Different between prokaryotic and eukaryotic

Learning Objectives • Identify features common to all cells • Contrast the composition and size of prokaryotic and eukaryotic cells Cells fall into one of two broad categories: prokaryotic and eukaryotic. The single-celled organisms of the domains Bacteria and Archaea are classified as prokaryotes ( pro = before; karyon– = nucleus). Animal cells, plant cells, fungi, and protists are eukaryotes ( eu = true). Components of Prokaryotic Cells All cells share four common components: (1) a plasma membrane, an outer covering that separates the cell’s interior from its surrounding environment; (2) cytoplasm, consisting of a jelly-like region within the cell in which other cellular components are found; (3) DNA, the genetic material of the cell; and (4) ribosomes, particles that synthesize proteins. However, prokaryotes differ from eukaryotic cells in several ways. Figure 1. This figure shows the generalized structure of a prokaryotic cell. A prokaryotic cell is a simple, single-celled (unicellular) organism that lacks a nucleus, or any other membrane-bound organelle. We will shortly come to see that this is significantly different in eukaryotes. Prokaryotic DNA is found in the central part of the cell: a darkened region called the nucleoid (Figure 1). Unlike Archaea and eukaryotes, bacteria have a cell wall made of peptidoglycan, comprised of sugars and amino acids, and many have a polysaccharide capsule (Figure 1). The cell wall acts as an extra layer of protection, helps the cel...

Prokaryotes vs. Eukaryotes S.N. Character Prokaryotes Eukaryotes 1. Term Origin Greek for “primitive nucleus” Greek for “true nucleus” 2. Definition Organisms are made up of cell(s) that lack a cell nucleus or any membrane-encased organelles. Organisms are 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. Nuclear 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 amount...

\( \newcommand\) • • • Learning Outcomes Compare prokaryotic and eukaryotic gene regulation To understand how gene expression is regulated, we must first understand how a gene codes for a functional protein in a cell. The process occurs in both prokaryotic and eukaryotic cells, just in slightly different manners. Prokaryotic organisms are single-celled organisms that lack a cell nucleus, and their DNA therefore floats freely in the cell cytoplasm. To synthesize a protein, the processes of transcription and translation occur almost simultaneously. When the resulting protein is no longer needed, transcription stops. As a result, the primary method to control what type of protein and how much of each protein is expressed in a prokaryotic cell is the regulation of DNA transcription. All of the subsequent steps occur automatically. When more protein is required, more transcription occurs. Therefore, in prokaryotic cells, the control of gene expression is mostly at the transcriptional level. Eukaryotic cells, in contrast, have intracellular organelles that add to their complexity. In eukaryotic cells, the DNA is contained inside the cell’s nucleus and there it is transcribed into RNA. The newly synthesized RNA is then transported out of the nucleus into the cytoplasm, where ribosomes translate the RNA into protein. The processes of transcription and translation are physically separated by the nuclear membrane; transcription occurs only within the nucleus, and translation occurs ...

All cells on Earth can be divided into two types: prokaryotes and eukaryotes. Prokaryotes are always unicellular organisms and may be bacteria or archaea. Eukaryotes may be unicellular or multicellular and include plants, animals, fungi, and protists are all made up of eukaryotic cells. Eukaryotic cells are much larger and more complex than prokaryotes and contain several cell structures and organelles that are missing from prokaryotic cells. Prokaryotes Eukaryotes Types of organelles No nucleus or other membrane-bound organelles Nucleus and membrane bound organelles DNA storage Nucleoid region with free-floating DNA DNA stored in nucleus Unicellular vs. multicellular Always unicellular Can be unicellular or multicellular Types of organisms Bacteria, archaea Plants, animals, fungi, protists Cell size 0.2-2.0 µm in diameter 10-100µm in diameter Type of cell division Binary fission Mitosis and meiosis Type of reproduction Asexual Sexual Prokaryotic vs. eukaryotic cells What Are Prokaryotes and Eukaryotes? Prokaryotes and eukaryotes are both types of cells; in fact, they’re the only two cell types on Earth. Prokaryotic organisms are always unicellular and may be bacteria or archaea. Eukaryotic organisms, however, may be unicellular or multicellular and include plants, animals, fungi, and protists. Prokaryotic vs. eukaryotic organisms Differences Between Prokaryotes and Eukaryotes Eukaryotic cells are more complex than prokaryotic cells, and there are several structural differ...

Although they are found all around us, prokaryotes can be hard to detect, count, and classify. The prokaryotic species we know of today are a tiny fraction of all prokaryotic species thought to exist. 1 ^1 1 start superscript, 1, end superscript In fact, the very idea of a “species” becomes complicated in the world of prokaryotes! However, work by microbiologist Carl Woese in the 1970s showed that prokaryotes are divided into two distinct lineages, or lines of descent: Archaea and Bacteria. Today, these groups are considered to form two out of three domains of life. The third domain (Eukarya) includes all eukaryotes, such as plants, animals, and fungi. 2 ^2 2 squared This phylogeny (evolutionary tree) depicts the evolutionary relationships between the three domains of life: Eukarya, Archaea, and Bacteria. The two prokaryotic domains (Archaea and Bacteria) each comprise several smaller taxonomic groupings. Within the Archaea are the euryarchaeotes, crenarchaeotes, nanoarchaeotes, and korarchaeotes. Within the Bacteria are proteobacteria, chlamydias, spirochetes, cyanobacteria, and gram-positive bacteria. The proteobacteria are subdivided into five groups, alpha through epsilon. Species in these groups have a wide range of lifestyles. Some are symbiotic with plants, others live in hot vents deep under the sea, and others yet cause human diseases, such as stomach ulcers ( Helicobacter pylori) and food poisoning ( Salmonella). Characteristics of the five phyla of bacteria are ...