organelles Flashcards
1
Q
what’s the endomembrane system
A
membranes of the system are either directly connected or connected by transport vesicles
2
Q
what organelles are in the endomembrane system
A
nucleus
ribosomes
endoplasmic reticulum
Golgi apparatus
lysosome
vacuoles
3
Q
nucleus characteristics
A
- contains most of the cells gene
- nucleolus located within it - site of RNA synthesis
- DNA and proteins form genetic material (chromatin) - condenses into chromosomes
- nuclear envelope (double bilayer) separates it from cytoplasm
- nuclear pores regulate the exit and entry of molecules
- shape maintained by nuclear lamina composed of protein filaments
4
Q
ribosomes characteristics
A
- particles of ribosomal RNA and protein that covert RNA -> protein
- carry out protein synthesis in 2 locations:
-cytosol (free ribosomes): make protein for use in the cytosol
-outside of ER: make proteins for use elsewhere
5
Q
endoplasmic reticulum characteristics
A
- continuous with nuclear envelope
- 2 distinct regions:
-smooth ER: lacks ribosomes - synthesises lipids, metabolises carbs, detoxifies poison, stores calcium
-rough ER: w/ ribosomes that excrete glycoproteins - distributes transport vesicles + synthesises membrane for the cell
6
Q
Golgi apparatus characteristics
A
- modifies products of the ER
- Sorts and packages materials into transport vesicles
- contains flattened membrane sacs = cisternae
7
Q
lysosome characteristics
A
- membrane sac of hydrolytic enzymes that can digest macromolecules
- autophagy = recycle of the cells own organelles and macromolecules
8
Q
vacuoles characteristics
A
- fungi and plants (may have several)
- storage containers
- food vacuoles - formed by phagocytosis
- contractile vacuoles - pump excess water out of cells
- central vacuoles - hold organic compounds + water
9
Q
what organelles are included in energy conversion
A
mitochondria
chloroplasts
peroxisomes
10
Q
mitochondria characteristics
A
- site of energy production (atp)
- site of where some metabolic steps of cellular respiration are catalysed
- smooth outer membrane
- ## inner membrane folded into cristae + creates 2 compartments: inter membrane space + matrix
11
Q
chloroplast characteristics
A
- CO2 -> sugars
- member of plastids
- contains chlorophyll + enzymes for photosynthesis
- structure includes: thylakoids + stroma
12
Q
peroxisomes characteristics
A
- metabolic compartments bounded by single membrane that break down molecules
- produce hydrogen peroxide (toxic) which is converted to H2O
13
Q
3 cytoskeleton microfibres
A
microtubules
microfilaments
intermediate filaments
14
Q
microfilaments structure
A
2 intertwined strands of actin
14
Q
microtubules structure
A
hollow tubes (tublin)
