Brainscape's Knowledge GenomeTM

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


See full index

QCAA Unit 1 & 2 Biology > 1.1.5 Energy and Metabolism > Flashcards

1.1.5 Energy and Metabolism Flashcards

1
Q

Where does the body undergo respiration?

A

The mitochondria

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

Recall the aerobic respiration equation

A

oxygen + glucose –> carbon dioxide + water + ATP

6O2 + C6H12O6 –> 6CO2 + 6H2O + 38ATP

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

Why is ATP considered a universal energy currency?

A

It is a high-energy molecules which can be used by all organisms at any time to release energy for almost all reactions

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

Recall the process of Glycolysis

A
  1. Glucose (6 Carbon) undergoes phosphorylation, where 2 x ATP are hydrolysed and the energy released is used to attach Pi to the Glucose, making hexose phosphate. This destabilizes glucose, preventing it from leaving the cell. In this stage 2x ATP are used up.
  2. The molecule of hexose phosphate is split into two molecules of triose phosphate (3 Carbon)
  3. The two triose phosphate molecules get oxidized into two molecules of pyruvate. Hydrogen is removed from each of the two triose phosphate molecules and transfers to a coenzyme called NAD to form NADH. Four ATP molecules are formed from the energy released during this oxidation (because 2 each triose phosphate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the final products of glycolysis for each glucose molecule entering the reaction?

A
  • 2 molecules of ATP are used
  • 4 molecules of ATP are produced
  • so there is a net gain of 2 ATP molecules
  • 2 molecules of reduced NAD are produced
  • Glucose is converted to 2 molecules of pyruvate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Recall the process of the link reaction:

A
  1. One carbon atom is removed from pyruvate in the form of CO2.
  2. Another oxidation reaction occurs when NAD+ collects more hydrogen ions. This forms NADH
  3. This produces acetate
  4. Acetate combines with coenzyme A to produce Acetyl Coenzyme A (acetyl CoA)
  5. No ATP is produced in this reaction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the final products of the Link Reaction for each glucose molecule entering the reaction?

A
  • 2 Acetyl Coenzyme A: go into Krebs cycle
  • 2 Carbon dioxide: released as a waste product
  • 2 NADH: go to the electron transport chain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Recall the process of the Krebs Cycle:

A
  1. the 2C Acetyl CoA combines with 4C oxaloacetate to form 6C citrate.
  2. The citrate is decarboxylated (CO2 goes out as waste) and dehydrogenated (NAD –> NADH), forming a 5C compound.
  3. This happens again to the now 5C compound, forming a 4C compound
  4. The 4C compound is changed into another 4C compound and ATP is produced.
  5. The 4C compound is changed into another 4C compound and FADH is produced
  6. The 4C compound is changed into oxaloacetate and NADH is produced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Recall the CONA CONA A FA NA song

A
  • Remember that Acetyl CoA enters the cycle
    1. CONA: production of CO2 and NADH
    2. CONA: production of CO2 and NADH
    3. A: Production of ATP
    4. FA: Production of FADH
    5. NA: Production of NADH
  • Remember that Oxaloacetate finishes the cycle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the final products of the Krebs Cycle for each glucose molecule entering the reaction?

A
  • 1 x oxaloacetate
  • 2 x CO2
  • 3 x NADH
  • 1 x FADH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Recall the process of the ETC:

A
  1. NADH and FADH donate H atoms to the electron carriers. H is split into protons and electrons
  2. Electrons are accepted from NADH by first electron carrier. FADH binds to Complex II to release its hydrogen. Protons go into solution in the matrix.
  3. The electrons are passed along a chain of electron carriers. This is the electron transport chain
  4. As electrons flow along the ETC, energy is released. This energy is used to pump protons across the intermembrane space.
  5. This produces a proton gradient. Potential energy therefore builds up in the intermembrane space.
  6. The protons cannot escape through the lipid part of the inner membrane. They have to diffuse through the the ATP synthase. The flow of protons is chemiosmosis.
  7. Protons flowing through ATP synthase cause the rotation of part of the enzyme, causing ADP and Pi to join, forming ATP.
  8. The electrons that has been passing along the ETC are passed from the last carrier to molecular oxygen. This is the final electron acceptor.
  9. Hydrogen ions also join the oxygen, causing it to be reduced to water.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the final electron acceptor?

A

oxygen; where it combines with protons and electrons to form water

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

ETC Summary:

A
  1. Hydrogen atoms released from reduced NAD and FAD as they are oxidized
  2. Hydrogen atoms split into protons and electrons
  3. Electrons move along the ETC, releasing energy at each carrier
  4. This energy is used to pull the protons through the pumps, into the intermembrane space
  5. This forms a proton gradient.
  6. Protons must move back to matrix via ATP synthase
  7. This movement drives the synthesis of ATP from ADP and inorganic phosphate
  8. The final electron acceptor, oxygen, combines with protons and electrons to form water.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How many ATP will FAD generate?

A

2, due to two proton pumps

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

How many ATP will NAD generate?

A

3, due to three proton pumps

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

Summary: How many ATP is made from Glycolysis, Link reaction, Krebs Cycle, ETC from NADH and ETC from FADH?

A

Glycolysis: 2

Link Reaction: 0

Krebs Cycle: 2

ETC from NADH: 30 (10 NADH made in previous stages and 3 ATP produced per NADH molecule)

ETC from FADH: 4 (2 FADH made in previous stages and 2 ATP is produced per FADH molecule)

17
Q

Where does photosynthesis occur?

A

In the chloroplasts

18
Q

Where does Glycolysis occur?

A

cytoplasm

19
Q

Where does the Link Reaction occur?

A

mitochondrial matrix

20
Q

Where does the Krebs Cycle occur?

A

In the mitochondrial matrix

21
Q

Where does the ETC occur?

A

In the mitochondrial inner membrane: from matrix across cristae into inter-membrane space and back to matrix

22
Q

What is the photosynthesis equation?

A

Carbon dioxide + water –> glucose + oxygen

6CO2 + 6H2O –> C6H12O6 + 6O2

23
Q

Where does the light-dependent stage of photosynthesis occur?

A
  • Takes place on the thylakoid membranes
24
Q

Does the light-dependent stage use PSI and PSII?

A

yes

25
Q

What happens in the light-dependent stage?

A
  • light energy converted to ATP, called photophosphorylation
  • two types of photophosphorylation:
  • cyclic and non-cyclic
26
Q

Recall the process of Cyclic Photophosphorylation

A

Light will hit PSI, exciting electrons and causing them to pass to an electron acceptor then back to the chlorophyll molecule, and producing small amounts of ATP. This process will continue to cycle through, recycling electrons as long as light is present.
NOTE:
- no photolysis of water (splitting of water molecule into H ions, oxygen, electrons in presence of light)
- no production of reduced NADP (NADPH)

27
Q

Recall the process of Non-cyclic photophosphorylation

A
  1. Light energy excites electrons in chlorophyll.
    - light energy absorbed by PSII, exciting electrons in chlorophyll
    - electrons move to a higher energy level
    - high energy electrons move along the electron transport chain, producing ATP
    - electrons eventually replace those lost by PSI
  2. Energy from the excited electrons make ATP
    - excited electrons lose energy as they move along the ETC, energy which is used to transport protons into the thylakoid. The thylakoid has a higher concentration of protons than the stroma, forming a proton gradient across the membrane.
    - protons move down the concentration gradient, into the stroma, via ATP synthase
    - this movement synthesizes ATP from ADP and inorganic phosphate
    NOTE:
    - same as what happens in respiration, just in the stroma rather than matrix
  3. Photolysis of water
    - as the excited electrons from chlorophyll leave PSII, they must be replaced
    - this can be done via photolysis, where light energy split water into protons (H ions), electrons and oxygen (2H2O –> 4H + 3e + O2)
  4. Generation of NADPH
    - light energy has also been absorbed by PSI, which has again excited electrons to a higher energy level
    - these electrons and a proton made from photolysis of water join NADP, producing NADPH
28
Q

which photosystem/s does non-cyclic photophosphorylation use?

A
  • uses PSI and PSII
  • produces ATP, NADPH and oxygen
  • PSI and PSII are linked by electron carriers, which are proteins that transfer electrons.
29
Q

summary: explain the light dependent stage of photosynthesis

A

Takes place on the thylakoid membranes
Needs light energy

Cyclic photophosphorylation:

  • PSI
  • Photons cause..
  • ..electron to be excited
  • Captured by electron acceptor and is passed back to chlorophyll.
  • Energy is released to make ATP from ADP + Pi

Non-cyclic photophosphorylation:
- Excited electrons emitted from the primary pigments of both reaction centers of PSI and PSII
- The electrons lost from PSI are replaced by electrons transferred from PSII by electron carriers
- PS II receives replacement electrons from the photolysis of water
(2H2O  4H+ + 4e- + O2)
- ATP is synthesized as electrons lose energy whilst passing along the electron carrier chain from PS II to PS I
- Hydrogen ions (photolysis) combine with electrons from PS I and NADP to form reduced NADP.

30
Q

Where does the light independent stage take place?

A

In the stroma of chloroplasts

31
Q

What are the products of the light independent stage?

A
  • triose phosphate from carbon dioxide and ribulose bisphosphate
  • the reactions are linked in a cycle which means the starting compound, ribulose bisphosphate is regenerated
32
Q

what does the light-independent stage require to keep going?

A

ATP and H ions

33
Q

Recall the Light independent stage (Calvin cycle):

A
  1. CO2 combines with Ribulose Bisphosphate (RuBP) to form an unstable compound that breaks into two molecules of Glyerate-3-phosphate (GP)
  2. ATP from the light-dependent reaction turns GP (3C) into TP. This also requires H from NADP. 1 x TP is then converted into useful compounds such as hexose sugars.
  3. RuBP is regenerated by the 5 x TP molecules. This regeneration also requires the rest of the ATP made in the light dependent reaction.
34
Q

Is oxygen produced in the light-dependent or light-independent reaction:

A

light-dependent

35
Q

Is carbon dioxide fixed in the light-dependent or light-independent reaction?

A

light-independent

36
Q

Is ATP produced in the light-dependent or light-independent reaction?

A

light-dependent

37
Q

does the light-dependent or light-independent reaction use NADPH?

A

light-independent

38
Q

does the light-dependent or light-independent reaction occur in the stroma?

A

light-independent

39
Q

What will happen to the body when there’s no oxygen?

A

undergo anaerobic respiration - ineffective:
Glucose –> lactic acid + 2ATP
- NADH must be deoxidized to NAD
- Pyruvate is the hydrogen acceptor, making lactate
NAD is now oxidized and so able to accept more H atoms from glucose
- Allows glycolysis to continue, providing 2ATP

QCAA Unit 1 & 2 Biology (7 decks)

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