Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology eduquas > photosynthesis > Flashcards

photosynthesis Flashcards

(68 cards)

Start Studying
1
Q

photosynthesis equation

A

6CO2 + 6H20 = C6H12O6 + 6O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

adaptions of a leaf for photosynthesis

A
  • large SA
  • thin
  • stomatal pores
  • air spaces in spongy mesophyll
  • spaces between palisade cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

large SA significance for photosynthesis

A

capture as much light as possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

thin leaf significance for photosynthesis

A

light penetrates through the leaf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

stomatal pores significance for photosynthesis

A

allows CO2 to diffuse into the leaf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

spaces between palisade cells and air spaces in spongy mesophyll significance for photosynthesis

A

allows CO2 to diffuse into to the photosynthesising cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

leaf cell adaptions for photosynthesis

A
  • transparent cuticle and epidermis
  • thin cellulose cell walls
  • large vacuole in palisade cells
  • cylindrical palisade cells
  • palisade cells elongated at right angles to leaf surface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

transparent cuticle and epidermis, and thin cellulose cell walls significance for photosynthesis

A

light penetrates through to mesophyll

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

large vacuole in palisade cells significance for photosynthesis

A

chloroplasts form a single layer so they don’t shade each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

cylindrical and elongated at right angles palisade cells significance for photosynthesis

A
  • leaves accommodate a large number of palisade cells
  • light only passes through 2 epidermal cell walls and 1 palisade cell wall to reach chloroplasts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

chloroplast adaptions for photosynthesis

A
  • large SA
  • can move and rotate within palisade cells
  • pigments in thylakoid in single layer at surface of thylakoid membrane
  • more chloroplasts in palisade than spongy mesophyll cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

chloroplast large SA significance for photosynthesis

A

maximum absorption of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

chloroplasts can move and rotate within palisade cells significance for photosynthesis

A
  • move to top of cell on dull days for max light absorption
  • high light intensity moves to bottom to protect pigments from bleaching
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

pigments in thylakoid in single layer at surface of thylakoid membrane significance for photosynthesis

A

thylakoids maximise light absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

more chloroplasts in palisade than spongy mesophyll cells significance for photosynthesis

A

palisade cells are at top of leaf so more exposed so chloroplasts can maximise light absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

pigments in thylakoids are in a single layer at surface of thylakoid membrane significance for photosynthesis

A

pigments maximise light absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

photophosphorylation

A

an endergonic reaction bonding a phosphate ion to a molecule of ADP, using energy from light, making ATP
- non-cyclic vs cyclic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

thylakoid lamellae

A

folded inner membrane of chloroplasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

stroma

A

fluid filled chloroplast interior
bathes thylakoids and grana
location of light independent stage
contains enzymes for photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

grana

A

stacks of thylakoids
location of photosynthetic pigments
location of light dependent stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

why are starch grains white?

A

stain binds to lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

where are chloroplasts found in a leaf?

A
  • leaves and stems
    areas exposed to light
  • in palisade and spongy mesophyll
  • in guard cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is a transducer?

A

changes energy from one form to another.
biological transducers waste little energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how are chloroplasts transducers?

A

they turn energy in photons of light into chemical energy, made available through ATP and incorporated into molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is a photosynthetic pigment?
a molecule that absorbs specific wavelengths of light traps light energy different pigments = trap different wavelengths
26
types of photosynthetic pigments
- chlorophyll a = blue/green - chlorophyll b = yellow/green - b-carotene = orange - xanthophyll = yellow
27
chlorophyll definitation
protein containing magnesium, bound to thylakoid membrane
28
absorption spectrum
a graph showing how much light is absorbed at different wavelengths ( relative absorption)
29
patterns of absorption spectrum
- chlorophyll a+b absorb light energy in red/blue-violet regions, and reflect green - carotenoids absorb light energy in blue/green region, so appear yellow/orange
30
action spectrum
graphs showing rate of photosynthesis at different wavelengths - measured by mass of carb synthesised by plant at various wavelengths
31
where are photosystems found
in the plane of the thylakoid membrane
32
what is a photosystem made of?
- antenna complex - reaction centre they are a collection of accessory pigments
33
antenna complex
- contains photosynthetic pigments, anchored into phospholipids of thylakoid membrane held together by clusters of protein molecules - consists of one cluster - pigments combos = various wavelengths absorbed - transfer energy to chlorophyll a in reaction centre
34
reaction centre of photosystems
- within antenna complex - 2 molecules of primary pigments (chlorophyll a). absorbs light, excitation emits 1 electron each
35
PS1
arranged around chlorophyll a molecule absorption peak = 700nm
36
PS2
arranged around chlorophyll a molecule absorption peak = 680nm
37
accessory pigments
- chlorophyll b and carotenoids light absorbing molecules, pass energy through to reaction centre to reach chlorophyll a excited chlorophyll a electrons = energy level raised
38
chlorophyll a
- primary pigment passes energy to subsequent reactions of photosynthesis
39
what does the light dependent stage produce?
- ATP, to synthesis molecules (glucose) - reduced NADP, to reduce synthesising molecules - oxygen, by-product, diffuses out leaf
40
cyclic photophosphorylation
- PS1 - electrons cycle - in all photosynthetic organisms
41
non-cyclic photophosphorylation
- PS1 + PS2 - linear electron pathway - in plants, algae, cyanobacteria
42
cyclic photophosphorylation stages
- PS1 absorb photons, excites chlorophyll a electrons (in reaction centre) - electrons emitted and picked up by electron acceptor - pass down electron carriers to PS1 - energy released phosphorylates ADP to ATP - electrons path: PS1 to electron acceptor to PS1 - electron recycled into chlorophyll a
43
non-cyclic photophosphorylation stages
- PS2 absorbs light energy, excites pair of electrons in chlorophyll a and leave it - electron carrier takes up pair - electrons need to be replaced. photolysis of water provides electrons - electrons pass down transport chain, each stage loses energy - lost energy combines Pi with ADP = ATP - light energy absorbed by PS1 excites electrons - electrons and 2H transferred to NADP = reduced NADP enters independent reaction
44
photolysis of water
- splitting of water molecules by light in thylakoid spaces - indirectly produces 2H, 2 electrons, 1/2 oxygen - electrons replace those lost from PS2 - protons and electrons (from PS1) reduce NADP - oxygen diffuses out stomata (waste product)
45
Rf value calculation
distance travelled by pigment divided by distance travelled by solvent front
46
what is chemiosmosis?
the process of moving ions (protons) to the other side of a biological membrane - through ATP synthetase, into stroma - produces electrochemical gradient - once in stroma protons can reduce NADP
47
3 factors that maintain proton gradient between thylakoid space and stroma
- proton pump (protons into thylakoid space) - photolysis of water - removal of protons from stroma, reduces NADP
48
carboxylation of light independent stage steps
- CO2 enters chloroplasts - CO2 combines with RuBP (5C) catalysed by rubisco - unstable 6C compound formed - 6C splits into 2 molecules of a 3C compound, glycerate-3-phosphate (GP)
49
reduction of light independent stage steps
- GP reduced to TP (3C). reduced NADP provides H ions, ATP provides energy - NADP reformed and recycled - TP converted to useful compounds (glucose), then to starch
50
regeneration of light independent stage steps
- 5/6 TP molecules produced regenerate RuBP - rest of ATP provides energy
51
products of calvin cycle
- carbohydrate: hexose sugar, glucose (fructose bisphosphate) - lipids: produced from TP - proteins: amino acids produced using nitrogen from nitrates
52
hexose sugars
- monosaccharide, 6C - made by joining 2TP - 1 hexose sugar = 6 calvin cycle turns
53
what is a limiting factor?
- factor that limits the rate of a physical process by being in short supply
54
how does CO2 limit photosynthesis?
- when in short supply it limits photosynthesis - CO2 increase = photosynthesis increases - eventually plateaus
55
how does light intensity limit photosynthesis ?
- plant in darkness = light dependent reaction can't occur - light intensity increases = efficiency of light dependent reaction increases - eventually reaches max rate - if too high = photosynthetic pigments damaged = no photosynthesis
56
how does temperature limit photosynthesis?
- involves enzymes, so increase in temp = increased KE = increase successful collisions = increased rate of reaction - temp above optimum = enzymes denature = decreases rate
57
how does water limit photosynthesis?
- when water is scarce, plant cells plasmolyse = stomata close = wilting
58
sun plants
most efficient at high light intensities
59
shade plants
most efficient at low light intensities
60
light compensation rate
light intensity at which a plant has no net gas exchange. volumes of gases used and produced in photosynthesis and respiration are equal - low light intensity = decreased rate of photosynthesis = decreased CO2 uptake. so respiration provides all the CO2 needed. and all the O2 needed for respiration is provided by photosynthesis
61
roles of inorganic nutrients in plants
- structural - synthesis of compounds for growth - form molecule parts, e.g. magnesium in chlorophyll
62
function of nitrogen in plants
- synthesis of nucleic acids, proteins and chlorophylls - become amino groups of amino acids
63
symptoms of nitrogen deficincy
- reduced growth of entire plant - yellow leaves = chlorosis
64
function of magnesium in plants
- chlorophyll production
65
symptoms of magnesium deficiency
- yellow leaves = chlorosis begins in older veins as Mg is prioritised to newer leaves
66
explain the advantage of plants having more than one pigment in their leaves
- light can be absorbed over a greater range of wavelengths - more light absorbed = more products from light dependent stage - greater rate of photosynthesis
67
68

Biology eduquas (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions