Eukaryotes

Question 1

Describe the eukaryote and its basic features.

Answer 1

• contains a membrane bound nucleus and membrane bound organelles
• single or multicellular and much larger

Question 2

Why are the advantages of having many organelles?

Answer 2

1. helps separate incompatible reactions
2. increased efficiency of chemical reactions

Question 3

Why does having many organelles increase efficiency of chemical reactions?

Answer 3

-localized, high concentrations of substrates/enzymes
-clustered pathways (product of one rxn=substrate of the next)

Question 4

What structure appears in animal cells, but not plant?

Answer 4

lysosomes

Question 5

What structure appears in plant cells, but not animal?

Answer 5

cell wall, vacuole, chloroplasts

Question 6

What are the components of the nucleus?

Answer 6

• nuclear envelope
• nuclear lamina
• nucleolus

Question 7

Describe the nuclear envelope and its function.

Answer 7

• double membrane
• pore-like openings allow passage of materials

Question 8

Describe the nuclear lamina and its function.

Answer 8

• “nuclear cytoskeleton”
• maintains shape

Question 9

The nuclear lamina can be compared to what other structure?

Answer 9

cytoskeleton

Question 10

What is the purpose of the nucleolus?

Answer 10

ribosomal RNA synthesis

Question 11

What is the function of ribosomes?

Answer 11

protein synthesis

Question 12

List the characteristics of ribosomes.

Answer 12

• NOT an organelle
• no membrane

Question 13

In free ribosomes, proteins made are used ______ the cytosol.

Answer 13

inside

Question 14

In ribosomes bound to ER, proteins made are used ______ the cytosol.

Answer 14

outside

Question 15

The rough ER functions in…

Answer 15

protein synthesis

Question 16

The smooth ER functions in…

Answer 16

lipid synthesis or breakdown

Question 17

What is the function of the lysosome?

Answer 17

digestion and recycling

Question 18

Describe the membrane of lysosome.

Answer 18

single membrane containing proton pumps

Question 19

What are the components of the lysosome?

Answer 19

acid hydrolases (catalyze hydrolysis reactions)

Question 20

How is pH maintained in the lysosome?

Answer 20

through proton pumps (higher concentration of p+, the lower the pH)

Question 21

Describe the pH of the lysosome.

Answer 21

acidic pH (optimal for the hydrolases)

Question 22

Describe the membrane of vacuoles.

Answer 22

single, contains transporters for selected molecules

Question 23

What are the components of a vacuole?

Answer 23

vary…
- carbohydrates
- pigments
- oils
- toxins
- hydrolases

Question 24

What is the function of a vacuole?

Answer 24

-storage centers of plants and fungi
- water storage
-similar to lysosomes
- filled w/ colorful pigments
- filled with defensive chemicals

Question 25

What are the components of peroxisomes?

Answer 25

important enzymes - catalase: breaks down h202 which is a toxic byproduct of many rxns - alcohol dehydrogenase (ADH)

Question 26

Describe the membrane of peroxisomes.

Answer 26

single and contain transporters for selected macromolecules

Question 27

What is the function of peroxisomes?

Answer 27

-oxidation of fatty acids, ethanol, or other compounds -centers for redox rxs

Question 28

What is the mitochrondria?

Answer 28

- powerhouse of cell provides ATP for the cell

Question 29

Describe the membrane of the mitochrondria.

Answer 29

-double and inner layer contains enzymes for the production of ATP (forms cristae) - solution is inside matrix

Question 30

What are the components of the mitochondria?

Answer 30

-enzymes that harvest energy from molecules to make ATP -also contain its own DNA and ribosomes

Question 31

What is the main function of the mitochondria?

Answer 31

ATP production

Question 32

Chloroplasts are the sites for....

Answer 32

photosynthesis

Question 33

Describe the membrane of a chloroplast?

Answer 33

-triple membrane - contains individual thylakoids that are stacked into grana - solution in between is stroma

Question 34

What are the components of chloroplasts?

Answer 34

-pigments - enzymes that use light energy to make sugars (photosynthesis)

Question 35

What are the functions of a chloroplast?

Answer 35

production of sugars via photosynthesis

Question 36

What are the functions of the cytoskeleton?

Answer 36

- cell shape - structural stability - movement of materials (organelles) within the cell

Question 37

What are the 3 filaments in the cytoskeleton?

Answer 37

- microfilaments - intermediate filaments - microtubules

Question 38

microfilament function

Answer 38

movement

Question 39

intermediate filament function

Answer 39

structure and stability

Question 40

microtubule function

Answer 40

tracks for the movement of organelles

Question 41

Describe the membrane of the cytoskeleton.

Answer 41

there isn't one

Question 42

Describe the membrane of the plasma membrane.

Answer 42

single, contains transport and receptor proteins

Question 43

What are the components of the plasma membrane?

Answer 43

- phospholipid bilayer with transport and receptor proteins

Question 44

What is the function of the plasma membrane?

Answer 44

selective permeability: maintains intracellular environment

Question 45

Describe the membrane of the cell wall.

Answer 45

there isn't one

Question 46

What are the components of the cell wall?

Answer 46

carbohydrate fibers running through carbohydrate or protein matrix

Question 47

What is the function of the cell wall?

Answer 47

protection, structural support

Question 48

What compose the endomembrane system?

Answer 48

1. rough ER 2. smooth ER 3. lysosomes 4. golgi

Question 49

Describe the membrane of the golgi.

Answer 49

single, contains receptors for products of the rough ER

Question 50

What are the components of the golgi?

Answer 50

stack of flattened, distinct cisternae

Question 51

What is the function of the golgi?

Answer 51

protein, lipid, and carb processing

Question 52

What is symbiogenesis?

Answer 52

mitochondria and chloroplasts were once free-living bacteria that were engulfed by ancestors of eukaryotes, and evolved a mutually beneficial relationship

Question 53

What evidence is there for symbiogenesis?

Answer 53

- circular chromosomes - small ribosomes - grow and divide independently of cell division