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Apoptos eller programmerad celldöd är ett sätt för celler i organismer att på ett kontrollerat sätt begå självmord utan att skada sin omgivning, till skillnad från den mer kaotiska nekrosen. Vid apoptos tar cellen emot signaler som bl.a. leder till att cellkärnan fragmenteras, cytoskelettet bryts ner och plasmamembranet förändras så att cellen kan fagocyteras av omgivande celler utan att det uppstår en inflammation. Processen är evolutionärt väl bevarad mellan olika arter; den upptäcktes i rundmasken Caenorhabditis elegans vilket belönades med Nobelpriset.

A plasmid is an extra-chromosomal DNA molecule separate from the chromosomal DNA which is capable of replicating independently of the chromosomal DNA.[1] In many cases, it is circular and double-stranded. Plasmids usually occur naturally in bacteria, but are sometimes found in eukaryotic organisms (e.g., the 2-micrometre-ring in Saccharomyces cerevisiae). Plasmid size varies from 1 to over 1,000 kilobase pairs (kbp).[2][3][4] The number of identical plasmids within a single cell can range anywhere from one to even thousands under some circumstances. Plasmids can be considered to be part of the mobilome, since they are often associated with conjugation, a mechanism of horizontal gene transfer.

Plasmids used in genetic engineering are called vectors. Plasmids serve as important tools in genetics and biotechnology labs, where they are commonly used to multiply (make many copies of) or express particular genes.[2] Many plasmids are commercially available for such uses. The gene to be replicated is inserted into copies of a plasmid containing genes that make cells resistant to particular antibiotics and a multiple cloning site (MCS, or polylinker), which is a short region containing several commonly used restriction sites allowing the easy insertion of DNA fragments at this location. Next, the plasmids are inserted into bacteria by a process called transformation. Then, the bacteria are exposed to the particular antibiotics. Only bacteria which take up copies of the plasmid survive , since the plasmid makes them resistant. In particular, the protecting genes are expressed (used to make a protein) and the expressed protein breaks down the antibiotics. In this way the antibiotics act as a filter to select only the modified bacteria

Chloroplast

Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.[

Nekros (gr. ne'krosis, "bortdöende"), sjuklig celldöd i en organism , till skillnad från apoptos som innebär en programmerad celldöd som gynnar organismen. Blir nekrosen tillräckligt stor kan det leda till organismens död.

Varenda cell i kroppen innehåller en biologisk "apparat" som bearbetar och sorterar bland annat proteiner. Den heter Golgi och är unik bland cellens "organ" genom att den faller sönder vid celldelningen. Detta gör Golgi särskilt intressant inom cancerforskning.