FT LEC: Proteins and Enzymes Flashcards
1
Q
All _________ contain the elements carbon, hydrogen, oxygen, and nitrogen; most also contain sulfur
A
PROTEINS
2
Q
the main protein of milk, contains phosphorus
A
Casein
2
Q
Other elements, such as phosphorus and iron, are essential constituents of certain specialized proteins
A
- Casein
- Hemoglobin
2
Q
The presence of nitrogen sets them apart from carbohydrates and lipids, which most often do not contain nitrogen.
A
PROTEINS
3
Q
the oxygen-transporting protein of blood, contains iron
A
Hemoglobin
4
Q
Casein, the main protein of milk, contains ________
A
phosphorus
5
Q
Hemoglobin, the oxygen-transporting protein of blood, contains _______
A
iron
6
Q
Proteins are naturally occurring polymers in which the monomer units are ________
A
amino acids
7
Q
The Building Blocks for Proteins
A
AMINO ACIDS
8
Q
an organic compound that contains both an amino (-NH2) group and a carboxyl (-COOH) group
A
AMINO ACIDS
9
Q
Amino acids found in proteins
A
α-amino acid
10
Q
the amino group and the carboxyl group are attached to the α-carbon atom
A
α-amino acid
11
Q
distinguishes α-amino acids from each other
A
R group
12
Q
amino acid side chain
A
R group
13
Q
STANDARD AMINO ACIDS
A
- Nonpolar Amino Acid
- Polar Amino Acid
14
Q
has nonpolar side chain
A
Nonpolar Amino Acid
15
Q
hydrophobic (water-fearing)
A
Nonpolar Amino Acid
16
Q
Found in the interior of proteins, where there is limited contact with water
A
Nonpolar Amino Acid
17
Q
R group – hydrocarbons (aliphatic or aromatic)
A
Nonpolar Amino Acid
18
Q
has polar side chain
A
Polar Amino Acid
19
Q
hydrophilic (water-loving)
A
Polar Amino Acid
20
Q
Found on the surfaces of proteins
A
Polar Amino Acid
21
Q
Subcategorized to: Polar neutral, polar acidic, and polar basic
A
Polar Amino Acid
22
Q
Side chain of Polar neutral
A
has groups containing heteroatoms
22
TYPES OF POLAR AMINO ACIDS
1. Polar Neutral
2. Polar Acidic
3. Polar Basic
23
contain polar but neutral side chain (R group)
Polar neutral
24
contain a carboxyl group as part of the side chains
Polar acidic
25
Side chain of polar acidic:
carboxylic acid
26
contain an amino group as part of the side chain
Polar basic
27
Side chain of polar basic
amine, imine
28
The ________ of one amino acid interacts with the amino group of the other amino acid.
carboxyl group
29
Amino acids are linked together by an _______
amide (peptide) bond via a condensation reaction
30
The four levels of protein structure are
Primary (1o)
Secondary (2o)
Tertiary (3o)
Quaternary (4o)
31
Amino acid sequence
Primary (1o)
32
Overall 3D shape of folded protein
Tertiary (3o)
32
H-bonds on protein backbone
Secondary (2o)
33
Subunit organization
Quaternary (4o)
34
is the order/sequence in which amino acids are linked together in a protein
PRIMARY STUCTURE (1o)
35
Amino acids are linked to each other by ____________
peptide bonds
36
Arrangement in space adopted by the hydrogen-bonded arrangement of the backbone portion of a protein
SECONDARY STRUCTURE (2o)
37
Common types of secondary structures
1. α helix
2. β pleated sheet (β-sheet)
37
Folding is stabilized by noncovalent interactions
SECONDARY STRUCTURE (2o)
38
Composed of 1 polypeptide chain
α helix
39
H bonds are within a single polypeptide chain (backbone only)
α helix
40
R-groups are outside
α helix
41
Right-handed or clockwise, spiral
α helix
42
Composed of two or more polypeptide chains
β pleated sheet (β-sheet)
43
H-bonds are between adjacent strands
β pleated sheet (β-sheet)
44
H-bonds are between adjacent strands
β pleated sheet (β-sheet)
45
A single protein chain adopts a shape that resembles a coiled spring (helix)
ALPHA-HELIX STRUCTURE
46
Coil configuration maintained by
hydrogen bonds
47
Two fully extended protein chain segments in the same or different molecules
BETA-PLEATED SHEET STRUCTURE
47
Twist of the helix forms a
right-handed, or clockwise, spiral
48
Hydrogen bonds between C=O and N—H entities are orientated ________ to the axis of the helix
parallel
49
Overall three-dimensional shape of a protein
TERTIARY STRUCTURE (3o)
50
chains (R groups) that are widely separated from each other
TERTIARY STRUCTURE (3o)
51
There are two main factors for folding of a protein:
- hydrophobic residues
- polar residues
52
Covalent, strong, and involve two cysteine units
Covalent disulfide bonds
53
Can occur between amino acids with polar R groups
Hydrogen bonds
53
Involve the interaction between charged side chains of acidic and basic amino acids
Electrostatic attractions (salt bridges)
54
Occur when two nonpolar side chains are close to each other
Hydrophobic attractions
55
Highest level of protein organization
QUATERNARY STRUCTURE (4o)
55
Organization among the various peptide subunits in a multimeric protein
QUATERNARY STRUCTURE (4o)
56
found in proteins that have two or more polypeptide chains (subunits)
QUATERNARY STRUCTURE (4o)
57
Subunits are independent of each other and not covalently bonded to each other
QUATERNARY STRUCTURE (4o)
58
Contain even number of subunits
QUATERNARY STRUCTURE (4o)
59
Reverse of peptide bond formation
PROTEIN HYDROLYSIS
60
Results in the regeneration of an amine and carboxylic acid functional groups
PROTEIN HYDROLYSIS
61
is when all peptide bonds are broken, and the only products are amino acids
Complete hydrolysis
62
is when some but not all peptide bonds are broken, and the product is a mixture of amino acids and small peptides
Partial hydrolysis
63
Partial or complete disorganization of a protein’s characteristic three-dimensional shape
PROTEIN DENATURATION
64
Filamentous or elongated shape
FIBROUS PROTEIN
64
PROTEIN CLASSIFICATION BASED ON SHAPE
1. FIBROUS PROTEIN
2. GLOBULAR PROTEIN
65
Function is mostly structural (strength/support)
FIBROUS PROTEIN
66
Repetitive AA sequence
FIBROUS PROTEIN
67
Usually water-insoluble
FIBROUS PROTEIN
68
Provide protective coating for organisms
α-Keratin
69
Major protein constituent of hair, feather, nails, horns, and turtle shells
α-Keratin
70
Mainly made of hydrophobic amino acid residues
α-Keratin
71
Most abundant protein in humans
COLLAGEN
72
Organic component of bones and teeth
COLLAGEN
73
Major structural material in tendons, ligaments, blood vessels, and skin
COLLAGEN
74
help maintain the structure of the triple-helix
Glycine and proline
75
Spherical or globular shape
GLOBULAR PROTEIN
76
Function is mostly as catalyst, transport, etc.
GLOBULAR PROTEIN
77
irregular AA sequence
GLOBULAR PROTEIN
78
Usually, water-soluble
GLOBULAR PROTEIN
79
Oxygen-storage molecule in muscles
MYOGLOBIN
80
Consists of a single peptide chain and one heme unit
Monomer
81
An oxygen-carrier molecule in blood
HEMOGLOBIN
82
Each subunit contains a heme group (four polypeptide chains)
Tetramer
83
A compound, usually a PROTEIN, that acts as a CATALYST for a biochemical reaction.
ENZYME
84
Most enzymes are __________
GLOBULAR PROTEINS
85
enzyme composed only of protein (amino acid chains)
Simple enzyme
86
enzyme that has a nonprotein and protein parts
Conjugated enzyme
87
Redox reactions
Oxidoreductase
88
CLASSES OF ENZYME
Ligase
Isomerase
Lyase
Hydrolase
Oxidoreductase
Transferase
89
Transfer of functional groups
Transferase
90
Isomerization
Isomerase
90
Hydrolysis reactions
Hydrolase
90
Addition of groups to double bonds or removal of groups to form double bonds
Lyase
91
Joining of two molecules (hydrolysis of ATP as energy source)
Ligase
92
an enzyme that catalyzes an oxidation-reduction reaction
OXIDOREDUCTASE
93
an enzyme that catalyzes the transfer of a functional group from one molecule to another
TRANSFERASE
94
help disposal of nitrogen during the metabolism of amino acids for energy production or for synthesis of bioactive compounds from amino acids
Aminotransferases
95
an enzyme that catalyzes a hydrolysis reaction in which the addition of a water molecule to a bond causes the bond to break
HYDROLASE
96
effect the breaking of glycosidic bonds in oligo- and polysaccharides
Carbohydrases
97
effect the breaking of peptide linkages in proteins
Proteases
98
effect the breaking of ester linkages in triacylglycerols
Lipases
99
an enzyme that catalyzes addition or removal of atoms across a double bond
LYASE
100
adds water across the double bond in trans-Enoyl CoA during the oxidation of fatty acids for biochemical energy production
Enoyl CoA hydratase
101
small part of an enzyme’s structure that is involved in catalysis; it is where the substrate binds to the enzyme
ACTIVE SITE
102
formed due to folding and bending of the protein
ACTIVE SITE
103
“CREVICE-LIKE” location in the enzyme
ACTIVE SITE
104
contains catalytic amino acid residues or groups
ACTIVE SITE
105
FACTORS AFFECTING ENZYME ACTIVITY
* Temperature
* pH
* Substrate Concentration
* Enzyme Concentration
105
is the maximum amount of substrate molecules that an enzyme can convert to products
Turnover number
