Differences between Prokaryotes and Eukaryotes

 

Differences between Prokaryotes and Eukaryotes

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S.N.	Character	Prokaryotes	Eukaryotes
1.	Term Origin	Greek for “primitive nucleus”	Greek for “true nucleus”
2.	Definition	Organisms made up of cell(s) that lack a cell nucleus or any membrane-encased organelles.	Organisms made up of cells that possess a membrane-bound nucleus as well as membrane-bound organelles.
3.	Major groups	Bacteria, Archae, and Bluegreen algae	Algae, fungi, protozoa, plants, animals
4.	Origin	Around 3.5 billion years ago.	Around 2 billion years ago.
5.	Size (approximate)	0.5-3.0 μm	>5 μm
6.	Cell Type	Usually unicellular (some cyanobacteria may be multicellular)	Usually multicellular
7.	Complexity	Simple	Complex organization.
8.	Nucleus Location	Free in the cytoplasm, attached to mesosomes	Contained in membrane bound structure
9.	Nucleur membrane	No nuclear membrane.	Classic membrane present.
10.	Nucleolus	Absent	Present
11.	Chromosome number	One	More than one
12.	Chromosome shape	Circular	Linear
13.	Genes	Expressed in groups called operons.	Expressed individually
14.	Genome	DNA haploid genome	DNA diploid genome
15.	DNA base ratio (G+C %)	28-73	About 40
16.	DNA wrapping on proteins	Multiple proteins act together to fold and condense prokaryotic DNA. Folded DNA is then organized into a variety of conformations that are supercoiled and wound around tetramers of the HU protein.	Eukaryotes wrap their DNA around proteins called histones.

17.	Genome nature	Efficient and compact with little repetitive DNA.	With large amounts of non-coding repetitive DNA.
18.	Membrane-bound organelles	Absent	Present
19.	Ribosomes (sedimentation coefficient)	70S (50S + 30S).Smaller.	80S (60S + 40S). Larger.
20.	Ribosome’s location	Free in cytoplasm or bound to cell membrane	Attached to rough endoplasmic reticulum
21.	Mitochondria	Absent	Present
22.	Golgi bodies	Absent	Present
23.	Endoplasmic reticulum	Absent	Present
24.	Mesosomes	Present. Performs the function of Golgi bodies and mitochondria and also help in the separation of chromosome during cell division.	Absent
25.	Lysosomes	Absent	Present
26.	Peroxisomes	Absent	Present
27.	Chloroplasts	Absent; chlorophyll scattered in the cytoplasm	Present (in plants)
28.	Fimbriae	Prokaryotes may have pili and fimbriae (appendage that can be found on many Gram-negative and some Gram-positive bacteria).	Absent
29.	Microtubules	Absent or rare	Present
30.	Centrosome	Absent	Present except in flowering plants.
31.	Cytoskeleton	May be absent	Present
32.	Glycocalyx	Present	Only in some
33.	Cytoplasmic streaming	Absent	Present
34.	Cytoplasmic membrane	Does not contain sterols (except Mycoplasma)	Contains sterols
35.	Cell wall	Complex structure containing protein, lipids, and peptidoglycans	Present for plant cells and fungi; otherwise absent
36.	Muramic acid	Present	Absent
37.	Movement	Simple flagellum, if present	Complex flagellum, if present
38.	Respiration	Via cytoplasmic membrane	Via mitochondria
39.	Energy production site	Electron transport chain located in the cell membrane	Within membrane bound mitochondria
40.	Metabolic rate	Higher due to larger surface area to volume ratio	Comparatively slow
41.	Reproduction	Asexual (binary fission)	Sexual and asexual/ Mitotic division
42.	Generation time	Shorter	Comparatively longer
43.	Genetic Recombination	Partial, unidirectional transfer	Meiosis and fusion of gametes
44.	Zygote	Merozygotic (partially diploid)	Diploid
45.	Extrachromosomal DNA	Plasmid	Inside the mitochondria
46.	DNA replication	Occurs in cytoplasm.	Occurs in the nucleus.
47.	Transcription and translation	Occurs simultaneously.	Transcription occurs in nucleus and then translation occurs in cytoplasm.