Brainscape's Knowledge GenomeTM

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


See full index

Biology > topic 4 - bioenergetics > Flashcards

topic 4 - bioenergetics Flashcards

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

what is photosynthesis?

A

an endothermic reaction by which plants synthesise glucose by absorbing light energy from the sun

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

where does photosynthesis take place?

A

in the leaves of a plant

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

what absorbs light energy?

A

chlorophyll

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

what is the word equation for photosynthesis?

A

carbon dioxide + water -> glucose + oxygen

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

what is the symbol equation for photosynthesis?

A

6CO2 + 6H2O -> C6H12O6 + 6O2

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

why is photosynthesis an endothermic reaction?

A

because energy is transferred from the environment to chloroplasts by light

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

what are the four main factors that affect the rate of photosynthesis?

A
  • temperature
  • light intensity
  • carbon dioxide concentration
  • the amount of chlorophyll
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how does temperature affect the rate of photosynthesis?

A
  • as the temperature increases, the enzymes involved in photosynthesis work faster so the rate increases
  • if we keep increasing the temperature, the enzymes will denature and the rate of photosynthesis falls
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how does light intensity affect the rate of photosynthesis?

A

increasing the light intensity increases the rate of photosynthesis until another factor becomes limiting

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

how does carbon dioxide concentration affect the rate of photosynthesis?

A

increasing the carbon dioxide concentration increases the rate of photosynthesis as CO2 is required to make glucose

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

how does the amount of chlorophyll affect the rate of photosynthesis?

A

decreasing the amount of chlorophyll decreases the rate of photosynthesis as chlorophyll is required to absorb light energy

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

what is a limiting factor?

A

an environmental factor which restricts the rate of photosynthesis

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

what are the uses of glucose produced in photosynthesis?

A
  • used for respiration
  • converted into insoluble starch for storage
  • used to produce fat or oil for storage
  • used to produce cellulose, which strengthens the cell wall
  • used to produce amino acids for protein synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

where does respiration take place in a cell?

A

in the mitochondria

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

how are amino acids from glucose made?

A

plants need to absorb nitrate ions from the soil

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

how can you calculate the rate of photosynthesis? REQUIRED PRACTICAL 6

A
  • take a boiling tube and place it 10cm away from an LED light source - an LED light is used as they do not release much heat
  • fill the boiling tube with sodium hydrogen carbonate solution
  • sodium hydrogen carbonate solution releases carbon dioxide, which is needed for photosynthesis
  • put a piece of pondweed into the boiling tube with the cut end at the top
  • leave this for 5 minutes to acclimatise to the conditions in the boiling tube
  • start a stop watch and count the number of bubbles produced in one minute. Repeat two more times and calculate the mean number of bubbles produced in one minute
  • Do the whole experiment again from the start at 20cm, then 30cm, then 40cm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the problems with practical 6?

A
  • the number of bubbles can be too fast to count
  • the bubbles are not always the same size. A large bubble would count the same as a small bubble
18
Q

how can the problems with practical 6 be solved?

A
  • place the pond weed under a funnel and catch the bubbles in a measuring cylinder
  • then use the measuring cylinder to measure the volume of the oxygen gas produced
19
Q

what is the inverse square law?

A

if we double the distance, the light falls by four times

20
Q

why do mammals need the energy to keep warm?

A
  • humans and other mammals need energy to keep warm
  • we need energy for chemical reactions to build larger molecules
21
Q

what is aerobic respiration?

A

an exothermic reaction in which glucose reacts with oxygen to release energy which can be used by cells

22
Q

what is the word equation for aerobic respiration?

A

glucose + oxygen -> carbon dioxide + water

23
Q

what is the symbol equation for aerobic respiration?

A

C6H12O6 + 6O2 -> 6CO2 + 6H2O

24
Q

why does aerobic respiration release a great deal of energy?

A

because the glucose molecule has been fully oxidised

25
Q

what is the equation for anaerobic respiration in muscles?

A

glucose -> lactic acid

26
Q

what is anaerobic respiration?

A

an exothermic reaction in which glucose is broken down to release energy in the absence of oxygen

27
Q

why does anaerobic respiration release much less energy than aerobic respiration?

A
  • in anaerobic respiration, the oxidation of glucose is incomplete
28
Q

what is the equation for anaerobic respiration in plant and yeast cells?

A

glucose -> ethanol + carbon dioxide

29
Q

why can anaerobic respiration lead to muscle fatigue?

A

lactic acid builds up in muscles, preventing efficient contraction

30
Q

what is fermentation?

A

a type of anaerobic respiration that occurs in yeast cells

31
Q

what are the uses of fermentation?

A
  • the alcohol in beer is ethanol and that is produced by fermentation
  • the carbon dioxide produced by fermentation creates bubbles in the dough causing the bread to rise
32
Q

what happens to the human body during exercise?

A
  • the heart rate, breathing rate and breath volume increase to supply the muscles with more oxygenated blood
33
Q

how is lactic acid removed from muscles?

A
  • when lactic acid is transported out of the muscles by the blood
  • the lactic acid is then taken to the liver and converted back to glucose in a series of chemical reactions
  • reacting with the accumulated lactic acid and removing it from the cells requires oxygen
34
Q

what is oxygen debt?

A

the amount of extra oxygen the body needs after exercise to react with the accumulated lactic acid and remove it from the cells

35
Q

what is metabolism?

A

the sum of all the reactions in a cell or the body

36
Q

what do muscles store glucose as?

A

as glycogen

37
Q

how do cells use the energy transferred by respiration?

A

the energy released by respiration is used by enzymes to synthesise new molecules in the cell

38
Q

what are the uses of glucose in plants?

A
  • converted into cellulose which strengthens the plant cell wall
  • converted into storage form of glucose
  • converted into amino acids and nitrate ions which are used to synthesise proteins
39
Q

what are the uses of glucose in humans?

A
  • converted to glycogen which is a storage form of glucose
40
Q

how are lipids formed?

A

1 glycerol molecule + 3 fatty acid molecules = lipids which are found in the cell membrane

41
Q

what happens to excess proteins?

A
  • excess proteins are broken down into the chemical urea
  • the urea is then excreted by the kidneys

Biology (7 decks)

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