Scientist over the course of 200 years, define it ..
All organisms are composed of one or more cells
Cells arise only from division of preexisting cells
Cell is the basic structural and functional unit of all living s organisms
Some of them have cilia or flagella
Flagella helps propel the cell
The filia helps move the cell surrounding
The other seem to be organism in groups or remain individually
Their shape is diff.
They all have some form of barrier or membrane
All have cytoplasm within the membrane, they do all have dna but you can’t see anything
High surface area to volume ratio
Cell size and scale
Relevant units: scale and size are important
Important to still appreciate how big tings are
Scale and size become hazy in terms of concept
(typically)Prokaryotes are smaller than 10 um, bigger than protein but smaller than living cells
Eukaryotes 10-100 um
Ribosomes 10-15 nm
Cells have high surface area ratio to volume
Why are cells so small tho?
Cause the ability to transport things in and out of da cell
Nutriments need to get in and out, waster as well, others need to be assisted the membrane is a
barrier, prevents certain things from entering and leaving,
Large cells: instead of one large cell have 8 smaller cells
There are no perfectly cubic cells
Equilibrate the cell, sustain the activities …. Not efficient?
Produce less waste, more efficient less membrane,
Many small cells, ratio is much high r much less membrane less membrane to contain,
everything is much faster and efficient Minimal amount of space needed?
Evolution has brought us to theses cells sizes, can possibly get smaller cell sizes??????? Work
together and become more complex and achieve more complex tasks
How do they work together? Similar characteristics and to become more complex
Eukaryotes can assemble cells that are of the same character. Like tissues, that’s why there are
more complex organisms
Archaean are between bacteria and eukaryotes? Is this the case?
Archaea closer to euka
They look alot like bacteria, but really they are closer relatives to euka.
The have similar features, the lack of peptidoglycans in their cell struc.
Ribosomal rna, machinery used to build proteins is much closer to the one used for eukaryotes
Phospholipids to something means they are closer to euk
Unicellular, no organelles, no internal transport sys.small genomes, keep it simple, means they
can adapt quickly to any sys.
Get away with having a much smaller genome
Bp → base pair, dna is a double strand each strand is a chain of nucleotides. Bc they are
complementary to each other they are facing each other called base pairs, if you count the base
pairs gives unit of measure of length of dna,
Larger, elaborate membranes, transport sys, larger genome
Typical rod shaped bacteria
Flagellar: movement of organelles of some bacteria
Cell wall, can be diff with every bacteria, some will have a harder cell wall(capsule)
No all bacteria have these features
Typical plant cells
Similar to animal cell, but diff features, such as vacuole, chloroplasts, cell wall
No cell wall
theory of endosymbiosis
mutually beneficial relationship, endosymbiosis
had to have had their own dna, eukaryotes have their own dna
original genome taking up by the nucleus, allowed the to maintain a set of genes to accomplish
a task of …
1. Morphology: shape of mito and chloro. And size same as bacteria
2. Reproduction: only by binary fission
3. Genome: circular mtDNA and cpDNA
4. Transcription and translation: machinery in place
5. Electron transport: double membrane with ETC
6. Sequence: bacterial branch on tree of life (mitochondria=proteobacteria,
chloroplasts=cyanobacteria), compare genetic sequence of these to bacteria you can
see they share homology
Mitochondria had ability to produce energy use photorespiration chloro were able to synthesize,
Electron transport chain..
Genome mito, and chloro, compared to bacteria share homology to proteobacteria
Infolding of the membrane started building the entire endomembrane system, key to building all
the organelles, membrane bound, ability distinct from other functional compartments
Endosymbiotic one organism within the other, gut bacteria , benefit from being there, in our
Bioluminescence bacteria in fish, because they live there they are protected, they are well
nourished and able to bioluminesce
Coral reef salamander,
Not a mutually beneficial relationship steals the chloroplast from the plant, sucks them out ,
gives the slug the ability to photosynthesize, not good for the plant, but good for that slug,
Scientist over the course of 200 years, define it All organisms are composed of one or more cells. Cells arise only from division of preexisting cells. Cell is the basic structural and functional unit of all living s organisms. The other seem to be organism in groups or remain individually. They all have some form of barrier or membrane. All have cytoplasm within the membrane, they do all have dna but you can"t see anything. Important to still appreciate how big tings are. Scale and size become hazy in terms of concept (typically)prokaryotes are smaller than 10 um, bigger than protein but smaller than living cells. Cells have high surface area ratio to volume. Cause the ability to transport things in and out of da cell. Nutriments need to get in and out, waster as well, others need to be assisted the membrane is a barrier, prevents certain things from entering and leaving,