Topic 5 - Energy Transferes In And Between Organisms Flashcards
Phosphorylation and photophosphorylation
Adding phosphate molecules
Adding phosphate using light energy
Photolysis
Splitting of molecule using light
Water molecule in PS2 slip by light releasing 2 electrons to replace ones moved away down ETC.
O2 also produced
Photoionisation
Light excited electrons in an atom giving them more energy causing them to be released
Chloroplast
- chlorophyll
- thylakoid
- grana
- lamellea
- stroma
LDR summary
- requires light
- electrons excited
- electrons transfere energy to PS1
- phosphate added to ADP to make ATP and reduce NASP
- hydrogen transferred
LIR summary
- Calvin cycle
- relays on products from light dependent reaction
- in stroma
- atp and reduce nadp supplies energy and h for simple sugars from CO2
Photophophorylation: cyclic and non cyclic
Non cyclic - produces atp reduced nadp and O2. Non-cyclic because electrons moved from PS2 dont return to PS2
Cyclic - produces atp. Electrons from PS1 return back to PS1
Where does the light independent reaction t ake place
Stroma
DCPIP? What is it?
Blue when oxidised
Colourless when reduced by electrons
- chemical that shows rate of photosynthesis
What inhibits decolorisation:
- less ATP
- less reduced nadp
- less gp to top
LDP KEY POINTS
- light hits chloroplast and excited electrons which more from PS11 to PS1 and transference energy as the move down ETC
- energy used in Active T to diffuse H+ into thylakoid
- h+ reduce nadp
- h+ diffuse through atp synthase and produce atp for Calvin cycle
LDR photoionisation
- chlorophyll absorbs light
- electron excited
- electrons lost ???
- chlorophyll positively charged
LIR KEY POINTS
- Calvin cycle
- rubisco enzyme catalyses reaction between CO2 and RuBP
- 2x G3P formed from unstable 6 carbon compound
- ATP and RNADP from LDR converts GP to TP (2x 3C)
- 1 carbon released from TP
- TP converted to 5 carbon compound RuBP again by ATP
- cycle repeats 6x to make hexose sugar
Advantages of having different pigment
All absorb different wavelengths of light for photosynthesis
Where is rubisco found ?
Stroma in chloroplast
Two products of LDR require for LIR
ATP
NADPH (reduced)
Hydrolysis from atp
What are the h+ ions that travel fin to the thylakoid during LDR
- proton from stroma diffuse via AT into thylakoid
- creates proton gradient in thylakoid membrane
Photolysis of water ???
- light splits water into electrons protons and oxygen
- electrons replace those lost from pigments during photoionisation
- protons are used for ATP production
- protons and electrons reduce NADP
What converts GP to TP
ATP
NADPH
Optimum conditions for photosynthesis
- high light intensity Of certain wavelength
- temperature of around 25 degrees C
- CO2 at 0.4% ( any higher and stomata might close
- constant supply of water (too much cases water logging or suffocates plant)
Limiting factors of photosynthesis
- all at right level manage the constant rate of photosynthesis
- anyone too high or too low can limit it
- saturation point if when one factor has reached max amount and is no longer limiting factor because something else is limiting
What do farmers do to manage limiting factors to ensure plants grow to the max rate and max yield
- CO2 added to air in greenhouse by burning propane in CO2 generator
- light provided by lamp
- temperature maintained by sunlight trapped in greenhouse but heating and cooling systems maintain constant temp and air circulation can be controlled
What is mobile and stationary phase in chromatography
- mobile - molecules move due to liquid solvent
- stationary - can’t move
Aim of glycolysis
Glucose to pyruvate
Where does glycolysis take place
Cytoplasm
Glycolysis summary
- glucose phosphorylated by 2ATP to make glucose phosphate
- another phosphate added to make hexose bisphosphate using atp energy
- unstable so broken down into 2 triose phosphates
- then oxidised by nad by removal of H to form reduced nad
- each triose phosphates converted into glucose releasing 4 ATP (NET OF 2ATP)
Where is link reaction
Matrix of mitochondria
Aim of link reaction
- produce acetyl coenzyme
- reduce nad
- produce CO2
Link reaction summary
- “links” glycolysis and Krebs
- pyruvate from glycolysis DECARBOXYLATED and DEHYDROGENATED (co2 and h2 removed)
- combined with coenzyme A to form acetylene coenzyme A
- process happens 2x
Link reaction equation
Pyruvate + nad + CoA —-»» acetyl CoA + nadh
Aim and place of krebs
Produce:
- ATP
- NADH
- FADH
In MATRIX
KREBS SUMMARY
- acetyl coenzyme enters circular pathway from link reaction
- combines with oxaloacetate (4c) to citrate (6c)
- citrate decarboxylated by losing carbon as CO2
- 2 H also lost forming NADH
- 5 carbon decarboxylated again and dehydrogenated forming 4C (oxaloacteate)
- carbon lost
- 6 carbons released
- 1 fadh made
- 3 nadh made
- 2CO2 released
Where if oxidative phosphorylation and why does it happen
Inner mitochondrial membrane
Produces water and atp
Oxidative phosphorylation and electron transfer chain
- reduced nad and fad release h atoms as they are oxidised
- h atoms split into protons and electrons
- electrons move down ETC losing energy at each carrier
- energy lost used to drive active t of protons to the inter membrane space for the matrix to create a chemical gradient
- protons move down gradient through ATP synthase catalysing synthesis of ATP from adp and inorganic phosphate in the process (chemo osmosis)
- protons and electrons combine to form water
- O2 is final electron acceptor
No. Of ATP in respiration as a whole
32
Anaerobic equation (lactate fermentation)
- pyruvate -> lactate (nadh to nad)
- nad back to glycolysis
Why is too much lactic acid bad
- changes ph bad for enzymes
Anaerobic respiration summary
- h from nadh added to pyruvate to form lactate
- pyruvate reduced to lactate by lactate dehydrogenase enzyme
- pyruvate is hydrogen acceptor
- nad available to accept electrons and proton ready for glycolysis again
What happens if lactate is further metabolised ?
- can be oxidised to pyruvate to Krebs cycle fro atp synthesis (needs extra O2 causing 02 dept)
- converted into glycogen and stored in liver
Fermentation process of respiration summary
- pyruvate decarboxylated to ethanol
- Produced CO2
- hydrogen from nadh turns ethanAL to ethanOL with enzyme ALCOHOL DEHYDROGENASE as catalyst
- ethanAL is hydrogen acceptor
- ethanOL is waste
Fermentation equation
Pyruvate + reduced nad > ethanol + co2 + oxidised nad
- pyruvate decarboxylated
- co2 can be measured to estimate rate of photosynthesis
- CO2 is waste
Why converting pyruvate to lactate in anaerobic respiration allowed continued production of ATP?
Produces/reduced NAD so used in glycolysis so continues atp sysnthesis
How does yeast respire
Anaerobically
Why is respiration reaction apparatus left for certain periods of time before investigation starts?
- to allow respiration rate to stabilise in new conditions
- to reach equilibrium
- allow pressure changes
NOT ACCLIMATISE
Advantage or Bohr effect during intense ec=xcercise
- low o2 affinity
- less lactate
- faster aerobics respiration
Why is production of lactate advantage to people during intense exercise
When lactate is produced, nad is also produced when oxidised which goes back to glycolysis to produce more atp for energy during exercise
How is Krebs cycle affected if electron carrier is inhibited
- na FAD or NAD is produced from transfer chain
How does pyruvate from glycolysis enteer mitochondrial matrix
Active transport
Name other respiratory substrates
Breakdown products of lipids and amino acids which enter the Krebs cycle
NPP
Net primary production
- chemical energy store after respiratory losses
Gross primary product
GPP
- producers
- total amount of chemical energy converted from light energy by plants in a given area
- some lost in respiration
- chemical energy store in given area or vol
Equation for net primary production
NPP=GPP-R
GPP = gross primary production
R = respiration
Measure biomass?
Dry organism in oven
Mass of carbon or dry tissue per area
Requires sacrifice leading to ethical issues
What is detritus
DOM
What are detritivores
- reduce SA of DOM fro decomposes
- worms
Saprophytes
Decomposers
How is energy lost between trophic levels
- not all of each organism is consumed e.g. hair and teeth
- thermal energy lost
- faeces of aminal
Net production equation
N = I - (F+R)
Net production = chemical energy store of food - (energy lost in faeces + energy lost in respiration)
% efficiency
Energy available after transfer / energy availed before transfer X 100
Pyramids of number
- no. Of animals species not biomass
- doesn’t show energy loss
- inverted pyramids
Pyramids of biomass
- in Kg
- mass of creature at each level
- may have different energy levels in comparison to their masses
- have to empty (starve) and dry organism to get true biomass which is unethical
Pyramids of energy
-kj
- energy passed form one organism to the next and what’s lost
- taken at given time
More reliable as it shows energy levels in equal bars
Increase productivity of intesive farming
- for cattle, heat pens, antibiotics, steroids to produce more meat, and high protein diet
- monocultures require rich fertiliser, pesticides and more space which required hedgerow removal
Gross productivity units
Unit of energy/mass per area or year
Why simplify foods webs
- reduces energy loss to other organisms
- human controlled
- getting rid of pests (farmers use pest control)
Types of pest control
- insecticides
- herbicides
- biological control:
Parasites
Pathogenic bacteria and viruses
What is intergrated method that farmers use
Intergraded of both biological and chemical methods of pest control to reduce pest numbers more to increase NPP
How and why do farmers reduce respiratory losses
So energy is transferred more efficiently
To increase net production
- restrict movement so less respiration energy loss
- indoor and warm to prevent energy used to warm body temp
-
Carbon cycle
Decay
Respiration
Decomposition
Atmosphere
Nitrogen fixation
- N gas in atmos to N compounds
- nitrogen fixing bacteria
- lightning
- harbour process
Nitrogen fixation bacteria
RHIZOBIUM
- with enzyme nitrogenase converts nitrogen and hydrogen to ammonia and then ammonium ions for plant to use
- in root nodules
Ammonification
- nitrogen into ammonia from dead organism decay
- saphriphites in soil
Nitrification
- ammonium ions oxidised to nitrates
- plant uses
- nitrifying bacteria converts
- ammonia > nitrites > nitrates
Denitrification
- denitrifying bacteria in soil during respiration
- produced nitrogen gas to atmos
- anaerobic conditions e.g. waterlogged soil
Phosphorus used for …
ATP
Phospholipids
Nucleic acids
Phosphors cycle
- no gas stage
- enters soil from rock erosion
- absorbed by plants
- passed to animal via feeding
- saphrophites break down noragnic molecules and release phosphate ions into soil
Fertilisers cause….
Eutrophication and leaching
What is mycorrhizae
- fungi
- symbiotic relationship
- extends plant root systems to absorb more water and minerals
In oxidative phosphorylation why is O2 the final electron acceptor
Binds electron and proton to make water as product of photosynthesis
Chemeosmosis
Energy from electron traveling down ETC produces atp from adp and pi
