Unit 2 Week 10/12

Question 1

Prokaryotic cell

Answer 1

A cell without membrane bound organelles

Single cellular but can aggregate

Bacteria and archaebacteria

Question 2

Archaebacteria

Answer 2

NOT BACTERIA

live in extreme environments (salty/hot/acidic)

Question 3

Nucleoid

Answer 3

Region where DNA is found

-DNA of prokaryotes are circular

Question 4

Pilli

Answer 4

Attachment appendages

• fimbria
• sex pilli- helps in bacterial conjugation (transferring DNA in bacteria)
• type IV pilli- attaches to surface and then contracts movement

Question 5

How do prokaryotic organisms perform cellular functions without compartmentalizing areas?

Answer 5

The cell membrane forms pockets of compartments

Question 6

What is the cell theory?

Answer 6

Three parts

1) all cells come from pre existing cells (but what about the first cell?
2) all life is made of cells (chloroplasts and mitochondria can replicate on its own and has own DNA)
3) cells are the smallest, basic unit of life

Question 7

Endomembranous system

Answer 7

Series of membranous organelles connected physically or by vesicles

Question 8

Advantage of having a nucleus

Answer 8

Protection of materials inside it

Question 9

Advantage of prokaryote not having nucleus

Answer 9

Transcription and translation can occur simultaneously

Question 10

How are cells able to move?

Answer 10

• cytoskeleton
• flagella
• cilia (only in eukaryotes)
• pili (only in prokaryotes)

Question 11

How does the flagella move?

Answer 11

Eukaryotes- whip like motion back and forth, driven by ATP

Prokaryotes- rotor movement, driven by proteins

Question 12

Microtubules

Answer 12

Structure/protein type: Tubulin
Diameter: 25nm
Location: extends throughout the cell

Question 13

Microtubules function

Answer 13

• attaches to chromosomes and moves them in cell division
• structure~resists compression (spring shape)
• provides a track for organelles to move on

Question 14

Kenesin

Answer 14

Moves organelles toward the plus end

Question 15

Dynein

Answer 15

Moves organelles to minus end

Question 16

Microtubules: cell motility

Answer 16

• found in flagella and cilia

- 9+2 array (9 pairs of Microtubules surrounding 2 central Microtubules) found in motile cilia

Question 17

Primary cilia

Answer 17

• 9+0 array, doesn’t help movement

- the proteins connecting the Microtubule pairs are Dynein (sliding) and nexin (leads to bending)

Question 18

Dynamic istability

Answer 18

The depolymerizing and repolymerizing

Question 19

Microfilaments

Answer 19

Structure/protein shape: actin (g alone, f with 2 strands
Diameter: 7-9 nm
Location: found on the perimeter of the cell (tends to be found in the folds (microvilli) of cells in the small intestine)

Question 20

Functions of Microfilaments

Answer 20

• structure: resists shear/tension
• works with myosin in muscle contractions
• helps pinch in cell during cell division
• participates in cytoplasmic streaming

Question 21

Microfilament motility

Answer 21

• as actin polymerizes, it expands the cell membrane forward
• myosin dependent contractions propel cell forward

Question 22

Intermediate filaments

Answer 22

Types of protein- keratin, many proteins
Diameter: 8-12 nm
Functions: permanent scaffold in the cell, throughout the cell

Question 23

Thick filaments

Answer 23

Types of protein: myosin

Functions: muscle contractions and helps cytoplasm propel forward

Question 24

Endosymbiotic theory

Answer 24

Evidence the mitochondria was once it’s own:

1) has its own DNA
2) DNA is round, similar to DNA in prokaryotic cells
3) can replicate on their own
4) similar inner membrane in proteins it carries to prokaryotes
- same evidence with chloroplasts