2.3

Question 1

all cells have

Answer 1

similar biological membranes

Question 2

two categories of organisms

Answer 2

prokaryotes - NO membrane enclosed organelles
eukaryotes - membrane enclosed organelles

Question 3

nucleoid

Answer 3

prokaryote’s chromosomes are located in a region of the cytoplasm called the nucleoid

Question 4

chromosomes

Answer 4

supercoiled, circular DNA, RNA, and proteins

Question 5

plasmid

Answer 5

small circular DNA that some prokaryotic cells have

Question 6

cell wall

Answer 6

made of peptidoglycans (+ an outer membrane)
protection and shape

Question 7

capsule

Answer 7

slimy polysaccharide layer (due to -OH groups)
hydration of cell

Question 8

flagellum

Answer 8

made of protein flagellin
cell movement

Question 9

animal cells vs. plant cells

Answer 9

animal cells have centrioles and lysosomes
plant cells have vacuoles and chloroplasts

Question 10

nucleus

Answer 10

contains most of the cellular DNA and is the site of replication and transcription

Question 11

nucleolus

Answer 11

RNA is synthesized, ribosome subunits assembled (synthesis)

Question 12

nucleoplasm

Answer 12

chromatin, the DNA-protein complex is assembled

Question 13

nuclear envelope

Answer 13

a lipid double membrane containing thousands of nuclear pores
surrounds the nucleus
separates chromatin from cytoplasm

Question 14

nuclear pore

Answer 14

large complex of multi-subunit proteins and regulates the transport of macromolecules

Question 15

FG Nups layer

Answer 15

made up of phenyalanine and glycine
macromolecules need the assistance of special proteins to pass here

Question 16

site of protein synthesis

Answer 16

always begins on free ribosomes in the cytosol

Question 17

ribosomes

Answer 17

site of protein synthesis
similar structure in prokaryotes and eukaryotes
lack membranes
consist of two subunits made up of rRNA and numerous proteins

Question 18

signal sequence

Answer 18

added to the polypeptide chain during translation indicating where it in cell it belongs
added to the N-terminus of newly synthesized proteins
binds to receptor proteins on the surface of an organelle
removed by proteases after translation

Question 19

post-translational translocation

Answer 19

proteins are synthesized by free ribosomes in the cytosol and then sorted to a specific organelle via signal sequences
leads to peroxisomes, plastids, mitochondria, or the nucleus

Question 20

nuclear localization signal (NLS)

Answer 20

directs a protein to the nucleus
consists of one or more clusters of positively charged lysine or arginine
binds to a special protein (nuclear transport protein) for import

Question 21

co-translational translocation

Answer 21

ER signal sequence causes translation to pause and directions ribosomes to the rough ER
a signal recognition particle in the cytoplasm binds to the ER signal sequence and bring the polypeptide-ribosome complex to the RER

Question 22

endomembrane system

Answer 22

group of membranes and organelles that works together to process and transport proteins and lipids

Question 23

vesicles

Answer 23

shuttle between parts of the endomembrane system

Question 24

endoplasmic reticulum

Answer 24

network of membranes in the cytoplasm
continuous with the nuclear envelope
2 regions - smooth and rough ER

Question 25

rough endoplasmic reticulum

Answer 25

formed when ribosomes attach to the ER membrane - in the ribosome attached to the outside of the RER --protein synthesis occurs - in the lumen of RER -- protein folding -- protein modification (glycosylation, proteolysis of signal peptide) --protein translocation to other locations in vesicle

Question 26

smooth endoplasmic reticulum

Answer 26

lacks ribosomes chemical modification of small toxic molecules taken in by the cell glycogen degradation in animal cells synthesis of lipids (phospholipids, steroids) storage of calcium ions

Question 27

golgi apparatus

Answer 27

flattened membranous sacs (cisternae) and small membrane enclosed vesicles cis face - receives proteins from RER (closest to RER) medial face - in between trans face - ships content to the cell membrane, etc. via vesicles (closest to membrane)

Question 28

golgi apparatus function

Answer 28

modifies, processes, packages, and sorts proteins in its lumen before they are sent to their destination -protein modification (glycosylation, -modification of carbohydrates) -proteolysis of precursor proteins into smaller, functional fragments -synthesis of polysaccharides for the cell wall -protein targeting to their destination