viruses are not alive but affect living things

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VIRUSES ARE NOT ALIVE BUT AFFECT LIVING THINGS

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VIRUSES ARE NOT ALIVE BUT AFFECT LIVING THINGS. VIRUSES SHARE SOME CHARACTERISTICS WITH LIVING THINGS. VIRUSES MULTIPLY INSIDE LIVING CELLS VIRUSES MAY HARM HOST CELLS. VIRUSES. VIRUS means poison; much smaller than bacteria, can’t even be “filtered” out of a liquid like bacteria can be. - PowerPoint PPT Presentation

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Page 1: VIRUSES ARE NOT ALIVE BUT AFFECT LIVING THINGS

VIRUSES ARE NOT ALIVE BUT AFFECT LIVING

THINGS

Page 2: VIRUSES ARE NOT ALIVE BUT AFFECT LIVING THINGS

VIRUSES SHARE SOME CHARACTERISTICS WITH

LIVING THINGS• VIRUSES MULTIPLY INSIDE LIVING

CELLS

• VIRUSES MAY HARM HOST CELLS

Page 3: VIRUSES ARE NOT ALIVE BUT AFFECT LIVING THINGS

VIRUSES• VIRUS means poison; much smaller than bacteria,

can’t even be “filtered” out of a liquid like bacteria can be.

• Viruses have genetic material inside of a protective protein coat called a CAPSID.

• They come in many shapes & sizes, but all have a CAPSID and GENETIC MATERIAL.

• VIRUSES must use a host cell to reproduce (by making genetic material & capsids).

• Viruses do not grow & don’t respond to changes in the environment, so they are not living organisms

Page 4: VIRUSES ARE NOT ALIVE BUT AFFECT LIVING THINGS
Page 5: VIRUSES ARE NOT ALIVE BUT AFFECT LIVING THINGS

Viruses Multiply inside Living Cells• Viruses use HOST CELLS to make copies of themselves. A

bacteriophage (means bacteria eater) is used to show the process.• ATTACHMENT: virus attaches to cell • INJECTION: injects its DNA inside• PRODUCTION: uses cell’s machinery to copy the viral DNA and

capsids• ASSEMBLY: viral DNA forces infected cell to assemble new

viruses• RELEASE: cell bursts open, releasing 100+ new viruses to infect

other cells.• Viruses have proteins on surface that look like proteins the host

cell normally needs to fool it & “dock” onto sites of cell membrane

Page 6: VIRUSES ARE NOT ALIVE BUT AFFECT LIVING THINGS
Page 7: VIRUSES ARE NOT ALIVE BUT AFFECT LIVING THINGS

Viruses May Harm Host Cells• Virus uses cell’s material, energy , and processes to

reproduce often bursting out & destroying the host cell. (some just hide in cell or just make 1 virus at a time & not be as harmful)

• About 25 million people died of influenza virus in outbreak after WWI.

• Plant viruses can stunt growth & kill plants• Plant, animals, bacteria & all other living things can be

infected by viruses.• Scientists can use viruses to insert pieces of genetic

material into living cells. (like a marine organisms DNA into other tissue causing it to glow so can study it better)

Page 8: VIRUSES ARE NOT ALIVE BUT AFFECT LIVING THINGS