plant cell biology

Question 1

what are chloroplasts

Answer 1

plant specific organelles that use light and carbon dioxide to produce oxygen and sugar

Question 2

chloroplast are surrounded by a

Answer 2

double membrane

Question 3

chloroplasts have..

Answer 3

their own genme

Question 4

thylakoid

Answer 4

membrane compartment that surrounds the lumen

Question 5

granum

Answer 5

stack of thylakoid

Question 6

stroma

Answer 6

matrix of the chloroplast

Question 7

stroma contains

Answer 7

• carbon fixing enzymes
• chloroplast DNA
• ribosomes

Question 8

inner mem. contains

Answer 8

chloroplast

0-import and export machinery

Question 9

thylakoid space

Answer 9

-light capturing system and ATP synthase

Question 10

how much sun light absorbed

Answer 10

1%

Question 11

28%

Answer 11

of the energy is chemically bound

Question 12

why are plants green

Answer 12

-chlorophyll absorbs blue and red light–> green plants do not use a large part of the visible spectrum

Question 13

photosynthetic electron transfer- light dependent reaction

Answer 13

1. red light is absorbed by chlorophyll which cleaves water thereby generating: 1 O2, 4 protons and 1 electron
2. e- is transferred across the mem. which pumps 1 proton across the membrane
3. the electron is further excited in the Photosytem I
4. Electron is transferred onto NADP+ resulting in NADPH
5. Proton gradient is utilized to generate ATP

Question 14

how do chloroplasts and mitochondria cooperate

Answer 14

chloroplasts use sunlight t produce oxygen and sugar, which the mitochondria use to produce ATP to power the cell. this produces water and CO2 which is then used by the chloroplasts.

Question 15

chloroplasts

Answer 15

photosynthesis

Question 16

amyloplasts

Answer 16

starch storage

Question 17

chromoplast

Answer 17

colouring

Question 18

chloroplasts are

Answer 18

motile organelles and this helps them avoid photo damage

Question 19

when there is strong light

Answer 19

the chloroplasts go to the outside of the cell

Question 20

when there is weak light the chloroplasts

Answer 20

are equally distributed around the cell

Question 21

3 steps of the chloroplast photo relocation

Answer 21

1) photoreception: plants blue light photoreceptors perceive the light (phototropins)
2) signal transduction- calcium signalling
3) chloroplast movement: motor dependent movement of chloroplasts (myosin and kineins)

Question 22

which ion is used in signal transduction during photo relocation

Answer 22

calcium

Question 23

what occurs independent to chloroplast movement

Answer 23

cytoplasmic steaming

Question 24

cytoplasmic streaming depends on

Answer 24

energy and requires F-actin

Question 25

what does cytoplasmic streaming support

Answer 25

tip growth of pollen tubes

Question 26

cytoplasmic streaming in Nitella spec.

Answer 26

distributes nutrients and organelles- fastest directed transport at 50-100 um/s

Question 27

cytoplasmic streaming occurs

Answer 27

around the vacuole

Question 28

How doescytoplasmic streaming occur

Answer 28

myosin XI walk to organelle along the actin filament

Question 29

a mobile endoplasm moves against

Answer 29

a stationary exoplasm

Question 30

which mysosins do plants contain

Answer 30

XI, XIII and VIII

Question 31

plasmodesmata

Answer 31

plants are connected via cytoplasmic bridges, allowing free passage of small molecules --> proven by GFP diffusing through plants

Question 32

how many plasmodesmata connects cells

Answer 32

1000-10,000

Question 33

what molecules do plasmodesmata slow passage of

Answer 33

ions, water, sugars, amino acids and even some larger proteins

Question 34

plasmodesmata can be regulated or even closed by..

Answer 34

local formation of callose

Question 35

what widen the plasmadesmara

Answer 35

movement proteins

Question 36

during cytokinesis , microtubules form

Answer 36

a plant specific array

Question 37

cell plate formation starts in the

Answer 37

middle of the cell

Question 38

what crosses the cell pasta

Answer 38

endoplasmic reticulum

Question 39

when are plasmodesmata formed

Answer 39

during cytokinesis

Question 40

mitosis and cell division

Answer 40

o Cortical interphase microtubule array concentrate in the middle of the cell o The nuclear envelope breaks down and a spindle is formed o Cytokinesis is accompanied by de novo synthesis of plasma membrane and cell wall o An array of microtubules (the phragmoplast, 1) guides and supports the formation of the cell plate (2) o The microtubules guide secretory vesicles (3) to forming the cell plate