Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
55 Cards in this Set
- Front
- Back
Virus
|
- 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 |
|
Virus Genome
|
- Either DNA or RNA (not both)
- Single or double stranded - Linear or circular - Contained in a protein capsid shell |
|
Bacteriophage
|
Virus that infects bacteria
|
|
Bacteriophage Genome
|
- 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 |
|
Bacteriophage Structures (4)
|
- Head
- Tail Fiber - Sheath - Capsid |
|
Head
|
Genome located here
|
|
Tail Fiber and Base Plate
|
What attaches to the cell's surface
|
|
Sheath
|
- Injects Genome into host by contracting
- Uses stored ATP as energy - Need to puncture cell walls |
|
Capsid
|
Protein coat surrounding viral genome structure used to classify viruses
|
|
Animal Viruses
Envelope |
- Surrounds capsid
- Derived from the membrane of its host |
|
Animal Viruses
Budding |
- How a virus gets the envelope covering
|
|
Animal Viruses
"Naked" Virus |
- Don't have envelopes, don't need them
- Associated with cell walls, plant viruses, phages... |
|
Lytic Cycle
|
- Rapid increase in numbers
- Destroys host cell in the process - Phage genome made from dNTP of degraded host genome |
|
Hydrolase
|
- Lytic Cycle
- "Early Gene" which is transcribed first, degrades host genome - Expressed immediately after infection |
|
Lysozyme
|
- Typical "Late Gene"
- Destroys bacterial cell wall (which protects against osmotic pressure) - Cell bursts, releases viruses |
|
Lysogenic
|
- Clever girls...
- Virus genome incorporates itself into host genome - When host replicates genome it replicates prophage |
|
Prophage
|
- 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. |
|
Animal Virus Replication
Protein Receptors |
- 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 |
|
Endocytosis
|
- Animal Virus Replication
- How the virus gets in, host cell engulfs it and internalizes it (recall membrane coat) |
|
Provirus
|
Same thing as a prophage (virus DNA inserted into DNA of host)
|
|
Life Cycles of Animal Virus
|
- Lytic
- Lysogenic - Productive |
|
(+) RNA Virus
|
- 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 |
|
(-) RNA Virus
|
- Must carry RNA dependent RNA polymerase and encode it
- Makes a (+) strand when it infects host, and uses this (+) strand to make (-) strands. |
|
Retroviruses
|
- 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 |
|
What's special about Prokaryotes?
|
- No membrane bound organelles (nucleus, mitochondria, lysosome)
- Can still do cellular respiration and photosynthesis! |
|
Shapes (3)
|
Cocci - Round
Bacilli - Rod Spiralla - Spiral |
|
Prokaryotic Cytoplasm
|
- No nucleus, so the genome is here (circular)
- Plasmid is here - Transcription and translation occur in the same place, at the same time |
|
Plasmid
|
- Circular piece of ds-DNA smaller than the actual genome
- Has genes that are advantageous, help with exchange of info in conjugation |
|
Prokaryotic Cell Wall
|
- Has a lipid bilayer, outside of which is a cell wall (prevent lysis from osmotic pressure)
|
|
Peptidoglycan
|
- Unique construction of cross-linking sugars
- What's actually in the cell wall of prokaryotes |
|
Gram (+) Stains
|
- Cell wall with peptidoglycan
- Lipid Bilayer - Cytoplasm - Stain DARK! |
|
Gram (-) Stains
|
- Outer Membrane
- Periplasmic space with peptidoglycan - Inner Membrane - Stain LIGHT |
|
Prokaryotic Flagella
|
- Whiplike filaments used for moving
- Can have one, at both ends, or many - Different from eukaryotic! |
|
What affects Bacterial Growth?
|
- Temperature
- Nutrition |
|
Chemoautotroph
|
Build stuff from carbon dioxide using chemical energy
|
|
Chemoheterotroph
|
Rely on organic cmpounds for carbon and use energy from chemicals (this is us)
|
|
Photoautotroph
|
Use carbon dioxide as carbon source and light for energy (plants)
|
|
Obligate Aerobes
|
Love oxygen, need it to live
|
|
Facultative Anaerobes
|
Don't need oxygen, but will use it if it's there
|
|
Tolerant Anaerobes
|
Grow with oxygen or without it, won't use it
|
|
Obligate Anaerobes
|
Hate oxygen, it's a poison to them because they lack the enzyme that gets rid of oxygen free radicals
|
|
Binary Fission
|
- 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 |
|
Lag Phase
|
- Cell division doesn't happen here even in good times
- Need time to get division materials ready (genome) |
|
Log Phase
|
- Major Groph
- If time to double is 20 minutes, and we start with 1 bacteria, after 4 hours we get 4096 bacteria |
|
Stationary
|
- No dividing, because nutrients are getting limited
|
|
Carrying Capacity
|
- Maximum number the population that can withstand in an environment
- Limited by nutrients |
|
Endospores
|
- Gram (+) Bacteria
- Form in unfavorable conditions - Thick shells made of peptidoglycan, inside is everything needed to be metabolically active - Sleep through bad times |
|
Sex in Bacteria (3)
|
- Tranduction
- Transformation - Conjugation |
|
Transduction
|
Transfer of one genome to another
|
|
Transformation
|
Eat DNA, get new genes
|
|
Conjugation
|
- 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 |
|
F Plasmid
|
Has genes to produce sex pillus
|
|
Fungi Composition
|
- Multicellular eukaryotes
- Cell walls are rigid and made of chitin - Chemoheterotrophs that feed primary through absorption (digestion outside cells) |
|
Fungi Reproduction (Asexual - 3)
|
- Budding
- Fragmentation - Spore Formation |
|
Fungi Reproduction (Sexual)
|
- Adults are haploid (n)
- Fuse to form diploid (2n), which produce by meiosis to get more haploids. - Do this through having opposite hyphae (+ and -) |