Chapter 20 Biology Miller & Levine

a particle made up of proteins, nucleic acids and sometimes lipids that can replicate only by infecting living cells - smaller and simpler than the smallest cells - developed after living cells - evolving for billions of years
the protein coat surrounding a virus
how do viruses infect living cells?
viruses have proteins on the surface that attach to the protein on the host cell - they trick the host cell into into taking the virus or its genetic material
what happens when virus infects host cell?
it uses the cell's genetic information to make copies of itself
single-celled organisms that lack a nucleus - their DNA is found in their cytoplam - they are classified as either bacteria or archaea - smaller than eukaryotic cells- 1 - 5 micrometers, some use flagella to move and others put down slime and glide along it and some don't move at all - they also get and release energy differently
live almost everywhere. This molecule is made up of sugar and amino acids. Some have a cell membrane outside the cell that protects them. They may also use flagella or pili for movement.
part of bacteria that helps it move and helps prokaryotes to move
help bacteria move and also help them attach to the surfaces or other bacteria
rod-shaped prokaryotes
spiral and cork-shaped prokaryptes
sphere-shaped prokarotes
binary fission
a type of asexual reproduction in which an organism relicates its DNA and divides in half, producing two identical daughter cells
Why are prokaryotes (bacteria) so important?
decompose dead organisms and waste and help to sanitize water.
organism that can cause sickness
chemicals that upset the normal activity of the host
how can you control bacteria
wash hands, wash surfaces, (washing removes but doesn't kill bacteria. disinfectants kill bacteria)
a preparation of weakened or killed pathogens used to produce immunity to a disease
drugs to treat bacterial infection - keeps bacteria from growing and reproducing - do not harm host cell
best way to protect against virus
prevention - wash your hands, use vaccines, only antiviral meds to treat viruses - not antibiotics
like bacteria that are resistant to many antibiotics
new viruses
virus that evolves and jumps from one host species to another like bird flu or HIV
formed when a certain type of protein (PrP3) folds incorrectly and as they build up they cause damage to brain cells. spread when animals eat infected animals. Can infect humans too.