PHOTOSYNTHESIS Flashcards
1
Q
The process by which green plants and some other organisms use
sunlight to synthesize foods from carbon dioxide and water.
A
Photosynthesis
2
Q
in plants, it generally involves the green pigment
chlorophyll and generates oxygen as a by-product.
A
Photosynthesis
3
Q
- essential for growth and survival of autotrophs
- for providing oxygen to the atmosphere
A
Photosynthesis
4
Q
noted that plants appeared to “eat”
air and sunlight
A
Ancient civilizations (Greeks and Egyptians) [pre-17th century]
5
Q
concluded that water
was the source of a plant’s increased mass
A
Jan Baptista Van Helmont
6
Q
- conducted experiments with a variety of gases, including “dephlogisticated air” (now known as oxygen).
- observed that plants exposed to sunlight
released a gas that could relight a burning candle,
which we now recognize as oxygen.
A
Joseph Priestley
7
Q
dephlogisticated air
A
Oxygen
8
Q
All life needs a constant input of
A
energy
9
Q
Decribe HETEROTROPHS (3)
A
- Get their energy from “eating others”
- CONSUMERS (of other organisms)
- Consume ORGANIC MOLECULES
10
Q
Example of heterotrophs
A
Animals
Fungi
Most of bacteria
11
Q
Decribe AUTOTROPHS (3)
A
- Get their energy from “self”; sunlight
- PRODUCERS
- Use light energy to SYNTHESIZE ORGANIC MOLECULES
12
Q
Examples of autotrophs
A
- Plants
- Photosynthetic bacteria
- Blue-green algae
13
Q
Decribe ENERGY CYCLE
A
- CO2 and H2O + light energy are used for photosynthesis
- produce GLUCOSE (C6H12O6) as main product; OXYGEN (O2) as by-product
- produce ATP through CELLULAR RESPIRATION
- REPEAT
14
Q
List of raw materials needed by plants for photosynthesis (4) and which part of the plant it will be obtained
A
- sunlight [in the form of light energy (photons)] - LEAVES (solar collectors)
- Carbon dioxide - STOMATES (gas exchange)
- Oxygen - uptake from ROOTS
- Nutrients - uptake from ROOTS
15
Q
What does it mean to be a plant?
The need to: (4)
A
- COLLECT LIGHT ENERGY (transform to chemical energy)
- STORE LIGHT ENERGY (in a stable form to be moved around plant; saved for rainy days)
- GET BUILDING BLOCKS OF ATOM FROM ENVIRONMENT (C,H,O,N,P,S)
- PRODUCE ALL ORGANIC MOLECULES NEEDED FOR GROWTH (carbohydrates, proteins, lipids, nucleic acids)
16
Q
Chloroplast is consist of:
A
- double membrane
- stroma
- thylakoid sacs
- grana stacks
17
Q
Chlorophyll and ETC in _______
A
Thylakoid membrane
18
Q
Build up of _________ within thylakoid sac
A
H+ gradient
19
Q
is sheathed with an upper and lower epidermis
A
Leaf
20
Q
The exposed surfaces of the epidermal cells are coated with?
A
Cuticle
21
Q
The photosynthetic tissues is identified as?
A
Mesophyll (meso - middle; phyll - leaf)
22
Q
upper photosynthetic tissue generally consists of?
A
one to three layers of
palisade mesophyll cells
23
Q
are elongated, cylindrical cells with the long axis perpendicular to the surface of the leaf
A
Palisade cells
24
Q
Lower photosynthetic tissue is consists of?
A
Spongy mesophyll
25
Why does spongy mesophyll named "spongy"?
because of the prominent air
spaces between the cells
26
ARE
PHOTOSYNTHETIC
MACHINES THAT
MAXIMIZE
THE ABSORPTION
OF LIGHT
Leaves
27
Which layer of epidermis do stomata located?
Lower epidermis
28
has both wave and particle nature.
Sunlight
29
are the smallest unit of
light
Photons
30
The light emitted from the sun contains photons in a
wide spectrum of wavelengths called?
Electromagnetic Spectrum
31
PHOTONS
OSCILLATE ALONG
A PATH CALLED?
Wavelength
32
What is the relationship of wavelength to frequency and energy?
Inversely proportional
33
Photosynthetic
organisms use only a
short portion of the
electromagnetic
spectrum called?
Visible light
34
On the electromagnetic spectrum, visible light has a wavelength that ranges from?
380 nm – 750 nm (nanometers)
35
IT FACILITATE THE CAPTURE OF WAVELENGTHS OF LIGHT IN THE VISIBLE LIGHT RANGE.
Pigment
36
Chloroplasts are green because?
It ABSORB light wavelengths in RED and BLUE but REFLECT GREEN (and yellow) back out
37
wavelengths that provide
the energy needed that is
used for photosynthesis
Red and blue wavelengths (only woth absorbed)
38
a dominant pigment, absorbed BEST - red and blue; LEAST - green
Chlorophyll a
39
Chemical formula for photosynthesis
6CO_2 + 6H_2O -----> C_6H_12O_6 + 6H_2O
40
The reactions that synthesize glucose occurs in the?
Stroma
41
The light dependent reactions occurs in the?
Thylakoids
42
Conversion of solar energy to chemical energy and the production of ATP happens in?
Light reactions
43
This process uses chemical energy (NADPH and ATP) to reduce CO_2 to build C_6H_12O_6 (sugars)
Calvin cycle
44
It is a collection of chlorophyll molecules.
Photosystems
45
Act as light-gathering "antenna complex"
2 photosystems in thylakoid membrane (Photosystem II & I)
46
also referred as P_680 (absorbs 680nm wavelength red light), has chlorophyll a
Photosystem II
47
also referred as P_700 (absorbs 700nm wavelength red light), has chlorophyll b
Photosystem I
48
It is the key to the photosynthetic electron transport chain.
Presence of photosystem I (PSI) and photosystem II (PSII).
49
These are the two large, multimolecular, pigment-protein complexes.
photosystem I (PSI) and photosystem II (PSII)
50
These two photosystems operate in series linked by a third
multiprotein aggregate called?
cytochrome complex
51
The effect of the chain is to extract low-energy electrons from water
and, using light energy trapped by chlorophyll, raise the energy level
of those electrons to produce a strong reductant called?
NADPH
52
NADPH stands for
Nicotinamide-adenine dinucleotide phosphate
53
ATP & ADP stands for?
Adenosine Triphosphate & Adenosine Diphosphate
54
The bulk of the chlorophyll in the photosystem functions
as?
Antenna chlorophyll
55
The association of chlorophyll with specific proteins
forms a number of different ___________
chlorophyll-protein (CP)
complexes
56
Within the pigment molecules, the absorbed light energy excites electrons to a
higher state
57
It will channel the excitation energy gathered by the pigment molecules to a reaction center chlorophyll
molecule which will then pass the electrons to a series of
proteins located at the thylakoid membrane.
Photosystems
58
Photons of light strike Photosystems I and II _______
simultaneously
59
What are the two core antennas for photosystem II?
Chlorophyll-proteins (CP):
- CP43
- CP47
60
How many molecules of chlorophyll a do CP complexes have each?
20 - 25 molecules of chlorophyll a
61
T or F?
The core antenna chlorophyll a absorb light but do not participate directly in photochemical reaction.
T
62
They are directly involved in light-
driven redox reactions.
reaction center chlorophyll plus associated proteins
63
is the site of the primary photochemical
redox reaction; it is here that light energy is actually converted to chemical energy.
reaction center chlorophyll a
64
Reaction center chlorophyll is described as _________ due to its longest-wavelength and lowest-energy-absorbing
chlorophyll in the complex.
Energy sink
65
What is the reaction center of PSI? PSII?
P_700 ; P_680
66
It OXIDIZES
WATER TO
PRODUCE
OXYGEN
Photosystem II
67
T or F?
Electron transport actually begins with the arrival of excitation energy at the photosystem II reaction center chlorophyll, P700, which is located near the
lumenal side of the reaction center.
F
[P_700 ----> P_680]
68
This excitation energy is required to change the redox potential of P680
from
+0.8 eV to about −0.4 eV
69
T or F?
As a consequence of the initial endergonic excitation process, P680* can rapidly (within picoseconds, 10−12 s) transfer electrons exergonically to pheophytin (Pheo).
T
70
T or F
Since this initial oxidation of P680 is light dependent, this is called a
photooxidation event, which results in the formation of P680+ and Pheo−, a charge separation. This charge separation effectively stores light energy as redox potential
energy and represents the actual conversion of light energy to chemical energy.
T
71
Two reaction proteins that binds and orients specific redox carriers of the PSII reaction center in such a way as to decrease the probability of
charge recombination between P680+ and Pheo−.
D1 and D2
72
I. In a Z-Scheme, the redox components are arranged according to their
approximate midpoint redox potentials.
II. The vertical direction indicates
a constant energy level .
III. The horizontal direction indicates electron flow.
IV. The downhill transfer of electrons between P680* and P700 represents a positive free energy change.
V. Some of this energy is used to establish a proton gradient, which in turn drives ATP synthesis.
Which statement/s is/are true?
A. I and only
B. II, III, and IV only
C. I, III, and V only
D. All of the statements are correct.
C.
II = constant - change in
IV = positive - negative
