CH6 Part 1

Question 1

Hooke Cell Theory

Answer 1

1. All living organisms are composed of one or more cells
2. Cells are the monomer of any organism
3. New cells arise from pre-existing, living cells

Question 2

Additions to Hooke cell theory

Answer 2

1. No matter the species, chemical composition of cells is similar
2. DNA is source of heredity
3. Biochemical energy flows within cells
4. organisms activity is product of cell activity

Question 3

Major difference between Prokaryotes and Eukaryotes

Answer 3

Prok. dont have membrane-bound organelles (“before the nucleus”)

Question 4

Prokaryotes

Answer 4

Bacteria, archaea, blue green algae

Question 5

Largest taxonomic division and the three recognized

Answer 5

Domain: Archaea, Bacteria (preceding are Prok.), Eukarya

Question 6

Taxonomic division under domain

Answer 6

Kingdom, Eukaryotes: Animalia, Plantae, Fungi

Question 7

What genetic elements can be found in a prokaryote

Answer 7

1. Single double stranded DNA
2. Polyribosome
3. plasmid (circular peice of ds-DNA much smaller than genome) also known as an extrochromosal genetic element. Typically confer an advantage. Also facilitate conjugation - prokaryotic sharing of info.

Question 8

Bacteria Shapes and proper name?

Answer 8

1. Round - Cocci
2. Rod-shaped - Bacilli
3. spiral-shaped - Spirochetes or spirillia

Question 9

Bacterial Cell Wall

Answer 9

Rigid, composed of peptidoglycan which also contains D-alanine (both are unique to prokaryotes).
Note: lysozyme destroys the cell wall resulting in a protoblast

Question 10

Gram Staining

Answer 10

Gram-positive: stains dark purple. Has thick wall of peptidoglycan.

Gram-negative: stains pinkish. Thin wall of peptidoglycan but additional exterior wall of lipopolysaccaride. Space between two walls = periplasmic space (can contain enzymes that degrade antibiotics)

Question 11

Endotoxins

Answer 11

Found in outer membrane of gram-negative bacteria

Not inherently toxic, but cause strong immune reaction

if many bacteria die, releasing endotoxins, can cause a patient to experience septic shock. Aqueous blood is leaked into tissue causing large drop in blood pressure.

Question 12

Exotoxins

Answer 12

Secreted by both gram(+) and gram(-). Help bacteria compete against other - sometimes natural bacterias.

Disease examples: Botulism, diptheria, tetanus, toxic shock syndrome

Question 13

Capsule

Answer 13

Also known as glycocalyx.

Sticky layer of polysaccaride surrounding bacteria/colony

Prevents immune detection and improves adhesion to surfaces.

Question 14

Flagella Distribution

Answer 14

Monotrichous - flagella at one end

Amphitrichous - flagella at both ends

Peritrichous - multiple flagella

Question 15

Flagella Structure

Answer 15

Filament
Hook - like a 90o bend
Basal Structures - anchor to inner and outer membrane, and rotate rod

Powered by diffusion of H+ down proton gradient across inner membrane

*Note: different microtubule formation than in eukaryotes

Question 16

Chemotaxis

Answer 16

Orienting toward or away from food or toxins respectively. Detected by chemoreceptors.

Question 17

Pili

Answer 17

Long projections involved in attaching to different surfaces.

Question 18

Sex pilus

Answer 18

Facilitates Conjugation Bridges between F+ (male) and F- (female) bacteria.

Question 19

Fimbrae

Answer 19

Facilitate adhesion to surfaces.

Question 20

Bacteria and Temperature

Answer 20

Can be used to classify bacteria.

Mesophiles: Prefer mild temperatures (30oC)

Thermophiles: survive up to 100oC

psychrophiles: near 0oC

Question 21

Bacteria classification with Nutrition

Answer 21

Autotrophs - CO2 as carbon source

Heterotrophs - organic nutrients

Chemotrophs - energy from chemicals

Phototrophs - energy from light

But all bacteria are either Autotroph or Heterotroph and Chemotroph or Phototroph

Question 22

4 Types of Bacteria

Answer 22

Chemoautotrophs: Build organic molecules from CO2 using chemical energy derived from inorganic molecules like H2S

Chemoheterotrophs: Require organic material as carbon source and energy

Photoautotrophs: CO2 as carbon source and energy from the sun

Photoheterotrophs: Energy from sun, but require organic molecule from other organism

Question 23

Minimal Medium

Answer 23

Contains only glucose

Question 24

Lawn and Plaque

Answer 24

Lawn is a dense growth of bacteria. Plaque is a gap in growth.

Question 25

Auxotroph

Answer 25

A bacteria that cannot survive in minimal media, because can't produce a molecule it needs to survive. Requires AUXillary Trophic substance to survive. Ex. Arginine

Question 26

Obligate Aerobes

Answer 26

require oxygen

Question 27

Anaerobes

Answer 27

Do not require oxygen

Question 28

Faculative Anaerobes

Answer 28

Use O2 when around, but not needed

Question 29

Tolerant Anaerobes

Answer 29

Do not O2 in metabolism but can have present

Question 30

Obligate Anaerobes

Answer 30

Poisoned by oxygen

Question 31

Fermentation v. Respiration

Answer 31

Respiration: Glucose catabolism with inorganic molecule Fermentation: Glucose catabolism without an electron acceptor - produces a byproduct

Question 32

Anaerobic Respiration

Answer 32

Glucose metabolism with electron transport and oxidative phosphorylation without oxygen (ex. SO4, H2S, CO2, CH4)

Question 33

Log Phase

Answer 33

Exponential growth phase of bacteria (Log of exponential curve is linear), following lag phase and stationary phase)

Question 34

Lag phase

Answer 34

precedes exponential growth and occurs for bacteria that were not previously growing, Result of needing to produce components for cell division ex. dNTPs

Question 35

Stationary phase

Answer 35

Cease to divide due to lack of nutrients

Question 36

Endospores

Answer 36

Formed by gram-positive bacteria under poor growth conditions. Contains genome, ribosomes, and RNA in hard shell of peptidoglycan. Can withstand up to 100oC. Cannot divide during this period. Metabolic reactivation = germination.

Question 37

Bacterial means to acquire new genetic info

Answer 37

Transduction - Transfer of DNA by a lysogenic phage Transformation - Under certain conditions, pure DNA will simply be integrated into cell. Conjugation -

Question 38

Conjugation

Answer 38

Two bacteria form conjugation bridge and one cell dopies DNA and transfers to other cell. F (fertility) factor is key. If have F factor = F+ and male. If not F- and female. F factor is exchanged during conjugation, so "sex" is transferred.

Question 39

F factor

Answer 39

Fertility factor: singular circular DNA molecule. Contains many genes involved in conjugation ex. to form sex pili.

Question 40

Hfr Cell

Answer 40

High Frequency Recombination Cell - F factor can become integrated into genome through recombination. Can still drive conjugation. Note recombination can occur during conjugation as some genes in the F- cell will now be duplicate.

Question 41

Conjugation Mapping

Answer 41

Can be performed using Hfr cells. Review pg. 157 for more detail

Question 42

Archaea

Answer 42

Live in most extreme environments. Have cell wal without peptidoglycan. Similar traits to Eukaryotes: introns, mRNA sequences that are similar. Reproduce via fusion or fission. Extremely beneficial for industrial research.

Question 43

Parasitic Bacteria

Answer 43

Obligate - must be inside a host to replicate Faculative - can replicate inside or outside a host cell

Question 44

Symbiotic Bacteria

Answer 44

Ex. Rhizobia - fixes nitrogen in the roots of legumes Ex 2. Cyanobacteria in marine environments fix nitrogen