component 1 revision and exam errors Flashcards
strategies that can be used to prevent overfishing
aquaculture
minimum net mesh size, so that younger fish will not be caught
establishing exclusion zones, so certain areas that might contain breeding fish will not be fished
quotas should be introduced
why are farmed fishes more susceptible to lice
they are more closely packed, so the lice can spread from fish to fish
why is eliminating lice a problem for fish farms
lice is resistant to pesticides, and so are not easily killed
why is it important to prevent the escape of farmed fish from their pens
they might spread diseases to native fish in other areas
competition with other fish in other habitats for food, mates, habitat…..
they might breed with fish in their new habitat, thereby reducing genetic diversity
they might predate other fishes in their new habitats, thereby reducing biodiversity in the habitat
reasons why people might be concerned with the illegal reintroduction of beavers into sites in the UK
they might introduce certain diseases to the habitat or site
it could lead to the destruction of the habitat due to deforestation and reduced water flow
the site or habitat might be inappropriate for the beavers
what should scientists consider when planning the successful reintroduction of beavers
whether the habitat is suitable for the beaver
that the beaver does not occupy the same niche as other species in the habitat
that a suitable disease free beaver population is being reintroduced
planetary boundaries
the threshold for a global process that is affected by human activity. above this threshold, the global process will not be stable
how can deforestation directly affect the planetary boundary for climate change?
deforestation reduces the carbon dioxide uptake by plants during photosynthesis
using fuels in the processing of trees also releases carbon dioxide into the atmosphere
the decay of waste tree material also releases carbon dioxide into the atmosphere
using your knowledge of natural selection, suggest why more species have become extinct recently, compared to pre-industrial times
increased human population has caused environmental change
some species were selected against due to these environmental changes, like climate change
these species were not able to adapt in a short period of time and became extinct consequently
how can biodiversity loss be delayed using conservation methods
breeding programmes
trade restrictions
fishing quotas
restricting habitat destruction
red kites almost became extinct in the UK in 1995. An attempt was made to recover the red kite population.
In areas where they were absent and then re-introduced, their numbers increased more rapidly than re-introducing them in areas where they were already established. suggest why
fewer predators
less intraspecific competition for food or shelter
less likely to pass on disease as there are fewer of them in those areas
Briefly describe how reduced FAD and reduced NAD are used to create an electrochemical gradient.
reduced NAD and reduced FAD pass electrons onto the ETC
the high energy electrons provide energy to power proton pumps in the inner mitochondrial membrane
hydrogen ions are pumped into the intermembrane space
an electrochemical gradient is generated consequently
Suggest a suitable tissue to examine the mitochondrial function and explain why you have chosen this
tissue with respect to patient safety.
muscle
high number of mitochondria and easy to access
What could be deduced if the oxygen consumption was low with the pyruvate as a substrate but high
with α-ketoglutarate as a substrate?
NB: the latter is a substrate of the Krebs cycle
the link reaction is not working or
enzymes of the link reaction are not active
the pathway between α-ketoglutarate and the rest of the cycle is not working correctly or
there is not enough NAD or FAD to drive the ETC
What could be deduced if there was a build-up of any one of the Krebs cycle intermediates?
enzymes that are supposed to catalyze the conversion of the intermediate to the next in the cycle are not functional, so the intermediate cannot be converted
How do we measure biomass ?
In terms of mass of carbon
Or dry mass of tissue
Suggest three different ways that abundance can be quantified in an ecosystem
Through
Percentage area cover, density or percentage frequency
How is biomass measured
In terms of the mass of carbon
Or dry mass of tissue
Explain why there is a raised blood lactate level in many patients with mitochondrial disease
The krebs cycle might not be working well
Pyruvate levels build up
Excess pyruvate are then converted to lactate
What happens to the carbon dioxide removed during the link reaction and the Krebs cycle (or during respiration)
Diffuses out of the mitochondria into the blood plasma, where it is carried as hydrogen carbonate ions
It is breathed out
Outline the pathway for the production of triose phosphate in glycolysis
Glucose is phosphorylase’s twice to form 1,6- glucoseBIphosphate
2ATP are used in this process , so 2ADP molecules are formed
1,6- glucoseBIphosphate is split into 2 triode triose phosphate molecules
explain the biochemical reasons for carrying out lactic acid fermentation, although lactate is toxic in high concentrations
NAD can be regenerated during this reaction
ATP can therefore be produced without the use of the ETC or oxygen
therefore glycolysis can continue and ATP can keep being produced
lactic acid fermentation sometimes occurs in muscle fibres when a short burst of very rapid ATP production is needed.
suggest a reason for this
it is a quicker process, compared to aerobic respiration, as only glycolysis is required
suggest why substrate level phosphorylation is referred to as the simplest and oldest way to make ATP
because it does not involve the ETC
it does not require oxygen
it does not require ATP synthase
it does not need an electrochemical gradient
where precisely in the cell does oxidative phosphorylation occur
on the inner mitochondrial membrane
full name of ATP
Adenosine Triphosphate
name five processes in cells which require energy
muscle contraction
protein synthesis
active transport
cell division
nerve conduction
explain why FAD and NAD synthesise different numbers of ATP molecules
because NAD use 3 proton pumps and FAD uses only 2 pumps in the ETC
describe what would happen to the pyruvate molecules formed under anaerobic conditions in the human muscle
pyruvate is reduced to form lactic acid
NAD is regenerated as NADH loses hydrogen to the pyruvate
describe the production of nitrogenous waste and state where this takes place
Amino acids are deaminated in the liver
pyruvic acid is left over
the amino group combines with carbon dioxide to form urea
describe the position of the “high energy bond of ATP”
the bond between the last 2 phosphate groups on ATP
explain how the arrangement of pigments in the photosystem harvests light energy
different wavelengths of light are absorbed by different pigments in the antenna complex of the photosystem
chlorophyll a( the primary pigment) in the reaction center absorbs slightly different wavelengths of light
in paper chromatography, why is the origin line drawn in pencil, and why is the level of solvent used below the origin line?
because a pencil would not dissolve in the solvent
otherwise, the pigments in the sample would dissolve in the solvent
state two variables that would need to be controlled if paper chromatography or thin-layer chromatography was being used to compare pigments in the leaves of 2 different species of plant
same solvent
same chromatography paper
same TLC medium
state the name given to a change in gene expression brought about by methylation
Epigenetics
carbon dioxide and atmospheric nitrogen can be fixed by living organisms
State the meaning of the word fixed as used in this context
it means they can be converted into a form that can be used by living organisms
Active transport
a process by which cells move molecules or ions across their cell membrane from a region of low concentration to a region of high concentration, against their concentration gradient
how is ADP phosphorylated due to there being a high proton gradient in the intermembrane space
protons flow through ATP synthase
down their proton gradient(concentration gradient) by facilitated diffusion into the matrix
the energy provided as the protons flow through ATP synthase is used to phosphorylate ADP with phosphate to form ATP
the name of the molecules that electrons are passed along on the inner membrane
electron carriers
how is ATP produced via respiration used in the calvin cycle
Used to provide energy to reduce GP to TP
Used in the molecular rearrangement of Tp to RUBP
can NADH be directly used in photosynthesis
describe how NADH is used in photosynthesis
no
it indirectly provides energy to the Calvin cycle, by donating electrons to the electron transport chain during cellular respiration, which produces ATP
what does a decrease in percentage change mean
it means whatever is being measured in decreasing
advantage and disadvantage of expressing a change in population as a percentage
it helps to compare changes in different populations, and it can help to make the data more accessible to the wider audience
if the population is small, then a small change in population could result to a large change in percentage
Cyanide is an extremely poisonous chemical that affects aerobic respiration in the mitochondria. Cyanide inhibits the final electron carrier. explain how cyanide would prevent the process of AEROBIC respiration
ATP synthesis via the electron transport chain stops.
because cyanide stops the transfer of electrons to the final electron acceptor ( which is oxygen)
the flow of electrons stops, as electrons cannot be accepted by electron carriers
NADH and FADH cannot be oxidized as a result
Cyanide is an extremely poisonous chemical that affects aerobic respiration in the mitochondria. Cyanide inhibits the final electron carrier. explain how cyanide would prevent the process of AEROBIC respiration
explain why blood lactate levels rise as a symptom of cyanide poisoning
NADH cannot pass to the Krebs cycle
hydrogen donated to pyruvate to make lactate (pyruvate reduced )
so NAD regenerated, to be reused in glycolysis
so more ATP continues to be synthesized in Glycolysis
climax community
the final stage of succession in which species composition remains relatively stable
explain how an increase in global warming could have a contributory factor in the planetary boundary for biodiversity being crossed
sea temperature increases to above the threshold level
ice caps melt, causing destruction of habitat for organisms like polar bears
for a bacteria with a surface area to volume ratio of 10:1, with reference to their size, explain how the bacteria are able to gain sufficient minerals from nutrient-poor waters
they are small, so have a large surface area to volume ratio
so a larger area for nutrients to diffuse
short diffusion distance as well, increasing the diffusion rate
give an example of when ATP is used in an anabolic reaction and in a catabolic reaction
protein synthesis or condensation reactions
digestion, respiration, hydrolysis
state what is meant by substrate-level phosphorylation
energy is derived directly from the breakdown of a substrate to phosphorylate ADP with phosphate to make ATP
Explain how the Internal structures of the mitochondria are adapted to carry out respiration
They have cristae which is folded to increase the surface area of the mitochondria for diffusion of Oxygen into it
They have ribosomes that synthesise enzymes like dehydrogenase that carry out respiration
The inner mitochondrial membrane contains the ETC, which contains ATP synthase, to synthesise ATP
The inner mitochondrial membrane is impermeable , so a proton gradient can be created
Explain how the internal structures of the chloroplasts are adapted to carry out photosynthesis
The thylakoid membranes have photosystems, which contain numerous photosynthetic pigments that absorb light energy
Stroma contains enzymes of the Calvin cycle
They have Ribosomes that produce enzymes like rubisco that carry out photosynthesis
The thylakoid space enables the establishment of a proton gradient
Describe the evidence that suggests that mitochondria and chloroplasts evolved from bacteria
They both have a double membrane
They both have a circular DNA
Their DNA is not enclosed by a nuclear membrane
They both have 70s ribosomes
Describe the effects of increasing carbon dioxide levels and global temperatures on aquatic environments
Carbon dioxide dissolved in the oceans , and forms carbonic acid , thereby increasing the acidity of the water
Increased temperature increase the rate of photosynthesis
Increased algal blooms
Increased respiratory rate due to increased temperature , so high oxygen demand , leading to some aquatic organisms suffocating and dying
Increased temperatures could cause aquatic organisms to migrate to cooler habitats
Could cause coral reef destruction
Control experiments vs control variables
An experiment without the independent variable
Vs
Factors that are kept the same
Reasons for doing control experiments
To compare with the other setups with the independent variable
Reasons for control variables
To ensure that the experiment is valid , and that only the independent variable affects the results
To improve the reliability of an experiment, what do we do
Repeat the experiment
Identify and ignore anomalies
Calculate the mean
Have a large sample size
How to improve validity of an experiment
Keep control variables the same
Standardise procedures ( collecting data in the same way)
How to improve the accuracy of an experiment
Use smaller intervals
Use equipment with higher resolutions
