Biol 121 overall

Viral Replication Cycle

• Adsorption: Virus attaches to receptors
• Penetration: Inject nucleic acid into host cell
• Replication: Synthesis of viral material and combine
• Maturation: Release of new virions
• Release: Lytic and lysogenic/temperature phage

Lytic and Lysogenic/Temperature Phage

• Lytic phage: Kill host cell
• Lysogenic/Temperature phage:
  • Prophage: Integrate into host’s chromosome
  • Replicates with host cell
  • Stresses → reactivate the lytic cycle

Phages in Biomedicine

• EBI: Used on unprocessed foods
• Bacteriophage enzyme
• Display of immunodominant region of HBV on bacteriophage H7

Quantifying Bacteriophage

• Agar plate with E. coli

Viruses Benefits and Disadvantages

• Advantages:
  • Planetary force
  • Control the amount of bacteria
• Disadvantages:
  • Impact on health
  • Impact of microbes

Taxonomy for Viruses

• International Committee on Taxonomy of Viruses (ICTV)
• Molecular composition of genome
• Sequence similarity
• Virion/capsid structure
• Presence of an envelope
• Host range
• Pathogenicity

Baltimore System of Virus Classification

• Viral genome must make mRNA which can be read by ribosomes
• mRNA: +ssRNA (ribosome ready)
• +dsDNA
• Complementary: - (minus)

Infection Pathway

• Transformation into tumour cell
• Lysis
• Persistent infection (Slow release of virus, X cell death)
• Latent infection (→ Lytic infection)

Virus Life Cycle

• Entry: Viruses attach to receptors
• Replication: Viral protein synthesis of mRNA, viral genome generation
• Exit:
  • Virus inserts viral glycoprotein on the surface of the membrane
  • Capsid migrates to the cell membrane

Fungi as Drugs

• Penicillin (antibiotics)
• Statin: Inhibit biosynthesis of cholesterol, reduce plasma cholesterol level

General Properties, Structures, and Hosts of Viruses

• Viruses: Simple, minuscule, infectious, obligate intracellular parasite comprising genetic material surrounded by a protein coat deprived from a host cell membrane
• Genetic material of virus: DNA & RNA
• Virus existence in 2 states:
  • Intracellular virus (After infecting the host cell) [Replication]
  • Extracellular Virion (Outside host cell) [Transmission]

Shapes of Capsid

• Helical
• Polyhedral
• Binal
• Function of capsid:
  • Protects nucleic acid from being digested
  • Attaches to the host cell
  • Penetrates host cell membrane

Cyanobacteria

• Highly resistant to extreme conditions
• Contain calcium dipicolinate, which binds free water and helps dehydrate the cell
• Some cyanobacteria contain iron and have a special protein that protects their DNA, allowing them to orient themselves in magnetic fields

Bacterial Nutrition and Growth

• Nutrients provide elements for the synthesis of cell material
• Macronutrients are required in large amounts and include elements like C, O, H, N, P, S, K, Ca, and Mg
• Micronutrients are required in small amounts and include elements like Cu, Zn, Ni, V, and Se
• Bacteria can grow in culture media, which provides all the necessary elements for growth
• Culture media can be chemically defined, complex, or a nutrient agar plate
• Bacteria can also grow in liquid media, such as Erlenmeyer flasks or test tubes

Bacterial Growth Phases

• Bacterial growth occurs in four phases: lag, log, stationary, and death
• The lag phase is a period of slow growth, followed by the log phase, where growth is rapid and exponential
• The stationary phase is where growth slows down due to resource depletion, and the death phase is where cell death occurs
• Bacterial growth can be measured using direct microscopic count, culturable count, or serial dilution

Metabolic Classification of Bacteria

• Bacteria can be classified based on their carbon and energy resources
• Heterotrophs use organic compounds as their carbon source, while autotrophs use CO2
• Phototrophs use light as their energy source, while chemotrophs use chemical reactions
• Environmental factors like oxygen, temperature, pH, and osmolarity can affect bacterial growth and metabolism

Microbiology

• Microbiology is the study of organisms that are too small to be seen by the unaided eye
• Microorganisms can be beneficial or harmful to humans
• Microbiology involves the study of diseases caused by pathogens, and the control of these diseases through vaccination, antibiotics, and personal hygiene

Three Domains of Life

• The three domains of life are Eukaryota, Bacteria, and Archaea
• Eukaryotes have one or more cells with a nucleus and well-developed intracellular compartments
• Bacteria are prokaryotic microorganisms that are typically small and simple in structure
• Archaea are prokaryotes that are similar to bacteria in size and simplicity, but have distinct molecular characteristics

Cell Structure and Function

• Cell membrane functions include barrier function, respiration/photosynthesis, and energy conservation
• Cell wall determines and maintains the shape of the cell, and protects it from osmotic lysis
• Gram-positive and Gram-negative cell walls have different structures and functions
• Capsule, fimbriae, and pili are important structures involved in bacterial attachment and protection

Bacterial Cytoplasm

• Nucleoid is an irregularly shaped region that contains the genetic material
• Plasmids are small, closed circular DNA molecules that exist and replicate independently of the chromosome
• Cellular inclusions are granules of material that are reserved for future use
• Endospores are highly resistant structures that can survive for long periods of time

How Bacteria Cause Diseases

• Most bacteria are harmless, and the host immune system prevents them from causing disease
• Pathogens are organisms that cause diseases by impairing or interfering with normal physiological activities
• Pathogenicity is the ability to cause disease, and virulence is the degree of pathogenicity
• Infection and disease are different, with infection being the presence of a pathogen, and disease being the impairment of normal physiological activities

Steps in Infectious Diseases

• The steps in infectious diseases include the reservoir, transfer to host, colonization, adherence, and infection
• The reservoir is where the bacterial pathogen lives and reproduces, and can be a human, animal, or environment
• Transfer to host can occur through direct or indirect contact, or through vectors or vehicles

Fungi

• Fungi are eukaryotes that are extremely diverse, with cell walls made of chitin and polysaccharides
• Fungi can be saprophytes, necrophytes, or biotrophs, and can reproduce both sexually and asexually
• Fungi can be single-celled or multicellular, and can form colonies or mycelium
• Yeasts are single-celled fungi that reproduce asexually by budding, while filamentous fungi are multicellular and reproduce by forming spores

Cyanobacteria

• Highly resistant to extreme conditions
• Contain calcium dipicolinate, which binds free water and helps dehydrate the cell
• Some cyanobacteria contain iron and have a special protein that protects their DNA, allowing them to orient themselves in magnetic fields

Bacterial Nutrition and Growth

• Nutrients provide elements for the synthesis of cell material
• Macronutrients are required in large amounts and include elements like C, O, H, N, P, S, K, Ca, and Mg
• Micronutrients are required in small amounts and include elements like Cu, Zn, Ni, V, and Se
• Bacteria can grow in culture media, which provides all the necessary elements for growth
• Culture media can be chemically defined, complex, or a nutrient agar plate
• Bacteria can also grow in liquid media, such as Erlenmeyer flasks or test tubes

Bacterial Growth Phases

• Bacterial growth occurs in four phases: lag, log, stationary, and death
• The lag phase is a period of slow growth, followed by the log phase, where growth is rapid and exponential
• The stationary phase is where growth slows down due to resource depletion, and the death phase is where cell death occurs
• Bacterial growth can be measured using direct microscopic count, culturable count, or serial dilution

Metabolic Classification of Bacteria

• Bacteria can be classified based on their carbon and energy resources
• Heterotrophs use organic compounds as their carbon source, while autotrophs use CO2
• Phototrophs use light as their energy source, while chemotrophs use chemical reactions
• Environmental factors like oxygen, temperature, pH, and osmolarity can affect bacterial growth and metabolism

Microbiology

• Microbiology is the study of organisms that are too small to be seen by the unaided eye
• Microorganisms can be beneficial or harmful to humans
• Microbiology involves the study of diseases caused by pathogens, and the control of these diseases through vaccination, antibiotics, and personal hygiene

Three Domains of Life

• The three domains of life are Eukaryota, Bacteria, and Archaea
• Eukaryotes have one or more cells with a nucleus and well-developed intracellular compartments
• Bacteria are prokaryotic microorganisms that are typically small and simple in structure
• Archaea are prokaryotes that are similar to bacteria in size and simplicity, but have distinct molecular characteristics

Cell Structure and Function

• Cell membrane functions include barrier function, respiration/photosynthesis, and energy conservation
• Cell wall determines and maintains the shape of the cell, and protects it from osmotic lysis
• Gram-positive and Gram-negative cell walls have different structures and functions
• Capsule, fimbriae, and pili are important structures involved in bacterial attachment and protection

Bacterial Cytoplasm

• Nucleoid is an irregularly shaped region that contains the genetic material
• Plasmids are small, closed circular DNA molecules that exist and replicate independently of the chromosome
• Cellular inclusions are granules of material that are reserved for future use
• Endospores are highly resistant structures that can survive for long periods of time

How Bacteria Cause Diseases

• Most bacteria are harmless, and the host immune system prevents them from causing disease
• Pathogens are organisms that cause diseases by impairing or interfering with normal physiological activities
• Pathogenicity is the ability to cause disease, and virulence is the degree of pathogenicity
• Infection and disease are different, with infection being the presence of a pathogen, and disease being the impairment of normal physiological activities

Steps in Infectious Diseases

• The steps in infectious diseases include the reservoir, transfer to host, colonization, adherence, and infection
• The reservoir is where the bacterial pathogen lives and reproduces, and can be a human, animal, or environment
• Transfer to host can occur through direct or indirect contact, or through vectors or vehicles

Fungi

• Fungi are eukaryotes that are extremely diverse, with cell walls made of chitin and polysaccharides
• Fungi can be saprophytes, necrophytes, or biotrophs, and can reproduce both sexually and asexually
• Fungi can be single-celled or multicellular, and can form colonies or mycelium
• Yeasts are single-celled fungi that reproduce asexually by budding, while filamentous fungi are multicellular and reproduce by forming spores

Cyanobacteria

• Highly resistant to extreme conditions
• Contain calcium dipicolinate, which binds free water and helps dehydrate the cell
• Some cyanobacteria contain iron and have a special protein that protects their DNA, allowing them to orient themselves in magnetic fields

Bacterial Nutrition and Growth

• Nutrients provide elements for the synthesis of cell material
• Macronutrients are required in large amounts and include elements like C, O, H, N, P, S, K, Ca, and Mg
• Micronutrients are required in small amounts and include elements like Cu, Zn, Ni, V, and Se
• Bacteria can grow in culture media, which provides all the necessary elements for growth
• Culture media can be chemically defined, complex, or a nutrient agar plate
• Bacteria can also grow in liquid media, such as Erlenmeyer flasks or test tubes

Bacterial Growth Phases

• Bacterial growth occurs in four phases: lag, log, stationary, and death
• The lag phase is a period of slow growth, followed by the log phase, where growth is rapid and exponential
• The stationary phase is where growth slows down due to resource depletion, and the death phase is where cell death occurs
• Bacterial growth can be measured using direct microscopic count, culturable count, or serial dilution

Metabolic Classification of Bacteria

• Bacteria can be classified based on their carbon and energy resources
• Heterotrophs use organic compounds as their carbon source, while autotrophs use CO2
• Phototrophs use light as their energy source, while chemotrophs use chemical reactions
• Environmental factors like oxygen, temperature, pH, and osmolarity can affect bacterial growth and metabolism

Microbiology

• Microbiology is the study of organisms that are too small to be seen by the unaided eye
• Microorganisms can be beneficial or harmful to humans
• Microbiology involves the study of diseases caused by pathogens, and the control of these diseases through vaccination, antibiotics, and personal hygiene

Three Domains of Life

• The three domains of life are Eukaryota, Bacteria, and Archaea
• Eukaryotes have one or more cells with a nucleus and well-developed intracellular compartments
• Bacteria are prokaryotic microorganisms that are typically small and simple in structure
• Archaea are prokaryotes that are similar to bacteria in size and simplicity, but have distinct molecular characteristics

Cell Structure and Function

• Cell membrane functions include barrier function, respiration/photosynthesis, and energy conservation
• Cell wall determines and maintains the shape of the cell, and protects it from osmotic lysis
• Gram-positive and Gram-negative cell walls have different structures and functions
• Capsule, fimbriae, and pili are important structures involved in bacterial attachment and protection

Bacterial Cytoplasm

• Nucleoid is an irregularly shaped region that contains the genetic material
• Plasmids are small, closed circular DNA molecules that exist and replicate independently of the chromosome
• Cellular inclusions are granules of material that are reserved for future use
• Endospores are highly resistant structures that can survive for long periods of time

How Bacteria Cause Diseases

• Most bacteria are harmless, and the host immune system prevents them from causing disease
• Pathogens are organisms that cause diseases by impairing or interfering with normal physiological activities
• Pathogenicity is the ability to cause disease, and virulence is the degree of pathogenicity
• Infection and disease are different, with infection being the presence of a pathogen, and disease being the impairment of normal physiological activities

Steps in Infectious Diseases

• The steps in infectious diseases include the reservoir, transfer to host, colonization, adherence, and infection
• The reservoir is where the bacterial pathogen lives and reproduces, and can be a human, animal, or environment
• Transfer to host can occur through direct or indirect contact, or through vectors or vehicles

Fungi

• Fungi are eukaryotes that are extremely diverse, with cell walls made of chitin and polysaccharides
• Fungi can be saprophytes, necrophytes, or biotrophs, and can reproduce both sexually and asexually
• Fungi can be single-celled or multicellular, and can form colonies or mycelium
• Yeasts are single-celled fungi that reproduce asexually by budding, while filamentous fungi are multicellular and reproduce by forming spores

Cyanobacteria

• Highly resistant to extreme conditions
• Contain calcium dipicolinate, which binds free water and helps dehydrate the cell
• Some cyanobacteria contain iron and have a special protein that protects their DNA, allowing them to orient themselves in magnetic fields

Bacterial Nutrition and Growth

• Nutrients provide elements for the synthesis of cell material
• Macronutrients are required in large amounts and include elements like C, O, H, N, P, S, K, Ca, and Mg
• Micronutrients are required in small amounts and include elements like Cu, Zn, Ni, V, and Se
• Bacteria can grow in culture media, which provides all the necessary elements for growth
• Culture media can be chemically defined, complex, or a nutrient agar plate
• Bacteria can also grow in liquid media, such as Erlenmeyer flasks or test tubes

Bacterial Growth Phases

• Bacterial growth occurs in four phases: lag, log, stationary, and death
• The lag phase is a period of slow growth, followed by the log phase, where growth is rapid and exponential
• The stationary phase is where growth slows down due to resource depletion, and the death phase is where cell death occurs
• Bacterial growth can be measured using direct microscopic count, culturable count, or serial dilution

Metabolic Classification of Bacteria

• Bacteria can be classified based on their carbon and energy resources
• Heterotrophs use organic compounds as their carbon source, while autotrophs use CO2
• Phototrophs use light as their energy source, while chemotrophs use chemical reactions
• Environmental factors like oxygen, temperature, pH, and osmolarity can affect bacterial growth and metabolism

Microbiology

• Microbiology is the study of organisms that are too small to be seen by the unaided eye
• Microorganisms can be beneficial or harmful to humans
• Microbiology involves the study of diseases caused by pathogens, and the control of these diseases through vaccination, antibiotics, and personal hygiene

Three Domains of Life

• The three domains of life are Eukaryota, Bacteria, and Archaea
• Eukaryotes have one or more cells with a nucleus and well-developed intracellular compartments
• Bacteria are prokaryotic microorganisms that are typically small and simple in structure
• Archaea are prokaryotes that are similar to bacteria in size and simplicity, but have distinct molecular characteristics

Cell Structure and Function

• Cell membrane functions include barrier function, respiration/photosynthesis, and energy conservation
• Cell wall determines and maintains the shape of the cell, and protects it from osmotic lysis
• Gram-positive and Gram-negative cell walls have different structures and functions
• Capsule, fimbriae, and pili are important structures involved in bacterial attachment and protection

Bacterial Cytoplasm

• Nucleoid is an irregularly shaped region that contains the genetic material
• Plasmids are small, closed circular DNA molecules that exist and replicate independently of the chromosome
• Cellular inclusions are granules of material that are reserved for future use
• Endospores are highly resistant structures that can survive for long periods of time

How Bacteria Cause Diseases

• Most bacteria are harmless, and the host immune system prevents them from causing disease
• Pathogens are organisms that cause diseases by impairing or interfering with normal physiological activities
• Pathogenicity is the ability to cause disease, and virulence is the degree of pathogenicity
• Infection and disease are different, with infection being the presence of a pathogen, and disease being the impairment of normal physiological activities

Steps in Infectious Diseases

• The steps in infectious diseases include the reservoir, transfer to host, colonization, adherence, and infection
• The reservoir is where the bacterial pathogen lives and reproduces, and can be a human, animal, or environment
• Transfer to host can occur through direct or indirect contact, or through vectors or vehicles

Fungi

• Fungi are eukaryotes that are extremely diverse, with cell walls made of chitin and polysaccharides
• Fungi can be saprophytes, necrophytes, or biotrophs, and can reproduce both sexually and asexually
• Fungi can be single-celled or multicellular, and can form colonies or mycelium
• Yeasts are single-celled fungi that reproduce asexually by budding, while filamentous fungi are multicellular and reproduce by forming spores

This quiz covers the different stages of the life cycle of bacteriophages, including adsorption, penetration, replication, maturation, and release. It also explores the differences between lytic and lysogenic bacteriophages.