Brainscape's Knowledge GenomeTM

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


See full index

Biology A-Level > Photosynthesis and Respiration > Flashcards

Photosynthesis and Respiration Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What do plants use energy for?

A
  • Photosynthesis
  • AT
  • DNA replication
  • Cell division
  • Protein synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do animals use energy for?

A
  • Muscle contraction
  • Maintenance of body temperature
  • AT
  • DNA replication
  • Cell division
  • Protein synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define photosynthesis

A

Process where energy from light is used to make glucose from water and carbon dioxide

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

What is the overall equation for photosynthesis?

A

6CO2 + 6H2O + Energy => C6H12O6 + 6O2

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

Define respiration

A

Process of releasing energy from glucose

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

What is the overall equation for aerobic respiration?

A

C6H12O6 + 6O2 => 6CO2 + 6H2O + Energy

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

What are the products of anaerobic respiration in plants and yeast?

A
  • Ethanol
  • CO2
  • Releases energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the products of anaerobic respiration inhumans?

A
  • Lactate
  • Releases energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What makes ATP a good energy source?

A
  • Releases small manageable amount of energy so no energy is wasted as heat
  • Small + soluble so can easily be transported
  • Quickly re-made
  • Can make other molecules more reactive by transferring its phosphate group (phosphorylation)
  • Can’t pass out cell so always has immediate supply of energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define metabolic pathway

A

Series of small reactions controlled by enzymes

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

Define phosphorylation

A

Adding phosphate to a molecule

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

Define photophosphorylation

A

Adding phosphate to a molecule using light

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

Define photolysis

A

Splitting a molecule using light energy

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

Define photoionisation

A
  • Light energy excites e- in an atom/molecule, giving them more energy + causing them to be released.
  • Release of e- causes atom/molecule to become +ve-charged ion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define decarboxylation

A

Removal of CO<strong>2</strong> from molecule

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

Define dehydrogenation

A

Removal of H+ from molecule

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

Define coenzyme

A

Molecule that aids the function of an enzyme

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

Give an example of a coenzyme used in photosynthesis

A
  • NADP
  • Tranfers H<strong>+</strong> from one molecule to another
  • Can reduce/oxidise molecule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Give examples of a coenzyme used in respiration

A
  • NAD and FAD - tranfers H+ from one molecule to another
  • Coenzyme A - tranfers acetate btw molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where does photosynthesis take place?

A

Chloroplast

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

What do chloroplasts contain?

A
  • Photosynthetic pigments
  • eg. chlorophyll a, chlorophyll b + carotene
  • Coloured substances that absorb light energy needed for photosynthesis
  • Found in thylakoid membranes - attached to proteins
  • Pigment + protein = photosystem
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the wavelengths used by both photosystems for absorbing light energy?

A
  • Photosystem I - absorbs light at wavelength of 700nm
  • Phtosystem II - absorbs light at 680nm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does the stroma conatin?

A
  • Enzymes
  • Sugars
  • Organic acids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How are carbs produced by phtosynthesis stored as and where?

A
  • Starch grains
  • Stroma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where does the light-dependent reaction take place?

A

Thylakoid membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where does the light-independent reaction take place?

A

Stroma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

In the light-dependent reaction, what is the energy from the photoionisation of chlorophyll used for?

A
  • Making ATP from ADP + inorganic phosphate (photophosphorylation)
  • Making reduced NADP from NADP
  • Splitting water into protons, e<strong>-</strong> + O2 (photolysis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are electron carriers?

A

Proteins that transfer electrons

29
Q

What do photosystems and electron carriers form?

A
  • Electron transport chain
  • Chain of proteins where excited e- flow through
30
Q

Outline the light-dependent reaction

A
  • Light absorbed by PSII
  • Excites e- to higher energy level
  • High Ee- released from chlorophyll + move down ETC to PSI, e- must be replaced
  • Light splits water to H+, e- + O2
  • Ee- lose energy as they move down ETC
  • Energy used to transport H<strong>+</strong> to thylakoid so has a higher conc of H+ than stroma- forms proton gradient
  • Protons move down conc gradient into stroma via enzyme ATP Synthase
  • Energy released forms ATP
  • Light energy absorbed by PSI exciting e- to even higher energy level
  • E- transferred to NADP along w/ H+ from stroma forming reduced NADP
31
Q

Define chemiosmosis

A

Process of e- flowing down ETC and creating proton gradient across membrane to drive ATP synthesis

32
Q

What are the products of non-cyclic photophosphorylation

A
  • ATP
  • Reduced NADP
  • O2
33
Q

What are the products of cyclic photophosphorylation and why is it called cyclic?

A
  • ATP
  • Only uses PSI
  • E- from chlorophyll aren’t passed to NADP but passed back to PSI via e- carriers - e- recycled
34
Q

Where does the light-independent (calvin cycle) reaction take place?

A

Stroma

35
Q

Outline the light-independent reaction

A
  • CO2 enters leaf + diffuses into stroma
  • CO2 combines w/ ribulose biphosphate (5C) catalysed by rubisco
  • Gives unstable 6C breaking into 2 glycerate 3-phosphate (3C)
  • Hydrolysis of ATP provides energy turning GP to triose phosphate (3C), also requires H+ from reduced NADP (both from LDR)
  • Some TP coverted to useful compounds (glucose) + some continue to regenerate RuBP
  • 5/6 of TP aren’t used to make hexose but to regenerate RuBP - uses rest of ATP produced by LDR
36
Q

Name the substance triphosphate and glycerate 3-phosphate are converted to

A
  • Carbs - hexose sugars: join 2 TP together, larger carbs: join hexose sugars in diff ways
  • Lipids - made using glycerol synthesised from TP + fatty acids synthesised from glycerate 3-phosphate
  • AA - made from glycerate 3-phosphate
37
Q

How many calvin cycle turns, ATP and reduced NADP does there need to be to make a one hexose sugar

A
  • 6 cycles
  • 18 ATP
  • 12 reduced NADP
38
Q

What are the optimum conditions for photosynthesis?

A
  • High light intensity w/ certain wavelength - light provides energy. Photosynthetic pigments only absorb red + blue light (reflect green)
  • Temp 25oC - involves enzymes, below 10oC enzymes inactive, above 45oC enzymes denature + stomata close to avoid losing water - photosynthesis slows down bc less CO2 enters
  • CO2 at 0.4% - higher rate of photosynthesis, higher: stomata closes
39
Q

Name the factors limiting photosynthesis

A
  • Light intensity
  • Temp
  • CO2 conc
40
Q

Define the saturation point

A

Where factor is no longer limiting the reaction - something else becomes the limiting factor

41
Q

How do growers manage glasshouses to create optimum conditions for plants to grow?

A
  • CO2 conc - added to air by burning propane in CO2 generator
  • Light - LED lights
  • Temp - heaters and coolers. Air circulation systems makes sure temp is even throughout glasshouse
42
Q

What process can you use to determine what pigments are present in the leaves of a plant?

A
  • Thin layer chromatography:
  • Mobile phase - molecules can move, liquid solevent
  • Stationary phase - molecules can’t move, solid plate w/ thin layer of gel ontop
43
Q

Describe how you carry out a TLC to compare pigments in diff. plants

A
  • Grind up leaves w/ anhydrous sodium sulfate, add drops of propanone
  • Transfer liquid to test tube, add petroleum ether and shake. 2 distinct layers form - top is pigments mixed w/ PE
  • Transfer top layer to another test tube w/ anhydrous sodium sulfate
  • Draw pencil line at bottom of TLC plate. Build up conc spot - point of origin
  • Place plate in glass w/ solvent just below line.
  • When solevent has nearly reached the top, mark w/ pencil
  • Calculate the Rf value
44
Q

What’s the equation to work out the Rf value?

A

Rf value = distance travelled by spot / distance travelled by solvent

45
Q

In the photosystem I, during the light-dependent stage of photosynethesis, NADP acts as e- acceptor + is reduced. What is this reaction catalysed by?

A

Dehydrogenase enzyme

46
Q

Describe how to investigate the effect of light intensity on dehydrogenase activity in extracts of chloroplasts

A
  • Add redox indicator dye (DCPIP) to extract chloroplast. Dye acts as e- acceptor + when reduced, goes blue to colourless
  • If dehydrogenase activity is taking place, absorbance dec in colorimeter as DCPIP gets reduced + loses blue colour
  • Stronger light intensity, faster absorbance dec, faster rate of dehydrogenase activity
47
Q

What are the stages in aerobic respiration?

A
  • Glycolysis
  • Link reaction
  • Krebs cycle
  • Oxidative phosphorylation
48
Q

Where does glycolysis occur?

A

Cytoplasm

49
Q

Outline the 2 stages in glycolysis

A
  • Phosphorylation:
  • Glucose is phosphorylated using phosphate from ATP, creates 1 glucose phosphate (6C) + 1 ADP
  • ATP used to add phosphate forming hexose biphosphate (6C)
  • Hexose biphosphate split into 2 triose phosphate (3C)
  • Oxidation:
  • TP is oxidised forming 2 pyruvate
  • NAD collects H+ forming 2 reduced NAD
  • 4 ATP produced
50
Q

Does glycolysis require oxygen?

A

No, it’s an anaerobic process

51
Q

During aerobic respiration, what happens to the products after glycolysis?

A
  • 2 reduced NAD go to oxidative phosphorylation
  • 2 pyruvate AT into matrix of mitochondria for link reaction
52
Q

What is the net gain after glycolysis?

A
  • 2 ATP
  • 2 reduced NAD
53
Q

During anaerobic respiration, what is the pyruvate converted into in animals and some bacteria?

A
  • Lactate
  • Oxidises reduced NAD to NAD
54
Q

During anaerobic respiration, what is the pyruvate converted into in plants and yeast?

A
  • Ethanal, releasing CO2
  • Converted into ethanol
  • Oxidises reduced NAD to NAD
55
Q

During anaerobic respiration, how can glycolysis continue in the presence of v. little oxygen?

A
  • Production of ethanol/lactate regenerates oxidised NAD
  • Small amount of ATP produced
56
Q

Where does the link reaction and the kreb cycle occur?

A

Matrix of mitochondria

57
Q

Outline what happens during the link reaction

A
  • Pyruvate (3C) is decarboxylated (C atom is removed in form of CO2)
  • Pyruvate oxidised to form acetate (2C) and NAD is reduced
  • Acetate combines w/ coenzyme A forming acetyl coenzyme A
  • No ATP produced
58
Q

What happens for every glucose molecule that enters glycolysis?

A
  • 2 molecules of acetyl coA go into krebs cycle
  • 2 CO2 released as waste product
  • 2 reduced NAD formed + go to oxidative phosphorylation
  • Link reaction + kreb cycle occur twice
59
Q

Outline the krebs cycle

A
  • Acetyl coA from link reaction combine w/ 4C molecule to form 6C molecule
  • Coenzyme A goes back to link reaction
  • 6C citrate converted to 5C
  • Decorboxylation (CO2 removed) + dehydrogenation occurs, H+ used to produce reduced NAD from NAD
  • 5C converted to 4C
  • Decorb + dehyd occurs producing 1 reduced FAD + 2 reduced NAD
  • ATP produced by direct transfer of phosphate group from intermediate to ADP
60
Q

Define substrate-level phosphorylation

A

Phosphate group transferred from 1 molecule to another

61
Q

What are the products of the krebs cycle and where does it go?

A
  • Coenzyme A - Link reaction
  • Oxaloacetate - regenerated for next KC
  • 2 CO2 - Waste product
  • 1 ATP - energy
  • 3 reduced NAD - oxi phosph
  • 1 reduced FAD - oxi phosph
62
Q

What does oxidative phosphorylation involve?

A
  • e- transport chain
  • Chemiosmosis
63
Q

Where does oxidative phosphorylation occur?

A

Inner mitochondrial membrane

64
Q

Outline oxidative phosphorylation

A
  • H atoms released from reduced NAD + FAD. H split into H+ and e-
  • e- move down e- transport chain losing energy at each carrier
  • Energy used by EC to pump H+ from mitochondrial matrix into intermembrane space
  • Conc of H+ higher in intermembrane space than matrix - forms electrochemical gradient
  • H+ move down electrochemical gradient via ATP synthase. Movement synthesise ATP (chemiosmosis)
  • In matrix H+, e- + O2 (final e- acceptor) combine to form water
65
Q

How much ATP can be made from 1 glucose molecule?

A

32

66
Q

Outline how ATP production can be affected by mitochondrial diseases and it’s effects

A
  • Mitochondrial diseases affect protein involved in oxi phosph/Krebs cycle function, reducing ATP production
  • May cause inc anaerobic respiration, results in lots of lactate being produced leading to muscle fatigue + weakness. Lactate will also diffuse into bloodstream, high lactate conc in blood
67
Q

What other substrates, aside from glucose, can be used in aerobic respiration?

A
  • Fatty acids from lipids
  • AA from proteins
  • Able to enter Krebs cycle
68
Q

Outline the procedure needed when investigating how temperature affects respiration in single-celled organisms during aerobic respiration

A
  • Put known vol + conc of substrate sol in test tube. Add known vol of buffer sol
  • Place in water bath to 1 of the temp. Leave for 10 mins to allow temp of substrate to stabalise
  • Add known mass of dried yeast to tube + stir
  • Put bung w/ tube attached to gas syringe set to 0
  • Start stop watch
  • As yeast respire, CO<strong>2</strong> formed will travel into gas syringe. Record at regular intervals
  • Compare w/ control (w/o yeast)
69
Q

Outline the procedure needed when investigating how temperature affects respiration in single-celled organisms during anaerobic respiration

A
  • Same 1-3 steps as aerobic respiration experiment
  • After yeast dissolved, add liquid parffin to cover whole SA of substrate to stop O2 entering (yeast will respire anaerobically)
  • Follow last steps from aerobic respiration experiment

Biology A-Level (10 decks)

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