BIOL 1104 Introductory Biology II - Single-celled life (Fall 2024) PDF

BIOL 1104 Introductory Biology II 2.2 Single-celled life BIOL 1104 | Fall 2024 | Sep 30 | 10:00-11:15am Module 2: Diversity of life, Single-celled life, Plants, Fungi Topics for the module 1. Diversity of life 2. Single-celled life 3. Plants 4. Fung...

BIOL 1104 Introductory Biology II 2.2 Single-celled life BIOL 1104 | Fall 2024 | Sep 30 | 10:00-11:15am Module 2: Diversity of life, Single-celled life, Plants, Fungi Topics for the module 1. Diversity of life 2. Single-celled life 3. Plants 4. Fungi M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life Topic 2: Single-celled life 1. Prokaryotes 2. Single-celled eukaryotes M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes Topic 2: Single-celled life 1. Prokaryotes 1. Evolutionary history and classification 2. Anatomy 3. Life history and ecology 4. Prokaryotes and humans M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 1/4 Evolutionary history and classification 1. Potential path to origin of life M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 1/4 Evolutionary history and classification 1. Potential path to origin of life 1. Synthesis of monomers M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 1/4 Evolutionary history and classification 1. Potential path to origin of life 1. Synthesis of monomers 2. Linking to form polymers M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 1/4 Evolutionary history and classification 1. Potential path to origin of life 1. Synthesis of monomers 2. Linking to form polymers 3. Self-replication of polymers M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 1/4 Evolutionary history and classification 1. Potential path to origin of life 1. Synthesis of monomers 2. Linking to form polymers 3. Self-replication of polymers 4. Lipid “bubbles” and first cells M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 1/4 Evolutionary history and classification 2. Early Life on Earth Prokaryotes were first known life on Earth Atmosphere ~no oxygen for 2 billion years Life was anaerobic Atmosphere: very low O2, high CO2 First phototrophs in first billion years Cyanobacteria in second billion years used CO2 as source of carbonw waste product: O2 Atmosphere: oxygen levels increase  first great extinction  evolution of other life forms M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 1/4 Evolutionary history and classification 2. Early Life on Earth Early prokaryotes found in ocean depths and underground in rock Microbial mats: multi-layered sheet of bacteria and/or archaea Different metabolic pathways -> different colors reflected Obtained energy from hydrothermal vents Figure 13.3 (a) This microbial mat grows over a hydrothermal vent in the Pacific Ocean. Chimneys such as the one indicated by the arrow allow gases to escape. (b) This photo shows stromatolites that are nearly 1.5 billion years old, found in Glacier National Park, Montana. M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 1/4 Evolutionary history and classification 2. Early Life on Earth Fossilized microbial mats Stromatolite: sedimentary structure formed when minerals are precipitated from water Layered rocks made of carbonate or silicate Caused by layers of microbial mats becoming fossilized M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 1/4 Evolutionary history and classification M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 1/4 Evolutionary history and classification 3. Domains of life Prokaryotes: Archaea Bacteria M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes Topic 2: Single-celled life 1. Prokaryotes 1. Evolutionary history and classification 2. Anatomy 3. Life history and ecology 4. Prokaryotes and humans M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 2/4 Anatomy 1. Prokaryotic cells No membrane-bound organelles Genome: one long, circular chromosome into the nucleoid region May have small, circular DNA molecules called plasmids replicate independently of the chromosome Figure 13.5 The features of a typical bacterium cell are shown. M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 2/4 Anatomy 2. Prokaryote cell shapes All cells have four common structures: 1. plasma membrane 2. cytoplasm 3. genetic material 4. ribosomes Common prokaryotic cell shapes: 1. Spherical (coccus/cocci) 2. Rod-shaped (bacillus/bacilli) 3. Spiral-shaped (spirilla, spirochetes) M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 2/4 Anatomy 3. Bacteria cell walls: structure Protects the cell against osmotic lysis and provides rigidity Bacteria can be classified by shape and by reaction to a Gram stain. Gram-positive bacteria: thick layer of peptidoglycan. Gram-negative bacteria: thin layer of peptidoglycan. M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 2/4 Anatomy 3. Bacteria cell walls: Gram staining M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 2/4 Anatomy 3. Bacteria cell walls: surface May be covered in a capsule: sticky layer of polysaccharides or protein allows attachment to surfaces and other cells shields pathogenic prokaryotes from attacks by a host’s immune system M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 2/4 Anatomy 4. Projections from prokaryote cells External structures that extend beyond the cell wall: Flagella = movement in response to chemical or physical signals Pili are used for conjugation Fimbriae (hair-like projections) stick to a surface or each other latch onto host cells M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 2/4 Anatomy 5. Endospores inactive cells remain dormant through harsh conditions survive extreme heat or cold! boiling may not kill them M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes Topic 2: Single-celled life 1. Prokaryotes 1. Evolutionary history and classification 2. Anatomy 3. Life history and ecology 4. Prokaryotes and humans M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 3/4 Life history 1. Biofilms Biofilm: microbial community held together in a gummy-textured matrix Composed of one or several species of prokaryotes May include fungi and protists! Form on most any support: rocks, soil, organic material, surface of stagnant water May cause medical, environmental, industrial problems M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 3/4 Life history 2. Reproduction Prokaryotes reproduce via binary fission, not mitosis Rapid process and adaptability Transformation: cell takes in DNA from its environment Rise of pathogens (disease- causing organisms) Transduction: viruses move DNA from one bacteria to another Conjugation: movement of DNA using a pilus M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 3/4 Life history 3. Obtaining energy and carbon More nutritional diversity than eukaryotes! Two sources of energy: phototrophs - energy from sunlight chemotrophs - energy stored in chemicals M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 3/4 Life history 3. Obtaining energy and carbon Extremophile prokaryotes Deep-sea vents Underground Hot springs M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes Topic 2: Single-celled life 1. Prokaryotes 1. Evolutionary history and classification 2. Anatomy 3. Life history and ecology 4. Prokaryotes and humans M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans 1. Diseases Records of infectious diseases go as far back as 3000 BCE Pandemics have led to the decline of cities and cultures  3-prokaryotes Plague: bacteria Yersinia pestis 1300s: killed 75-200 million in Europe 1600s: killed ~100 million 2010-2015: killed ~580 Cases in Georgia (1970-2020): 1 M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans 1. Diseases Bacteria Vibrio cholerae and Cholera M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans Bacteria Vibrio cholerae and Cholera M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans Archaea, Bacteria and gum disease Most Archaea are not associated with human disease M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans 2. Antibiotic Crisis Antibiotic: chemicals that inhibit growth of prokaryotes “Superbugs,” bacteria resistant to antibiotics, are prevalent due to: Overuse and incorrect use of antibiotics Excessive use of antibiotics in livestock Methicillin-resistant Staphylococcus aureus (MRSA) infections are common in healthcare facilities due to their resistance to many antibiotics Methicillin-resistant Staphylococcus aureus (MRSA) infection M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans 3. Foodborne Diseases Result from food contaminated with pathogenic bacteria, viruses, or parasites Example: Botulism and Clostridium botulinum potentially fatal disease C. botulinum Anaerobic bacterium Produces neurotoxins Will thrive in cans, jars, package M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans 4. Beneficial Prokaryotes Clostridium botulinum neurotoxin used in “botox” procedures M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans 4. Beneficial Prokaryotes Decomposing dead organisms Fermenting foods Cheeses Salami Yogurts Sauerkraut Fish sauce Soy sauce M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans 4. Beneficial Prokaryotes Prokaryotes are useful for cleaning up pollution great nutritional diversity quickly adaptable some produce methane gas CH4 = methane = natural gas Used for: Agricultural pollution Oil spills City water treatment plants Industrial pollution M2 Diversity, single-celled, plants, fungi | 2/4 Single-celled life | 1. Prokaryotes | 4/4 Prokaryotes and humans 5. Microbiome: you are not just Homo sapiens Supply essential vitamins and extract nutrition from food molecules that we can’t otherwise digest Housekeeping functions such as decomposing dead skin cells. Guard against pathogens Imbalances linked to diseases