Unit 2 - Endomembrane System - Feb 24/27

Question 1

Nucleoid

Answer 1

Circular supercoiled chromosome found in only prokaryotes

Question 2

Motile

Answer 2

self moving, many bacteria are motile due to flagella

Question 3

Plasmid

Answer 3

small, circular piece of extra-chromosomal DNA

Question 4

Peptidoglycan

Answer 4

makes up semi-rigid but permeable cell wall that almost all bacteria have and prevents osmotic lysis (hypotonic cell)

Question 5

All Cells Have

Answer 5

Plasma Membrane
DNA
Cytosol
Ribosomes
Cytoskeleton

Question 6

Only Some Cells Have

Answer 6

Nucleus
Organelles
Cell Wall
Flagellum/Cilium

Question 7

Cytosol

Answer 7

aqueous fluid contained by plasma membrane. So densely packed with proteins=jelly-like

Question 8

Flagellum/Cilium

Answer 8

a membrane covered projection used to create movement

Question 9

Vacuoles

Answer 9

water-filled organelles that contribute to structural rigidity of plants by maintaining turgor pressure against cells walls

Question 10

Mitochondria

Answer 10

organelles found in virtually all eukaryotes that harness energy from chemical compounds (e.g., glucose, fats) and convert it into ATP

Question 11

Chloroplasts

Answer 11

organelles that capture the sun’s energy to synthesize simple sugars through photosynthesis

Question 12

The Endomembrane System evolved from

Answer 12

inner folds of plasma membrane that pinched off and enclosed DNA, creating eukaryotes.

Question 13

Endosymbiotic Theory

Answer 13

mitochondria and chloroplasts evolved from engulfed prokaryotes that gave an advantage to the host eukaryotic cell

Question 14

ZIP CODE Hypothesis

Answer 14

proteins are directed to the correct cellular location by signals within their amino acid sequence. (without specific zip code, default location is cytosol)

Question 15

Nuclear Envelope

Answer 15

a double-membrane structure that is linked with the ER, supported by a cytoskeletal structure called the nuclear lamina, and gated by multiple nuclear pore complexes (study structure)

Question 16

Nuclear Pore Complexes (NPCs)

Answer 16

allow selective passage of molecules between nucleus and cytoplasm

Question 17

The Endomembrane System is and includes?

Answer 17

a set of intracellular organelles interconnected by vesicular traffic. (ER, Golgi, lysosome, endosomes, plasma membrane)

Question 18

Exocytosis

Answer 18

process where an endomembrane vesicle can fuse with the plasma membrane and deliver contents into extracellular space

Question 19

Endocytosis

Answer 19

when material from outside cell is brought into vesicle that can fuse with other organelles

Question 20

Vesicular Transport

Answer 20

when a vesicle can pinch off one membrane and fuse with another (because of lipid bilayer fluidity)

Question 21

Steps of Vesicular Transport

Answer 21

1. lumen (inside donor compartment)
2. Budding of vesicle from lumen
3. Fusion of vesicle to target compartment

Question 22

The Rough ER

Answer 22

contains translating ribosomes and is where integral membrane and luminal proteins are synthesized

Question 23

The Smooth ER

Answer 23

where lipid-y stuff is synthesized

Question 24

Secretion (exocytosis) and steps?

Answer 24

entire process of vesicular transport out of the cell.

Steps:
1.Proteins from ER
2.secretory vesicle from Golgi
3.vesicles fuse plasma membrane
4.Integral membrane proteins -> plasma membrane proteins
5. Luminal proteins secreted extracellular

Question 25

Glycosylation

Answer 25

in Golgi, when integral membrane and secreted proteins are modified by carbohydrates, packaged, and sorted (takes place in the lumen)

Question 26

Endocytic Pathway

Answer 26

stuff outside cell or in plasma membrane can be brought into cell by endocytosis. This endocytic “cargo” can be recycled (sent to PM or lysosome)

Question 27

Lysosomes

Answer 27

acidic (maintained by protein pumps for acidic enzymes) and degradative organelles that breakdown any biological molecule into building blocks for reuse (cell’s compost bin)

Question 28

Signal Sequence

Answer 28

in protein currently being made directs ribosome to surface of ER

Question 29

Signal Anchor Sequences

Answer 29

become transmembrane domains, are released from translocation channel into ER membrane and diffuse into lipid bilayer