Lesson 1-4 Biochemistry Flashcards
(155 cards)
1
Q
What is the trend of electronegativity in a column of the periodic table?
A
Electronegativity increases from bottom to top in a column
2
Q
What is the trend of electronegativity across a period in the periodic table?
A
Electronegativity increases from left to right across a period
3
Q
What does electronegativity measure?
A
Electronegativity is a measure of an atom’s ability to attract a shared electron pair when it is participating in a covalent bond
4
Q
What type of bonds do elements that are far apart in the periodic table usually form?
A
Ionic bonds
5
Q
What type of bonds do elements that are closer together in the periodic table usually form?
A
Covalent bonds
6
Q
How is the polarity of a molecule determined?
A
By the element whose valence shell has a greater hold on the electron that is being shared
7
Q
What characterizes a non-polar covalent bond?
A
Electronegativity difference is zero
8
Q
What characterizes a polar covalent bond?
A
Electrons are shared unequally
9
Q
True or False: Non-polar covalent bonds have electrons shared equally.
A
True
10
Q
What is a polar molecule?
A
A molecule with an unequal distribution of charge as a result of its polar bonds and its shape
11
Q
What is an example of a polar molecule?
A
Water (H2O)
12
Q
What charge does the Oxygen end of a water molecule have?
A
Slightly negative charge
13
Q
What charge do the Hydrogen atoms of a water molecule have?
A
Slightly positive charge
14
Q
What are the forces of attraction between water molecules called?
A
Hydrogen bonds
15
Q
What happens to salt when it dissociates in water?
A
Water molecules quickly form hydration shells around the Na+ and Cl- ions
16
Q
What effect do surrounding water molecules have on the attraction between salt ions?
A
They reduce the attraction so much that ions separate from their normal crystal lattice structure
17
Q
What is the density characteristic of water when frozen?
A
Water expands when frozen
18
Q
What geometric shape do water molecules form when frozen?
A
Hexagonal shape
19
Q
What property allows a lizard to run across the top of water?
A
Surface tension and cohesion
20
Q
What is adhesion?
A
Attraction between the molecules of two different substances
21
Q
What is cohesion?
A
Attraction between the molecules or atoms of the same substance
22
Q
What are polar substances said to be?
A
Hydrophilic (‘water-loving’)
23
Q
What are non-polar substances said to be?
A
Hydrophobic (‘water-fearing’)
24
Q
Fill in the blank: Hydrophilic substances create a _______ contact angle with water.
A
smaller
25
Fill in the blank: Hydrophobic substances create a _______ contact angle with water.
larger
26
What is autoionization of water?
When two water molecules react, one transfers an H+ ion to the other, forming a hydronium ion (H3O+) and a hydroxide ion (OH-)
27
What does autoionization of water always produce?
An equal number of hydronium and hydroxide ions
28
Define calorie (cal).
A unit of heat required to raise the temperature of 1g of water by 1°C
29
Define kilocalorie (kcal).
Quantity of heat required to raise the temperature of 1 kg of water by 1°C
30
What is the specific heat capacity of water?
1 cal/(g * °C)
31
What is the heat of vaporization?
The quantity of heat a liquid must absorb for 1g of it to be converted from liquid to gaseous state
32
What does the phrase 'like dissolves like' refer to?
The principle that polar solvents dissolve polar solutes and non-polar solvents dissolve non-polar solutes
33
What does hydrophobic mean?
“water-fearing” - Any substance that does not have an affinity (or likeness) for water (water fearing)
34
What does hydrophilic mean?
"water loving" - Any substance that has an affinity (or likeness) for water
35
What property of water allows for the bubble shield to be created around the wash cloth in space
Cohesion (water molecules stick together and form a shield)
Adhesion (water molecules stick to his hands)
36
Describe in more detail how the lizard is able to run across the water
strong hydrogen bonds formed between water molecules (water molecules stick together - cohesion), which results in a high surface tension of the water enabling the lizard to quickly run across.
*Surface tension/cohesion
37
38
What is dehydration synthesis?
Larger molecules are joined by the removal of water
## Footnote
Water is a product in this reaction, commonly used to assemble macromolecules like complex carbohydrates and proteins.
39
What is the 1-2 glycosidic linkage?
A bond that forms between larger molecules as water is removed during dehydration synthesis
## Footnote
The 1-2 notation denotes which carbons are involved in the bond.
40
What is a hydrolysis reaction?
The reverse of dehydration synthesis, where water is used to split large molecules into smaller ones
## Footnote
Water acts as a reactant in this process.
41
What occurs during a neutralization reaction?
A reaction between acids and bases that produces salt and water
42
What are redox reactions?
Reactions involving the transfer of electrons
## Footnote
They include oxidation (loss of electrons) and reduction (gain of electrons).
43
What does LEO goes GER stand for?
LEO: losing electrons is oxidation; GER: gaining electrons is reduction
44
What is produced during complete oxidation?
Carbon dioxide (CO2)
45
What is produced during incomplete oxidation?
Carbon monoxide (CO)
46
What elements comprise roughly 99% of the mass of most cells?
C, H, O, N
## Footnote
These are the most abundant elements in organic matter.
47
What are some trace elements important in organic matter?
S, P, Na, K, Cl, Mg
48
What differentiates organic compounds from inorganic compounds?
Organic compounds must contain carbon atoms, while inorganic compounds usually do not
## Footnote
Organic compounds are often found and produced by living organisms and typically have carbon-hydrogen bonds and are organized into chains or rings. Inorganic compounds have none of these things.
49
What is the central atom in organic compounds?
Carbon
50
Why is carbon considered versatile in biological systems?
It can bond covalently with other atoms, forming various geometrical structures
51
What are functional groups?
Specific groups of atoms within complex biomolecules involved in chemical reactions
## Footnote
They influence the chemical behavior of a macromolecule.
52
List the six functional groups.
* Hydroxyl (OH)
* Carbonyl (-C=O)
* Carboxyl (O=C-OH)
* Amino (C-NH2)
* Sulfhydryl (C-SH)
* Phosphate (C-PO4)
53
What is true about the functional groups in terms of solubility?
They are hydrophilic and polar, which can make macromolecules soluble in water
54
Can many compounds have more than one functional group?
Yes
55
What is the role of each functional group in cell metabolism?
Each functional group has a specific role in influencing the organic molecules they are found in
56
What are the four groups of lipids?
* Fats
* Phospholipids
* Steroids
* Waxes
57
What is the primary function of fats?
Long-term energy storage and insulation
58
How much energy does 1 gram of fat store compared to carbohydrates?
1 g of fat = 9 cal; 1 g of carb = 4 cal
59
What elements are lipids primarily composed of?
Carbon, hydrogen, and oxygen
60
What characteristic makes lipids non-polar biological molecules?
Lipids are hydrophobic and do not dissolve in water
61
Name three food sources of lipids.
* Fish/krill oils
* Nuts
* Avocado
62
What two molecules are fats (triglycerides) made from?
* Glycerol
* Fatty acids
63
What is a glycerol molecule?
A 3-carbon chain with 3 hydroxyl groups
64
What type of bond forms between glycerol and fatty acids in triglycerides?
Ester linkages
65
What reaction creates a triglyceride?
Dehydration synthesis reaction
66
What distinguishes saturated fatty acids from unsaturated fatty acids?
Saturated fatty acids have single bonds and maximum hydrogen atoms; unsaturated have one or more double bonds
67
What happens to the structure of unsaturated fatty acids due to double bonds?
They have kinks and bends in the molecule
68
Why are saturated fats typically solid at room temperature?
They can be easily stacked due to no bends or kinks
69
What are the two types of unsaturated fatty acids?
* Monounsaturated (one double bond)
* Polyunsaturated (more than one double bond)
70
What are phospholipids composed of?
* 2 fatty acids
* Glycerol
* Phosphate group
* Choline
71
What are the hydrophobic and hydrophilic components of phospholipids?
* Hydrophobic tails (2 fatty acids)
* Hydrophilic head (glycerol, phosphate group, polar unit)
72
What is the term for molecules that contain both hydrophobic and hydrophilic regions?
Amphipathic molecules
73
What is the structure of phospholipids in water?
They self-assemble into a bilayer with hydrophobic tails inward and hydrophilic heads outward
74
What is a micelle?
A spherical structure formed by surfactant molecules in water with hydrophobic tails facing inward
75
What are steroids characterized by?
A carbon skeleton consisting of 4 fused rings
76
What is the role of cholesterol in the body?
It is an important component of animal cell membranes and a precursor to lipid-based hormones
77
What health issue is associated with high cholesterol levels?
Cardiovascular disease
78
What are waxes primarily composed of?
Long fatty acid chains linked to alcohols or carbon rings
79
What is atherosclerosis?
A cardiovascular disease characterized by plaque deposits in blood vessels
80
What is thrombosis?
A dislodged mass that causes a blockage in blood vessels
81
True or False: Trans fats are associated with increased rates of coronary artery diseases.
True
82
Fill in the blank: Saturated fatty acids have _______ double bonds.
no
83
Fill in the blank: Unsaturated fatty acids with hydrogen atoms on the same side are called _______.
cis
84
Fill in the blank: Unsaturated fatty acids with hydrogen atoms on opposite sides are called _______.
trans
85
Function of fats
Long term energy storage and insulation
86
Function of phospholipids
Forms cell membranes
87
Function of steroids
Hormone signalling
88
Function of waxes
Water resistance and protection
89
What elements do proteins contain?
Carbon, hydrogen, oxygen, and nitrogen
90
What are the monomers that make up proteins?
Amino acids
91
What distinguishes proteins from other biological molecules?
Proteins contain nitrogen
92
What percentage of the mass of most cells is made up of proteins?
50%
93
Give two examples of proteins.
* Meat
* Enzymes (biological catalysts)
94
What is the primary function of enzymatic proteins?
Selective acceleration of chemical reactions
95
What is a function of defensive proteins?
Protection against disease
96
What do storage proteins do?
Store amino acids
97
What is the role of transport proteins?
Transport of substances
98
What function do hormonal proteins serve?
Coordination of an organism's activities
99
What is the role of receptor proteins?
Response of cells to chemical stimuli
100
What do contractile and motor proteins facilitate?
Movement
101
What is the primary structure of a protein?
The unique linear sequence of amino acids in a polypeptide chain
102
What is the secondary structure of a protein characterized by?
Coils and/or folds in the polypeptide chain
103
What is an example of a coil structure in secondary protein structure?
α-helix
104
What is an example of a folded structure in secondary protein structure?
β-pleated sheet
105
What determines the tertiary structure of a protein?
Interactions between various R-groups
106
What type of bonds stabilize a protein's tertiary structure?
Disulfide bridges (S-S)
107
What is a polypeptide?
A polymer of more than 50 amino acids in length
108
What is the quaternary structure of a protein?
When two or more polypeptide chains interact to form a protein
109
What is sickle-cell disease a result of?
A single amino acid change in primary structure
110
What is denaturation of proteins?
The loss of a protein's normal shape
111
What can cause a protein to denature?
Changing the pH or temperature
112
What is the significance of protein folding?
Determines the protein's function
113
What is the protein folding problem?
Proteins can be folded in new/different ways that yield a new/altered/beneficial function
114
What diseases can result from protein misfolding?
* Alzheimer's disease
* Parkinson's
* ALS
115
What role do tau proteins play in neurons?
Support the stability of microtubules
116
What happens when tau proteins misfold?
They lose their function and microtubules can fray, becoming unstable
117
What is the consequence of the accumulation of misfolded tau proteins?
Limits the number and quality of synapses made in the brain
118
Fill in the blank: Essential amino acids must be obtained from _______.
our diets
119
Fill in the blank: The N-terminus of a peptide chain has an _______ group.
amino
120
Fill in the blank: The C-terminus of a peptide chain has a _______ group.
carboxyl
121
What are the common overall function of proteins?
Some recurring functions include: Structural support, Storage, Transport, Cellular communications, Movement and Defense against foreign substances
122
What is a peptide?
A chain of amino acids linked by peptide bonds
123
Alanine
Ala - A
124
Arginine -
Arg - R
125
Aspartic Acid -
Asp - D
126
Asparagine -
Ash - N
127
Cysteine -
Cys - C
128
Glutamic acid -
Glu - E
129
Glutamine -
Gln - Q
130
Glycine -
Gly - G
131
Histidine -
His - H
132
Isoleucine -
Ile - I
133
Leucine -
Leu - L
134
Lysine -
Lys - K
135
Methionine -
Met - M
136
Phenylalanine -
Phe - F
137
Proline -
Pro - P
138
Serine -
Ser - S
139
Threonine -
Thr - T
140
Tryptophan -
Trp - W
141
Tyrosine -
Tyr - Y
142
Valine -
Val - V
143
What are amino acids composed of?
Amino acids are composed of five components: central 𝛂-carbon, amino group (-NH2), carboxyl group (-COOH), hydrogen atom, R-group (1 of 20 different side chains)
144
Function of structural proteins:
support. Ex. Keratin (in hair), collagen provide fibrous framework in connective tissues.
145
What is the function of a protein dependent on?
The function of a protein is dependent on the combination of types of amino acids.
146
How do peptides form proteins?
| General
Peptides → Polypeptides → Proteins
Peptides fold up or combine with other peptides to form proteins
147
By what type of reaction are peptides formed?
Peptides are formed by dehydration synthesis
148
How are peptide bonds formed?
Peptide bonds are formed by the dehydration synthesis between the amino group of one amino acid and the carboxyl group of another
149
What are the bonds formed by dehydration synthesis between amino groups and carboxyl group of amino acids?
Peptide bonds
150
What chemical properties result from the functional group in fatty acids?
Acidic
151
What type of bonds contribute to secondary structure?
Secondary structure is due to hydrogen bonds between different amino acids in the polypeptide chain
152
What relationship between proteins does sickle cell disease represent?
Sickle cell disease represents the protein structure and function relationship
## Footnote
Sickle-cell disease: the amino acid glutamic acid is switched to valine in the protein hemoglobin
A single amino acid change in structure can alter or destroy the biological function of the protein.
153
Which is the good steroid - HDL or LDL?
HDL
154
Which is the bad steroid - HDL or LDL?
LDL
155
Which steroid contributes to cardiovascular disease?
LDL
