1.2 Prokaryotic vs Eukaryotic cells

Question 1

protists

Answer 1

unicellular eukaryotes

Question 2

Cell division

Answer 2

process by which cells make more cells

Question 3

In order for a cell to divide successfully…

Answer 3

1. It must be large enough to divide in 2
   
   2. Be able to contribute sufficient nuclear and cytoplasmic components to each daughter cells
      Before the cell divides, key cellular components are divided

Question 4

how do prokaryotic cells divide

Answer 4

binary fission

Question 5

Binary Fission

Answer 5

1. Cell replicates DNA
   
   2. Increases in size
   3. Divides into 2 daughter cells with copy of the replicated parental DNA

form of asexual reproduction

Question 6

where else does binary fission occur

Answer 6

• Similar in archaeon
  
  • Chloroplasts
  • Mitochondria
  • Organelles within plant, fungal, and animal cells that evolved from free-living prokaryotic cells

Question 7

Process of BINARY FISSION!

Answer 7

1. Circular genome of E. coli is attached by proteins to the inside of the plasma membrane
   
   2. DNA replication is initiated at origin of replication, a Specific location on the circular DNA
      a. continues in opposite directions around the circle
      b. Results in 2 DNA molecules!!
      i. Attached to plasma membrane at different sites!
   3. Cell elongates, causing the 2 DNA attachment sites move apart
   4. When cell is 2x og size and DNA molecules are very separated, a constriction forms at midpoint of cell
   5. New membrane and cell wall are synthesized at the sit of the constriction, dividing the single cell into two
   6. BOOM WE GOT TWO NEW DAUGHTER CELLS

Question 8

generation time

Answer 8

time it takes the population of cells to double

○ Often how growth rate of a population of bacteria is expressed

Question 9

PHASES OF BACTERIAL GROWTH

Answer 9

• lag phase
• exponential phase
• stationary phase
• death phase

Question 10

lag phase

Answer 10

individual bacterial cells are growing but not readily dividing
- Just making the tools
- Expressing genes that encode for particular proteins
- Structural proteins
- Enzymes
- Integral membrane proteins
- Synthesizing macromolecular building blocks for cell structure and growth
- Length of phase depends on how different the current environmental conditions were from the last one in which bacteria was found
- No net increase of growth

Question 11

exponential phase

Answer 11

Overall population of bacterial cells undergo binary fission at a constant rate
- Now fully adapted to your environment
- Will maximize all the benefits they can from the nutrient media
- Call number increases exponentially
- 2^n

Question 12

3. STATIONARY PHASE

Answer 12

Key nutrients are beginning to deplete so bacteria begin to compete with other cells in order to obtain nutrients
- Metabolic waste products also begin to build up
- Toxic to many of the bacterial cells
- Curve plateaus
Net zero growth in overall population

Question 13

4. DEATH PHASE

Answer 13

Loss of nutrients, build up of waste products and lack of optimal conditions results in the death of many bacterial cells
More cells are dying than actively dividing

Question 14

Endomembrane system

Answer 14

dynamic cytoskeleton that eukaryotes have!!

§ Nuclear envelope
§ Endoplasmidyc reticulum
§ Golgi apparatus
§ Plasma membrane

Are interconnected –> dynamic continuinity

Question 15

endocytosis

Answer 15

○ Engulf molecules/particles

Question 16

Phagocytosis

Answer 16

Molecules or cytoplasmic waste from within the cell are packaged in vesicles and moved to the cell surface for removal

Question 17

DNA replication in eukaryotes vs prokaryotes

Answer 17

FOR BACTERIA AND ARCHAEA:
- rapid deployment of metabolic enzymes and rapid reproduction are key to exploiting patchily distributed nutrients
○ Dna replication needs to be fast!! Is limited bc of the single circular chromosome

EUKARYOTES:
- Eukaryotes have multiple linear chromosomes and can begin replication from many sites on each one
○ Can replicate simutaneously and rapidly
○ No evolutionary pressure for streamlining
§ Can have DNA that doesn’t code for proteins, but instead is regulartory
□ Gives fine control of gene expression required for multicellular development and complex life cycles
□ Two major features of eukaryotic diversity

Question 18

how do bacteria and archaea generate genetic diversity

Answer 18

horizontal gene transfer