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Lyf Sel Syzohmz



Lyf Selz 2 Basic Typz

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Prokaryotes Vs. Eukaryotes…Comparing the Two Basic Types of Cells

by Laura Klappenbach

All living organisms can be sorted into one of two groups depending on the fundamental structure of their cells: the prokaryotes and the eukaryotes.

Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-encased organelles.

Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus that holds genetic material as well as membrane-bound organelles.


Pikchrz Kuhmpehreeng Prokaryote And Eukaryote Typs Uhv Lyf Selz

prokaryotic-vs-eukaryotic-cell-n.jpg
General%2BComparisons%2BProkaryote%2BEukaryote.jpg

Thuh Nekst Tekst Wuhz Fruhm:

Prokaryotes Vs. Eukaryotes…Comparing the Two Basic Types of Cells

by Laura Klappenbach

All living organisms can be sorted into one of two groups depending on the fundamental structure of their cells: the prokaryotes and the eukaryotes.

Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-encased organelles.

Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus that holds genetic material as well as membrane-bound organelles.


prokaryotic-vs-eukaryotic-cell-n.jpg
General%2BComparisons%2BProkaryote%2BEukaryote.jpg

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Aspects of cells

Homeostasis – The property of either an open system or a closed system, especially a living organism, that regulates its internal environment so as to maintain a stable, constant condition.

Life – A condition of growth through metabolism, reproduction, and the power of adaptation to environment through changes originating internally.

Microscopic – The scale of objects, like cells, that are too small to be seen easily by the naked eye and which require a lens or microscope to see them clearly.

Unicellular – Organisms which are composed of only one cell.

Multicellular – Organisms consisting of more than one cell and having differentiated cells that perform specialized functions.

Tissues – A collection of interconnected cells that perform a similar function within an organism.

Cellular differentiation – A concept in developmental biology whereby less specialized cells become a more specialized cell type in multicellular organisms.


Cytology:

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Pronunciation
(Received Pronunciation) IPA(key): /saɪˈtɒləd͡ʒi/
(General American) IPA(key): /saɪˈtɑləd͡ʒi/

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Etymology
cyto- (“cell”) +‎ Suffix logy

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Medical Definition of Cytology

Cytology: The medical and scientific study of cells. Cytology refers to a branch of pathology, the medical specialty that deals with making diagnoses of diseases and conditions through the examination of tissue samples from the body.

Cytologic examinations may be performed on body fluids (examples are blood, urine, and cerebrospinal fluid) or on material that is aspirated (drawn out via suction into a syringe) from the body. Cytology also can involve examinations of preparations that are scraped or washed (irrigated with a sterile solution) from specific areas of the body. For example, a common example of diagnostic cytology is the evaluation of cervical smears (referred to as the Papanicolaou test or Pap smear).

In order for cytologic evaluation to be carried out, the material to be examined is spread onto glass slides and stained. A pathologist then uses a microscope to examine the individual cells in the sample.


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General cellular anatomy

Cellular compartment – All closed parts within a cell whose lumen is usually surrounded by a single or double lipid layer membrane.

Organelles – a specialized subunit within a cell that has a specific function, and is separately enclosed within its own lipid membrane or traditionally any subcellular functional unit.

Organelles

Endomembrane system

Endoplasmic reticulum – An organelle composed of an interconnected network of tubules, vesicles and cisternae.

Smooth endoplasmic reticulum – A section of endoplasmic reticulum on which ribosomes are not attached is termed as smooth endoplasmic reticulum. It has functions in several metabolic processes, including synthesis of lipids, metabolism of carbohydrates and calcium concentration, drug detoxification, and attachment of receptors on cell membrane proteins.

Rough endoplasmic reticulum – A section of the endoplasmic reticulum on with the protein manufacturing organelle i.e. ribosomes are attached is termed as rough endoplasmic reticulum which give it a "rough" appearance (hence its name).[5] Its primary function is the synthesis of enzymes and other proteins.

Vesicle – A relatively small intracellular, membrane-enclosed sac that stores or transports substances.

Golgi apparatus – A eukaryotic organelle that processes and packages macromolecules such as proteins and lipids that are synthesized by the cell.

Nuclear envelope – It is the double lipid bilayer membrane which surrounds the genetic material and nucleolus in eukaryotic cells.The nuclear membrane consists of two lipid bilayers -
Inner nuclear membrane

Outer nuclear membrane.

Perinuclear space – space between the nuclear membranes, a region contiguous with the lumen (inside) of the endoplasmic reticulum. The nuclear membrane has many small holes called nuclear pores that allow material to move in and out of the nucleus.

Lysosomes – It is a membrane-bound cell organelle found in most animal cells (they are absent in red blood cells). Structurally and chemically, they are spherical vesicles containing hydrolytic enzymes capable of breaking down virtually all kinds of biomolecules, including proteins, nucleic acids, carbohydrates, lipids, and cellular debris. lysosomes act as the waste disposal system of the cell by digesting unwanted materials in the cytoplasm, both from outside of the cell and obsolete components inside the cell. For this function they are popularly referred to as "suicide bags" or "suicide sacs" of the cell.

Endosomes – It is a membrane-bounded compartment inside eukaryotic cells. It is a compartment of the endocytic membrane transport pathway from the plasma membrane to the lysosome. Endosomes represent a major sorting compartment of the endomembrane system in cells.

Cell nucleus – A membrane-enclosed organelle found in most eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes.

Nucleoplasm – Viscous fluid, inside the nuclear envelope, similar to cytoplasm.

Nucleolus – Where ribosomes are assembled from proteins and RNA.

Chromatin – All DNA and its associated proteins in the nucleus.

Chromosome – A single DNA molecule with attached proteins.

Energy creators

Mitochondrion – A membrane-enclosed organelle found in most eukaryotic cells.[6] Often called "cellular power plants", mitochondria generate most of cells' supply of adenosine triphosphate (ATP), the body's main source of energy.

Chloroplast – An organelles found in plant cells and eukaryotic algae that conduct photosynthesis.

Centrosome – The main microtubule organizing center of animal cells as well as a regulator of cell-cycle progression.

Lysosome – The organelles that contain digestive enzymes (acid hydrolases). They digest excess or worn-out organelles, food particles, and engulfed viruses or bacteria.

Peroxisome – A ubiquitous organelles in eukaryotes that participate in the metabolism of fatty acids and other metabolites. Peroxisomes have enzymes that rid the cell of toxic peroxides.

Ribosome – It is a large and complex molecular machine, found within all living cells, that serves as the site of biological protein synthesis (translation). Ribosomes build proteins from the genetic instructions held within messenger RNA.

Vacuole – A membrane-bound compartments within some eukaryotic cells that can serve a variety of secretory, excretory, and storage functions.

Structures

Cell membrane – (also called the plasma membrane, plasmalemma or "phospholipid bilayer") is a semipermeable lipid bilayer found in all cells; it contains a wide array of functional macromolecules.

Cell wall – A fairly rigid layer surrounding a cell, located external to the cell membrane, which provides the cell with structural support, protection, and acts as a filtering mechanism.

Centriole – A barrel shaped microtubule structure found in most eukaryotic cells other than those of plants and fungi.

Cluster of differentiation – A cell surface molecules present on white blood cells initially but found in almost any kind of cell of the body, providing targets for immunophenotyping of cells. Physiologically, CD molecules can act in numerous ways, often acting as receptors or ligands (the molecule that activates a receptor) important to the cell. A signal cascade is usually initiated, altering the behavior of the cell (see cell signaling).

Cytoskeleton – It is a cellular "scaffolding" or "skeleton" contained within the cytoplasm it is composed of three types of fibers: microfilaments, intermediate filaments, and microtubules.

Cytoplasm – A gelatinous, semi-transparent fluid that fills most cells, it includes all cytosol, organelles and cytoplasmic inclusions.

Cytosol – It is the internal fluid of the cell, and where a portion of cell metabolism occurs.

Inclusions – A chemical substances found suspended directly in the cytosol.

Photosystem – They are functional and structural units of protein complexes involved in photosynthesis that together carry out the primary photochemistry of photosynthesis: the absorption of light and the transfer of energy and electrons. They are found in the thylakoid membranes of plants, algae and cyanobacteria (in plants and algae these are located in the chloroplasts), or in the cytoplasmic membrane of photosynthetic bacteria.

Plasmid – An extrachromosomal DNA molecule separate from the chromosomal DNA and capable of sexual replication, it is typically ring shaped and found in bacteria.

Spindle fiber – The structure that separates the chromosomes into the daughter cells during cell division.

Stroma – The colorless fluid surrounding the grana within the chloroplast. Within the stroma are grana, stacks of thylakoids, the sub-organelles, the daughter cells, where photosynthesis is commenced before the chemical changes are completed in the stroma.

Thylakoid membrane – It is the site of the light-dependent reactions of photosynthesis with the photosynthetic pigments embedded directly in the membrane.


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