Chapter 2

Question 1

what Luca means

Answer 1

last universal common ancestor

Question 2

properties of all cells (4)

Answer 2

• • all cells have intracellular composition different from the outside
    1. metabolism (cells take up nutrients,transform them, and expelled waste
    2. growth (nutrients from the environment are converted into new cells materials to form new cells)
    3. evolution (cells evolve to display new properties)

Question 3

two aspects of the metabolism (a propriety of all cells)

Answer 3

1. genetic

2. catalytic

Question 4

4 properties of some cells

Answer 4

1. differentiation (some cells can form new cell structuressuch as a spore)
2. communication (interact with each other by chemical messenger)
3. genetical exchange (by different mecanisms)
4. motility (capable of cell propulsion)

Question 5

definition of metabolism

Answer 5

generation of precursors of macromolecules (sugars, amino acids, fatty acids..)

Question 6

the bigger you get….

Answer 6

the relatively less surface you have

Question 7

what are the limits in diameter

Answer 7

0,5 um- 750 um

Question 8

3 roles of the membrane

Answer 8

1. permeability barrier
2. protein anchor
3. energy conservation

Question 9

major phospholipids in the membrane found in the bacteria

Answer 9

phosphatidylethanolamine

Question 10

in the structure of the phospholipids, what the archaea doesn’t have compare to the bacteria/eukaryote

Answer 10

the double bond (ether bond instead of the ester)

Question 11

membrane of archea is bi or monobilayer

Answer 11

monolayer

Question 12

type of sterol in animal cells, fungi and plant cells

Answer 12

animal: cholesterol
fungi: ergosterol
plant and some protozoans: stigmasterol

Question 13

in bacteria + archaea, sterol are majority absent so the membrane is stabilize by what

Answer 13

hopanoid

Question 14

storage structure present in bacteria but not eukaryote

Answer 14

plasmid

Question 15

the place DNA is is found in :bacteria, eukaryote

Answer 15

bacteria: cytoplasm
eukaryote: nucleus

Question 16

robosome is composed of (2)

Answer 16

ribosomal RNA and proteins

Question 17

role of ribosome

Answer 17

translate mRNA into amino acids chains in order to form proteins

Question 18

where are the robosomes in bacteria and eukaryote

Answer 18

bacteria: free in the cytoplasm or attached to the cytoplasmic membrane
eukaryote: free in the cytoplasm or bound to the endoplasmic reticulum

Question 19

number of subunits in the ribosome of prokaryotes

Answer 19

70S (30S + 50S) subunits

Question 20

number of subunits in the ribosome of eukaryotes

Answer 20

80S (40S + 60S) subunits

Question 21

what are organelles

Answer 21

compartiment made of membranes (phospholipids bilayer and proteins)

Question 22

cellulose (polymer of glucose) is the composition of the cell membranes of which species (3)

Answer 22

plants, algae and some fungi

Question 23

cell wall molecules of fungi

Answer 23

chitin (polymer of N-acetylglucosamine

Question 24

characteristics of euchromatin (2)

Answer 24

loosely packed, actively transcribed

Question 25

characteristics of heterochromatin (20

Answer 25

densely packed, low level of transcritption

Question 26

DNA wraped around _____ which form loops of DNA called ______. These ____ coil and stack together to form fibers called ______. These ones in turn form larger loops and coils to form _______

Answer 26

histones nucleosome chromatin chromosome

Question 27

what is formed during translation

Answer 27

ribosome-mRNA complex

Question 28

what happens to the ribosome-mRNA complex in the case of cytoplasmic proteins

Answer 28

they stay free in the cytoplasm

Question 29

what happens to the ribosome-mRNA complex in the case of membrane proteins, secreted proteins or vesicular proteins

Answer 29

it is directed to the ER

Question 30

what is the endoplasmic reticulum

Answer 30

a system of membranous channel, the membrane is composed of a bilayer of phospholipid

Question 31

characteristics of rough ER

Answer 31

studded with ribosomes | important for protein synthesis

Question 32

characteristics of smooth ER

Answer 32

no ribosomes, involved in synthesis of lipid

Question 33

proteins destined for secretion are synthesizedd by what

Answer 33

ribosomes attached to the endoplasmic reticulum

Question 34

what is the Golgi body + role

Answer 34

a set of membrane compartiments involved in further processing of proteins and their distribution. Proteins are packaged in vesicles and transported to where they are required

Question 35

Golgi body- an example is the lysosomes (what is it + function)

Answer 35

internal vesicles that contains hydrolytic enzymes required for degradation of material brought brought in by phagocytos and endocytos

Question 36

role of mitochondria + what they are able to synthesize

Answer 36

production of the majority of the ATP required by the cells | able to synthesize some of their own proteins (the other ones are imported from the cytoplasm of the cell)

Question 37

characteristics of the outer membrane of the mitochondria

Answer 37

many porins proteins, makes this membrane permeable to small molecules

Question 38

characteristics of the inner membrane of mitochondria

Answer 38

``` 75% proteins, 25% lipids transports proteins (regulated transport), enzymes,cytochromes, ATPase ```

Question 39

composition of the matrix of the mitochondria (3)

Answer 39

enzyme (citric acid cycle), DNA, ribosomes (70S)

Question 40

3 characteristics of stroma and it is the site of what

Answer 40

circular DNA 70S ribosomes enzymes of the Calvin cycle stroma is the site of the Calvin cycle: assimilation of CO2, biosynthesis

Question 41

what is thylakoid

Answer 41

closed system of interconnecting sacks and tubules

Question 42

what thylakoids contains

Answer 42

enzymes and pigments that harvest light energy and the membrane-bound ATPases that use this energy to produce ATP

Question 43

3 examples of intermediaire filament

Answer 43

keratin, desmin, vimentin

Question 44

name of the 2 proteins that attach to vesicles or organelles and walk on microtubules to transport their cargos to where they are required

Answer 44

kinesin and dynein

Question 45

role of microtubules

Answer 45

microtubules serve as highways for the transport of organelles and vesicles around the cytoplasm

Question 46

structure of actin filament

Answer 46

strands in double helix

Question 47

structure of intermediaire filaments

Answer 47

fibers wound into thicker cables

Question 48

structure of microtubules

Answer 48

hollow tube

Question 49

4 role of actin filament

Answer 49

1. maintain cell shape by resisting tension 2. move cells via muscle contraction or cell crawling 3. divide animal cells in two 4. move organelles and cytoplasm in plants, fungi and animals

Question 50

2 roles of intermediate filaments

Answer 50

1. maintain cell shape by resisting tension | 2. anchor nucleus and other organelles

Question 51

6 roles of microtubules

Answer 51

1. maintain cell shape by resisting compression (push) 2. move cells via flagella or cilia 3. move chromosome during cell division 4. assist formation of plate during plant cell division 5. move organelles 6. provide track for intracellular transport

Question 52

how does the dynein arms create movement

Answer 52

they slide the doublets past each other, creating movement

Question 53

2 major differences between membranes of bacteria and archaea

Answer 53

- bacteria/eukaryotes: ester linkages and fatty acids | - archaea: ether linkages and isoprene units to form a phytanyl group, not a fatty acid

Question 54

4 membrane proteins

Answer 54

transporters enzymes sensors adhesins