane, muscles), to transport molecules in the body, antibodies
5
Q
What are carbohydrates needed for
A
to store and provide energy, functioning in nervous system
6
Q
What are fats and oils needed for
A
insulation, to store some vitamins, to provide energy, in cell membranes
7
Q
Define proteins
A
large molecules composed of one or more long chains of amino acids.
8
Q
What are the monomers of proteins
A
amino acids
9
Q
How many amino acids are there in the body
A
20
10
Q
Can all these 20 amino acids be made by the body
A
no
11
Q
How do we get amino acids that can’t be made in our body
A
through our food
12
Q
What are essential amino acids
A
amino acids that cannot be synthesised by animals from materials in their diets and therefore must be supplied directly in the diet.
13
Q
What elements make up amino acids
A
C, H, O, N and sometimes S and P
14
Q
What are the amino acids used to synthesise proteins in the body called
A
2-amino acids or alpha amino acids
15
Q
What is the structure of amino acids
A
CH, R, COOH, NH2
16
Q
What properties can the R chain have
A
polar, non-polar, acidic or basic
17
Q
Are amino acids soluble and why
A
they are soluble as they can form H bonds with water
18
Q
Can amino act as acids, bases or both
A
both
19
Q
What can amino acids act as
A
dipolar ions/zwitterions
20
Q
What is a zwitterion
A
contain equal positive and negative charges
21
Q
What does an amino acid look like as a zwitterion
A
NH3+ and COO-
22
Q
When does an amino acid act as a zwitterion
A
pure solid state and in aqueous solutions in neutral pH, e.g. water
23
Q
What will happen to amino acid in acidic environment
A
will act as base and so will have NH3+ with COOH
24
Q
What will happen to amino acid in basic environment
A
will act as an acid and so will have NH2 and COO-
25
What is a sequence of amino acids called
a peptide chain
26
Between what molecules is the bond in a peptide chain
between the CO and the NH2 (O=C-N-H)
27
What is the bond in a peptide chain called
peptide bond
28
What is the name of the link between the C and the N
amide linkage
29
When is a polypeptide called a protein
more than 50 amino acids/ molar mass >5000gmol-1
30
How do you name a polypeptide (3)
by the sequence of amino acids from which they are made - which amino acid it derived from and put the abbreviation and then just put a dash to the next one, and it is written from left to right
31
Where is the N-terminus in a polypeptide chain
left side
32
Where is the C-terminus in a polypeptide chain
right side
33
What is the amino acids components of a polypeptide called
amino-acid residue
34
Define polypeptide
many amino acid residues bonded together.
35
Define primary structure
the order of amino acids in a polypeptide chain
36
Define secondary structure
structure formed folding of the polypeptide chain due to hydrogen bonding between carboxyl and amino groups in a protein molecule.
37
Important to note about secondary structure
the hydrogen bonding is at different positions of the chain
38
What causes alpha helices
H bonding between partially partially positive NH group and the partially negative COOH
39
What causes beta pleated sheet
H bonding between peptide links
40
Define tertiary structure
3D structure formed from side-group interaction, including hydrogen bonding, ionic bonding, dipole–dipole interactions and disulfide bridges
41
Define quaternary structure
multiple polypeptide chains joined together
42
Define denaturation
loss of structure or function of a protein
43
What causes denaturation
pH changes and heat
44
Why do pH changes and heat cause denaturation
damages bonds in polypeptide
45
Can denaturation be partial + why
yes if it doesn’t break primary covalent (peptide) bonds but just secondary and tertiary bonds e.g. warm milk
46
Define enzymes
biological catalysts that speed up reactions through providing an alternate pathway for the reaction which requires less energy
47
What is the general suffix of enzymes
ase
48
Examples of enzymes that don’t end in ase
trypsin, pepsin
49
What are the two types of proteins
globular and fibrous
50
What is the solubility of globular/fibrous
globular is soluble and fibrous is insoluble
51
What is the lock and key model
the specific shape of the active site fits exactly the shape of the substrate it will act on, hence will only act on that substrate.
52
What is the induced fit model
the specific shape of the active site of the enzyme varies slightly from that of the substrate and the two fit only after contact when the substrate induces a complementary shape at the active site of the enzyme.
53
Define active site
A region on an enzyme that binds to a protein or other substance during a reaction.
54
Define substrate
The substance on which an enzyme acts.
55
Do enzymes take part in a reaction
no
56
Define coenzyme
organic non-protein molecules required to temporarily and loosely bind with the protein molecule to form an active enzyme.
57
Are coenzymes specific
not always
58
Define hydrolysis
the chemical breakdown of a compound due to the addition of water.
59
What is the general formula for carbohydrates
Cx(H2O)y
60
What elements do carbohydrates contain
C, H, O
61
What is the monomer for sugars
monosaccharides
62
Are carbohydrates soluble and why
due to the multiple -OH groups, they are highly soluble in water because can form H bonding
63
Do all monosaccharides have the same formula
yes (and so are isomers)
64
Can monosaccharides be linear
yes, but most are cyclic
65
What bonds are between sugar molecules
ether/glycosidic links
66
Where does the bond occur between monosaccharides
between the OH groups (and H2O is lost)
67
What polymers are in starch
amylose and amylopectin
68
Is amylose branched or linear
linear
69
Is amylopectin branched or linear
branched
70
What type of isomers are glucose and galactose
stereoisomers
71
What does amylase break starch into
maltose
72
What does maltase break maltose into
glucose
73
What is another name for cellulose
fibre
74
What does GI stand for
glycaemic index
75
What is GI
A figure representing the relative ability of a carbohydrate food to increase the level of glucose in the blood
76
Examples of food high GI
lollies, chocolate, ice-cream
77
Examples of food low GI
brown rice, wholemeal bread, pasta
78
How is glycaemic load calculated
grams in serve * GI /100
79
What is the standard for GI
glucose at 100
80
Why are fruits low GI
because fructose has to be converted to glucose (takes time)
81
What is aspartame
artificial sweetener
82
What are glucose blood levels measured in
mmol-1 (mM)
83
What is called when there is too much blood glucose
hyperglycaemia
84
What is it called when there is too little blood glucose
hypoglycaemia
85
What are the three categories of carbohydrates
monosaccharides, disaccharides, polysaccharides
86
What are the two types of glucose
alpha and beta
87
Where is the OH located on alpha glucose
bottom
88
Where is the OH located on beta glucose
top
89
How many monomers to make polysaccharide
more than 10
90
What are ogliosaccharides
Three to ten monosaccharides bonded together.
91
What is the general suffix for sugars
ose
92
How many times sweeter is aspartame compared to glucose
200 times sweeter
93
Are amylose/amylopectin soluble/insoluble
amylose is soluble and amylopectin is insoluble
94
General formula for glycogen
(C6H12O5)n
95
Properties of glycogen
soluble, highly branched, alpha glucose
96
Properties of starch
slightly soluble, moderately branched, alpha glucose
97
Properties of cellulose
insoluble, unbranched, beta glucose
98
Types of disaccharides (3)
lactose (galactose + glucose), maltose (glucose + glucose), sucrose (glucose + fructose)
99
Types of polysaccharides (3)
starch, cellulose, glycogen
100
What are vitamins
organic compounds that are needed in minute quantities on a regular basis as part of a healthy diet.
101
How many vitamins are required by body
13
102
Can we make vitamins
no, except for Vitamin D
103
Two categories of vitamins
fat soluble and water soluble
104
Examples of fat soluble vitamins
D, A, K, E
105
Examples of water soluble vitamins
B, C
106
Can water soluble vitamins be stored
no
107
Where are fat soluble vitamins stored
in fat (adipose tissue)
108
What is the only non-essential vitamin
Vitamin D
109
What are vitamins needed for
regulating metabolic processes e.g. producing energy, supporting the immune system
110
Are fats solids/liquids
solids
111
Are oils solids/liquids
liquids
112
What enzyme digests fats
lipase
113
What is the formula for a fatty acid with 0 double bonds
CnH2n+1COOH
114
What is the formula for a fatty acid with 1 double bond
CnH2n-1COOH
115
What is the formula for a fatty acid with 2 double bonds
CnH2n-3COOH
116
What are fatty acids
long-chain carboxylic acid containing an even number of carbon atoms.
117
Saturated fatty acid
no double bonds
118
Mono-unsaturated fatty acid
1 double bond
119
Polyunsaturated fatty acid
more than 1 double bond
120
What is the link called in a fatty acid
ester link
121
What are the essential fatty acids of the body
alpha-linolenic acid (ALA) and linoleic acid (LA).
122
What are essential fatty acids also called
omega fatty acids
123
What is omega 3 fatty acid
alpha-linolenic acid
124
What is omega 6 fatty acid
linoleic acid
125
What is the order of energy sources in body
carbohydrates, then fats then proteins
126
Are saturated or unsaturated more likely to go rancid
unsaturated as less stable
127
What is the omega group in fatty acid
methyl
128
What emulsion
breaking down fats (bile)
129
What is calorimetry
Method used to determine the changes in energy of a system by measuring heat exchanges with the surroundings. It is the measurement of the amount of heat released or absorbed in a chemical reaction, change of state or formation of a solution.
130
What is a calorimeter
Apparatus used to measure heat changes during a chemical reaction or change of state.
131
What are different types of calorimeters
bomb calorimeters and solution calorimeters
132
Formula for energy in calorimetry (2)
E = V * I * t or E = n * delta H
133
What is metabolism
chemical processes that involve breaking down and building different substances
134
What is calibration factor
the amount of energy that is required to change the contents of the calorimeter by 1 degree
135
Formula for calibration factor in calorimetry
Cf = E/delta T
136
Unit for calibration factor
J / degrees Celsius
137
Is calories with a lower case c or upper case c
lower case c
138
Is it usually cis or trans in unsaturated fatty acids
cis
139
What is the functional group of monosaccharides
OH
140
What type of double bond (cis or trans) occurs in nature
cis
141
Can trans bonds occur in nature
no
