Lecture 19: Introduction of Photosynthesis

Question 1

reactions of photosynthesis

Answer 1

1. photochemical reaction
2. electron transfer
3. biochemical reaction

Question 2

what reactions occur in the thylakoid membrane

Answer 2

light reactions like the capture of light energy as ATP and reducing power, NADPH

Question 3

what reactions happen in the chloroplast stroma

Answer 3

carbon fixing reactions like the transfer of energy and reducing power from ATP and NADPH to CO2

Question 4

is oxidizing carbon in CO2 high energy or low energy

Answer 4

low

Question 5

is reducing carbon (sugar) high energy or low energy

Answer 5

high

Question 6

endergonic (energy in) reaction

Answer 6

potential energy of substrate is less than the product

Question 7

exergonic (energy out) reaction

Answer 7

potential energy of substrate is greater than the product

Question 8

what organism other than plants can photosynthesize

Answer 8

chlamydomonas cells

Question 9

2 types of photosynthesis

Answer 9

oxygenic photosynthesis
anoxygenic photosynthesis

Question 10

oxygenic photosynthesis

Answer 10

removal of electrons from H2O leading to release of O2 and the reduction of CO2 to carbohydrate

Question 11

anoxygenic photosynthesis

Answer 11

do not extract electrons from water

Question 12

types of plastids

Answer 12

proplastid, amyloplast, chromoplast, etioplast, and chromoplast

Question 13

etioplast

Answer 13

dark grown photosynthetic tissue
NO chlorophyll

Question 14

proplastid

Answer 14

undifferentiated, colourless
seeds, embryonic meristems, and reproductive tissues

Question 15

chromoplast

Answer 15

red and yellow pigment (carotenoids)
flower (petal), fruit

Question 16

what are the identity and abundance of plastids controlled by

Answer 16

developmental and environmental cues

Question 17

what do all plastids diverge from

Answer 17

proplastid

Question 18

______ induces conversion from etioplast to chloroplast

Answer 18

light

Question 19

parts of thylakoid

Answer 19

outer membrane, inner membrane, stroma, thylakoids, lamella, granum, stroma

Question 20

appressed thylakoid

Answer 20

not exposed to stroma

Question 21

non-appressed thylakoid

Answer 21

exposed to the stroma

Question 22

can the distribution of chloroplast move in response to light intensity

Answer 22

yes, it is crucial for plants living under a canopy

Question 23

different distributions of chloroplasts based on light

Answer 23

accumulation - shaded by canopy. chloroplasts are on top and bottom
avoidance - full light. chloroplasts are on side
dark position - no light, chloroplasts are on bottom

Question 24

chlorophylls

Answer 24

the essential pigments that harvest the light energy and transduce it into chemical energy

Question 25

all chlorophyll-based photosynthesis systems use __________

Answer 25

chlorophyll a

Question 26

accessory pigments

Answer 26

chlorophyll b B-carotene phycoerythrin phycocyanin

Question 27

what uses chlorophyll b

Answer 27

land plants, green algae, and cyanobacteria

Question 28

what uses carotenoids

Answer 28

all chlorophyll-based photosynthesis systems

Question 29

what uses phycoerythrin

Answer 29

non-green algae

Question 30

what uses phycocyanin

Answer 30

cyanobacteria

Question 31

protoporphyrin IX

Answer 31

a precursor of Mg-containing chlorophyll and Fe-containing heme

Question 32

without ____, you cannot make chlorophyll

Answer 32

Mg 2+

Question 33

main structures of chlorophylls

Answer 33

Oxygenase, tetrapyrrole ring, and phytol tail

Question 34

difference in structures of chlorophyll a and b

Answer 34

a has a methyl group b has a formyl group

Question 35

chlorophylls are _________ molecules

Answer 35

amphipathic

Question 36

what does amphipathic mean

Answer 36

has both hydrophobic and hydrophillic structures

Question 37

light absorbtion is affected by

Answer 37

1. chemical structure of chlorophylls 2. non-covalent interaction of chlorophylls with proteins in photosynthetic membranes

Question 38

what are chromoplasts and what do they contain

Answer 38

they are oil bodies that contain pigments, specifically carotenoids

Question 39

what are the functions of carotenoids

Answer 39

1. accessory pigments 2. protecting photosynthesizing organisms from destructive photooxidation (anti-oxidant) 3. structural role in assemble of light harvesting complex

Question 40

types of phycobilins

Answer 40

phycocyanin and phycoerythrin

Question 41

phycobilins (accessory pigments) are

Answer 41

1. linear tetrapyrroles (come from same pathway as chlorophyll and heme 2. water soluble 3. accessory pigment with no associated metal

Question 42

what do amyloplasts lack

Answer 42

pigments and elaborate inner membranes

Question 43

function of amyloplast

Answer 43

starch storage

Question 44

statoliths

Answer 44

starch-filled amyloplasts that function in gravity sensing

Question 45

chlorophyll biosynthesis

Answer 45

protoporphyrin IX is a precursor of Mg-containing chlorophyll