Molecular Biology Flashcards
A1.1 Water A1.2 Nucleic Acid B1.1 & B1.2 - Carbs, Lipids, and Proteins C1.1 - Enzymes C1.2 Cellular Respiration C1.3 Photosynthesis D1.1 DNA Replication D1.2 Protein Synthesis D1.3 Mutations and Gene Editing D2.3 Water Potential (157 cards)
1
Q
What does molecular biology explain?
A
Living processes in terms of the chemical substances involved.
2
Q
What allows carbon atoms to form stable compounds?
A
Carbon atoms can form four covalent bonds.
3
Q
What is metabolism?
A
The web of all enzyme-catalyzed reactions in a cell or organism.
4
Q
Define anabolism
a condensation reaction
A
Synthesis of complex molecules from simpler ones.
5
Q
Define catabolism
hydrolysis
A
Breakdown of complex molecules into simpler ones.
synthesis of complex molecules from simpler units; it requires energy
6
Q
What is organic chemistry?
A
The study of the properties and structures of organic compounds.
7
Q
What is a key property of carbon?
A
Carbon can form strong and stable carbon-carbon bonds.
8
Q
What are polymers?
A
Complex macromolecules made of smaller, recurring subunits called monomers.
9
Q
What is condensation?
A
A reaction that makes bonds, releases water, and is anabolic.
10
Q
What is hydrolysis?
A
A reaction that breaks bonds, requires water, and is catabolic.
11
Q
What did vitalism propose?
A
Organic molecules can only be synthesized by living things.
12
Q
What disproved vitalism?
A
Urea was produced from inorganic chemicals in 1800.
13
Q
What type of bond forms between water molecules?
A
Hydrogen bonds form between water molecules due to their polarity.
14
Q
What properties of water are explained by hydrogen bonding?
A
Cohesive, adhesive, thermal, and solvent properties.
15
Q
What is the structure of water ?
A
Composed of two hydrogen atoms covalently bonded to one oxygen atom.
16
Q
What is a polar covalent bond?
A
A bond where electrons are shared unequally, resulting in a polar molecule.
17
Q
What is cohesion in water?
A
Attraction between molecules of the same type, due to hydrogen bonds.
18
Q
What is adhesion in water?
A
Attraction between water and other unlike molecules, due to hydrogen bonds.
19
Q
What is a hydrophilic molecule?
A
A water-loving molecule, attracted to water (e.g., carbohydrates).
20
Q
What is a hydrophobic molecule?
A
A water-hating molecule, not attracted to water (e.g., fatty acids).
21
Q
What is an amphipathic molecule?
A
A molecule with both hydrophilic and hydrophobic parts (e.g., phospholipids).
22
Q
How does water act as a solvent?
A
Water dissolves substances with charged particles or electronegative atoms.
23
Q
What is the role of water as a coolant in sweat?
A
Water absorbs heat through evaporation, cooling the body.
24
Q
How do glucose and amino acids transport in blood?
A
They are transported in blood due to their solubility in water.
25
What is the function of water in plants?
Transports dissolved substances such as sugars and minerals
26
What is blood in animals primarily responsible for?
Carrying dissolved nutrients like glucose, amino acids, and ions.
27
What does high specific heat capacity of water mean?
Water can absorb a lot of energy before increasing in temperature
28
Why is sweat effective for cooling?
It absorbs a lot of heat energy before evaporating
29
What are stomata in plants used for?
Allow vaporizing water to escape, cooling the plant
30
How does polarity affect water's thermal properties?
Water's polarity allows for hydrogen bonding, requiring more energy to change state.
31
What is formed by condensation reactions of monosaccharides?
Disaccharides and polysaccharides
32
What are the three classes of carbohydrates?
Monosaccharides, disaccharides, polysaccharides
33
What is glycogen?
A polysaccharide used for energy storage in animals
34
What is the main function of cellulose?
Structural component in plant cell walls
35
What is the difference between saturated and unsaturated fatty acids?
Saturated have no double bonds; unsaturated have one or more double bonds
36
What are triglycerides formed from?
Three fatty acids and one glycerol
37
What is the health risk associated with trans fats?
Linked to increased heart disease risk
38
How is body mass index (BMI) determined?
By calculation or using a nomogram
39
What is the structure of glucose?
Monosaccharide, energy molecule used in cell respiration
40
What is lactose made of?
Glucose + Galactose
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What is sucrose composed of?
Glucose + Fructose
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What is the source of maltose?
Hydrolyzed starch
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What happens during the digestion of polysaccharides?
Hydrolysis of bonds between monosaccharides
44
Why can't humans digest cellulose?
Humans lack the enzyme cellulase
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What is glycogen used for?
Storage of extra glucose molecules in animals
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What does cellulose construct?
Plant cell walls
47
What are fatty acids key components of?
Lipids in plants, animals, and microorganisms
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What structure do saturated fatty acids have?
Straight structure with single bonds between carbon atoms
49
What is the state of saturated fatty acids at room temperature?
Solid
50
What is a characteristic of unsaturated fatty acids?
Have one or more double bonds, causing bends in the chain
51
What are the two types of polyunsaturated fats?
Cis and Trans
52
What do cis-fatty acids look like?
Hydrogens on the same side of the double bond, causing a bend
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What do cis-fatty acids look like?
Hydrogens on the same side of the double bond, causing a bend
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What are trans-fatty acids known for?
Hydrogens on opposite sides of the double bond, making them straight
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What are the three main types of lipids?
Triglycerides, Phospholipids, Steroids
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What are phospholipids made from?
Glycerol bonded to two fatty acids and one phosphate group
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What is the structure of steroids?
Four fused rings
58
What do triglycerides primarily function as?
Long-term energy storage
59
How are triglycerides formed?
From one glycerol bonded to three fatty acids
60
What is the difference in energy storage between carbohydrates and lipids?
Carbohydrates are short-term, lipids are long-term
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What is the storage function of triglycerides?
* Short-term energy storage
* Long-term energy storage
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How do triglycerides affect osmolality
* More effect on osmotic pressure
* Less effect on osmotic pressure
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What is the digestion difference between triglycerides and phospholipids?
* More readily digested: for aerobic or anaerobic respiration
* Less easily digested: only for aerobic respiration
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What is the ATP yield of triglycerides?
* Stores half as much ATP per gram
* Stores twice as much ATP per gram
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What is the solubility of triglycerides?
* Water soluble as monomers, easier to transport
* Non-water soluble (hydrophobic), more difficult to transport
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What health problems can lipids cause?
* High cholesterol
* Obesity
* Diabetes
* High blood pressure
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What is the relationship between trans-fats and health?
Positive correlation between trans-fats and coronary heart disease rates.
68
What does BMI stand for?
Body Mass Index
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How is BMI calculated?
(weight in kilograms)/(height in meters )^2 =BMI
70
What is the primary structure of a protein?
Sequence of amino acids in the polypeptide chain.
71
What links amino acids in proteins?
Peptide bonds (amide links).
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What is unique about each polypeptide?
Their length, amino acids present, and order of amino acids.
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What are the four levels of protein structure?
1. Primary Structure
2. Secondary Structure
3. Tertiary Structure
4. Quaternary Structurep
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What is the role of the amino acid sequence in proteins ?
It determines the three-dimensional conformation and function of a protein.
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What defines the structure and function of a protein?
The unique sequence of amino acids
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What is the secondary structure of a protein?
Folding of the polypeptide due to hydrogen bonding
77
What stabilizes the secondary structure of proteins?
Hydrogen bonds
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What are the two forms of secondary structure?
Alpha-helix and beta-pleated sheets
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What does the tertiary structure of a protein refer to?
Twisting and folding of the secondary structure
80
What holds the tertiary structure of proteins together?
Interactions between side chains (R groups)
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What is the quaternary structure of proteins?
Interactions between multiple polypeptide chains
82
What is denaturation of proteins?
pH changes or temperature
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What is an example of a structural protein?
Collagen
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What is the function of hemoglobin?
Transport of oxygen in red blood cells
85
What do enzymes do?
Act as biological catalysts to increase reaction rates
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What is the active site of an enzyme?
Small section where substrates bind
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What factors affect enzyme activity?
Temperature, pH, and substrate concentration
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What is the product in an enzyme reaction?
The molecule produced at the end of the reaction
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What is an example of an enzyme involved in photosynthesis?
Rubisco
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What is referred to as the substrate?
The molecule that binds to an enzyme's active site.
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What is produced at the end of the reaction?
The product
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What suffix do enzymes typically end with?
ase
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What does the induced-fit model state?
The active site changes shape to enfold a substrate.
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How does temperature affect enzyme activity?
Increases activity by doubling for every 10°C until denaturation occurs
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What happens to enzymes at high temperatures?
They become denatured and stop working.
96
How does pH affect enzyme activity?
Increases to an optimum point, then decreases if too alkaline.
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What happens at high substrate concentrations?
The active site becomes saturated, limiting activity increase.
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What is an immobilized enzyme?
An enzyme attached to an inert, insoluble material.
99
What is a major use of immobilized enzymes?
Production of lactose-free milk.
100
What does lactase do?
Breaks down lactose into glucose and galactose.
101
What is an advantage of immobilized enzymes?
They can be reused and are more stable.
102
What is a disadvantage of immobilized enzymes?
Requires extra time, equipment, and may affect reaction rates.
103
What are the purification requirements for immobilized enzymes?
Purification is not necessary when enzymes are immobilized.
104
What happens to reaction rates if enzymes cannot mix freely with the substrate?
There may be a reaction in reaction rates.
105
When can't immobilized enzymes be used?
When one of the substrates is insoluble.
106
How can immobilized enzymes benefit lactose-intolerant individuals?
They can be a source of dairy.
107
What is one use of immobilized enzymes in ice cream production?
To reduce crystallization.
108
What are nucleic acids made of?
Polymers of nucleotides.
109
How does DNA differ from RNA?
In number of strands, base composition, and type of pentose.
110
What is the structure of DNA
A double helix made of two antiparallel strands linked by hydrogen bon
111
What are the three parts of a nucleotide?
* Pentose group
* Phosphate group
* Nitrogenous base
112
What is the type of pentose in RNA?
Ribose.
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114
What base is found in DNA but not in RNA?
Thymine.
115
What pairs with Adenine in DNA?
Thymine via two hydrogen bonds.
116
What pairs with Guanine in DNA?
Cytosine via three hydrogen bonds.
117
What is Chargaff's rule?
Adenine equals Thymine; Cytosine equals Guanine.
118
What is the replication method of DNA?
Helicase
119
What does DNA polymerase do?
Links nucleotides to form a new strand.
120
What is transcription?
Synthesis of mRNA from DNA by RNA polymerase.
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What is translation?
Synthesis of polypeptides on ribosomes.
122
What determines the amino acid sequence of polypeptides?
mRNA according to the genetic code.
123
What corresponds to one amino acid in a polypeptide?
Codons of three bases on mRNA.
124
What is required for translation to occur?
Complementary base pairing between codons on mRNA and anticodons.
125
What do codons on mRNA correspond to?
One amino acid in a polypeptide
126
What is needed for translation?
Complementary base pairing between codons on mRNA and anticodons on tRNA
127
What is Taq DNA polymerase used for?
To produce multiple copies of DNA rapidly via PCR
128
What is an example of the universality of the genetic code?
Production of human insulin in bacteria
129
What is the purpose of DNA replication?
To produce two identical copies of a DNA molecule
130
What does DNA helicase do?
Separates the two polynucleotide strands of DNA
131
What direction does DNA polymerase move?
5’ to 3’ direction
132
What does semi-conservative DNA replication mean?
Each strand contains one original and one new strand
133
What did the Meselson-Stahl experiment demonstrate?
DNA replication is semi-conservative
134
What are the three main types of RNA?
* mRNA (messenger RNA)
* rRNA (ribosomal RNA)
* tRNA (transfer RNA)
135
What is the role of mRNA?
Carries DNA codes from the nucleus to the ribosome
136
What is the role of rRNA?
Makes up the ribosome
137
What is the role of tRNA?
Carries a specific amino acid to the ribosome
138
Where does transcription occur?
In the nucleus.
139
What enzyme is used in transcription?
RNA polymerase.
140
What is the antisense strand?
The DNA strand that is transcribed and complementary to RNA.
141
What is the sense strand?
The DNA strand not transcribed, identical to RNA (with T instead of U).
142
Where does translation occur?
In the cytoplasm
143
What structure synthesizes proteins during translation?
The ribosome.
144
What are codons?
Groups of three nucleotides on mRNA that code for amino acids.
145
What are anticodons?
Groups of three nucleotides on tRNA that are complementary to mRNA codons.
146
What is the genetic code?
Universal code where triplets correspond to amino acids across organisms.
147
What is PCR?
Polymerase chain reaction, used to amplify small DNA samples.
148
# 1.
What are the three steps of PCR?
1. Denaturation: DNA strands separate.
2. Annealing: Primers attach.
3. Elongation: DNA is copied.
149
What is Taq polymerase?
Heat-tolerant DNA polymerase from Thermus aquaticus.
150
What does one cycle of PCR yield?
Two identical copies of the DNA sequence
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What is the purpose of Taq polymerase in PCR?
Breaks hydrogen bonds without denaturing the polymerase enzyme
152
What is cell respiration?
Controlled release of energy from organic compounds to produce ATP
153
What is the immediate source of energy in the cell?
ATP (adenosine triphosphate)
154
What does anaerobic cell respiration yield?
A small yield of ATP from glucose
155
What does aerobic cell respiration require?
Oxygen
156
What is produced in yeast during anaerobic respiration?
Ethanol and carbon dioxide
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