BIOL 1411 1st Edition Lecture 5 Outline of Current Lecture 1 Cell theory 2 How we study cells 3 Common features of cells 4 Prokaryotic cells features 5 Eukaryotic cells features Current Lecture Cell theory and it s implications o Cells fundamental to life smallest entity that can be alive and function independently o All organisms consist of one or more of cells o They are microscopic 1 100 micrometers in diameter o All cells come from preexisting cells smallest unit of production o How do we study cells Bright field microscopy Phase contrast microscopy Differential interference contrast microscopy Stained bright field microscopy Fluorescent microscopy Use florescent labels to distinguish structures or specific molecules within a cell Absorbs light of low wavelength emits at higher wavelengths Fluorescent molecule attaches to antibody which allows us to specify where certain proteins are inside a cell Confocal microscopy Electron microscopy shower of electrons provides high resolution cells not a good method for living cells however These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute o Why are cells so small So they can exchange materials within the environment Step by step process goes like this Nutrients in Distribution Cell metabolism Metabolic wastes out Exchange with environment and cell occur at surface and are limited by surface area Distribution and metabolic reactions are limited by the inside volume of cell As cell size increases cell volume increases more than surface area SA VOL ratio decreases with increases cell dimensions but increases with decreased cell dimensions o Common features of cells Plasma membrane makes up outer cell Cytoplasm inner cell water based cytosol Genome of DNA Ribosomes Molecule machines for making cell proteins o Prokaryotic cells Bacteria and archea Smallest structurally simplest of cells Genomes consisting of one or two molecules of DNA concentrated in a nucleoid Great metabolic diversity o Found everywhere on earth o Can use a wide array of energy sources o Can exist as free living single cells though also live in aggregates chains clusters or biofilms Variable structural features Exterior o Many have a rigid cell wall o Some have outer membrane additionally o Some have slimy capsule of polysaccharides o Some have flagella and or pili hair like projections Interior o Extensions in folding of plasma membranes for energy transformation processes or cell division o Cytoskeleton in a few only o Eukaryotic cells Protists fungi plants animals Generally larger more complex than prokaryotic cells Larger genomes organized chromosomes Organelles Membrane enclosed compartments within cell Each organelle has specific role in cell function different chemical reactions happen within each individual cell Separations of celluar activities has allowed diversification of functions and specialization of eukaryotic cells Organization of cell Must have plasma membrane cytoplasm and a nucleus for a eukaryotic cell to function Cytoplasm must have cytosol water based organelles cytoskeleton to function properly Major organelles Nucleus o Large dense visible with light microscope o Houses nucleolus as well as DNA Nucleolus is where DNA is made Nuclear envelope o Two membrane layer with pores o Pores important so enzymes can pass in and out to transfer DNA Endomembrane system o Interconnected system of membranes that includes the nuclear envelope endoplasmic reticulum golgi lysosomes and plasma membrane o Tiny membrane surrounded vesicles shuttle substances between the various components