lecture 3 Flashcards
1
Q
commonality of cells?
A
- plasma membrane
- cytoplasm (gelatinous fluid fills inside centre)
- genetic material
- mitosis (clonal reproduction of cells)
- meiosis (cell division)
2
Q
prokaryote
A
- circular chromosome
- no membrane bound organelles
- small sized
- archea are chemosynthetic
3
Q
eukaryotes
A
- chromosomes enclosed in dbl membrane
- membrane bound organelles
- larger
4
Q
evolution of eukaryotes
A
- autogenesis hypothesis
- endosymbiosis hypothesis
5
Q
autogenesis
A
- organelles found arose from ancestral prokaryotic cell
- undwerwent compartmentalisation of function (as it grew, volume surface area ratio was off then unable to absorb enough nutrients)
- infolding of the membrane, pinching off forming endoplasmic reticulum, nuclear envelope and golgi apparatus
- anaerobic protobacterium enters cell, becomes endosymbiont
- eventually becomes mitochondrion
- cyanobacterium enters forming chloroplasts
6
Q
endosymbiosis and evidence
A
- ancestral cell prokaryotes as food
- not digested, stayed as symbionts
- occured more than once (serial endosymbiosis)
- anaerobic ancester, eukaryote cell absorbed aerobic heterotrophic prokaryote
- over time became mitochondrion
- photsynthetic prokaryote enters primitive eukaryote cell
- eventually assimilated into cell becoming plastid (chloroplast).
- smaller size
- own dbl circular DNA strand
- dbl membranes
- own ribosomes
- reproduce by binary fission
- doesn’t explain origin of organelles
- aerobic protobacterium enters cell, becomes endosymbiont
- eventually becomes mitochondrion
- cyanobacterium enters forming chloroplasts
- cell is now aerobic
7
Q
general animal/plant cell
A
- nucleus
- endoplasmic reticulum
- plasma membrane
- golgi apparatus
- ribosomes
- cytoskeleton
8
Q
animal cell unqiue
A
- centrosomes (microtubules)
- flagellum (motility)
- lysosomes (digestive, help break down of macromolecules)
9
Q
plant cell unique
A
- cell wall (shape+protection)
- plasmodesmata (channels connect cytoplasms of two cells)
- chloroplasts (photsynthetic)
- central vacuole (prominent in plant growth, breakdown of was and hydrolysis of macromolecules)
10
Q
endomembrane
A
- synthesis of proteins
- transport+modification of proteins
- metabolism
- detoxification of proteins
11
Q
nucleus
A
- contains most of genes (chromatin/chromosomes)
- information center
- pores in envelope lined with protein sturcture (pore complex)
- regulates entry/exit of proteins/RNAs/macromolecules
- nucleolus (RNA synthesis)
12
Q
cell membrane
A
- dbl bilayer of phospholipids
- embedded with proteins
- outside has carbohydrate chains
- selective barrier
13
Q
Endoplasmic reticulum
A
- netwrok of membranes (membranous sacs and tubules cisternae)
- smooth ER
- no ribomoes attatched
- synthesis of lipids
- detoxification of poisons
- storage of calcium ions
- rough ER
- ribosomes attatched
- protein synthesis of secretory proteins/phospholipids
- modification of proteins
- used in forming transport vesicles (travel to Golgi)
14
Q
Golgi apparatus
A
- vesicles transport synthesese from rough er to golgi
- flattened membranous sacs (cisternae)
- receives moleculed from rough er
- modifies molecules
- packages into vesicles and transports
- disting structural directionality (different thickness on sides of sacs, different molecular composition)
15
Q
vesicles
A
- organelles containing different substances
- relatively round
- surrounding membrane and some fluif
