Intro to Plant Cell

Question 1

robert hooke

Answer 1

discovered “cell” cork bark w microscope

Question 2

matthias schleiden

Answer 2

plants are composed of cells

Question 3

theodor schwann

Answer 3

animals are composed of cells

Question 4

schleiden and schwann cell theory

Answer 4

organisms = 1 or more cells
cell = basic unit
new cells come from existing cells

Question 5

antoine van leeuwenhoek

Answer 5

microscope

Question 6

microscopes (3 types)

Answer 6

light microscope (compound/dissecting)
electron microscope (TEM/SEM)
fluorescence microscope (epifluorescence/confocal/autofluorescence)

Question 7

epifluorescence

Answer 7

xenon arc or mercury vapour lamps (excite fluorophores)

Question 8

confocal

Answer 8

lasers (generate optical sections, improves resolution)

Question 9

autofluorescence

Answer 9

fluorescence of naturally occurring substances

Question 10

first form of life

Answer 10

prokaryotes

Question 11

first eukaryotes

Answer 11

protists

Question 12

first plants

Answer 12

green algae began transition
(water -> land)

Question 13

fungi not in plant kingdom - why?

Answer 13

don’t photosynthesize

Question 14

pro vs euk

Answer 14

prokaryote:
unicellular (asexual)

eukaryote:
unicellular (asexual)
multicellular (asexual/sexual)

share common prokaryote ancestor, 4 macromolecules, metabolic processes, cell membrane

Question 15

phospholipid bilayer components

Answer 15

phosphate heads - hydrophilic
fatty acid tails - hydrophobic

Question 16

membrane carbohydrate functions

Answer 16

cell recognition
structural support

Question 17

membrane proteins functions

Answer 17

selective transport
receptors
recognize disease
attachment sites

Question 18

prokaryotes (cyanobacteria)

Answer 18

marine and fresh
phototroph
Great Oxidation Event
“blooms”
photosynthesis w thylakoids, not full chloroplasts
NOT blue-green algae

Question 19

golgi names

Answer 19

dicytosome (plant)
golgi apparatus (animal)

Question 20

signature plant cell organelles

Answer 20

plastids
vacuoles

Question 21

plastids types (2)
- make or store food/pigments
- can change types (interconversion)

Answer 21

Leucoplasts - colourless (starch, oil, protein)
Chromoplasts - pigmented plastids for tissue colour

Question 22

vacuoles - functions (5)
(surrounded by membrane - tonoplast)

Answer 22

cell shape (turgor)
sequester toxins
store ions, H2O, dissolved pigments
crystal formation in specialized cells
break down large macromolecules/organelles

Question 23

endosymbiosis

Answer 23

• account for development of double-membrane organelles (mitochondria/chloroplasts)
• aerobic prokaryotes + photosynthetic bacteria -> invade prokaryotic host

Question 24

plant cell wall (composition)

Answer 24

• polysaccharides and proteins
• cellulose - main scaffolding, bundled -> form microfibrils
• hemicelluloses - carbohydrates that crosslink cellulose microfibrils
• pectins - carbohydrates that “gel” & regulate cell-cell adhesion
• glycoproteins - sugar proteins

Question 25

plant cell wall (layers)

Answer 25

primary cell wall - contacts plasma membrane

middle lamella - pectin-rich layer that binds neighbouring primary cell walls

secondary cell wall (if present) - between plasma membrane and primary cell wall, reinforced w LIGNIN

Question 26

plasmodesmata

Answer 26

tiny strands of cytoplasm that connect cells

Question 27

desmotubules

Answer 27

tube-like extensions formed by ER of neighbouring cells

Question 28

cytoskeleton

Answer 28

network of thread-like proteins throughout cytoplasm
- cell shape, cell division, organelle anchoring/movement
(in plants, cell walls + central vacuole = more important for shape)

Question 29

cytoskeleton (main components in plants) (3)

Answer 29

microtubules
microfilaments
intermediate filaments

Question 30

microtubules (component+function)

Answer 30

alpha + beta tubular proteins
stacked 13 rows -> form alpha helixes
- cell motility (pro+euk)
- vesicle & chromosome movement (w cell wall cellulose microfibrils)
- cell division, phragmoplasts, + trap Golgi vesicles to make cell plate

Question 31

microfilaments

Answer 31

actin protein in helical chains around each other
- cell shape
- move cell contents around central vacuole (cytoplasmic streaming/cyclosis)
- phragmoplasts

Question 32

intermediate filaments

Answer 32

several types of linear proteins combined
- not well-defined role in plants/fungi
- in animals, hold nucleus in position + control nuclear shape (nuclear lamins)

Question 33

motor proteins

Answer 33

• transport throughout cytoplasm
• microtubules + microfilaments provide scaffolding (guide motor proteins)
• ATP-dependent
• myosin - motor proteins that interact w actin for cytoplasmic streaming