Cell Biology chapter 1

The Cell Theory
cells are building blocks of all living tissues; ” cells are generated from pre-existing cells and inherit their characteristics”

Nerve cell (cerebellum)
branching processes to communicate with 100,000 other neurons

If the plant stem is red…

If the plant stem is orange…

Paramecium “pond scum”
a protozoan, moves using cilia

small carnivorous bacteria, propelled using single flagellum

Human white cells are engulfing…
red blood cells

What do all cells have in common?
the central Dogma of Molecular biology; “The flow of genetic material”

Central Dogma (flow of genetic material)
1.DNA synthesis-Replication; information storage; the hard drive
2.RNA synthesis-Transcription; temporary message; “the cache”
3. Protein synthesis-Translation; functional units; “the program”

Viruses-“Molecular Parasites”
Exception to central dogma; some are dna, rna, double-stranded, single stranded; can not replicate without a host cell

Our genes hold the code, but its their_______ that determines function

Every cell has all the ________(DNA) needed for an organism

produced by Israeli researchers; over half of the test tasters preferred this

How big are cells? molecules?
there are at least 10 million if not 100 million distinct cell types in the world; nerve/muscle cells can be nearly 1 meter; cactobacillus are 25 times smaller than a human hair

Conventional Light Microscopy (0.2 Um)
-transmitted light
-polarized light
-phase contrast (shadowing)
-fluorescence microscopy
-processing required so that light passes through tissue

Confocal Microscopy
-fluorescence microscopy
-using laser light, single wavelength
-focuses on single plane (layer)
-optical section to create 3-D images
-uses antibodies/dyes to visualize the cell

Electron Microscopy (0.2 nm)
-focus beam of electrons
-cells/tissues need much processing
-“fixing” “sectioning”
-cells/tissues are coated with electron dense heavy materials
-SEM scan layers creating fabolous 3-D images

living cells have a similar ____ _____
basic chemistry

all present-day cells have apparently evolved from…..
the same ancestor

Genes provide the instruction for cellular______
form, function, and complex behavior

Prokaryote vs. Eukaryote
Prokaryote: nucleoid, capsule, flagellum, cell wall, cell membrane, ribosomes
Eukaryote: nucleus, nucleolis, mitochondria

*small, single cellular organisms
*most diverse of cells
*can adapt to extreme environments
*2 domains: Bacteria or Archaea
*many different sources of “food” (oxygen, hydrogen, sulfur, some are even photosynthetic)
example: spherical cells (streptococcus), rod-shaped cells (E.coli), spiral cells (trepohema pallidum)

Confocal Microscopy
-fluorescence microscopy
-using laser light, single wavelength

*bigger, more elaborate cells
*single-celled organisms (yeast, aomeoboe)
*multi-cellular (plants, animals, fungi)
*always have a nucleus, organized, compartmentalized (membrane-bound)
*yeast is the most simple

the factories
*smallest structure you can clearly see here
*comprised of 80-90 molecules that catalyze
*translation-make new proteins to keep everything working

the power plant
*most abundant organelle
*oxidize food molecules to generate ATP; ‘cellular respiration’, contain their own DNA and reproduce themselves (like DNA), ancient symbiosis between eukaryotic cell and bacteria

the solar power plant
-green organelle found in plants and algae
-stacks of internal membranes containing chlorophyll
-evolved from bacteria

converts sunlight into chemical energy (sugar)

Rough Endoplasmic Reticulum
ribsosome coated ER which makes proteins to be secreted

Smooth Endoplasmic Reticulum
involved in lipid synthesis

Golgi Body
post office
*involved in packaging and modifying proteins to be secreted by the cell to other locations, which is how cells communicate

waste disposal system
*small, irregular shaped
*House intracellular degradation
-breaks down food and releases back to cell
-breaks down waste for recycling or excretion

chemical plant
*small, membrane enclosed vesicles
*contained environment for H20 reactions
H2O2 generated and degraded inside

Cytoskeleton-The Cells Scaffolding
allows directed movement; actin (thin); microtubules (thicker or hollower tubes); intermediate filaments ‘the cross hatch’

Eukaryotes likely evolved as a _____; large flexible membrane and cytoskeleton for movement; to allow _____
predator, eating

Nuclear compartment may have evolved to protect valuable genetic material from chaos of ______.

Escherichia Coli
-more understood than any other organism
-single, circular double strand of DNA
-4.6 million nucleotide pairs long
-produces 4300 different kinds of proteins

Saccharomyces cerevisiae
-minimal model eukaryote
-single cell fungus (as closely related to animals as it is to plants)
-small, well-known genome carries out all basic eukaryotic tasks

Arabidopsis Thaliana
-common wall cress
-produces thousands of offspring in 8-10 weeks
-easy to grow indoors
-complete DNA sequence is known

Drosophila Melanogaster
-more than any other organism, has shown us how to trace cause and effect from DNA instruction to structure of adult multicellular organism
-DNA genome well known, lots of lab supplies well known

Caenorhabditis elegans
-develop like clockwork; 959 body cells
-neurons of brain completely mapped
-led to understanding of programmed cell death
-used in alcohol studies at VCU

Danio reno
-transpart for the first 2 weeks of life
-excellent for developmental studies

Homo sapiens; Mus musculus
-different species share similar gene
-defect in kit gene, required for development and maintenance of pigment cells

model organisms
all evolved from common ancestors, many conserved processes. (e.coli, saccromyces, arabidopsis, the World of Animals)

E.coli(model organism)
simple, fast to grow, cheap, can manipulate easily

Saccromyces(model organism)
a simple eukaryotic cell, has mitochondria

Arabidopsis (model organism)
chosen out of 300,000 species as a model plant; grows fast, easily, flowering

The World of Animals (model organism)
represented by a Fly, Worm, Fish, Mouse, and Human Species

Comparing genome sequences reveals life’s_____ _______.
common heritage

Primary cell culture
-isolated directly from live organism
-limited lifespan(Hayflick Limit)

Immortalized cell line
‘transformed’ cells can grow indefinitely like cancer

Danio reno

Cytoskeleton-The Cells Scaffolding

Cytoskeleton-The Cells Scaffolding

Confocal Microscopy

Confocal Microscopy