Biology 3 (Microbiology)

Front 1

Virus

Back 1

- Obligate intracellular parasite
- Can only reproduce in other host's cells
- NOT LIVING
- Can't synthesize ATP on its own, have to hijack the host's cell

Front 2

Virus Genome

Back 2

- Either DNA or RNA (not both)
- Single or double stranded
- Linear or circular
- Contained in a protein capsid shell

Front 3

Bacteriophage

Back 3

Virus that infects bacteria

Front 4

Bacteriophage Genome

Back 4

- Rigid and economical in size
- Carries only really necessary genes and relies on host for transcription/translation proteins
- Can overlap reading frames to code for two proteins

Front 5

Bacteriophage Structures (4)

Back 5

- Head
- Tail Fiber
- Sheath
- Capsid

Front 6

Head

Back 6

Genome located here

Front 7

Tail Fiber and Base Plate

Back 7

What attaches to the cell's surface

Front 8

Sheath

Back 8

- Injects Genome into host by contracting
- Uses stored ATP as energy
- Need to puncture cell walls

Front 9

Capsid

Back 9

Protein coat surrounding viral genome structure used to classify viruses

Front 10

Animal Viruses
Envelope

Back 10

- Surrounds capsid
- Derived from the membrane of its host

Front 11

Animal Viruses
Budding

Back 11

- How a virus gets the envelope covering

Front 12

Animal Viruses
"Naked" Virus

Back 12

- Don't have envelopes, don't need them
- Associated with cell walls, plant viruses, phages...

Front 13

Lytic Cycle

Back 13

- Rapid increase in numbers
- Destroys host cell in the process
- Phage genome made from dNTP of degraded host genome

Front 14

Hydrolase

Back 14

- Lytic Cycle
- "Early Gene" which is transcribed first, degrades host genome
- Expressed immediately after infection

Front 15

Lysozyme

Back 15

- Typical "Late Gene"
- Destroys bacterial cell wall (which protects against osmotic pressure)
- Cell bursts, releases viruses

Front 16

Lysogenic

Back 16

- Clever girls...
- Virus genome incorporates itself into host genome
- When host replicates genome it replicates prophage

Front 17

Prophage

Back 17

- Virus phage genome
- "Silent". Genes not expressed, progeny not made directly
- Prevented from replicating itself by host proteins that bind to to operator
- The trick is that the virus doesn't care. It sits there..waiting..until it removes itself and enters lytic.

Front 18

Animal Virus Replication
Protein Receptors

Back 18

- Animal virus likes to hijack receptors on a cel that have a normal function, virus uses these to recognize its target cell (smart)
- Host can't change this process because they have normal physiological functions too

Front 19

Endocytosis

Back 19

- Animal Virus Replication
- How the virus gets in, host cell engulfs it and internalizes it (recall membrane coat)

Front 20

Provirus

Back 20

Same thing as a prophage (virus DNA inserted into DNA of host)

Front 21

Life Cycles of Animal Virus

Back 21

- Lytic
- Lysogenic
- Productive

Front 22

(+) RNA Virus

Back 22

- MUST encode RNA dependent RNA polymerase
- Don't have to carry this
- Simplest kind of viral genome
- Makes (-) strand before generating new (+) genomes
- Host can't distinguish between virus mRNA and its own, so it's replicated

Front 23

(-) RNA Virus

Back 23

- Must carry RNA dependent RNA polymerase and encode it
- Makes a (+) strand when it infects host, and uses this (+) strand to make (-) strands.

Front 24

Retroviruses

Back 24

- Must encode reverse transcriptase
- They are basically (+) RNA viruses that incorporate themselves into host genome as proviruses
- Lysogenic viruses
- Enter as RNA, use enzyme to turn to DNA

Front 25

What's special about Prokaryotes?

Back 25

- No membrane bound organelles (nucleus, mitochondria, lysosome)
- Can still do cellular respiration and photosynthesis!

Front 26

Shapes (3)

Back 26

Cocci - Round
Bacilli - Rod
Spiralla - Spiral

Front 27

Prokaryotic Cytoplasm

Back 27

- No nucleus, so the genome is here (circular)
- Plasmid is here
- Transcription and translation occur in the same place, at the same time

Front 28

Plasmid

Back 28

- Circular piece of ds-DNA smaller than the actual genome
- Has genes that are advantageous, help with exchange of info in conjugation

Front 29

Prokaryotic Cell Wall

Back 29

- Has a lipid bilayer, outside of which is a cell wall (prevent lysis from osmotic pressure)

Front 30

Peptidoglycan

Back 30

- Unique construction of cross-linking sugars
- What's actually in the cell wall of prokaryotes

Front 31

Gram (+) Stains

Back 31

- Cell wall with peptidoglycan
- Lipid Bilayer
- Cytoplasm

- Stain DARK!

Front 32

Gram (-) Stains

Back 32

- Outer Membrane
- Periplasmic space with peptidoglycan
- Inner Membrane

- Stain LIGHT

Front 33

Prokaryotic Flagella

Back 33

- Whiplike filaments used for moving
- Can have one, at both ends, or many
- Different from eukaryotic!

Front 34

What affects Bacterial Growth?

Back 34

- Temperature
- Nutrition

Front 35

Chemoautotroph

Back 35

Build stuff from carbon dioxide using chemical energy

Front 36

Chemoheterotroph

Back 36

Rely on organic cmpounds for carbon and use energy from chemicals (this is us)

Front 37

Photoautotroph

Back 37

Use carbon dioxide as carbon source and light for energy (plants)

Front 38

Obligate Aerobes

Back 38

Love oxygen, need it to live

Front 39

Facultative Anaerobes

Back 39

Don't need oxygen, but will use it if it's there

Front 40

Tolerant Anaerobes

Back 40

Grow with oxygen or without it, won't use it

Front 41

Obligate Anaerobes

Back 41

Hate oxygen, it's a poison to them because they lack the enzyme that gets rid of oxygen free radicals

Front 42

Binary Fission

Back 42

- Bacteria don't have mitosis or meiosis
- They grow in size until they've got enough genome for two of them, and then split in half
- Genetically identical cells

Front 43

Lag Phase

Back 43

- Cell division doesn't happen here even in good times
- Need time to get division materials ready (genome)

Front 44

Log Phase

Back 44

- Major Groph
- If time to double is 20 minutes, and we start with 1 bacteria, after 4 hours we get 4096 bacteria

Front 45

Stationary

Back 45

- No dividing, because nutrients are getting limited

Front 46

Carrying Capacity

Back 46

- Maximum number the population that can withstand in an environment
- Limited by nutrients

Front 47

Endospores

Back 47

- Gram (+) Bacteria
- Form in unfavorable conditions
- Thick shells made of peptidoglycan, inside is everything needed to be metabolically active
- Sleep through bad times

Front 48

Sex in Bacteria (3)

Back 48

- Tranduction
- Transformation
- Conjugation

Front 49

Transduction

Back 49

Transfer of one genome to another

Front 50

Transformation

Back 50

Eat DNA, get new genes

Front 51

Conjugation

Back 51

- Physical contact, bridges mae from F+ (males) to F- (females)
- Transfer "factor" to females, which then become males
- Only occurs in the presence of females

Front 52

F Plasmid

Back 52

Has genes to produce sex pillus

Front 53

Fungi Composition

Back 53

- Multicellular eukaryotes
- Cell walls are rigid and made of chitin
- Chemoheterotrophs that feed primary through absorption (digestion outside cells)

Front 54

Fungi Reproduction (Asexual - 3)

Back 54

- Budding
- Fragmentation
- Spore Formation

Front 55

Fungi Reproduction (Sexual)

Back 55

- Adults are haploid (n)
- Fuse to form diploid (2n), which produce by meiosis to get more haploids.
- Do this through having opposite hyphae (+ and -)