General Biology 1 Fall 2024 PDF

General Biology 1 Fall 2024 The cells part 2 Prof : Dr. Vincent Gagnon Book Raven, Biology, 13th edition  Chemical Basis of Life Study guide: Topic Refer...

General Biology 1 Fall 2024 The cells part 2 Prof : Dr. Vincent Gagnon Book Raven, Biology, 13th edition  Chemical Basis of Life Study guide: Topic References (13th Ed) Summarize the Cell Theory and list the key properties common to all cells Section 4.1 Discuss the impact of surface-to-volume ratios on cell size, and on Section 4.1, biological processes in general Figure 4.1 Distinguish between prokaryotic and eukaryotic cells. Section 4.2 & 4.3 Draw, and/or label diagrams of typical plant and animal cells as seen Figures 4.6 & 4.7. Lab through light and electron microscopes diagrams Identify and/or provide a simple explanation or function of the various Diagrams of Section cellular structures (organelles) found within typical eukaryotic cells. 4.4-4.7. Table 4.2 Table 4.3, Lab Compare the structural aspects of cells found in bacteria, protists, plants, Observations animals and fungi p. 561-563 Briefly study about the possible origins of life. Review the properties of life. Section 25.2 & 25.3 Describe features that must have been present in the earliest cells Section 25. 5, p. 534 Describe the endosymbiotic theory of the origins of eukaryotic organelles fig. 25.10 pp. 587-589 and the evidence supporting it. fig. 28.2, 28.3 & 28.4  Organelles Cell is like a medieval city Organelles: All the building  Endomembrane system Series of membranes throughout the cytoplasm (surround the organelles) Divides cell into compartments where different cellular functions occur The presence of endomembrane is one of the fundamental distinctions between eukaryotes and prokaryotes  Cell structure: Golgi Complex Ribosome Library Rough Endoplasmic Reticulum Vesicle Nucleus Golgi Complex Smooth Endoplasmic Reticulum Plasma Membrane  Golgi Complex Function: Collection, packaging and distribution Modify proteins and lipid Synthesized at one location (ex.: ER), receive by the Golgi and send to another place within the cell or even outside the cell Number: Protist: 1 to a few Animal: >20 Plant: >100 Golgi Complex  Golgi Complex Structure: Flattened membranes with bulging edges Cis face: Receiving side located near the ER Trans face: Exit side where they are discharged in secretory vesicles Electron microscope view  Golgi Complex Modify proteins and lipid Glycoprotein: Addition of a polysaccharide to the protein Glycolipid: Addition of a polysaccharide to the phospholipid  Cell structure: Vesicle Ribosome Library Endocytosis Vesicle Rough Endoplasmic Reticulum Exocytosis Vesicle Nucleus Vesicle Golgi Complex Smooth Endoplasmic Reticulum Plasma Membrane  Vesicles Structure: Small membrane sac made of bilayer of phospholipid Function: Transporting material within the cell Transporting material in and out of cell Two types of transport: Endocytosis: importing material into cell Exocytosis: exporting material out of cell  Cell structure: Lysosomes and Peroxisomes Ribosome Library Lysosome Endocytosis Vesicle Rough Endoplasmic Reticulum Exocytosis Vesicle Nucleus Vesicle Golgi Complex Smooth Endoplasmic Reticulum Plasma Membrane  Lysosomes Structure: Small round vesicles Arise from the Golgi apparatus Function: “Recycling truck” of cell. Contain digestive enzymes that can breakdown proteins, nucleic acids, lipids, and carbohydrates. They digest and remove old structures and organelles. Recycle their component molecules, allowing room for newly formed organelles. The very low pH inside the lysosomes activate the enzymes (thus important to have a vesicle to not digest the entire cell).  Peroxisomes Structure: Similar to lysosome but smaller Function: Oxidize fatty acids and some amino acids Produce hydrogen peroxide as a by-product of the activities of oxidative enzymes Contain enzyme catalase, which catalyzes the decomposition of hydrogen peroxide into water and oxygen  Cell structure: Mitochondria CO2 ATP Energy Glucose Mitochondria Oxygène Ribosome Library Lysosome Endocytosis Vesicle Rough Endoplasmic Reticulum Exocytosis Vesicle Nucleus Vesicle Golgi Complex Smooth Endoplasmic Reticulum Plasma Membrane  Mitochondria Structure: Rode shaped (size of a bacteria) Have two phospholipid bilayer membranes Outer membrane. Intermembrane space. Inner membrane shaped into folds called cristae. Matrix (most inner part) Function: “Powerhouse of cell” Generate ATP (energy currency of cell) Uses oxygen and glucose for energy Produces CO2 & H20  Mitochondria Fun facts Mitochondria contain their own circular DNA However some necessary genes are coded by the cell nucleus They can divide by themselves You inherit the mitochondria from your mother ☺  Cytoskeleton Structure: Network of protein fibers found in all eukaryotic cells Function: Supports the shape of the cell Keeps organelles in fixed locations Red : Actin filament Green : microtubules Blue : DNA  Cytoskeleton Structure: Network of protein fibers found in all eukaryotic cells Function: Supports the shape of the cell Keeps organelles in fixed locations Three Types of fibers 1. Actin filaments (Microfilaments) 2. Microtubules 3. Intermediate filaments Cytoskeleton Muscle cell contraction Red : Actin filament  Cytoskeleton Kinesin Protein Walking On Microtubule Red : Actin filament Green : microtubules Blue : DNA  Cytoskeleton Intermediate filaments The most durable element of the cytoskeleton Intermediate filaments constitute a mixed group of cytoskeletal fibers Example: Keratin is found in epithelial cells and associated structures such as hair and fingernails  Cilia and Flagella The city as a cell example breakdown for the for the cilia and flagella... Since a city don’t move! But you could say that the cilia and flagella are like the propulsion of a spaceship.  Cilia and Flagella (Eukaryote) Function: Both used for motion Flagellum: longer than cilia, few of them Example: in humans only found in the tail of sperm dadsclub.com.au Flagella of a sperm Cilia: shorter than flagellum, more of them Example: - Uterine tubes: move egg - Respiratory system: move mucus - Protist like paramecia Flagellum of green alga Cilia paramecia Cilia of epithelial cells of the lungs  Cilia and Flagella (Eukaryote) Structure: Circle of nine microtubule pairs surrounding two central microtubules Extension of the cytoplasm and plasma membrane outward This arrangement is referred to as the 9 + 2 structure As pairs of microtubules move past each other using arms composed of the motor protein dynein Eukaryotic flagellum undulates, or waves up and down, rather than rotates.  Centrosome Structure: Two centrioles arranged perpendicular to each other Function: Moves chromosomes to ends of cell during cell division Centrioles Centrosome Centriole 9X  Plant cell Special Structure: Central vacuole Cell wall Chloroplast No centrioles  Plant cell Vacuole Function: Storage sugar, ions and pigment Storage of waste Can also function as lysosomes Involve in the water balance  Plant cell Vacuole Structure: Plasma membrane surrounding the vacuole is called the tonoplast because it contains channels for water that are used to help the cell maintain its tonicity, or osmotic balance  Chloroplast Structure: Organelles present in cells of plants and some other eukaryotes Surrounded by two membranes Contain chlorophyll for photosynthesis Thylakoids are membranous sacs within the inner membrane Have their own DNA and ribosomes  How life began on Earth Landmarks in the evolution of metabolism Oxygenic photosynthesis. Carbon fixation (12C isotope).  How life began on Earth Landmarks in the evolution of metabolism Nitrogen fixation - Nitrogen gas (N2) is an essential element for life (DNA, amino acids, etc.) - However, nitrogen gas (N2) is not bioavailable to most organisms (plant and animal). - Nitrogen fixation is an important process by which microbe (nitrogen fixing bacteria) takes gaseous nitrogen (N2) of the atmosphere and make it into a biologically accessible to plants (ammonia NH3).  How life began on Earth Landmarks in the evolution of metabolism RNA is hypotheses to predate DNA, since it can store genetic information and catalyze chemical reaction (ribozyme) and serve as a structure molecule (ribosome). Cell membranes: Plasma Membrane − Separates cell’s internal environment from its external environment. − Increase the probability of metabolic reactions. Ribozyme Act as an enzyme made of RNA  Mitochondria endosymbiosis theory Capture of ancestral bacteria (now known a mitochondria) Double membrane. We have their own ribosome. We have their own circular DNA. Semi-autonomous organism that multiply by their own in the cell. All eukaryotic organisms have mitochondria (animals, plants, etc.).  Chloroplast endosymbiosis theory The origins of the chloroplast in Eukaryotes Double membrane. We have their own ribosome. We have their own circular DNA. Semi-autonomous organism that multiply by their own in the cell.  Chloroplast endosymbiosis theory The origins of the chloroplast in Eukaryotes Secondary endosymbiosis  Endosymbiosis theory Endosymbiosis  Prokaryotes Prokaryotes  Prokaryotes Characteristics: Are the simplest organism. No nucleus. Consist of a cytoplasm surrounded by a plasma membrane and encased within a rigid cell wall. Free circular DNA. May have a capsule. No membrane bound organelle. Have ribosomes. Two types of Prokaryotes: Bacteria Archaea  Prokaryotes - Bacteria Characteristics: Most bacterial cells are encased by a strong cell wall. ▪ Composed of peptidoglycan. ▪ Cell walls of plants, fungi and most protists are different. Protect the cell, maintain its shape, and prevent excessive uptake or loss of water. Susceptibility of bacteria to antibiotics often depends on the structure of their cell walls. Eukaryotic cell is 10 to 100 micrometers. Prokaryotic cells are only 1 to 10 micrometers.  Archaea Characteristics: Cell walls of archaea ▪ Composed of various chemical compounds, including polysaccharides and proteins and possibly even inorganic components. Archaea lack peptidoglycan. A common feature distinguishing archaea from bacteria is the nature of their membrane lipids include saturated hydrocarbons that are covalently attached to glycerol. These features seem to confer greater thermal stability to archaeal membranes. The cellular machinery that replicates DNA and synthesized proteins in archaea is more closely related to eukaryotic systems than to bacterial systems.  Prokaryotes flagella Some prokaryotes move by means of rotating flagella. There may be one or more per cell, or none, depending on the species. The rotary motor uses the energy stored in a gradient that transfers protons across the plasma membrane to power the movement of the flagellum. Prokaryotes flagella  Difference between a prokaryote and eukaryote Special Structure eukaryotes: Possess a membrane-bound nucleus. More complex than prokaryotic cells. Compartmentalization is achieved through membrane-bound organelles and endomembrane system. Possess a cytoskeleton for support and to maintain cellular structure. Difference between a prokaryote and eukaryote Eukaryote Prokaryote Difference between a prokaryote and eukaryote Review Eukaryote cell structure  Review Eukaryote cell structure (Peroxisomes) Review Eukaryote cell structure