Lecture Exam 2 SG Flashcards
(117 cards)
1
Q
What is the term for the sum of all chemical reactions in an organism?
Chapter 5
A
Metabolism
2
Q
For both catabolism and anabolism, describe the following: (a) is it used to build or break down
molecules, (b) does it use a hydrolysis or dehydration reaction, and (c) are the reactions exergonic or endergonic?
A
Catabolism: Break down, Hydrolysis, Exergonic
Anabolism: Build, Dehydration, Endergonic
3
Q
Describe an endergonic vs. an exergonic reaction. Give an example of each.
A
Endergonic: Cold, Absorbs energy, Photosynthesis
Exergonic: Hot, Releases energy, Explosion
4
Q
When a chemical bond forms, does this release or store energy?
A
This stores the energy which can be released by breaking the bond
5
Q
Does an exergonic or an endergonic reaction require a high amount of potential energy for the reaction to occur? Why?
A
An exergonic reaction requires more PE than an endergonic reaction because energy must be released as opposed to endergonic reactions which absorb energy
6
Q
What are the three types of metabolic pathway patterns? Give an example for each.
A
Linear: Starch hydrolysis
Branched: Glycolysis
Circular: Kreb’s cycle
7
Q
Why are some organisms able to carry out certain metabolic processes and while other organisms cannot? For example, yeast perform alcoholic fermentation and humans cannot. Why is the human body physiologically unable to perform alcoholic fermentation?
A
Metabolic pathways are determined by enzymes and enzymes are encoded by genes. If humans do not have the gene required to make enzymes that are needed for processes such as alcoholic fermentation we cannot perform these processes
8
Q
Why is it necessary for all organisms to possess some form of metabolism? Which class of macromolecule provides the most cellular energy?
A
- It is important for all organims to posses some form of metabolism because metabolism allows us to store and release energy using organic molecules. If this was not the case organims would need to constantly eat to survive
- Carbohydrates provide the most cellular energy as they can be oxidized.
9
Q
Which part of ATP’s structure allows it to store potential energy? What happens to ATP when its stored energy is released?
A
The phosphate component is where the energy is held. When energy is released from ATP it becomes ADP and Pi due to the loss of energy showing that a phosphate that had energy has been shed.
10
Q
Define the following terms: collision theory, activation energy, and reaction rate.
A
Collision Theory: Atoms/ molecules must collide to be able to react
Activation Energy: Minimum amount of energy required to make a reaction occur
Reaction Rate: Number of Products over seconds
11
Q
What are the ways that a reaction rate can be increased?
A
Increase heat, increase enzyme/substrate, increase pressure, aggitate
12
Q
A(n) ______________ is a type of protein that accelerates the rate at which a chemical reaction takes place in an organism.
A
Enzyme
13
Q
Enzymes are usually made of which type of macromolecule?
A
Polypeptides
14
Q
Does a specific enzyme usually catalyze one specific reaction or many types of reactions?
A
An enzyme usually catalyzes a specific reaction
15
Q
Lactose is the _________________ of the enzyme ___________________.
A
Substrate
Lactase
16
Q
How do enzymes work?
A
The globular protein has an activation site where a substrate can attach and this will induce a reaction that lowers the energy required to make a reaction occur. once the chemical reaction has occured, the product will be released and the enzyme can catalyze the reaction once more
17
Q
Name the region of the enzyme that binds to the substrate.
A
Active Site
18
Q
Define the following parts of an enzyme: apoenzyme, cofactors, holoenzyme, active site, and allosteric site.
A
Apoenzyme: Protein component of enzyme
Cofactor: Non protein component of enzyme
Holoenzyme: Apoenzyme + Cofactor (fully functional)
Active site: Location where substrate binds
Allosteric site: Molecular on/off switch for enzyme
19
Q
Name and describe two types of cofactors. What is the role of an enzyme cofactor?
A
Inorganic: Iron in heme, Mg, Cu
Cofactors: The non protein portion that helps a reaction occur. Often play a role in stabilizing the enzyme or catalyzing the enzymatic action
Organic (coenzymes): NAD+, NADP+, FAD, CoA
| NAD+, NADP+, FAD are all electron carriers
20
Q
Describe the mechanism of enzymatic action (4 steps)
A
- Substrate makes contact with binding site
- Enzyme and substrate form complex (induced fit)
- Substrate is transformed and released
- Enzyme remains unchanged and available for further reactions
21
Q
List the factors that influence enzymatic activity. Briefly describe how each factor affects enzymatic activity. (5)
A
Temperature - Increased molecular motion as temp increases
Pressure - Less space means more molecules bumping increasing reaction rate
pH - If pH is not ideal, the denatured enzyme can stop functioning
Concentration - More substrate or enzyme can increase reaction rate unless one factor is limited by the other
Inhibitors - Some inhibitors can either compete with substrates or turn off enzymes resulting in decreased reaction rates
22
Q
What is the difference between competitive and noncompetitive inhibition? Which type of inhibitor can be reversed by increasing the substrate concentration? Which type of inhibitor has a structure that is similar to the normal substrate?
A
Competitive: Competes with substrate to block activation site
Noncompetitive: Binds to allosteric site resulting in enzymatic shape change which makes enzyme inactive
- Competitive
- Competitive
23
Q
How does sulfanilamide inhibit the synthesis of folic acid? Why is this important?
A
Sulfadrug is a competitive inhibitor that is analogous with PABA. Because bacteria such as S. aureus or E. coli rely on making folate it will inhibit bacteria by competing for active sites
24
Q
Describe feedback (end-product) inhibition and how it works.
A
- A pathway in which the end product inhibits enzyme activity
- Excess product binds to allosteric site on the first enzyme in the pathway deforming activation site and shutting pathway down
- As [end product] decreases activesites reform and pathway resumes
25
For exoenzymes and endoenzymes, discuss the following: (a) where are these enzymes used (inside or outside the cell), (b) are the substrates usually large or small, and (c) what are those types of enzymes used for? (7)
Endoenzymes:
- Found inside the cell
- Typically smaller
- **Used for metabolic enzymes and essential processes**
Exoenzymes:
- Found outside the cell
- Typically larger
- Often used to breakdown contents that is too big to go into the cell
- **Used only when the need arises**
26
Compare constitutive and induced (adaptive) enzymes.
Constitutive:
- Always present
- Essential
Induced (adaptive):
- Not always present/produced
- Only made when a substrate is present
- Goal is to save energy
27
What are the RNA-based enzymes called in the nucleus that are responsible for splicing RNA?
Ribozymes:
Catalytic RNA -> enzymatic function
SnRNPs -> splicosome for RNA processing (small nuclear ribonuclear proteins)
28
For redox reactions, what type of reactions are used for the loss of electrons and what type of reactions are used for the gain of electrons?
Oxidation: Loss/removal of electrons
Reduction: Gain of electrons
Redox: Oxidation reaction paired with reduction reaction
**Always occur together**
29
What are the reactants and products of cellular respiration? (Hint: Use the overall equation.)
Equation: C6H12O6 + 6O2 -> 6CO2 + 6H2O + E
Reactants: Glucose and Oxygen
Products: CO2, H2O, Energy
30
What is the source of electrons in cellular respiration? What reactant became oxidized and which reactant became reduced?
- The source of electrons is Glucose
- Glucose is oxidized
- Oxygen is reduced
31
Name the electron carriers involved in cellular respiration. Are the oxidized or the reduced, electron carriers energy-rich?
32
Define the term phosphorylation. Name and describe the three mechanisms of phosphorylation involved in ATP synthesis.
Phosphorylation is the process of adding a phosphate group to a molecule
Ex. ADP + Pi ->ATP
Substrate level: When a molecule donates a phosphate group to an ADP making ATP
Oxidative Phosphorylation: A series of redox reactions release energy to form ATP in the ETC
Photophosphorylation: Conversion of light energy to ATP and NADPH
33
Compare aerobic respiration, anaerobic respiration, and fermentation.
Note: Aerobic Respiration includes Glycolysis, Kreb's, and ETC
34
What are the four steps involved in aerobic respiration
Glycolysis:
1 Glucose + 2NAD+ + 2ADP -> 2 Pyruvate + 2NADH + 2ATP (Substrate level phosphorylation)
Intermediate Step:
1 Pyruvate + CoA + NAD+ -> Acetyl-CoA + CO2 + NADH
Krebs Cycle:
Acetyl-CoA + 3NAD+ + FAD + ADP -> CoA + 3NADH + FADH2 + ATP+ 2CO2
(Substrate level phosphorylation)
ETC:
NADH( + H+) + FADH2 + 6 ADP + O2 -> NAD+ + FAD+ + 6 ATP + H2O
(Oxidative phosphorylation)
35
What is the function of oxygen in aerobic cellular respiration? What happens when oxygen is not present?
- Oxygen is the final electron acceptor at the end of aerobic respiration which produces water
- If no oxygen is present the hydrogens cannot be moved along the ETC which stops aerobic respiration
36
Glycolysis and the Kreb’s Cycle produce very little ATP compared to the Electron Transport Chain. Name the most important product of Glycolysis and the Kreb’s Cycle. Why is this product important?
NADH and FADH2 are electron carriers that pass electrons to the complexes in the ETC and power ATP synthesis
37
Describe what happens in the Electron Transport Chain and how the proton motive force is used to generate the bulk of the ATP during aerobic cellular respiration. (3)
1. When an electron is transported to plasma membrane it reaches the complexes of the ETC it travels through Complex I-IV. It is able to travel through th complexes due to increasing electronegativity
2. The electron's energy is used to pump protons across the plasma membrane into the periplasmic space which creates an electrochemical gradient
3. The proton motive force is what allows the energy of H+ traveling through ATP synthase to be used to make ATP from ADP. The protons will then be added to oxygen which makes water
38
What drives ATP synthase to produce ATP?
Proton Motive Force as protons move down their concentration gradient
39
Where do the steps of cellular respiration take place?
40
The reactions of fermentation function to produce ________________ molecules for use in glycolysis.
NAD+
41
True or False? Anaerobic respiration is also called fermentation. Explain your answer.
False
- Fermentation is a pathway that produces minimal energy through incomplete oxidation of glucose
- Anaerobic respiration is when a molecule other than oxygen is used as the FEA and fully breaks down a glucose generating more energy than in fermentation but slightly less than aerobic respiration
42
What are the two types of fermentation? What are the final electron acceptors in each type? What types of organisms do each type?
Lactic Acid Fermentation:
2 Pyruvate + 2NADH -> 2 Lactic Acid + 2NAD+
- Pyruvate is FEA
- Animal cells and some bacteria
Alcoholic Fermentation:
2 Pyruvate + 2NADH -> 2 Ethanol + CO2 + 2NAD+
- Acetaldehyde is FEA
- Carried out by yeast and mold
43
During intensive exercise, what is responsible for “muscle burn”?
Build up of protons from ATP production
44
What does it mean to say that an organism is homolactic or heterolactic?
Homolactic:
Lactic acid only is produced
Heterolactic:
Lactic acid and other acids are produced
45
Define the following terms: sterilization, disinfection, antisepsis, degerming, sanitization, bactericide,
and bacteriostatic.
Sterilization:Killing/destroying all microbial life on an object
Disinfection: Killing or inhibiting microbial populations on non-living surfaces
Antisepsis: The process of killing or inhibiting microbial populations on living tissue
Degerming: Removal of germs from a limited area
Sanitization: Lowering microbial count to safe levels
Bactericide: Kills bacteria
Bacteriostatic: Inhibits bacterial growth
46
Washing your hands would be an example of which type(s) of microbial control? Why?
Degerminating - You are lowering the microbial population to a safe level
47
During sterilization, what pattern does the rate of microbial death show (ie. constant, logarithmic, sporatic, etc.)? What is the kill time of a chemical dependent on?
- Logarithmic decline
- The time to kill is dependent on the number of cells
48
How does moist heat sterilization work? What is an autoclave, what is it used for, and what are the minimum operating conditions? If you tightly wrapped forceps in foil (and the steam could not contact the forceps), would the forceps be sterilized?
- Quickly denatures faster than dry heat
- Sterilizes heat stable items at 121C and 15 PSI
- No the steam must be in contact with the forceps to sterilize
49
If you set out to reduce spoilage organisms and potential pathogens in milk, juice, and wine, which physical control method would be the most practical? Why? Does this method sterilize the liquid?
- Pasteurization
- Slowly heats liquid to greatly reduce the amount of bacteria (-cidal) making it safer for consumption while not compromising taste
50
Which is a more efficient sterilization technique, dry heat or moist heat? Explain your answer.
Moist heat denatures quicker. Dry heat could give endospores the opportunity for vegatative cells to become spores
51
For each of the following physical control methods, list the way that the method controls microbial growth: low temperature, high pressure, desiccation, and osmotic pressure. For each method, indicate whether it is bacteriostatic or bactericidal.
Low temp:
- Bacteriostatic
- Flash freeze
High pressure:
- Disrupts cell structure and function
- Bacteriocidal
Desiccation:
- No moisture, but molds resist
- Bacteriostatic
Osmotic pressure:
- Plasmolysis
- Bacteriostatic
52
Which group of organisms are more resistant to osmotic pressure?
Molds and Yeast
53
How do surface tension depressants work?
They loosen contamination from surfaces
54
What is the best method to sterilize liquid solutions that may be damaged by heat (for example, medications)?
Filtration
55
How does filtration work?
Passing a substance through a physical barrier that ensures only the desired substance passes through
56
How does high energy/ ionizing radiation work to control microbial growth? What is high energy/ionizing reagent used for?
High Energy (ionizing):
- Turns water into free radicals
- Arrests fruit and veggie maturation
- No exposure to consumers
57
How does UV radiation control microbial growth? Is it bacteriostatic or bactericidal? Can it be used
to disinfect solutions inside a sealed glass bottle? Why or why not?
Low Energy (non-ionizing):
- UV light
- Causes T-T dimers in DNA
- Disinfects surfaces only
- Bacteriocidal
- It cannot disinfect solutions
58
What are the factors influencing the effectiveness of control agents?(7)
- Bacterial Population
- Age of cells
- Species
- Concentration (5% alcohol vs 50%)
- Temperature
- pH
- Time of exposure
59
Do most chemical agents achieve sterility? Explain your answer.
No, it is hard to kill all spores, vegatative cells, fungi, viruses and more due to their protective mechanisms
60
List organisms from the most resistant to the least resistant to antimicrobial chemicals. For each one, explain why they would be resistant (or not resistant) to antimicrobial chemicals.
61
What is selective toxicity and why is it important?
- The property of an antimicrobial agent being toxic to a microorganism and less/non-toxic to the host
- This is important because you can target bacteria without harming the host in the way many drugs target bacterial ribosomes since they are 70s and human ribosomes are 80s
62
What is the difference between a narrow spectrum drug and a broad spectrum drug?
A narrow spectrum drug is specialized at targetting a specific mechanism and avoids unwanted side effects more (gram + inhibition)
- A broad spectrum drug is effective against many microbes but can also harm the natural flora (gram + and - inhibition)
63
What is a superinfection and how can it occur?
An infection following a previous infection by a microorganism that has become resistant
Ex. methicillin resistant S. aureus (MRSA)
vancomycin intermediate S. areus (VISA)
Vancomycin resistant cocci (VRE)
64
Why is it difficult target a pathogenic virus, protozoan, fungus, or helminth without damaging the host’s cells?
- Virus do not have DNA and instead hijack host cells. They are not identified as living and re hard to target
- Protozoan, Fungus, and Helminths are eukaryotes and it is difficult to find a mechanism to attack that will not harm human cells
65
Why are antibiotics with a very broad spectrum of activity not as useful as one might first think?
- They also harm the natural flora which can lead to an opportunistic infection of fungus if bacteria are wiped out. It can also lead to superinfections
66
What is the difference between antimicrobial agents that are bacteriostatic versus those that are bactericidal?
Bacteriostatic: These pause bacterial growth and give the body time to adapt and mount a response. Good for gram negative as the rapid death of G- could release excess lipid A which can induce shock and even death
Bacteriocidal: Kills bacteria
67
If you have an infection with a Gram-negative organism, should you choose a drug that is bactericidal or bacteriostatic? Why?
Bacteriostatic. If all the bacteria are killed rapidly the release of toxic lipid A from cell walls may be too rapid for your body to adapt to leading to shock and death
68
Name and discuss the five modes of antimicrobial inhibition (Figure 20.2). For each of the 5 modes:
1. Inhibition of Cell Wall synthesis
- Selectively toxic target cell wall
- cidal
2. Inhibition of protein synthesis
- Attacks 70s not 80s
- static
3. Inhibition of nucleic acid replication and transcription
- inhibits RNA/DNA synthesis (gyrase not in humans)
- Static at low [] cidal at high[]
4. Injury to plasma membrane
- Usually topical as human plasma membrane is too similar
- cidal
5. Inhibition of metabolite synthesis
- Humans do not make their own folic acid
- static
69
Which class of antimicrobial drugs contain a β-lactam ring? How do these drugs inhibit microbial growth? Which group of organisms do those drugs target?
- Penicillins
- B-lactam rings prevent crosslinking of PG interfering with cell wall construction
- Gram positive bacteria
70
Which enzyme do bacteria produce that makes them to resistant to penicillin?
Penicillinase (B-lactamases)
71
What advantage do semi-synthetic penicillins have over natural penicillins?
- Their side chains make them resistant to penicillinases
- Side chains may also extend spectrum
72
What do the following antimicrobial drugs have in common, in terms of their structure: penicillin, amoxicillin, cephalosporin, and ampicillin?
B-Lactam antibiotics that disrupt cell wall
73
What are two polypeptide antibiotics that inhibit cell wall synthesis? What is each one used for?
Bacitracin:
- Good against some G+ bacteria
- Topical only
Vancomycin:
- Good against G+
- Good against antibiotic resistant infections such as MRSA
- VRE and VISA resist vancomycin
74
What disease is isoniazid and ethambutol used to treat?
Tuberculosis
- Isoniazid inhibit mycolic acid over a long treatment
- Ethambutol inhibits mycolic acid incorperation and synergizes with isoniazid (usually only for multidrug resistant TB)
75
How do streptomycin, tetracycline, and chloramphenicol all inhibit microbial growth?
They all target different parts of bacterial ribosomes
Tetracycline: blocks tRAN-mRNA complex
Streptomycin: denatures 30s subunit
Chloramphenicol: binds 50S and inhibits formation
76
What drug is used topically, is combined with bacitracin and neomycin in nonprescription ointments, and works by injury to the cell membrane?
Neosporin
77
What is the term for the effect of two drugs together is greater than the effect of either alone?
Synergy
78
List desirable characteristics of antibiotics. (8)
- Selective toxicity (reduce side effects)
- Means of administration (delivery)
- Efficacy (How well it works)
- Length of time and dosage
- Cost
- Availability
- Synergy
- Tissue solubility
79
What is the Kirby-Bauer method used for and how does it work? What would a plate look like if the organism is sensitive to the antibiotic? What would it look like if the organism is resistant to the antibiotic?
- Used to test drug sensitivity by dropping disks of drugs on a bacterial culture and comparing inhibition zones
- If the bacteria is sensitive there will be a large zone of inhibition
- The drug will not stop any of the bacterial growth
80
What are the advantages of using the Kirby-Bauer method?
- Can test multiple drug at the same time
-Very cheap
- Easy to interpret
81
If there is clearing around an antibiotic disk, does that mean that the bacteria is definitely dead in that area? Why or why not? How could you test if the bacteria in that area are dead?
- No, Some antibiotics are bacteriostatic
- Swab the clear zone and see if it grows on a plate without the antibiotic. If it does then the antibiotic was bacteriostatic
82
What type of test would you use to determine the minimal inhibitory concentration (MIC) for an antibiotic? How does the test work?
Broth Dilution Test
- The growth is monitored with respect to varrying drug concentrations
- This allows the MIC to be determined
E Test
- A gradient diffusion method
- Uses plastic strip (epsilometer) with increasing [] gradient of drug
- Estimates MIC
83
What are the four mechanisms of resistance to antibiotics? Describe each one.
1. Blocking entry
- Outer membranes, endospores, capsules, ect.
2. Inactivating Enzymes
- Periplasmic space, penicillinases, B-lactamases
3. Alteration of target molecules
- Mutation of target molecules
4. Efflux of antibiotic
- Drug is pumped out of bacteria
84
What are the 3 ways that bacteria can acquire the genes needed for antibiotic resistance? Describe each method for how it works.
Conjugation (Sex pilus or bridge):
- Sex pilus only possessed by gram negative bacteria
- Bridge forms allowing exchange of DNA bt bacteria
Transformation (Naked DNA):
- DNA obtained when bacteria takes in a dead bacteria's DNA (looting)
Transduction (Phage transfer):
- Defective virus takes up DNA from one bacteria and takes it into another
85
The duplication of a cell's DNA is called _________________________
Replication
86
Explain Frederick Griffith’s experiment using **Streptococcus pneumoniae** (for example, when living S strain cells were injected into mice, what happened?). How are the R strain and the S strain different? What was the conclusion from this experiment?
R strain: Had no capsule (not virulent)
S strain: Had capsule (virulent)
1. Living S injected into mice killed them and when isolated colonies were living S
2. Living R injected into mice let them lice and when isolated R colonies were living
3. Heat killed S injected into mice let them live and no S was isolated
4. Living R + heat killed S killed mice and when isolated, encapsulated S was isolated
- Conclusion: Bacteria R were able to take in DNA from killed S and get virulence genes resulting in the death of the mice
87
What is the difference between genotype and phenotype?
Genotype: Genetic information that may not be expressed
Phenotype: Traits that can be observed
88
What is transcription?
Transcription is when the DNA template is split and copied as a new strand of RNA
89
How many nucleotides are used in a codon?
Three
90
What molecule takes the information encoded in the DNA and transfer the information to the cytoplasm?
mRNA
91
What does it mean to say that the genetic code has redundancy?
If there are errors/mutations in the genetic code, they usually do not code for a stop and instead code for a different or sometimes even the same amino acid
- Redundant example is Leucine
- Unambigious example is Phenolalanine
92
How is the process of protein production different in prokaryotic and eukaryotic cells (hint: think of how the cell structure may influence these processes)?
Prokaryotic: Contain no introns as the DNA does not need to exit a nucleus
Eukaryotic: Contain introns and exons. Only exons exit the nucleus to be translated
93
In eukaryotic cells, which of the following processes occur in the nucleus: DNA replication, transcription, and/or translation?
DNA Replication and Transcription
94
What is the name of the site on DNA where RNA polymerase binds to initiate transcription?
Promoter Region
95
What are the 3 stages in transcription and what happens in each stage?
Initiation: TATA box is recognized and RNA Poly is recruited
Elongation: DNA Strand is split and RNA travels in a 5'->3' direction as complimentary nucleotides form an mRNA
Termination: mRNA reads Stop codon and mRNA strand stops growing and can now be used in translation (prokaryotes)
96
What do we call the segments of DNA that are expressed and code for proteins?
- Exons
- Introns are processed and removed but only eukaryotes have introns
97
True or false? RNA splicing occurs in prokaryotic cells. Explain your answer.
False: Prokaryotes do not have introns or mRNA processing therfore **translation and transcription** can occur at the same time
98
Translation converts the information stored in _________________ to ____________________
mRNA
Peptides
99
What organelle is the site of translation?
Ribosomes in the cytoplasm
100
What is a polyribosome?
When many ribosomes attach to the mRNA to translate
101
What do we call the genes that are essential and always expressed? What do we call the genes that are only expressed as needed?
- Constitutive genes: essential
- Adaptive genes: as needed
102
For adaptive genes, what kind of genes are influenced by substrate concentration, are used to conserve energy, and the default position is OFF? What is an example of this kind of regulation and what is the goal of those genes?
- Lactose processing gene can be influenced by concentration
- Lac Operon turns on when lactose is present and can be metabolized
- Only on if needed
103
For adaptive genes, what kind of genes are used when excess end-product results in suppression of genetic apparatus involved in enzyme production, have slow, but long-term effects, and the default position is ON? What is an example of this kind of regulation and what is the goal of those genes? This is referred to as ____________________ repression.
- Repressor genes are able to control transcription by blocking (repressor proteins block transcription) their own production as their concetration increases
- Ex. tryptophan
- Feedback
104
Compare feedback inhibition and feedback repression. How are they different?
Feedback Inhibition:
- Affects enzyme activity
- Short term effect
Feedback Repression:
- Affects enzyme/protein production rate
- Long term effect
105
True or false? Feedback repression affects the activity of an enzyme. Explain your answer.
False: The enzyme that is present will work at the same rate but it will decrease the concentration of the enzyme if the concentration is too high
106
When a mistake is made in DNA replication and not corrected, what is this referred to as?
Mutation
- Can be caused by mutagens (agents that cause mutation)
- Spontaneous mutations occur randomly (occurs 1 in a bill)
107
What do you call the mutations that change the DNA sequence by one or a few nucleotides?
Point Mutation
108
What do you call a mutation that does not change the number of nucleotides?
Base Substitution mutation:
- Results in new base pairing
109
What would happen to a protein if a mutation prematurely added a stop codon in the mRNA? What do we call this type of mutation? (3)
Nonsense Mutation:
- Causes early stop
- Protein fragments
- Cystic fibrosis
110
What do we call a mutation that does NOT change the amino acid?
Silent Mutation
111
What is a missense mutation?(2)
- When the wrong amino acid is coded for
- Sickle Cell
112
What happens to a DNA sequence if a non-multiple-of-3 is either added or deleted from a DNA sequence?(2)
- A frame shift occurs which means the order of reading the sequence changes resulting in many amino acids shifting
- Cancer or deadly disease
113
What is the definition of a mutagen? What are some examples of mutagens?
- An Agent that causes mutations
- Ionizing Radiation,UV light, Nucleoside Analogs, and Nucleotide Altering Chemicals
| IR-Xray/gamma,NAC-nitrous acid
114
What do we call a mutation that occurs in the absence of a mutagen?
Spontaneous Mutation
115
How are vertical gene transfer and horizontal gene transfer different?
Vertical:
- Mutations occur from one generation to next (mother to daughters results in mutation)
Horizontal:
- Genes are transfered between cells of the same generation
116
What are the three types of horizontal gene transfer?
Transformation: Naked DNA from dead bacteria is adopted
Transduction: Bacterial DNA is taken up by a phage and transfered into another bacteria where it is picked up
Conjugation: Bacteria have sex resulting in the exchange of genetic information
117
What types of genes can be transferred in horizontal gene transfer that give bacteria some sort of advantage?
Transformation:
- temp resistance, pigment, capsules, fimbriae, antibiotic resistance, virulence
Conjugation:
- Sex pilus info, F- to F+, temp resistance, pigment, capsules, fimbriae, antibiotic resistance, virulence
Transduction:
- Can be random DNA
- Can be specific temp resistance, pigment, capsules, fimbriae, antibiotic resistance, virulence
