Chapter 4 Eukaryotes

Question 1

Eukaryotes have many unique features that distinguishes them from prokaryotes

Answer 1

• Cilia-hairs-movement, rare
• Membrane sterols-1 bacteria has
• Ribosome structure- larger and denser
  
  • different RNA sequence
• Membrane bound organelles
  
  • nucleus
    
    • multiple

Question 2

Structures external to cell

Answer 2

• tubulin in 9+2 array with mem. covering
• Flagella- sperm only
  
  • larger
  • function in cell motility
  • long in relation to cell size- covered in membrane
  • wave not rotate
• Cilia
  
  • shorter, more numerous
  • move cell and propel substances across cell
  • same internal as flagella
  • power and recovery stroke

Question 3

Glycocalyx in Eukaryotes

Answer 3

• carbohydrate coating in animal cells
• surrounds and stabilizes plasma membrane
• active in cell-cell recognition-signaling, communication
• only in cells with no cell wall
• extracellular matrix

Question 4

Animal and protozoa cell walls

Answer 4

• plants, fungi, algae
• cellulose, chitin,glucan, mannan, silica,calcium carbonate
• NO PTG
• Protozoa have no cell wall but some have a pellicle, inorganic material, surrounding the plasma membrane

Question 5

Eukaryotic Plasma Membrane

Answer 5

• similar in function and structure to prokaryotes
  
  • phospholipid bilayer embedded with proteins
    -addition of carbohydrates and sterols (cholesterols,
    ergosterols)
    -cell signaling
  • cell recognition
  • stability
  • spacers

Question 6

Membrane protein functions

Answer 6

• transport
• maintain cell integrity
  
  • attachment of proteins to internal structures
• receptors for cell signaling
  
  • proteins in outer layer
    
    • receptors typically glycoproteins
• enzomatic functions
  
  • stabilization, connections b/w cells

Question 7

Transport across eukaryotic membrane

Answer 7

• no cell wall
• passive- simple and facilitated diffusion; osmosis
• active- active transport,endocytosis, exocytosis

Question 8

Endocytosis

Answer 8

• bring in material from surrounding environment
  
  • Pinocytosis- plas mem folds inward- fluid into cell
  • Phagocytosis- engulf particles and bring into cell

Question 9

Exocytosis

Answer 9

-releases contents into external environment

Question 10

Cytoskeleton

Answer 10

• dynamic network of protein filaments (microtubules,actin filaments, and intermediate filaments)
• anchor organelles, structural support, shape alteration, movement

Question 11

Centrosomes

Answer 11

• pair of centrioles and proteins found near the nucleus

- involved in the assembly of microtubules

Question 12

microtubules - tubulin polymers

Answer 12

• hollow tubes; walls- 13 columns of tubulin molecules
• protein subunit- tubulin
• main functions- maintenance of cell shape
  
  • cell motility
  • chromosome movements in division
  • organelle movements

Question 13

Microfilaments - actin filaments

Answer 13

• 2 intertwined strands of actin
• protein subunits- actin
• main functions-
  
  • maintenance of cell shape
  • changes in cell shape
  • muscle contractions
  • cytoplasmic streaming
  • cell motility
  • cell division

Question 14

Cytoplasmic streaming

Answer 14

movement of eukaryotic cytoplasm from one part of the cell to another- helps distribute nutrients and move the cell over a surface - expells wastes

Question 15

Least common filaments in euks

Answer 15

intermediate filaments

Question 16

Membrane-bound organelles

Answer 16

• compartmentalization
• allows for division of labor
  
  • nucleus
  • mitochondria and chloroplast
  • endoplasmic reticulum
  • golgi apparatus
  • lysosome and peroxisomes
  • some have double membrane

Question 17

Nucleus

Answer 17

• nuclear envelope - membrane around
  
  • double membrane with pores
• nucleolus -sites of RNA synthesis
• DNA typically in multiple pairs of linear chromosomes
  
  • associated with histone proteins

Question 18

sexual or asexual reproduction in _____ only

Answer 18

eukaryotes- mitosis and meiosis

Question 19

Endoplamic reticulum

Answer 19

• membrane synthesis organelle
• network of flattened tubules(cisterns) continuous with nuclear membrane
• rough ER-ribosomes present
  
  • site of protein synthesis
• smooth ER - no ribosomes
  
  • site of lipid/fat synthesis

Question 20

Ribosomes

Answer 20

-protein synthesis
- Eukary- 80s
-larger 60s and small 40s sub units
- membrane-bound; attached to ER and nuclear
membrane
- free in cytoplasm
-Pors- 70s
-in chloroplasts and mitochondria-contain own
ribosomes

Question 21

Golgi Body

Answer 21

• complex apparatus
• curved cisterns
• not continuous
• modifies, packages,and secretes products of ER
• produces lysosomes and vacuoles
  
  • receives, ID’s and processes them

Question 22

made by the golgi

Answer 22

lysosomes, peroxisomes, vacuoles

Question 23

Lysosomes are

Answer 23

• Formed in the Golgi
• membrane enclosed sac of digestive enzymes
  
  • non specific- garbage disposal

Question 24

apoptosis

Answer 24

• programmed cell death

- by golgi

Question 25

peroxisomes are

Answer 25

- bag of enzymes - oxidation of fatty acids; destroys water- specific actions - formed by dividing perosiomes - split in 1/2 to make more

Question 26

Vacuoles are

Answer 26

- derived from golgi - store nutrients - Primary purpose - sequester harmful substances

Question 27

Vacuole contents are determined by

Answer 27

cell type - plant - 1 large with water - animal - smaller- energy reserves, sugar

Question 28

Contractile Vacuoles are

Answer 28

single cell in fresh water | - holds water until full then pushes water out

Question 29

Endomembrane System

Answer 29

Network of internal membranes involved in synthesis or storage - ER - cell membrane - Golgi

Question 30

Mitochondria are

Answer 30

- double membrane -inner membrane is folded into cristae - site of cellular respiration; ATP production - 70s ribosomes and circular DNA; divide independently of cell -self replicating -binary fission

Question 31

No animal can make _____, instead animals process ____.

Answer 31

energy | energy

Question 32

Mitochondria are similar to _____, in that they have the same size ______ and same type of _______ DNA. They also replicate using _____ which is the same as well.

Answer 32

prokaryotes ribosomes circular binary fission

Question 33

Plastids are

Answer 33

- for synthesizing and storage - 2 compartment sugars - chloroplasts for photosynthesis - found in algae and green plants - contain chlorophyll pigment in the coin-like thylakoids - have stacked thylakoids-grana - 70s ribosomes and circular DNA; divide independently of cell

Question 34

Where do prokaryotes carry out photosynthesis?

Answer 34

Cell membrane

Question 35

Endosymbiotic Theory

Answer 35

Evolution from prokaryotes to eukaryotes - a pro engulfed another pro and over time became dependent upon each other - proof - inside the cell the mitochondria and plastids have same size ribosomes and same circular DNA

Question 36

Sugars are broken in the mitochondria and then used for

Answer 36

- ATP to do work | - moving material back and forth across the membrane