Brainscape's Knowledge GenomeTM

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


See full index

Biology > A2 Photosynthesis and Respiration > Flashcards

A2 Photosynthesis and Respiration Flashcards

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

What is the Equation for Photosynthesis?

A

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

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

What is the 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
3
Q

What Properties of ATP make it a Good Energy Source?

A
  • Releases small, manageable amount of energy, no energy wasted as heat
  • Small, soluble molecule, easily transported
  • Easily broken down, energy released quickly
  • Quickly re-made
  • Can make other molecules more reactive by transferring one of its phosphate groups
  • ATP cant pass out cell, always has immediate supply of energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define phosphorylation and photophosphorylation

A

Adding phosphate to a molecule (using light)

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

Define Photolysis

A

The splitting of a molecule using light energy

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

Define photoionisation

A

When light energy ‘excites’ electrons in an atom or molecule, giving them more energy, causing them to be released. Atom becomes a positively-charged ion

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

Define decarboxylation and dehydrogenation

A

Decarboxylation - removal of CO2 from a molecule

Dehydrogenation - removal of H from a molecule

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

Describe redox reactions

A

Reduction:
- Gained electrons and may have gained hydrogen or lost oxygen
Oxidation:
- Lost electrons and may have lost hydrogen or gained oxygen
Oxidation of one molecule always involves reduction of another

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

Describe what a Co-enzymes is and their Involvement in Photosynthesis and Respiration

A

Molecule that aids the function of an enzyme by transferring a chemical group from one molecule to another
Photosynthesis:
- NADP - transfers hydrogen from one molecule to another, it can reduce or oxidise a molecule
Respiration:
- NAD/FAD - same as NADP
- Coenzyme A - transfers acetate between molecules

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

Describe the Structure of a Chloroplast

A
  • Flattened organelles surrounded by double membrane
  • Thylakoids stacked into grana
  • Grana linked together by lamellae
  • Photosynthetic pigments contained in thylakoid membranes, attached to proteins
  • Protein and pigment called a photosystem
  • Stroma contains enzymes, sugars and organic acids
  • Carbohydrates stored as starch grains in stroma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the Products of the Light-Dependent Reaction?

A
  • ATP made from ADP and inorganic phosphate

- Reduced NADP made from NADP

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

Describe the First Stage of the Light-Dependent Reaction (Photoionisation)

A
  • Light energy absorbed by PSII
  • Excited electrons in chlorophyll move up to higher energy level
  • Electrons released from chlorophyll, move down ETC to PSI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the Second Stage of the Light- Dependent Reaction (Photolysis)

A
  • Electrons leaving PSII need replacing
  • Light energy splits water into Protons (H+), electrons and oxygen
  • H2O > 2H+ + 0.5O2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the Third Stage of the Light-Dependent Reaction (Chemiosmosis)

A
  • Electrons lose energy as they move down ETC
  • Energy used to transport protons into thylakoid, higher conc. of protons than stroma
  • Forms proton gradient across membrane
  • Protons move down conc. gradient into stroma via ATP synthase, embedded in thylakoid membrane
  • Energy from this combines ADP and inorganic phosphate to form ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the Fourth Stage of the Light-Dependent Reaction (Reduced NADP)

A
  • Light energy absorbed by PSI, excites electron to even higher energy level
  • Electrons transferred to NADP, along with a proton from stroma
  • Forms reduced NADP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe Cyclic Photophosphorylation

A
  • Only uses PSI
  • Electrons from chlorophyll not passed onto NADP, but passed back to PSI via electron carriers
  • Electrons recycled through PSI
  • No reduced NADP or oxygen produced, only produces small amount of ATP
17
Q

Describe the First Stage of the Light-Independent Reaction (Glycerate 3-Phosphate)

A
  • CO2 enters leaf through stomata, diffuses into stroma
  • Combines with ribulose bisphosphate (RuBP), 5C compound
  • Reaction catalysed by enzyme rubisco
  • Produces unstable 6C carbon
  • Breaks down into two 3C compounds, glycerate 3-phosphate (GP)
18
Q

Describe the Second Stage of the Light-Independent Reaction (Triose Phosphate)

A
  • Hydrolysis of ATP (from LDR) provides energy to turn 3C compound, GP, into different 3C compound, triose phosphate (TP)
  • Reaction requires H+ ions from reduced NADP (from LDR), reduced NADP recycled to NADP
  • Some TP converted to useful organic compounds (glucose) and some used to regenerate RuBP
19
Q

Describe the Third Stage of the Light-Independent Reaction (Ribulose bisphosphate)

A
  • 5 out of every 6 TP molecules used to regenerate RuBP, not make hexose sugar
  • Regenerating RuBP uses rest of ATP from LDR
20
Q

How are TP and GP Converted into Useful Organic Substances (Carbs, Lipids and Amino Acids)?

A
  • Carbs - hexose sugars made from 2 TP molecules joined together, larger carbs, by joining hexose sugars
  • Lipids - using glycerol, synthesised from TP, and fatty acids synthesised from GP
  • Amino acids - some are made from GP
21
Q

Explain Why the Calvin Cycle Turns 6 Times to Make 1 Hexose Sugar

A
  • 3 turns produces 6 TP, 2 TP made for every CO2 molecule used
  • 5 out of 6 TP molecules used to regenerate RuBP
  • 3 turns, only 1 TP available for making a hexose sugar
  • Hexose sugar has 6 carbons, 2 TP molecules needed
  • Cycle must turn 6 times to produce 2 TP molecules used to make 1 hexose sugar
  • 6 turns requires 18 ATP and 12 reduced NADP (from LDR)
22
Q

What are the Optimum Conditions for Photosynthesis? (Name 3)

A
  • High light intensity of certain wavelengths, only red and blue light absorbed from the sun
  • Temperature around 25 degrees C, temp below 10C, enzymes inactive. Temp above 45C, enzymes denature
  • Carbon dioxide at 0.4%, CO2 makes up 0.04% of atmosphere, increasing this, increases rate of photosynthesis
23
Q

How could Growers Create Optimum Conditions in Greenhouses (Name 2)

A
  • CO2 - CO2 added to air, burning small amount of propane in CO2 generator
  • Light - lamps provide light during night
  • Temperature - heaters and coolers can be used to keep constant optimum temperature. Air circulation systems can be used to keep temp. even throughout
24
Q

Describe the First Stage of Glycolysis (Phosphorylation)

A
  • Glucose phosphorylated using phosphate from ATP, creates 1 glucose phosphate and 1 ADP
  • ATP used to add another phosphate, makes hexose bisphosphate
  • Hexose bisphosphate split into 2 TP
25
Q

Describe the Second Stage of Glycolysis (Oxidation)

A
  • TP oxidised (loses hydrogen), forming 2 molecules of pyruvate
  • NAD collects hydrogen ions, forming 2 reduced NAD
  • 4 ATP produced, 2 were already used in stage one, net gain of 2 ATP
26
Q

Describe the Two Outcomes of Anaerobic Respiration (Ethanol/Lactate)

A
  • Alcoholic fermentation (plants/yeast)
    Pyruvate > Ethanal > Ethanol
    CO2 lost ^ ^Reduced NAD > NAD
  • Lactate fermentation (animals/bacteria)
    Pyruvate > Lactate
    ^ Reduced NAD > NAD
    Production of ethanol/lactate regenerates oxidised NAD so glycolysis can continue with little oxygen
27
Q

Describe the Link Reaction (Acetyl CoA)

A
  • Pyruvate decarboxylated, one carbon removed in form of CO2
  • Pyruvate oxidised, forms acetate and NAD reduced, forms reduced NAD
  • Acetate combines with coenzyme (CoA), forms acetyl coenzyme A (acetyl CoA)
  • No ATP produced
28
Q

Explain Why the Link Reaction Occurs Twice for Every Glucose Molecule

A
  • 2 pyruvate molecule made for 1 glucose

- Link reaction occurs twice for each glucose molecule, one for each pyruvate produces

29
Q

Describe the First Stage of the Krebs Cycle (Citrate)

A
  • Acetyl CoA combines with 4C molecule (oxaloacetate), forms 6C molecule (citrate)
  • Coenzyme A goes back to link reaction
30
Q

Describe the Second Stage of the Krebs Cycle (5-carbon molecule)

A
  • 6C citrate molecule converted to 5C molecule
  • Decarboxylation occurs
  • Dehydrogenation occurs
  • Hydrogen used to produce reduced NAD from NAD
31
Q

Describe the Third Stage of the Krebs Cycle (Oxaloacetate)

A
  • 5C molecule converted to 4C molecule
  • Decarboxylation and dehydrogenation occur, produces 1 reduced FAD and 2 reduced NAD
  • ATP produced by direct transfer of phosphate group from intermediate compound to ADP (substrate-level phosphorylation)
    Citrate now converted into oxaloacetate
32
Q

Name Products of the Krebs Cycle Used in Oxidative Phosphorylation

A
  • 1 Coenzyme A - next link reaction
  • Oxaloacetate
  • 2 CO2 - waste products
  • 1 ATP - for energy
  • 3 Reduced NAD - used in oxidative phosphorylation
  • 1 Reduced FAD - used in oxidative phosphorylation
33
Q

Describe the Process of Oxidative Phosphorylation (Chemiosmosis)

A
  • Hydrogen atoms released from reduced FAD and NAD, oxidised to FAD and NAD. H atoms then split into protons and electrons
  • Electrons move down ETC, lose energy at each carrier
  • Energy used to pump protons from matrix into intermembrane space
  • Conc. of protons now higher in intermembrane space than matrix, creates electrochemical gradient
  • Protons move down electrochemical gradient, via ATP synthase
  • Movement drives synthesis of ATP from ADP and Pi
  • Process of ATP production driven by movement of H ions across a membrane is called chemiosmosis
  • In matrix, end of ETC, protons, electrons and O2 form water. O2 said to be the final electron acceptor
34
Q

How much ATP can be Made from 1 Glucose Molecule?

A

32 ATP

  • Glycolysis - 2 ATP
  • Glycolysis - 2 reduced NAD - 5 ATP ( 2.5 each)
  • Link reaction (x2) - 2 reduced NAD - 5 ATP
  • Krebs cycle (x2) - 2 ATP
  • Krebs cycle (x2) - 6 reduced NAD - 15 ATP
  • Krebs cycle (x2) - 2 reduced FAD - 3 ATP (1.5 each)
35
Q

How can Mitochondrial Diseases Affect ATP Production?

A
  • Could affect how many proteins are involved in oxidative phosphorylation or Krebs cycle, reducing ATP production
  • May increase anaerobic respiration, to make up for ATP shortage
  • Results in more lactate production, causing muscle fatigue and weakness
  • Some lactate will diffuse into bloodstream, increasing lactate conc. in blood

Biology (18 decks)

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