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Biology A2 Flashcards

1
Q

where is photosynthesis take?
what organelle?

A

chloroplasts

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2
Q

what are the adaptations for photosynthesis?

A

large surface are so can absorb as much light
thin,so as much light can be absorbed
numerous stomata for gas exchange

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3
Q

what is the formula for photosynthesis?

A

602+6H20—> C6 H12 O6 + 6O2

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4
Q

what pigments is used in photosynthesis?

A

chlorophyll A
chlorophyll B
these absorb light

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5
Q

what is the dependant reaction?
where does it take place?

A

a reaction which need light energy
this occurs in the thylakoid membranes

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6
Q

what is photolysis?

A

splitting water into protons electrons and oxygen

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7
Q

what is photoionisation?

A

where light energy excites the photosystem
this positively charges the atom

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8
Q

what is phosphorylation?

A

is the addition of a phosphate molecule

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9
Q

what is photophosphorylation?

A

addition of a phosphate molecule using light

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10
Q

what is a coenzyme?
and where is it used?

A

is a molecule that aids the function of an enzyme

used in respiration cycle

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11
Q

explain the light dependent reaction?

6 MARKER

A

PSII gets excited

electron gets passed down the electron transport chain

photolysis occurs and increases the concentration of protons in the thylakoid space

protons cross thylakoid space via ATP synthase. ADP plus protons to make ATP

PS1 gets excited moving depleted electron down second ETC into stroma

goes through a reduction process turned NADP TO NADPH

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12
Q

what is the chemiosmotic theory

4 marker

A

protons from stroma is pumped into thylakoid via proton pumps

photolysis of water creating higher conc on protons

protons go down ATP Synthase to form ATP

proton joins with NADP to make NADPH

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13
Q

where is cyclic phosphorylation?

A

PS1 and ATP

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14
Q

where is noncyclic phosphorylation?

A

PSII (680nm) and PSI (700nm) and ATP and NADPH

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15
Q

what is the light independent reaction? (calvin cycle)

A

photosynthesis reaction that doesn’t require light energy

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16
Q

where does the calvin cycle take place?

A

takes place in the stroma

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17
Q

describe what happens in the calvin cycle?
and how is organic molecules formed?

6 marker

A

ribulose bisphosphate (RUBP) (5) joins with a carbon dioxide

it is catalysed by rubisco to make 2x glycerate phosphate (3)

ATP from dependent reaction is hydrolysed AND NADPH is oxidised to NADP

to form 2x triosphosphate (3)
fie out of six is used to regenerate RUBP and one is used for organic molecules

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18
Q

what wavelengths does PSI and PSII work at?

A

PSI = 700
PSII = 680

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19
Q

how many carbon molecules are in triosphosphate?

A

3 carbons

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20
Q

types of respiration and explain it?

A

aerobic respiration with oxygen
anaerobic respiration without oxygen

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21
Q

what are the stages of aerobic respiration?

A

glycolysis
link reaction
krebs cycle
oxidative phosphorylation

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22
Q

explain the process of aerobic respiration?

6 marker

A

glycolysis splits glucose into pyruvate by phosphorylation and oxidation
pyruvate is the used to turned into acetate by losing a carbon dioxide, acetate then binds to coenzyme to make acetyale coenzyme A
joins krebs cycle to make a 6 carbon molecule, then a 5 then a 4
FADH AND NADH is used in oxidative phosphorylation where they undergo chemisomotic theory

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23
Q

where does glycolysis take place?

A

cytoplasm

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24
Q

where does the kreb’s cycle take place?

A

matrix

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25
what happens in glycolysis?
the splitting of the 6 glucose molecule into a two carbon
26
what happens in the link reaction?
the pyruvate molecules enter into a series of reactions which lead to the formation of acetylecoenzyme
27
what happens in the anaerobic respiration?
goes through glycolysis and then becomes lactate for humans or ethanol for plants this is done by 2 ADP'S turing into 2 ATP's
28
what is the sequence of food web?
producers - primary consumer -secondary consumer -tertiary secondary
29
what is a producer?
photosynthetic organisms that manufacture organic substances
30
what do the arrows show on a food web?
shows the direction of energy flow
31
what are saprobionts?
these are decomposers which break down complexes materials in dead organisms
32
what is biomass?
the total mass of living material in a specific area
33
what is the main source of energy?
sun
34
why isnt all the sun energy absorbed?
alot is reflexted back is absorbed by dust and clouds light may not hit chlorophyll plants absorbs a small amount of energy
35
formula for NPP
NPP= GPP - R
36
why is a low percentage of energy transferred at each stage ?
no all organism is consumed some cant be consumed energy is lost from respiration and heat
37
how to calculate net production?
N= I - ( F + R )
38
why can food chains have four or five trophic levels?
because there will be insufficient energy will be available to support large populations
39
how to calculate energy efficiency?
energy after ------------------ x100 energy before
40
what are the stages of the nitrogen cycle?
nitrogen fixation ammonification nitrogen fixation denitrification
41
why is phosphorus important biological molecule?
needed for ATP, nucleic acids and phospholipids
42
what are the stages of the phosphorus cycle?
rocks are broken down releasing phosphate into the soil roots ( mycorrhizae ) pick up phosphate plants are eaten by organisms organism die phosphate is lost in waste products animals die allowing sacrobients to break down organic compounds into soil rocks get weathered allowing phosphate to transfer into rivers or oceans
43
what is mycorrhizae? and why is is good for plants?
this is a fungi that acts as an extensions for roots this is good because it allows a larger surface area so higher absorption of water and nutrients
44
what are the different types of fertilisers?
organic = consists of dead or decaying remains of plants or animals ie: manure, bone meal, slurry inorganic = man made chemical compounds to provide nutrients ie: pallets
45
how do fertilisers increase productivity ?
provides nitrogen which is needed for ATP nucleotides in DNA and amino acids plants will grow taller so increases photosynthesis
46
what is leaching?
the removal of nutrients from the soil
47
what is eutrophication?
process which nutrient concentrations increase in large bodies of water
48
what are the problems with eutrophication?
no photosynthesis for aquatic plants reduction in biodiversity if humans drink bodies of water can lead to cancer and stomach problems
49
what are the events/ process of eutrophication?
leaching in soil to the bodies of water high nutrients will lead to algae bloom so light become limiting factor in photosynthesis no oxygen is created for fish leading to death of aquatic animals
50
what is taxsis?
a direction response to towards a stimulus for organisms
51
what is kenisis?
a response from an organisms, this response is NOT towards or away from a stimulus
52
what is trophism? gives two examples of trophism?
a directional response for PLANTS one example is phototrophism where plants grow towards th ight another example is that gravitrophism this is where plants grow agasint gravity therefore negative
53
what are the growth factors of a plant?
light gravity water
54
how does IAA work in the phototrophism?
IAA is produced in the tips of the plants IAA is initiallty produced unevenly in the plant IAA starts from the light side and moves to the shaded side by light high concentraction of IAA in plant means elongation in the shaded side of the plant
55
how does IAA effect/ produced in the gravitriphism?
IAA is produced in the roots of the plant Initially IAA is transported around the roots everywhere gravity influences the movment of IAA from the upperside to the lower side of the roots high concentration of IAA in the lower side imhibits growth
56
how does IAA cause elongation?
active transport of hydrogen ions from the cytoplam into the cell wall allowing cell walls to become more elastic and plastic therefore elongation by expansion
57
what is the advantages of th reflex arc?
its an involentry so doesnt require a decision fast and short pathway so rapid protects the body form harm animals will benefit from this becasue it will allow them to escape from preditors
58
what is a stimulus?
a change in the internal or external enviroment
59
what is a response?
an answer/ resonding to a stimulus
60
what are the stages of the reflex arc?
stimulus receptor sensory neurone coordinator motor neurone effector response
61
what is the peripheral nervous system?
this is made up of neurones that originate either the brain or the spindal chord
62
what is volentary nervous system? and autonomic nervous system?
volentary= carries impulses around the body, is a consious control autonomic= carries impulses around the glands and smooth muscles this is NOT a consious control
63
what is the pacinian corpsule? and how does it work?
only responds to mechanical pressure done so by creating a generator potential by acting as a transducer
64
what is the process of the pacinian corpsule?
only responds to mechanical pressure when pressure is applied membrane becomes deformed influx of sodium ions change becomes depolarised creating a generator potenial this turns into action potental
65
where are photoreceptors found?
rods are found in the retina cones are found in the fovea
66
all the features of rods?
shaped like a rod 3 rods are connected to one bipolar neurone low visual aucity sensitive to low intensity light found i the retina only one type of rods
67
what pigment does rods contain?
rhodopsin.
68
what are all the features of cones?
cones are found in the foves one cone is connected to one bipolar neurone less cones than rods high visual aucity three types of cones not sensitve to low intensitve light
69
what pigment does cones contain?
iodopsin
70
what is the autonomic nervous system? what is it split up to?
controls the involentary activites (consious) parasypathetic and sympathetic
71
how is te heart mygonic?
as the heart initiate its own contraction making it myogenic
72
explain the process of controlling heart rate?
SAN is found in the right atrium it intiates the impulses by releasing depolarisation across the aria causing contraction AVN will RELEASE another wave of depolariastion to the bundles of HIS ( down the septum) there is a slight delay as there AVN waits for the artias to be fully emptied bundles of HIS pass the waves down to the PURKYENE fibres in the wall of the ventricles to contract the ventricles
73
what is parasympathetic ?
it is the sysetem which calms the body down ie: high blood pressure the medulla will send impulses through parasympathetic to reduce heart rate
74
what is sympathetic?
prepares your body for danger ie fight or flight this is done by increasing heart rate

A Level (4 decks)

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