Lecture 11 Flashcards
THREE DOMAINS:
Bacteria and Archaea (not subdivided into kingdoms, phyla, classes, etc. Instead they are divided into groups.)
Eukarya
The Archaeans are __ diverse than Bacteria, but are rather interesting as they often live in __
less
extreme conditions
which kingdoms have cell wall
almost all Bacteria
all archaea
some eukarya
Peptidoglycan in cell wall?
only most bacteria
Response to antibiotics?
bacteria Growth inhibited
Unicellular or multicellular
bacteria and archaea unicellular
eukarya Most multicellular, Some unicellular
Shapes and Organization of bacteria and archaea
Variety including coccus, bacillus, spiral
Single, diplo, strepto, staphylo
Shapes and Organization of eukarya
Variety (oval, columnar…)
Organized into tissues in multicellular organisms
Nuclear envelope?
only eukarya
Organelles?
only eukarya
Ribosomes
all kingdoms
Chromosome(s) in kigndoms?
bacteria and archaea: 1 (sometimes 2) circular
eukarya: Multiple linear in nucleus (circular in mitochondria & chloroplast)
Growth at >100°C?
only some archaea
Reproduction of kingdoms
bact and archaea: binary fission
eukarya: Mitosis, meiosis/sexual reproduction
rhizobium meaning
a nitrogen-fixing bacterium that is common in the soil
Phylum Proteobacteria:
rhizobium in plants
Problems in humans: food poisoning, stomach ulcers
Gram negative
Phylum Cyanobacteria:
Photosynthetic bacteria that fix carbon & nitrogen. release of large amounts of toxins. Most species are Gram negative.
Phylum Chlamydiae:
bacterium is the cause of a sexually transmitted infection
Gram negative.
Phylum Actinobacteria:
bacteria that make > 500 antibiotics identified so far. We culture them to make antibiotics. Gram positive.
size of Prokaryotes cells
1-10 µm
Most prokaryotic cells are 0.5–5 µm
Most are not much bigger than an organelle.
Why are prokaryotes everywhere?
Prokaryotes are highly adapted and diverse morphologically
Prokaryotes play crucial roles in ___-.
ecosystems
___ have both beneficial and harmful impacts on humans.
Bacteria
size of eukaryotic cells
10–100 µm
The 3 most common shapes of bacteria?
coccus, bacillus, and spiral
the diverse morphology is an adaptation to
survive in diverse environmental conditions.
can Spirillum be diplo, strepto, staphylo
nope, always single
Generalized cell structure for all prokaryotes
DNA - 1 circular chromosome in the nucleoid region -Multiple plasmids Ribosomes Cytoplasm Plasma membrane Cell wall
chromosome:
DNA + protein
plasmids?
are smaller circular fragments of DNA, that often have genes that code for proteins that make the bacteria resistant to certain antibiotics
are plasmids chromosomes
no
The genes of the plasmid are usually not essential to the ___, but they can increase their __
survival of the host bacteria
ability to survive in the presence of certain antibiotics.
Ribosomes in prokaryotes?
site of translation. Their structure is slightly different from that of ribosomes in eukaryotes.
function of cell wall?
maintains cell shape,
protects the cell and
prevents it from bursting in a hypotonic environment
Bacterial cell walls contain ?
peptidoglycan
Archaean cell walls contain __and __but lack __
polysaccharides
proteins
peptidoglycan
capsule function
This sticky covering and the fimbriae can be used to stick to a surface (ex your teeth), to other prokaryotic cells (to form a colony) or to protect the cell from the immune system of the host it’s invading.
endospores?
some bacterial cells can go into dormancy for CENTURIES, by forming endospores; they come out of dormancy when environmental conditions improve.