LO 2e - f Flashcards
Describe how chemical energy is recovered by cells and understand the connection between the processes of photosynthesis and cellular respiration
Chemical energy comes from the bonds of molecules eg (ATP)
Photosynthesis - use of sunlight to react CO2 into glucose process of glucose breakdown (glycolysis and cellular respiration) (water + co2 + light = sugar + oxygen)
All cells use glucose to metabolise hence this is a crucial system.
Describe the process of glycolysis and list the end products
2 phases energy investment and energy harvest phase
Investment - 1 glucose forms 1 fructose bisphosphate (depleting 2 ATPs in the process)
Harvest - fructose diphosphate forms 2 glyceraldehyde-3-phosphate (G3P). Then they form 2 pyruvates (4ADP recharge and 2NAD+ depleted)
Describe how the end-product of glycolysis (pyruvate) is processed prior to entry into the Krebs (citric acid) cycle, how the end products of glycolysis are further processed during the Krebs cycle, and state the outcomes of this process
Prior to the Krebs cycle the pyruvate form acetyl CoA by reacting with coenzyme A (NAD+ is depleted)
Understand the role of the electron transport chain (ETC) in re-oxidising NADH and FADH2 to facilitate continuous metabolism and maximise ATP generation
During glycolysis and the cellular respiration 10 NADH and 2FADH2 was produced for each glucose molecule. These each release 2 electrons into the ETC.
They travel through the chain and each protein the cross pumps more H+ ions across the matrix and these concentrations will be used to generate ATP during chemiosmosis.
As the H+ ion go through the ATP synthase they are caught in the ATP bonds, re-charging them.
Summarise the extraction of energy from fuel molecules such as glucose, including preliminary processing via glycolysis and more thorough energy extraction via the Krebs cycle
Cellular respiration extracts energy from elements in food like glucose, fats.
Proteins break down into amino acids into pyruvate, into acetyl CoA into the krebs cycle.
Carbohydrates break down into glucose into glycolysis following the regular process
Fats break down into (fatty acids into acetyl CoA) or (glycerol into glycolysis)
Describe the processes of fermentation, and the conditions under which fermentation is used or organisms
Glycolysis happens regardless of oxygen present, however under anaerobic conditions the 2 pyruvate forms 2 lactate, 2 ethanol and 2 CO2 (recharging 2 NADH)
Describe in general terms the process of photosynthesis
CO2 + H2O and light = glucose + oxygen
this is how plants metabolise
Draw a labelled diagram of the internal structure of a chloroplast; identify the stroma, grana, thylakoids, inner membrane, and outer membrane
Stroma - fluid inside the chloroplast
Grana - stacks of thylakoids forming a disc
Thylakoids - organelle inside chloroplasts that convert light into ATPs and NADPH
Inner membrane - inside the other membrane
Outer membrane - has cuticle which prevents water from evaporating
Describe the essential chemical processes that occur during photosynthesis in eukaryotes and where they take place
Photosystem 2 (thylakoid membrane) - photon of light are absorbed and energised as electron is ejected to the receptor (goes through ECT) pump H+ ions leading to ATP synthesis
Photosystem 1 (thylakoid membrane) - the electron leaves going into the PS1 until light strikes, then the primary electron acceptor catches it.
Each photstem has an ETC adjust to it (all occur in the thylakoids)
The calvin cycle occurring in the Stroma
Describe how pigments allow plants to absorb photons of light, and how this affects the colour of plant foliage
Chlorophyll absorbs every wavelength of light that is not green, that colour if reflected hence why plant appear green
Describe the process by which Photosystems I and II use solar energy to move electrons and protons across the thylakoid membrane and list the products of the process during the light-dependent reactions..
The light energy absorbed in chloroplast is used to move electrons from the reaction centre into the electron acceptor (PS2) then move it to ETC 2 where the energy expelled aids in hydrogen ions getting pumped into the thylakoid membrane. Then the electron is passed into another chronology reaction centre (PS1) when light aids its reaction it moves into the electron adapter and into ECT1 when 1 NADPH is made (for calvin cycle).
The hydrogen ions pumped during this process creates a concentration gradient which allows for TP synthesis in the chemiosmosis. As hydrogen ions flow down the concentration gradient it power ATP synthesis (ATP used in the calvin cycle)
Describe the sequence of events occurring in the Calvin-Benson cycle and the formation of glucose from G3P during the light-independent reactions
3 CO2 bonds with Rubisco (RuBP) to give 6 phosphoglyceric acid, using (6ATP and 6NADPH) 6 glyceraldehyde - 3 - phosphate, one is removed to later be stored and other produce RuBP (using 3 ATP).
