Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

biology factual recall questions > Energy Transfers in and between organisms > Flashcards

Energy Transfers in and between organisms Flashcards

1
Q

Name two purposes of light in the light-dependent reaction

A

Excites electrons in chlorophyll, leading to photoionisation. Cyclic photophosphorylation.
Photolysis of water

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

By what process does chlorophyll absorb light

A

Photoionization

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

Where are the electron carriers located

A

Thylakoid membranes

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

Write the equation for the photolysis of water

A

2H2O->4H++4e-+O2

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

What is the enzyme embedded in the chloroplast membranes

A

ATP synthase

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

What is produced in the light dependent reaction and subsequently used in the light independent one

A

Reduced NADP, ATP

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

What does CO2 react with and what does it form in the first stage of the light independent reaction

A

Reacts with RuBP to form 2xGP

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

What enzyme catalyses the light dependent reaction

A

Rubisco

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

What reduces GP to triose phosphate

A

Reduced NADP

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

What two things does triose phosphate go to

A

Reforms RuBP

Creates organic substances

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

List three environmental factors that may limit the rate of photosynthesis

A

Temperature
Light intensity
CO2 concentration

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

What is produced by respiration

A

ATP

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

What is the purpose of phosphorylating a molecule

A

Make it more reactive

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

Where does glycolysis occur

Why is this the case

A

Cytoplasm. Glucose is too large to enter the mitochondria

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

Is glycolysis aerobic or anaerobic

A

Anaerobic

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

What is glucose phosphorylated to

A

Glucose phosphate (Then triose phosphate)

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

By what process does triose phosphate turn into pyruvate

A

Oxidation

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

How many molecules of pyruvate are gained from one glucose molecule

A

2

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

In anaerobic respiration, what can pyruvate be converted to

A

Lactate or ethanol

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

By what process is pyruvate transported into the mitochondrial matrix

A

Active transport

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

When pyruvate is oxidised to acetate what is produced

A

Reduced NAD, CO2

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

In the link reaction, what combines with acetate

A

Coenzyme A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does acetylcoenzyme A react with to produce a 6 carbon molecule

A

4 carbon compound

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

What is produced in the Krebs cycle

A

2 CO2, 1 reduced FAD, 3 reduced NAD, 1 ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Outline chemiosmotic theory
Hydrogen atoms released by reduced NAD/FAD, split up into protons and electrons. Electrons move down transport chain, transporting protons into intermembranal space of mitochondria. protons diffuse down electrochemical gradient, driving the enzyme ATP synthase to produce ATP
26
What other respiratory substrates can enter the Krebs cycle
Proteins/ Lipids
27
What do plants use to synthesise organic compounds
Energy from sunlight
28
what is the main use of sugars produced by plants
Respiration
29
How can biomass be measured
Dry mass of carbon or dry mass of tissue per unit area per unit time
30
What is Gross Primary production
Total amount of chemical energy converted from light energy by plants
31
What is Net primary production
Net primary production is gross primary productivity with respiratory losses taken into account so NPP=GPP-R
32
Give an equation linking gross productivity, net productivity and respiratory losses for producers
NPP=GPP-R
33
Give an equation for net productivity in consumers involving chemical energy stored in ingested food (I), chemical energy lost to the environment in faeces and urine (F) and respiratory losses to the environment (R)
N=I-(F+R)
34
What effect does shortening a food web have
Increases the efficiency
35
Give three examples of ways to increase the efficiency of a food web in the raising of pigs on a farm
Restrict movement Keep them in heated conditions Give them easier to digest food Give them antibiotics
36
Give two samples of how nutrients are recycled within ecosystems
Nitrogen cycle | Phosphorous cycle
37
What bacteria are involved in decomposition
Saprobionts
38
How do these bacteria (saprobionts) help decompose dead organisms
Secrete enzymes
39
What substances can mycorrhizae help with the uptake of
Water and inorganic ions
40
What is used in ammonifaction to make ammonia
Dead organisms / faecal matter
41
Give the two stages of nitrification
Ammonia / Ammonium ions to nitrites | Nitrites to nitrates
42
Give the two locations at which nitrogen fixing bacteria are found
Nitrogen fixing bacteria in root nodules | Nitrogen fixing bacteria in soil
43
What conditions are required by denitrifying bacteria and when do these conditions occur
Anaerobic - waterlogged soil
44
What do denitrifying bacteria do
Nitrates in the soil are converted to atmospheric nitrogen
45
What is guano
Seagull excrement rich in phosphates
46
Where is the main reservoir of phosphorous
Rocks
47
What natural process helps phosphate ions become dissolved and available for absorption by plants
Weathering
48
What are two advantages of natural fertilisers
Slower release | Cheaper
49
What are two advantages of artificial fertilisers
Exact composition of minerals/ions required by crops | Easier to store
50
What is leaching
When fertiliser in the soil is washed into nearby water sources such as sea / lakes/rivers
51
What is eutrophication and why is it a problem
When algae grows on the surface of water bodies and prevents light reaching plants below. They die and bacteria decompose them, using up the water bodies oxygen supply. This removes oxygen from the water, causing death of marine life
52
What is a metabolic pathway
A series of small reactions controlled by enzymes (eg respiration or photosynthesis)
53
What is phosphorylation and give an example
Adding phosphate to a molecule | ADP is phosphorylation to ATP
54
What is photophosphorylation
Adding phosphate to a molecule using light
55
What is photolysis
The splitting of a molecule using light energy
56
What is Photoionisation
When light energy excites electrons in an atom or molecule, giving them more energy and causing them to be released The release of electrons causes the atom or molecule to become a positively charged ion
57
What is Hydrolysis
The splitting of a molecule using water
58
What is Decarboxylation
The removal of carbon dioxide from a molecule
59
What is dehydrogenation
Re removal of hydrogen from a molecule
60
What are redox reactions
Reactions that involve oxidation and reduction
61
Explain redox reactions
OILRIG - oxidation is loss, reduction is gain If something is reduced it has gained electrons and may have gained hydrogen or lost Oxygen If something is oxidised it has lost electrons and may have lost hydrogen and gained oxygen Oxidation of one molecule ALWAYS involves reduction of another molecule
62
Define coenzyme
A molecule that aids the function of an enzyme
63
Name the coenzyme used in photosynthesis
NADP
64
Name coenzymes used in respiration
NAD, coenzyme A FAD
65
What do NAD and FAD do
They transfer hydrogen from one molecule to another - this means that they can reduce or oxidise a molecule
66
What does Coenzyme A do
Transfers acetate between molecules
67
Where does the Calvin cycle take place
In the stoma of the chloroplasts
68
What is the first stage of the Calvin cycle/ light independent reaction
carbon dioxide enters leaf from stomata and diffuses into the storm a of the chloroplast. It combines with ribulose bisphosphate (RuBP) a 5 carbon compound. The reaction is catalysed by the enzyme rubisco. This gives an unstable 6 carbon compound which breaks down to form two molecules of glycerate 3 phosphate. (GP)
69
What happens in the second stage of the light independent reaction
ATP and reduced NADP are required for the reduction of GP to triose phosphate The hydrolysis of ATP provides energy to turn the 3 carbon compound GP,. Into a different 3 carbon compound Triose phosphate This also required H+ ions which domes from reduced NADP Reduced NADP is recycled to NADP Some triose Phosphate is then converted into useful organic compounds such as glucose and some continues in the Calvin cycle to regenerate RuBP
70
What happens in the 3rd stage of the light independent reaction
Ribulose bisphosphate is regenerated Five out of every six molecules of TP produced in the cycle are used to regenerate RuBP Regenerating RuBP also uses the rest of the ATP produced by the light dependent reaction
71
How many times does the Calvin cycle need to turn to make one Hexose sugar
6
72
What are the optimum conditions for photosynthesis
High light intensity of a certain wavelength Temperature around 25 degrees c Carbon dioxide at 0.4%
73
Why is 25 degrees c the optimum temperature for photosynthesis
Photosynthesis involves enzymes (ATP synthase, rubisco). If the temperature falls below 10 degrees C the enzymes become inactive. If it goes more than 45 degrees C they may start to denature
74
On a warm sunny windless day what is the limiting factor for photosynthesis
CO2
75
at night what is the limiting factor for photosynthesis
Light intensity
76
What is the saturation point
The point where a factor is no longer limiting the reaction
77
How can farmers use greenhouses/poly tunnels to increase plant growth
Lamps to provide nighttime light Burning a small amount of propane in a CO2 generator to increase CO2 levels Glasshouses trap heat energy from the sun warms the air Heaters can warm the air

biology factual recall questions (9 decks)

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