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Biology paper 1 - B1, B2, B3, B4 > B4 - Bioenergetics > Flashcards

B4 - Bioenergetics Flashcards

Photosynthesis and limiting factors, rate of photosynthesis, respiration, metabolism, aerobic/ anaerobic respiration, exercise (73 cards)

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1
Q

Photosynthesis and Limiting Factors -
What does photosynthesis use to do?

A

Uses energy to change carbon dioxide and water into glucose and oxygen

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2
Q

Photosynthesis and Limiting Factors -
Where does photosynthesis take place?

A

Chloroplasts (contain green pigment called chlorophyll to absorb light)

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3
Q

Photosynthesis and Limiting Factors -
How is energy transferred to the chloroplasts from the environment?

A

Light

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4
Q

Photosynthesis and Limiting Factors -
What type of reaction is photosynthesis?

A

Endothermic

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5
Q

Photosynthesis and Limiting Factors -
What does endothermic mean?

A

Energy transferred from environment during process

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6
Q

Photosynthesis and Limiting Factors -
What is the word equation for photosynthesis?

A

carbon dioxide + water –> glucose + oxygen

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7
Q

Photosynthesis and Limiting Factors -
What is the symbol equation for photosynthesis?

A

6CO2 + 6H2O –> C6H12O6 + 6O2

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8
Q

Photosynthesis and Limiting Factors -
What are the 5 ways that plants use glucose and acranim?

A

CROPS

  • Cellulose: making cellulose (cell walls)
  • Respiration: transfers energy from glucose enables plant convert rest of glucose into other useful substances.
  • Oils/ fats: turned into lipids for storing in seeds
  • Proteins (amino acids): glucose = nitrate ions make amino acids (made into proteins)
  • Starch: stored as starch in roots, stems, leaves (ready for use during photosynthesis)
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9
Q

Photosynthesis and Limiting Factors -
Why is starch much better for storing than glucose in winter?

A
  • starch insoluble: cell with lots of glucose draw in lots of water and swell up
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10
Q

Photosynthesis and Limiting Factors -
What are the limiting factors that affect rate of photosynthesis?

A
  • light intensity
  • conc of carbon dioxide
  • temperature
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11
Q

Photosynthesis and Limiting Factors -
What does limiting factor during photosynthesis mean?

A

Stopping photosynthesis happening any faster

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12
Q

Photosynthesis and Limiting Factors -
What is the limiting factor for photosynthesis at night?

A

Light intensity

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13
Q

Photosynthesis and Limiting Factors -
What is the limiting factors for photosynthesis during the winter?

A

Temperature

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14
Q

Photosynthesis and Limiting Factors -
What is the limiting factor for photosynthesis usually if it’s warm enough and bright enough?

A

Concentration of carbon dioxide

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15
Q

Photosynthesis and Limiting Factors -
What can also be a limiting factor of photosynthesis?

A

Chlorophyll

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16
Q

Photosynthesis and Limiting Factors -
How can the amount of chlorophyll in a plant be affected?

A
  • disease (TMV infection)
  • environmental stress (lack of nutrients)
    (can cause chlorophyll to become damaged or not make enough - rate reduced as not enough light being absorbed)
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17
Q

The Rate of Photosynthesis -
What happens as the light level is raised to the rate of photosynthesis?

A
  • increases steadily to a certain point
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18
Q

The Rate of Photosynthesis -
What happens beyond the certain point of light level to the rate of photosynthesis?

A

Makes no difference to rate of photosynthesis (because either temp or CO2 level now limiting factor)

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19
Q

The Rate of Photosynthesis -
How can you change the light intensity in a lab?

A

Moving lamp closer to or further away from plant

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20
Q

The Rate of Photosynthesis -
How do you get a graph displaying the light intensity against distance light from plant as shown on page 58?

A

Measure light intensity at the plant using a light meter

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21
Q

The Rate of Photosynthesis -
On the graph displaying photosynthesis and light intensity, which one is the y and which is the x axis?

A

y axis = rate of photosynthesis
x axis = light intensity

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22
Q

The Rate of Photosynthesis -
What is CO2?

A

One of the raw materials needed for photosynthesis

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23
Q

The Rate of Photosynthesis -
Until when does an increase in CO2 also increase rate of photosynthesis?

A

Up to a certain point (after, graph flattens out meaning CO2 no longer limiting factor)

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24
Q

The Rate of Photosynthesis -
What does it mean about the limiting factor of photosynthesis if CO2 and light intensity are in plentiful supply?

A

Limiting factor is temperature

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25
The Rate of Photosynthesis - When is temperature usually the limiting factor of photosynthesis and why?
when it's too low - enzymes needed work slowly at low temps
26
The Rate of Photosynthesis - What happens if the plant gets to hot?
- enzymes needed for photosynthesis damaged - other reactions needed are damaged
27
The Rate of Photosynthesis - At what temperature do enzymes and other reactions in plants become damaged?
45 degrees Celcius (can happen in greenhouses)
28
The Rate of Photosynthesis - Look at page 59 to see graphs that show one graph with more than 1 limiting factor
Look at page 59 to see graphs that show one graph with more than 1 limiting factor
29
The Rate of Photosynthesis - RP What does the rate at which pond weed produces oxygen correspond to?
Rate at which it's photosynthesising (faster producing oxygen, faster photosynthesising)
30
The Rate of Photosynthesis - RP Method: page 59 for apparatus set up
1. white light source placed at specific distance from pondweed 2. pondweed left to photosynthesise for set amount of time 3. as photosynthesises, oxygen produced collected in capillary tube. 4. At end, syringe used to draw gas bubbles in tube up alongside a ruler + length of gas bubbles measured (proportional to O2 produced) 5. repeat whole experiment twice with light source at same distance + calculate mean volume of O2 produced
31
The Rate of Photosynthesis - RP What are the control variables in this experiment?
- temperature - time pondweed given to photosynthesise
32
The Rate of Photosynthesis - RP How can you alter how you set up experiment to measure effect of temperature or CO2 on photosynthesis?
- test tube of pondweed put in water bath at set temp - measure amount sodium hydrocarbonate dissolved in water (gives off CO2) (can be repeated with different temps of water/ concs of sodium hydrocarbonate)
33
The Rate of Photosynthesis - What are light intensity and distance?
inversely proportional (as one increases, the other decreases)
34
The Rate of Photosynthesis - What is the equation for inverse square law?
light intensity @ 1 --------- distance squared @ = proportional sign
35
The Rate of Photosynthesis - What does the inverse square law mean in terms of distance and light intensity?
light intensity decreases in proportion to the square of the distance eg - if half distance, light intensity be 4 x greater - if double distance, light intensity 4 x smaller
36
The Rate of Photosynthesis - What is the most common way to artificially create ideal environment for plants?
Greenhouse
37
The Rate of Photosynthesis - What do greenhouses do?
- Help trap heat mean temp isn't limiting factor
38
The Rate of Photosynthesis - What do farmers do in the winter to keep temp of greenhouse at ideal level?
Use a heater
39
The Rate of Photosynthesis - What do farmers do in summer to keep the temp of greenhouse at ideal level?
Use shades + ventilation
40
The Rate of Photosynthesis - What do farmers use after the sun goes down to give plants more time to photosynthesise?
Artificial light
41
The Rate of Photosynthesis - How do farmers and gardeners increase level of carbon dioxide in greenhouses?
- paraffin heater (as burns it makes CO2 as a by product)
42
The Rate of Photosynthesis - What does using a greenhouse mean you can do?
- keep plants free from pests and disease
43
The Rate of Photosynthesis - What can farmers add to soil to provide minerals needed for healthy growth?
Fertilisers
44
Respiration and Metabolism - What is respiration?
The process of transferring energy from the breakdown of glucose
45
Respiration and Metabolism - Where does respiration occur?
In every cell in your animals and plants continuously
46
Respiration and Metabolism - What type of reaction is respiration?
Exothermic - transfer energy to the environment
47
Respiration and Metabolism - What are 3 examples of how organisms use the energy transferred by respiration?
- build up larger molecules from smaller molecules (protein from amino acids) - in animals: allow muscles to contract (so can move) - mammals + birds: energy used keep body temperature steady in cold.
48
Respiration and Metabolism - What is metabolism?
The sum of all reactions that happen in a cell or the body
49
Respiration and Metabolism - What are the chemical reactions taking place in a cell all the time controlled by?
Enzymes
50
Respiration and Metabolism - What are examples of a reactions when larger molecules are made from smaller molecules?
1. glucose molecules joined together in reaction form starch, glycogen, cellulose 2. lipid molecules each made from one molecule of glycerol and 3 fatty acids 3. glucose + nitrate ions make amino acids: made into proteins
51
Respiration and Metabolism - What are examples of a reactions when larger molecules are broken down into smaller molecules?
1. glucose broken down in respiration 2. excess protein broken down to produce urea (excreted inn urine)
52
Aerobic and Anaerobic Respiration - What is aerobic respiration?
Respiration using plenty of oxygen (most efficient way to transfer energy from glucose)
53
Aerobic and Anaerobic Respiration - When does aerobic respiration occur in plants and animals?
Constantly
54
Aerobic and Anaerobic Respiration - Where do most reactions during aerobic respiration happen?
In mitochondria
55
Aerobic and Anaerobic Respiration - What is the word equation for aerobic respiration?
glucose + oxygen --> carbon dioxide + water
56
Aerobic and Anaerobic Respiration - What is the symbol equation for aerobic respiration?
C6H12O6 + 6O2 --> 6CO2 + 6H2O
57
Aerobic and Anaerobic Respiration - When is anaerobic respiration used?
If there isn't enough oxygen
58
Aerobic and Anaerobic Respiration - When does anaerobic respiration occur?
- when doing vigorous exercise and body can't supply enough oxygen to your muscles they start doing anaerobic respiration as well as aerobic
59
Aerobic and Anaerobic Respiration - What is anaerobic respiration?
Incomplete breakdown of glucose making lactic acid
60
Aerobic and Anaerobic Respiration - What is the word equation for anaerobic respiration?
glucose --> lactic acid
61
Aerobic and Anaerobic Respiration - Why doesn't anaerobic respiration transfer as much energy as aerobic respiration?
glucose isn't fully oxidised
62
Aerobic and Anaerobic Respiration - When is anaerobic respiration only useful + example?
In emergencies eg during exercise allow you keep using muscles for longer
63
Aerobic and Anaerobic Respiration - What do plants and yeast cells produce during anaerobic respiration?
Ethanol and carbon dioxide (not lactic acid)
64
What is the word equation for anaerobic respiration in plant and yeast cells?
glucose --> ethanol + carbon dioxide
65
Aerobic and Anaerobic Respiration - What is anaerobic respiration called in yeast cells?
Fermentation
66
Aerobic and Anaerobic Respiration - Why is fermentation of great value in the food and drinks industry?
Used to make bread + alcoholic drinks
67
Aerobic and Anaerobic Respiration - What causes bread to rise?
Carbon dioxide from fermentation
68
Aerobic and Anaerobic Respiration - What produces alcohol in beer and wine making?
Fermentation process
69
Exercise - Why do you respire more when you exercise?
1. some muscles contract more frequently so need more energy which causes increased respiration 2. increase in respiration of cells means need to get more O2 into them 3. Breathing rate + breath volume increases (get more oxygen into blood) 4. Heart rate increase (get more oxygenated blood around body faster + remove CO2 quickly) 5.vigorous exercise, body can't supply enough oxygen to muscles quickly enough so start anaerobically respire. 6. Not best way transfer energy from glucose as lactic acid builds up in muscles (painful) 7. long periods of exercise cause muscle fatigue (muscles tires + stop contracting efficiently)
70
Exercise - How does anaerobic respiration cause an oxygen debt?
1. after anaerobically respiring during exercise, once finished you'll have an oxygen debt 2. oxygen debt = amount of extra oxygen body needs to react with lactic acids to remove it from cells (forms carbon dioxide and water)
71
Exercise - What does oxygen debt cause your body to do?
- keep breathing hard for a while after to get more oxygen into blood and too muscle cells - pulse + heart rate stay high (whilst high levels of lactic acids and CO2)
72
Exercise - What are the two ways your body copes with a build up of lactic acid?
- oxygen during oxygen debt reacts with lactic acid to produce CO2 and water - blood that enters your muscles transports lactic acids to liver (lactic acid converted back to glucose)
73
Exercise - How can you investigate the effect of exercise on your body?
1. measure breathing rate (count breaths) and heart rate (taking pulse) 2. take pulse after: - sitting down for 5 mins - again after 5 min gentle walk - again after 5 mins slow jogging - again after 5 mins running 3. Pulse rate increase the more intense exercise is (body needs more O2 to muscles + take more CO2 away from muscles) 4. do as group and plot average for each exercise to reduce effect of random error

Biology paper 1 - B1, B2, B3, B4 (4 decks)

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