Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

module 5 > 5.6 Photosynthesis > Flashcards

5.6 Photosynthesis Flashcards

1
Q

the interrelationship between the process of
photosynthesis and respiration

A

both are important in cycling carbon dioxide and oxygen in the atmosphere
the products of one process are the raw materials for the other

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

autotroph

A

uses light or chemical energy to synthesise large organic molecules from smaller imorganic ones

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

heterotroph

A

obtain energy/ large organic molecules from autotrophs

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

two types of autotrophs and what energy they use

A

chemoautotrophs - uses chemical energy
photoautotrophs - uses light energy

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

equation for photosynthesis

A

6CO2 + 6H20 + energy from photons -> C6H1206 + 6O2

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

what is photosynthesis

A

process of converting light energy from sunlight into chemical energy to synthesise large organic molecules

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

photon

A

a particle of light (each countains a quantum of energy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

main product of photosynthesis and what its converted/stored as

A

monosaccharide sugar - coverted to disaccharides for transport and starch for storage

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

what is photosynthesis an example of (explain it)

A

carbon fixation - process by which carbon dioxide is converted to sugars

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

what does photosynthesis/ carbon fixation help regulate

A

carbon dioxide levels in the atmosphere and oceans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what happens during respiration

A

glucose/ other organic molecules are oxidised to produce carbon dioxide and water and releases chemical energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

explain why heterotrophs use respiration

A

obtain energy from it by digesting the larger complex organic food to smaller molecules , energy released can be used in the organisms metabolism

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

explain what the compensation point is

A

when photosyntheis and respiration proceed at the same rate so there is no net gain or loss of carbohydrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the compensation period

A

the time taken for a plant to reach its compensation point

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

why does repiration not vary much but photosynthesis does across a 24 hour period

A

photosynthesis = dependant on sunlight for energy
respiration = oxygen always present
varies due to heat = increase enzyme activity

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

state the structure of a chloroplast

A

outer and inner membrane (double)
stroma
granum
thylakoids
(intergranal) lamallae

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

granum

A

inner part of chloroplast made of stacks of thylakoid membranes where the light dependant stage of photosynthesis takes place

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

photosynthetic pigment

A

pigment that absorbs specific wavelengths of light and traps the energy associated with the light

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

photosystem

A

system of photosynthetic pigments found in thylakoids that create a funnel shaped structure, to trap photons and is funnelled to the primary pigment reaction centre

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

stroma

A

fluid filled matrix of chloroplasts where the light independant stage of photosynthesis

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

thylakoid

A

flattened membrane bound sacs that contain photosynthetic pigments or photosystems and is the site of the light dependant stage

22
Q

Role in DNA in plants for photosynthesis

A

Loop of DNA contains genes that code for some of the proteins needed
Proteins assembled at the chloroplasts ribosomes

23
Q

What is chlorophyll

A

Light capturing photosynthetic pigment that absorb wavelengths of light

24
Q

Name types of chlorophyll

A

Chlorophyll a
Chlorophyll b
Chlorophyll carotenoids
Phaeophytin

25
Q

What is the absorption spectrum

A

Shows the wavelengths of light absorbed by different photosynthetic pigments

26
Q

What wavelength of light can the different types of chlorophyll absorb and describe the shape of the graph

A

A = 400 to 725 nm - double peak , highest one at 425 and slighlty smaller one at 700
B = 400-500nm and around 640nm - high peak at 450 and smaller peak at 650
Carotenoids = 400-500nm - very small curve
Xanthophylls = 375-550nm - sharp spike (triangle)
bacteriochlorophyll = up to 850nm - widest range, highpeak at 800 and peak at 350

27
Q

what light wavelength can PS1 and PS2 absorb

A

PS1= 700nm
PS2= 680nm

28
Q

Describe how to separate photosynthetic pigments using chromatography

A

Scraping/ mashing leaf
Using two microscope slides
Spot the chromophyll onto a slide coated with a thin layer of chromatography material
Solvent separates pigments as they have different Rf values

29
Q

what photosystems are used in non cyclic and cyclic photophosporylation

A

non cyclic = PS2 and PS1
cyclic = PS1

30
Q

name the steps of light dependant stage of photosynthesis

A

light harvesting
photolysis
photophosphorylation
formation of reduced NADP

31
Q

describe photolysis

A

splitting of water using light energy
splits it into protons, electrons and oxygen
2H20-> 4H+ + 4e- + O2

32
Q

name the two types of photophosphorylation and what photosystems it uses

A

non cyclic - PS1 and PS2
cyclic - only PS1

33
Q

what does non cyclic and cyclic photoposhorylation produce

A

non cyclic - ATP, oxygen and reduced NADP
cyclic - smaller quantities of ATP

34
Q

describe cyclic photophosphorylation

A

only uses PS1
as light energy strikes PS1= pair of electrons get excited = passes to an electron acceptor = goes down electron transport chain = passes back to PS1

35
Q

describe non cyclic photophosphorylation

A

PS1 and PS2 used
electrons get excited
passess to electron acceptor molecule and goes down the ETC
(electrons in PS2 get replaced by e- produced by photolysis)
sets up a proton (H+) gradient (proton pump ase- release energy)
known as chemiosmosis
electrons move to PS1 from PS2 , replaces e- lost by light in PS1
higher conc. of H+ ions inside the thylakoid space - sets up gradient - protons diffuse down the gradient through channels associated with ATP synthase enzymes = flow of protons causes ADP + Phosphate = ATP
as protons pass through channel they are accepted with electrons lost from PS1 by light - NADP becomes reduced
catalysed by NADP reductase

36
Q

how has light energy been converted to chemical energy

A

in the form of ATP by photophosphorylation

37
Q

what products from LDS are used in the light independant stage

A

ATP and reduced NADP

38
Q

what is the LIS stage called

A

the calvin cycle

39
Q

what does the LIS produce

A

6 turns of the cycle = 2TP molecules which is made into carbohydrates ( starch etc)

40
Q

main stages of the calvin cycle

A

RuBisCO catalyses CO2 and RuBP
creates an unstable 6carbon compund which splits into two 3 carbon compounds (GP)
the C02 is now fixed
the two GP molecules is reduced to 2 TP by ATP and hydrogen from reduced NADP from LDS
some of the TP is used to form hexose sugars (1/6)
some of the TP is used to regenerate RuBP and the cycle starts again (5/6)
6 turns of the cycle makes 2TP as a product and 6RuBP

41
Q

uses of triose phosphate

A

used to synthesise organic compounds
2TP can make 1 glucose
- glucose converted to starch, sucrose, cellulose
- some used to synthesise amino acids, fatty acids and glycerol

42
Q

how does daylight impact the LDS and LIS

A

light needed in the LDS to produce ATP AND reduced NADP for the LIS - continuously needed
in the LDS hydrogen ions are pumped into the thylakoid space = raises pH to 8 = optimum for enzyme RuBisCO
in daylight = magnesium ion concentration increases in the stroma = act as a cofactor for RuBisCO
the LIS stage doesn’t directly use light but needs to use the products created by light

43
Q

GP
TP
RuBP
RuBisCO

A

glycerate phosphate
triose phoshpate
ribulose bisphosphate
ribulose bisphosphate carboxylase oxygenase

44
Q

name limiting factors of photosynthesis

A

light intensity
C02 concentration
temperature

45
Q

describe how light intensity can impact photosynthesis

A

as light intensity increases the rate of photosynthesis increases
when there is little light
- GP cannot be reduced to TP as LDS products not produced
- TP levels fall and GP accumlates
- RuBP cannot be regenerated

46
Q

describe how C02 concentration can impact photosynthesis

A

if C02 levels decrease (below 0.01%) then
RuBP cannot acept it and accumulates
GP cannot be made
so TP not made

47
Q

describe how temperature can impact photosynthesis

A

as temp increases the ROP increases if no other factors are limiting
above 30 = growth rates reduce due to photorespiration = 02 competes with C02 for Rubisco enzyme = less C02 fixed and GP formed = so less TP produced
above 45 = enzymes denature = reduce levels of GP and TP and eventually RuBP as not being regenerated

48
Q

define water stress

A

a condition a plant experiences when water supply becomes limiting

49
Q

describe how water stress can impact photosynthesis

A

not enough water available = roots cannot take up enough to reduce water lost through transpiration = cells lose water and become plasmolysed = stomata closes = tissues become flaccid and wilt = ROP decreases

50
Q

how can you measure the rate of photosynthesis

A

using a photosynthometer

51
Q

limitations of using a photosynthometer

A

oxygen produced can be used in respiration
dissolved nitrogen in gas
needs to be air tight/ no air bubbles

52
Q

how do you collect results of a photosynthometer

A

gas given off by the plant is collected in the capillary tube
can be measured against the scale
length of bubble x (pie)r*2 = volume of gas collected

module 5 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions