Topic 1 Intro Cell Biology

Cells

small membrane-enclosed units, fundamental unit of life, single or multi cellular, size varies (few um to 10-100um)

Chemical requirement

chemical elements, energy source, electron source

Diverse function of cells in multicellular organisms

Production of substances, Mechanical work, Generation of electric currents, Passing of genetic information

Unity of cells

same type of molecules and chemical reactions, DNA, same chemical code for genetic info (Codons), Central Dogma

Genome

organsim full complement of DNA nucleotides

Differentiation

directs growth and development of cell types

Mutation

change in sequence of nucleotides

Sexual reproduction

shuffling of genetic info into new combinations for next gen

Evolution

living species gradually modified and adapte to their enviro

Light microscopes

light illuminates specimen, resolution 0.2 um, see nucleous/ mitchondria/chloroplast

Hooke

first light microscope, discovered cells in cork

van Leeuwenhoek

discovered first microbes

Schleidan and Schwann

cells as universal building block (base for cell theory)

Cell theory

All living cells formed by grwoth and division of pre existing cells

Pasteur

confirms cell theory

microscope stain

dyes cells to distinguish different components

Fluorescence microscopy

electronic image processing, see fluorescently labeled cell componets, resolution 20nm

Electron Microscopy

visualization of smaller organelles, beams of electron as source of illumination, stain with electron dense heavy metals

Transmission electron microscope

look at thin sections of tissue, inside of cell

Scanning electron microscope

look at surface details of cells, outisde of cell, how interact with others

Bacteria

first organism, mostly single celled, tough cell wall, no internal membrane bound structure

diversity of bacteria

aerobic or anaerobic, use wide range of carbon sources (organic or inorganic), can live inorganically, harmful or beneficial, photosynthesis, range of habitats, evolve quickly

Archaea

single celled prokaryotic, lacking internal structure, poorly understood, recycling nitrogen and carbon

how Archaea different from bacteria

chemistry of cell wall, lipids in membrane, chemical reaction

where archaea found

extreme environments, dominant in soil and seawater

Eukaryotic Cells

single or multi celled, complx internal structures

Protists/Protozoa

free-living, motile or sedentary, unicellular, eukaryotes, can be predatory

Parts of Protists/Protozoa

Sensory bristles, photoreceptors, sinuously beating cilia, stalk-like appendages, mouth parts, sting darts, muscle-like contractile bundles

Nucleus

contains DNA, double membrane

Mitochondria

generates chemical energy (cellular respiration), double membrane, cristae (increase surface area), has own DNA

Chloroplast

photosynthesis, double membrane, has own DNA, thylakoids/grana/stroma

Internal membranous compartment of eukaryotes

Endoplasmic reticulum, Golgi apparatus, Lysosomes, peroxisomes, transport vesicles

smooth ER

lipid synthesis, detoxification, Ca storage

Rough ER

has ribosomes, build proteins (exported), assemble membrane

Golgi apparatus

cis and trans face, stack of sac (discontinous), recieve vesicles, processing and tagging

lysosomes

low pH, digestion, breakdown dead cells/pathogens/food/damages organelles

peroxisomes

breakdown hazards, detoxify

Cytosol

site of many chemical reactions, behave like water-based gel

Cytoskeleton

directs cell movement, maintain cell shape, microtubules/actin(micro)filements/intermediate filaments

microtubules

made of tubulin dimers, shape/support, cell highway, cilia

actin/micro filaments

made actin protein, shape/support (prevent collapsing in)

intermediate filaments

keratin, support, anchor organelles

model organisms

knowledge gain from one can be contribute to another

example of model organisms

E. coli, Saccharomyces cerevisiae, Arabidopsis thaliana, Caenorhabditis elegans, Drosophila melanogaster, Zebrafish, Mouse, Human cells

E. coli

used study molecular biology, central dogma, recombinant DNA, genetic manipulation

Saccharomyce cerevisiae

Yeast, Model eukarytoic cells, genetic of sexual reproduction, cell division

Arabidopsis thaliana

model plant, plant mechanisms (towards sun/flowing in spring), coordinate development with the cycle of seasons

Caenorhabditis elegans

Worn, development of adult, apoptosis

Drosophila melanogastor

Fruit fly, Animal genetics, development zygote into adult

Zebrafish

transparent for 2 weeks, see how cell behave during development, heart and blood vessels

Mouse

Mammalian genetics, development, immunology, cell bio

Human cells

in vitro (on cells), in vivo (intact organisms)

homologous genes

genes of one organsim with close counterpart in other, exsit before domain of life, descended from common ancestral gene, determine evolutionary relatedness

bacteria genome

small, very efficient

Eukaryotes genome

huge, lots of non coding regions(telomers, regulation, homolog, junk)