Viral envelope - wikipedia Viral envelope Schematic of a Cytomegalovirus Some viruses ( e.g. HIV and many animal viruses ) have viral envelopes covering their protective protein capsids. The envelopes are typically derived from portions of the host cell membranes ( phospholipids and proteins ), but include some viral glycoproteins. They may help viruses avoid the host immune system. Glycoproteins on the surface of the envelope serve to identify and bind to receptor sites on the host 's membrane. The viral envelope then fuses with the host 's membrane, allowing the capsid and viral genome to enter and infect the host. The cell from which the virus itself buds will often die or be weakened and shed more viral particles for an extended period. The lipid bilayer envelope of these viruses is relatively sensitive to desiccation, heat, and detergents, therefore these viruses are easier to sterilize than non-enveloped viruses, have limited survival outside host environments, and typically must transfer directly from host to host. Enveloped viruses possess great adaptability and can change in a short time in order to evade the immune system. Enveloped viruses can cause persistent infections. Contents 1 Enveloped examples 1.1 DNA viruses 1.2 RNA viruses 1.3 Retroviruses 2 Nonenveloped examples 2.1 DNA viruses 2.2 RNA viruses 3 See also 4 References 5 External links Enveloped examples Classes of enveloped viruses that contain human pathogens : DNA viruses Herpesviruses Poxviruses Hepadnaviruses RNA viruses Flavivirus Togavirus Coronavirus Hepatitis D Orthomyxovirus Paramyxovirus Rhabdovirus Bunyavirus Filovirus Retroviruses Retroviruses Nonenveloped examples Classes of nonenveloped viruses that contain human pathogens : DNA viruses Adenoviridae Papillomaviridae RNA viruses Picornaviridae See also Bacterial capsule Cell envelope References Jump up ^ `` CHAPTER # 11 : VIRUSES ''. Archived from the original on 2008 - 11 - 10. Retrieved 2008 - 11 - 07. Jump up ^ `` The Rabies Virus ''. CDC. Archived from the original on 2017 - 01 - 18. Retrieved 2008 - 11 - 07. External links `` Virus Structure ''. Molecular Expressions : Images from the Microscope. Retrieved 2007 - 06 - 27. Microbiology : Virus Components Viral envelope Capsid Viral protein Viral life cycle Viral entry Viral replication Viral shedding Virus latency Viroplasm Genetics Reassortment Antigenic shift Antigenic drift Phenotype mixing By host Bacteriophage Virophage Mycovirus Plant virus ( Plant to Human ) Animal virus Human virome Archea virus Amoeba virus Other Viral disease Helper virus Laboratory diagnosis of viral infections Viral load Virus - like particle Virus quantification Antiviral drug Neurotropic virus Oncovirus Social history of viruses Satellite virus Giant virus Viral proteins ( early and late ) DNA Herpes simplex Herpes simplex virus protein vmw65 HHV capsid portal protein Hepatitis B HBsAg HBcAg HBeAg HBx Hepatitis B virus DNA polymerase Epstein -- Barr EBNA - 1 EBNA - 2 EBNA - 3 LMP - 1 LMP - 2 EBER RNA Rotavirus VNPs : NSP1 NSP2 NSP4 NSP5 NSP6 Influenza capsid : matrix protein M1 protein viral envelope M2 protein glycoprotein : Influenza hemagglutinin Neuraminidase Parainfluenza Parainfluenza hemagglutinin - neuraminidase Mumps Mumps hemagglutinin - neuraminidase Measles Measles hemagglutinin RSV Respiratory syncytial virus G protein Hepatitis C VSPs : E1 E2 VNPs : P7 NS2 NS3 NS4A NS4B NS5A NS5B RT Structure and genome of HIV VSPs : gag pol Integrase Reverse transcriptase HIV - 1 protease env gp120 gp41 VRAPs : transactivators Tat Rev Vpr Nef Vif Vpu Fusion protein Gag - onc fusion protein Other B13R Retrieved from `` https://en.wikipedia.org/w/index.php?title=Viral_envelope&oldid=860715634 '' Categories : Virology Talk Contents About Wikipedia Català Čeština Deutsch Español Français Galego Italiano עברית Nederlands 日本 語 Norsk nynorsk Português Русский Slovenščina Svenska Türkçe 中文 9 more Edit links This page was last edited on 22 September 2018, at 15 : 28 ( UTC ). Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: what is the origin of a viral envelope
Answer: portions of the host cell membranes (phospholipids and proteins)