TEST 3 Flashcards
(230 cards)
dmitosis results
-Results in two diploid (two copies of each chromosome)
daughter cells
meiosis results
-results in four haploid gametes
Cristae of mitochondria
-folded internal membranes
-Contain enzymes needed for respiration and ATP production
Matrix of mitochondria
-innermost area of mitochondrion
-Contains citric acid enzymes
Thylakoids in chloroplast
-flattened membrane discs contain
chlorophyll and ATP synthetic components, form proton motive force
rubisco
-key enzyme for calvin cycle
-found in inner membrane of mitochondria
Endosymbiotic hypothesis
-Mitochondria and chloroplasts descended from respiratory and
phototrophic bacterial cells, that were enveloped and used with nonphototrophic eukaryal hosts
-mitochondria utilized before chloroplasts
eukaryote origins
-fusion of archaeal host and mitochondrial precursor
Microtubules
hollow tubes made up of a & b tubulin
25nm
-Maintain cell shape, moves cell chromosomes and organelles
microfilaments
polymer of actin
7nm
-Maintain and change cell shape
Intermediate filaments
fibrous keratin proteins
8-12nm
-Maintain cell shape and position organelles
golgi complex
-stacks of membrane-bound sacs
modifying ER products
lysosomes
-membrane-enclosed compartments
containing digestive enzymes and recycling cell
components
Endoplasmic reticulum
-a network of membranes continuous with nuclear membrane
-rough and smooth
-rough has ribosomes; processes glycoproteins
-smooth does not; processes lipids
flagella composition
-Bundle of nine pairs of microtubules surrounding a central pair of microtubules
-Dynein is attached and uses ATP to drive motility
-eukarya and prokarya flagella are different
first phototrophs
anaerobic
Stromatolites
fossilized bacterial communities
ozone shield
-02 gave rise to collection of 03 in atmosphere
-03 in atmosphere blocks suns harmful radiation (UV)
-allows for organisms to colonize land
Phylogeny
-Evolutionary history of related DNA
sequences
bacteria and archaea divergence in relation to eukarya
before the emergence of eukarya
bacteria and archaea divergence time
3.7bya
eukaryas divergence from archaea divergence time
1.5-2.7bya
-oxygen may have spurred evolution
last eukaryotic common
ancestor LECA characteristic
-4000 genes
2/3 from bacteria (metabolic)
1/3 archaea (info processing)
70% are genes only in eukaryotes
evidence for endosymbiont theory
-Chloroplasts and mitochondria about the same size as bacteria
and independently replicate
-Both contain their own genomes of bacterial genes and are
circular
-Both contain bacterial ribosomes
-16S rRNA are characteristic of Bacteria
-Antibiotics inhibit both bacterial and organelle ribosome function