Topic 4- Biogenetics Flashcards
(79 cards)
1
Q
what is the metabolism
A
the sum of all reactions in a cell or the body
2
Q
what are 5 common metabolic reactions
A
- conversion of glucose to starch , glycogen and cellulose
- formation of lipid molecules from a molecule of glycerol and three molecules of fatty acids
- use of glucose and nitrate ions to form amino acids which in turn are used to synthesise proteins
- respiration
- breakdown of excess proteins to form urea for excretion
3
Q
what is energy used for in metabolism
A
energy transferred from respiration is used for the continual enzyme controlled processes
4
Q
what happens to the body during excerise
A
- it reacts to the increased demand for energy
- breathing rate and breath volume increases to get more oxygen into the blood
- heart rate increases to get this oxygenated blood around the body faster(removes co2 more quickly aswell)
5
Q
why does breathing rate, heart rate and breath volume increase
A
- muscles need more energy to contract from respiration so need more oxygen
6
Q
what is lactic acid caused by
A
caused by incomplete oxidation of glucose
7
Q
how is lactic acid converted back to glucose
A
blood throwing through the muscles transports the lactic acid to the liver where it is converted back into glucose
8
Q
what does the build up of lactic acid cause
A
muscle fatigue or cramp
9
Q
what is recovery time
A
the length of time needed for our body to get more oxygen and get rid of lactic acid
10
Q
what is oxygen debt
A
the amount of oxygen needed to break down the lactic acid in the cells
11
Q
what is the relationship between recovery time and fitness
A
the fitter you are the quicker your recovery time
12
Q
what happens during to your muscles during excerise
A
your muscles hurt due the muscles running out of oxygen for aerobic respiration, the body has to convert using anaerobic respiration which leads to build up of lactic acid in the legs. when you stop exercise, you still have to breathe hard, so you can get oxygen to breakdown the lactic acid
13
Q
what is aerobic respiration
A
- an exothermic reaction in which glucose is broken down using oxygen to produce carbon dioxide and water and release energy for cells
14
Q
where does aerobic respiration take place
A
in every living cell- in the mitochondria
15
Q
what is good about aerobic respiration
A
- the most efficient way to transfer energy
16
Q
why do cells need a lot of mitochondria
A
- cells that need to release lots of energy need lots of mitochondria
17
Q
what is the word equation for aerobic respiration
A
glucose + oxygen –> carbon dioxide + water
18
Q
what is the balanced symbol equation for aerobic respiration
A
C6H12O6 + 6O2 –> 6CO2 + 6H2O
19
Q
what is respiration
A
- the process of transferring energy from the breakdown of glucose, which goes on in every cell
20
Q
is respiration exothermic or endothermic
A
exothermic
21
Q
what does aerobic mean
A
with oxygen
22
Q
what does anaerobic mean
A
without oxygen
23
Q
what is respiration used for (energy) 4
A
- build up large molecules from smaller ones
- movement- muscles to contract
- to maintain body temperatures in mammals and birds
- to absorb substances(active transport)
24
Q
when is anaerobic respiration used
A
used if there’s not enough oxygen
25
what happens when you excerise(in terms of respiration)
when you do vigorous exercise and your body cant supply enough oxygen to your muscles, they start anaerobic and aerobic respiration
26
what is the word equation for anaerobic respiration
glucose---> lactic acid
27
why is much less oxygen transferred during anaerobic respiration
much less energy is transferred as oxidation of glucose is incomplete in anaerobic respiration
28
other than mammals, what else can respire without oxygen
plants and yeast cells
29
what do plants and yeast cells produce when they react with oxygen
ethanol and carbon dioxide
30
what is the word equation for anaerobic respiration in plants and yeast cells
glucose---> ethanol +carbon dioxide
31
what is anaerobic respiration in yeast cells called
fermentation
32
what is fermentation used to make
alcohol and bread
33
what does chronic alcohol abuse cause
destruction of liver cells, which results in scarring, alcohol hepatitis and cellular mutation which may lead to liver cancer
34
how can you investigate the effect of exercise on the body
- measure the breathing rate by counting breaths and heart rate by taking pulse
- you could take the pulse after sitting down for 5 mins, then after walking, running etc
35
why will pulse rate increase
the more intense the exercise is, the more the pulse rate will increase as the body needs to get more oxygen to the muscles and take the co2 away
36
what is the difference between breathing and respiration
- respiration is a chemical reaction and breathing allows us to get air into and out of our lungs- a muscular contraction
37
what is more efficient aerobic or anaerobic respiration
aerobic
38
what are the functions of the liver (5)
- production of bile to raise ph of chyme exiting the stomach so that the enzymes in the small intestine can act at their optimum rate
- detoxification of the blood to include the breakdown of ethanol
- breakdown lactic acid produced during anaerobic respiration to glucose
- conversion of glucose to glycogen when the level of glucose needs to be adjusted
- deamination of unwanted amino acids to ammonia
39
where does photosynthesis take place
in the chloroplasts in plant cells- contain chlorophyll that absorb light
40
what happens in the chlorophyll
absorb light for photosynthesis
41
what type of reaction is photosynthesis
endothermic- energy is transferred from the environment
42
what is the word equation for photosynthesis
carbon dioxide + water --> glucose +oxygen
43
what is the symbol equation for photosynthesis
6CO2 + 6H2O ---> C6H12O6 +6O2
44
how do plants use glucose (5)
- respiration
- making cellulose
- making amino acids
- stored as oil or fats
- stored as startch
45
how do plants use glucose for respiration
- this transfers energy from glucose which enables the plants to convert the rest of the glucose into other substances
46
how does plants use glucose to make cellulose
to make a strong plant cell wall
47
how does the plant use glucose to make amino acids
- glucose combined with nitrate ions for protein synthesis
48
how is glucose stored as oils and fats
glucose is turned into lipids for storing in seeds
49
how is glucose stored as starch
glucose is turned into starch and stored in roots, stems and leaves ready to use when photosynthesis isn't happening- starch is insoluble so is better for strong
50
what is a limiting factor
prevents the rate of photosynthesis increasing
51
what is the limiting factor at night
light
52
what is the limiting factor in winter
temperature
53
what is the limiting factor if its warm and bright enough
co2 level
54
what are the limiting factors (4)
- co2 level
- light intensity
- chlorophyll
- temperature
55
how can the amount of chlorophyll be affected? what happens then?
- by diseaes or environmental stress which causes chloroplasts to become damaged or to not make enough chlorophyll so cannot absorb as much light
56
what happens when a graph showing co2 level flattens out
as the amount of co2 increases, the rate no longer increases
57
what needs to be increases when the line on a graph showing co2 level flattens out
light or temperature
58
how does temperature affect the rate
it affects the enzymes involved
59
how do enzymes work at low temperatures
enzymes needed for photosynthesis work more slowly
60
what happens to the enzymes if it is too hot
enzymes will be damaged
- happens at about 45'
61
what has happened when the line on the graph of temperature touches the x axis
the enzymes have been destroyed
62
what does light provide
energy needed for photosynthesis
63
what happens when the light level is raised
the rate of photosynthesis increases steadily, but only to a certain point
64
what happens when as light increases, the rate does not
now either co2 or temperature is the limiting factor
65
how do we artificially create the environment for photosynthesis
grow plants in a greenhouse
66
how do greenhouses help the plants (to do with heat)
help trap the suns heat and make sure it doesn't become limiting
67
how will farmers keep the right temperature in the winter?
summer?
-use a heater
- might get too hot so use shades and ventillation
68
what do farmers do when the sunsets
supply artificial light when sun sets so plants photosynthesis more
69
what are the advantages of using a greenhouse for photosynthesis
- can increase levels of co2
- keeps them free from pests and disease
- can add fertilisers to soil to provide minerals
- crops will grow much faster and provide a decent crop which can be harvested more often
70
what is the disadvantage of using a greenhouse to grow crops
- costs a lot of money
71
what is important when using a greenhouse
- they must supply just the right amount of heat etc so they dont lose money
72
what is the inverse square law
light intensity decreases in proportion to the square of the distance
73
what is the equation for the inverse square law
light intensity= 1/ distance^2
74
what happens if you halve the distance (inverse square law)
the light intesnity will be 4 time greater
75
ESQ use the inverse square law to calculate the light intenity when the lamp is 10 cm from pondweed
1/d^2= 1/10^2
0.01 au (arbitrary units)
76
how can we tell how fast pondweed is photosynthesising
- the rate at which produces oxygen corresponds to the rate at which it is photosynthesising
77
what is the method for measuring the rate of photosynthesis (RP)
1. a source of white light is place at a specific distance from pondweed
2. pondweed is left to photosynthesis for a set amount of time - oxygen will be released and collected in capillary tube
3. at the end, the syringe is used to draw the gas bubbles in the tube up alongside a ruler and length of gas bubbles is measured
4. repeat the experiment twice with light at the same distance- calculate the mean
5. repeat whole experiment at different distances
78
measuring rate of photosynthesis
a) independent variable
b) control variable
c) dependant variable
a) distance of lamp
b) amount of pondweed, strengths of light
c) amount of oxygen produced
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