Module 3 Cells

Question 1

Robert Hooke 1665

Answer 1

Discovery of cells

Question 2

Cell size limited because:

Answer 2

Huge volumes pose problems for diffusion

Question 3

Radius, Surface Area, and Volume of Cell

Answer 3

• Radius: 1x, 2x, 3x
• Surface Area: 1(radius), 2(radius), 3(radius)
• Volume: 1(Surface Area), 2(Surface area), 3(Surface area)

Question 4

Cells overcome surface area-to-volume problem:

Answer 4

• Folding or expanding their shape
• Storing nutrients or compartmentalizing: don’t rely much on external diffusion

Question 5

Light Microscopes

Answer 5

• Magnifying lenses with VISIBLE light
• 200 nm apart
• Magnifies up to 1,200x

Question 6

Electron Microscopes

Answer 6

• Beams of electrons
• 0.2 nm apart
• Magnifies more than 500,000x

Question 7

Atomic Force Microscopy and Nextgen

Answer 7

View molecules beyond picometer scale

Question 8

Cell components

Answer 8

1. Plasma Membrane (Phospholipid bilayer)
2. Cytosol (Cytoplasm)
3. DNA (Chromosomes)
4. Ribsomes (rRNA + Protein)

Question 9

Plasma Membrane

Answer 9

Controls what goes in/out

Question 10

Cytosol (Cytoplasm)

Answer 10

Semifluid medium for biochemical processes

Question 11

DNA (Chromosomes)

Answer 11

Genetic information

Question 12

Ribosomes (rRNA + Protein)

Answer 12

Make proreins for the cell

Question 13

Two Cell Types

Answer 13

1. Prokaryotic
2. Eukaryotic

Question 14

Prokaryotic Cell Branches

Answer 14

Bacteria and Archaea Branch

Question 15

Eukaryotic Cell Branches

Answer 15

Eukarya

Question 16

IMPORTANT*

Prokaryotic Cell

Answer 16

• Lacks membrane-bound nucleus
• One circular chromosome (DNA) in nucleoid
• Plasmid
• Ribosomes
• No membrane-bound organelles
• Cell Wall: Prevent excessive uprake or loss of water
• Can have flagellum

Question 17

Plasmid

Answer 17

• Small circular DNA that carries extra genes
• Can be exchanged between cells

Question 18

IMPORTANT*

Eukaryotic Cell

Answer 18

• Multiple linear chromosomes in double-membrane Nucleus
• Extensive compartmentalization and organelles

Question 19

IMPORTANT*

IMPORTANT: STUDY ALL ORGANELLE LOCATIONS IN EUKARYOTIC CELL (look in slides)

Question 20

IMPORTANT*

Endosymbiotic theory: Lynn Margulis

Answer 20

Some of today’s eukaryotic organelles evolved by a symbiosis arising between two free-living cells.

Question 21

Endosymbiotic Theory Evidence

Answer 21

• Double membrane in both mitochondria and chloroplasts
• Ribosomes in organelles similar to bacterial ribosomes
• Mitochondria and Chloroplasts replicate independently in cell (similar to binary fusion)
• Have their own circular DNA

Question 22

IMPORTANT*

IMPORTANT: STUDY EUKARYOTC ORGANELLES CROSS SECTION (in slides)

Question 23

Cell Fractionation

Answer 23

1. Take cells in culture and put them in Homogenizator (blender) and disrupt membrane to break cells open (Homogenization)
2. All contents of cell released into environment. (Homogenization)
3. Take Homogenate and centrifuge it. (Differential Centrifugation)
4. Pellet: Nuclei and cellular debris
5. Supernatent: Solution containing rest of cell
6. Take Supernatent out and keep centrifuging. Most centrifuged pellet is rich in ribosomes.

Question 24

Endomembrane System

Answer 24

series of membranes that are functionally interrelated
* nucleus, nucleur envelope, ER, vessicles, Golgi Body

Question 25

Endoplasmic Reticulum

Answer 25

• Connected to nucleur envelope

Question 26

Rough Endoplasmic Reticulum (RER)

Answer 26

• Studded with ribosomes
• Synthesis of membrane proteins and proteins to be secreted by cell

Question 27

Smooth Endoplasmic Reticulum (SER)

Answer 27

• No ribosomes
• Lipid synthesis, stores CA2+, detoxification

Question 28

Golgi Apparatus

Answer 28

• Shipping and receiving of endomembrane
• Flattened stacks of interconnected membranes (Golgi bodies)
• Proteins from ER are tagged with moecules that function as addresses for final destination
• Packaged into vesicles with transport molecules to plasma membrae for exocytosis or become lysosomes

Question 29

Golgi Produces:

Answer 29

Transport vesicles and lysosomes