Lecture 5- Eukaryotic Cells

Question 1

steps of eukaryote evolution

Answer 1

1. compartmentalization
2. the endosymbiotic hypothesis

Question 2

the endosymbiotic hypothesis explains how mitochondria and chloroplasts ______

Answer 2

arose from bacteria living inside primate eukaryote

Question 3

the endomembrane system is a subset of organelles that are interconnected via _____ and evolved from _____

Answer 3

vesicles; membrane infolding

Question 4

endomembrane system pathway

Answer 4

ER - golgi - lysosome/plasma membrane

Question 5

nucleus function

Answer 5

where DNA is stored and packaged in multiple linear chromosomes

Question 6

nucleolus function

Answer 6

site of rRNA transcription and ribosomal subunit assembly

Question 7

nuclear envelope function

Answer 7

separates nucleoplasm from cytoplasm

Question 8

nuclear envelope structure

Answer 8

2 phospholipid bilayers and outer membrane is continuous with ER

Question 9

Why package DNA

Answer 9

to organize and protect it

Question 10

orders of packaging of DNA
1. nucleosome-DNA wraps around positively charged proteins called ______
2. _________- nucleus stack on top of one another facilitated by histone H1
3. ______ domains where 30nm fiber loops off a non-histone scaffold
4. mitotic chromosomes- fully condensed only in ______

Answer 10

histones; solenoid; looped; mitosis

Question 11

rough endoplasmic reticulum (RER) function

Answer 11

site of protein synthesis for proteins that functions within the endomembrane system; site of protein quality control

Question 12

ribosomes function

Answer 12

enzymes of translation

Question 13

ribosomes on RER are called _____

Answer 13

bound ribosomes

Question 14

cytoplasm proteins are made with

Answer 14

free ribosomes

Question 15

nucleoplasm proteins are made with

Answer 15

free ribosomes

Question 16

plasma membrane proteins are made with

Answer 16

bound ribosomes

Question 17

exported/secreted proteins are made with

Answer 17

bound ribosomes

Question 18

free ribosomes translate ______

Answer 18

proteins with functions outside of endomembrane system

Question 19

smooth ER function

Answer 19

ion storage, phospholipid synthesis, steroid synthesis, detoxification of drugs and alcohol

Question 20

golgi function

Answer 20

receives cargo from the ER and sorts that cargo to different destinations such as the lysosome, PM, or back to ER
- also packages cargo into vessicles

Question 21

golgi structure

Answer 21

set of flattened membranous sacs called cisternae

Question 22

cis golgi

Answer 22

receiving side

Question 23

trans golgi

Answer 23

shipping/transport side

Question 24

Vesicle trafficking

Answer 24

each cisterna remains in one place with unchanging enzymes, and the proteins move forward through the stack via vesicles that move from earlier to later cisternae (anterograde traffic)

Question 25

cisternal maturation

Answer 25

As a new cis cisterna is formed it traverses the Golgi stack, changing as it matures by accumulating medial, then trans enzymes through vesicles that move from later to earlier cisternae (retrograde traffic)

Question 26

evidence for vesicle trafficking

Answer 26

-small vesicle are associated with golgi -there are cisternal specific enzymes

Question 27

evidence for cisternal maturation

Answer 27

molecules too big to fit in golgi -associated vesicles can move through golgi

Question 28

lysosomes function

Answer 28

involved in the digestion of macromolecules from endocytosis -contains many hydrolytic enzymes that function best at pH 5

Question 29

lysosomes actively pump in _____ to maintain ___ pH to protect cells from _____

Answer 29

H+; low; autophagy

Question 30

autophagy

Answer 30

the lysosome is a site of organellular recycling (reusing old and damaged cell parts)

Question 31

apoptosis

Answer 31

cell suicide by rupturing lysosomes

Question 32

Tay sachs

Answer 32

lack enzymes to digest a particular lipid causing accumulation and cell death

Question 33

organelles not in the endomembrane system

Answer 33

do not receive vesicle traffic -mitochondria, chloroplasts, cytoskeleton

Question 34

the cytoskeleton is a network of three different fibers, _____________extending throughout the cytoplasm

Answer 34

microtubules, microfilaments, and intermediate filaments

Question 35

function of cytoskeleton

Answer 35

support. motility, and cell shape

Question 36

microtubules structure

Answer 36

polymer of tubulin -dimer (units of tubulin)

Question 37

dimers of microtubules assemble into 13 __________ into a tube

Answer 37

protofilaments

Question 38

function of microtubules

Answer 38

compression resistant and allows movement through the use of motor proteins

Question 39

motor proteins of microtubules

Answer 39

proteins that change shape with ATP hydrolysis and generate force

Question 40

kinesin

Answer 40

positive end directed motor protein

Question 41

dynein

Answer 41

negative end directed motor protein

Question 42

microtubule function in the eukaryotic flagellum

Answer 42

used to power cell movement (sperm tail) -whip like -powered by ATP -membrane bound

Question 43

microtubule function in the eukaryotic flagellum requires _____-based contraction - uses ______ MT membrane arrangement

Answer 43

dynein; 9+2

Question 44

microtubule function in the eukaryotic flagellum

Answer 44

used to power cell movement (sperm tail) -whip like -powered by ATP -membrane-bound

Question 45

microfilaments structure

Answer 45

polymer of actin that forms a twisted rope

Question 46

microfilaments function

Answer 46

tension/stretch resistant -allows for movements such as muscular contraction and cytokinesis

Question 47

myosin

Answer 47

motor molecule of actin

Question 48

intermediate filaments structure

Answer 48

form rope-like polymers/heterogenous polymers

Question 49

the function of intermediate filaments

Answer 49

tension resistance -not very dynamic (stable) -no motor proteins

Question 50

lamins

Answer 50

form nuclear lamina

Question 51

keratin

Answer 51

form hair and nails

Question 52

desmin

Answer 52

provides tensile strength to desmosomes