LECTURE 7

Question 1

Cytosol

Answer 1

The fluid portion of the cytoplasm. (Without structures or membranes)

Question 2

Cytoplasm

Answer 2

Interior of a prokaryotic or eukaryotic cell.

Question 3

Organelle

Answer 3

Any membrane-bound structure in a eukaryotic cell,

Question 4

Prokaryotic cells have

Answer 4

• No nucleus
• DNA in an unbound region called nucleoid
• no membrane-bound organelles
• cytoplasm bound by plasma membrane
• cell walls (bacteria and archaea, but composition is different)

Question 5

Why did eukaryotes evolve membrane outs organelles

Answer 5

They evolved a way to fold their membranes to increase the surface area.

Question 6

One simple model of endosymbiosis

Answer 6

1) ancestral cell that’s anaerobic
2) membrane folding
3) cell size increases
4) produces oxygen
5) aerobic prokaryotic ingested
6) bacterium not destroyed, developed into mitochondria. ( all non-photosynthetic eukaryotes)
7) photosynthesis bacterium ingested (chloroplast) ( all photosynthetic eukaryotes)

Question 7

The endosymbiosis hypothesis

Answer 7

• mitochondria and chloroplast arose in eukaryotes by endosymbiosis

0 mutually beneficial relationship derived form one cell living inside another cell.

Question 8

Mitchochondria are descended form an ancient ________. And it closely related to

Answer 8

Bacterium. a-proteobacteria (gram negative)

Question 9

Chloroplasts are descended form an an don’t

Answer 9

Cyanobacteria (photosynthetic bacterium)

Question 10

Evidence for endosymbiosis

Answer 10

Mitochondria and chloroplasts :

• have their own DNA (circular)
• genes are organized like prokaryote genome
• have their own ribosomes

Question 11

Ribosomes are big compels of

Answer 11

Proteins and RNA molecules

Question 12

Eukaryotes and prokaryote ribosomes differ in

Answer 12

Size and components

Question 13

The endowment and system contains

Answer 13

• nuclear membrane
• endoplasmic reticulum
• vacuoles
• Vesicles
• lysosomes
• golgi
• plasma membrane

Question 14

All of the endomembrane systems are related by either :

Answer 14

1) physical continuity

2) vesicles that transfer from one to another.

Question 15

What membrane-bound organelles are not part of the endomembrane system

Answer 15

• peroxisomes
• mitochondria
• chloroplasts

Question 16

The nucleus

Answer 16

• stores DNA, is a site for transcription

- contains multiple linear chromosomes

Question 17

Nuclear envoleop

Answer 17

• double membrane ( each membrane has a phospholipid bilayer)
• separates the nucleoplasm form the cytoplasm.

Question 18

Nuclear pore complexes

Answer 18

• span both bilayers

- regulates movement of substances in and out of nucleus

Question 19

Nuclear lamina

Answer 19

• Provides structural support of the nucleus

Question 20

What is the nuclear lamina composed of?

Answer 20

Intermediate filament called lamin, which assembles on the inner surface of the nuclear envelope.

Question 21

Nuclear envelope membrane order

Answer 21

• inner membrane
• outer membrane
• neculear pore

Question 22

Chromatin

Answer 22

DNA and proteins ( associated together because of electrostatic interaction)

Question 23

DNA is ________ charged, and histones are ________ charged

Answer 23

Negatively . Positively

Question 24

Why package DNA?

Answer 24

• organism the nucleus
• protect DNA form damage
• make it easier to move replicated DNA into daughter cell during cell division

Question 25

4 hi stone proteins assemble into a

Answer 25

Larger 8-subunit complex ( his tone octamer

Question 26

What are the four proteins that assemble into a large 8-sub into complex ?

Answer 26

H2A, H2B, H3, H4

Question 27

Histone H1 provides

Answer 27

Stability and protection to DNA, involved in packaging of nucleosomes

Question 28

Nucleolus (ribosome production factory)

Answer 28

- this is a visible sub-compartment of the nucleus ( not bound by membrane) - site of ribosomal RNA (rRNA) synthesis - site of assembly of ribosome protein subunits (each half of the ribosome enter the nucleus separately via nuclear pores)

Question 29

Steps to nucleolus (ribosomes production factory)

Answer 29

1) each subunit ( made in cytoplasm) must enter nucleus 2) ribosomal subunits associate with 4 different RNA molecules 3) final assembly occurs in the cytoplasm

Question 30

The tow types of endoplasmic reticulum ER

Answer 30

Smooth and rough

Question 31

Cells that provide a lot of proteins will tend to have more

Answer 31

Rough ER

Question 32

Cells that provide a lot of lipids (fats) will tend to have more

Answer 32

Smooth ER

Question 33

Are both types of ER found in both plants and animals

Answer 33

YES

Question 34

RER ribosomes are associated with the

Answer 34

Translation of proteins that aren’t destines for the endomembrane system

Question 35

Function of the rough ER

Answer 35

- site of protein synthesis and assembly | - site of quality control

Question 36

Ribosomes (protein factories)

Answer 36

- particles made of ribosomal RNA and protein | - assemble all peptides

Question 37

Where does the ribosomes assemble all peptides

Answer 37

- in the cytosol (free ribosomes) | - on the outside of the endoplasmic reticulum (bound ribosomes)

Question 38

Smooth ER functions

Answer 38

- ion storage - phospholipid, steroid synthesis - detox of drugs and alcohol - carbohydrate metabolism

Question 39

The Golgi apparatus

Answer 39

- Shipping and receiving - contains cisternae - cisternal maturation - cis face / trans face

Question 40

Cistercian’s

Answer 40

Golgi apparatus consists of flattened membranous sacs called cisternae

Question 41

Cis face

Answer 41

“Receiving” side of the golgi (faces nucleus)

Question 42

Trans face

Answer 42

“Shipping” side of the golgi (faces away from nucleus)

Question 43

Golgi apparatus functions

Answer 43

- modifies products of the ER - sorts and packages material into transport vesicles - it manufacturers some macromolecules

Question 44

Inclusion cell disease

Answer 44

Involves the loss of a modification in the golgi - proteins that should go to the lysosome instead get sent outside the cell.