LECTURE                                           CELLS

In this lecture you will learn about:

THE OVERVIEW OF BIOLOGY
We now move from biological molecules into living organisms, the 3 basic types of cells, and viruses.  Click HERE to go to the site shown at right and learn more. 

http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html


 
HOW BIG? 

wiki
 

Excellent overview of cells click HERE
 
VIRUS

- they are NOT cells, rather they are called the "undead" because they cant do anything without a host cell
- genome is either DNA or RNA, it is single stranded (SS) or double stranded (DS)
- there is a protein shell around the genome that protects the genome
- not shown but many viruses contain a second "coating" of cell membrane taken from the host cell as it leaves. click here
- viral genome coded enzymes may be included with viral package
- they are completely dependent on the host "machinery" to reproduce
- even bacteria have viruses called "phage"

BACTERIA - PROCARYOTE

excellent website click HERE

- bacteria are single celled 
- they have an inner cell membrane
- they have an outer cell WALL that is complex not like plant walls
- all functions are within the open cytoplasm of the cell
- they have a single (1N) double stranded circular DNA genome and MAY have extrachromosomal DNA called plasmids which are also circular and may carry other "bits" of genome, like phage (bacterial viruses)
- many species can move
- they are the most abundant cells on Earth in both number of species AND in sheer bulk
- they are "chemists" and different species can live on almost anything
- reproduction is by binary fission (splitting its cell into two) 
- DNA exchange by conjugation


PLANT CELL- EUCARYOTE

- all are photosynthetic
- single celled (algae) and multiple celled
- they have an inner cell membrane
- they have an outer cell WALL that is made of cellulose
- functions are divided into different organelles which are surrounded by cell membranes and called organelles
- genome is multiple chromosomes of the 2N number
- single celled plants in water like Phytoplankton reproduce by fission, sporulation, sexual reproduction by fusion to produce a zygospore.
- in the water many move
- on land they dont generally move

ANIMAL CELL- EUCARYOTE

excellent website click HERE

- multiple celled
- they have an inner cell membrane
- functions are divided into different organelles which are surrounded by cell membranes and called organelles
- genome is multiple chromosomes of the 2N number
- reproduction is sexual

FUNGI - EUCARYOTE
 
 

- reproduction fission click here


 
DNA, PROTEINS AND RELATED DNA PROCESSES
E. coli - procaryote Plants & animals - eucaryote
Cell Types 1 @ 200 different tissue types
Number of Chromosomes  1 multiple linear
Haploid Genome Size 4,639,221 bp  3.2 billion bp
Number of Protein Genes  4288  30 - 60,000 
Percent Non-Coding DNA  0.7%  99.7% <---- note how much!
repeating sequences  some common
junk DNA rare much
DNA type single closed circle  open, multiple, linear
DNA proteins some most - histones 
capping and tailing mRNA no yes
mRNA splicing rare common

 
DNA COMPARISON
ORGANISM GENES BASE PAIRS
small virus 3 4 x 10*3
large virus 200 3 x 10*5
bacteria 3000 3 x 10*6
yeast 10,000 1 x 10*7
mice 30,000  
rice 50,000  
human/fruit fly 100,000 1 x 10*8 
human 20,500  

 
COMPARISON OF PROCARYOTIC VS EUCARYOTIC DNA PACKAGING
PROCARYOTIC
EUCARYOTIC

 
SUMMARY OF EUCARYOTE VS PROCARYOTE VS VIRUS VS PRION
Eucaryote Procaryote  Viruses Prions
Some uni- but most multicellular unicellular not a cell  not a cell
Membrane bound organelles for greater specialization, more complexity No membrane bound organelles Cell membrane takes the place of specialized organelles none none
nucleus surrounded by nuclear membrane No true nucleus RNA or DNA surrounded by proteins only, or proteins + membrane none
ribosomes- (80S)  ribosomes (70S)  none none
mitochondria- respiration on cell membrane none none
endoplasmic reticulum - protein synthesis, post production  on cell membrane or free ribosomes none none
Golgi apparatus - package and export direct excretion none none
locomotor organelles 
1.flagella
2.cilia 
3.pseudopodia 
1. Flagella- only locomotor structure- 
chemotaxis 
2. .Fimbriae- attachment function 
3. Pilus- sex pilus for conjugation 
none none
cell wall made of cellulose or chitin outside the cell membrane, or just cell membrane reinforced with sterols like cholesterol  cell wall peptidoglycan
A. Lipoprotein and lipopolysaccharide (LPS) optional outer layer 
none none
Genes usually in paired linear DNA chromosomes which reproduce by mitosis and meiosis single circular DNA chromosome free in the cytoplasm + plasmids 
simple binary fission (splitting)
single or segmented
RNA or DNA
DS or SS
replication depends on host
none
Kingdoms containing eucaryotic cells 
1. Protista 2. Fungal 3. Plant 4. Animal 
Kingdom - Monera  Viridae none?
REVIEW QUESTIONS