Topic 5 Flashcards
(26 cards)
what is energy used for
movement, metabolic reactions, active transport, cell division, protein synthesis
cristae
folds of inner membrane of mitochondria which increases the surface area
where does glycolysis occur
cytoplasm
glycolysis
Overall
Steps (4)
Net ATP for one glucose molecule
Splitting of one 6C glucose molecule into two 3C pyruvate molecules
Hydrolysis of ATP produces phosphate molecules
Glucose is phosphorylated and becomes more reactive
- (Ea is lowered) -2ATP
Phosphorylated glucose splits into two 3C glycerate 3-phosphate (GP) molecules
Two GP molecules convert into two 3C pyruvate molecules
- (+2ATP and NAD -> NADH + 3ATP) x2
Net ATP for one glucose molecule: +8
where does the link reaction occur
mitochondrial matrix
link reaction
Steps (3)
Net ATP for one glucose molecule
Two pyruvate molecules are actively transported into the matrix of mitochondria
Two pyruvates combine with two co-enzyme A to form two 2C Acetyl coA molecules
Each releases one CO2 and NAD -> NADH + 3ATP
Net ATP for one glucose molecule: +6
where does the Krebs cycle occur
mitochondrial matrix
Krebs cycle
Steps (3)
Net ATP for one glucose molecule
For each molecule of 2C Acetyl coA joins with 4C oxaloacetate to form 6C citrate
6C citrate -> 5C + CO2
- NAD -> NADH + 3ATP
- ADP + Pi -> ATP
5C -> 4C oxaloacetate + CO2
- 2NAD -> 2NADH + 6ATP
- FAD -> FADH + 2ATP
- Net ATP for one glucose molecule: +24
Total net ATP for one glucose molecule in aerobic respiration
8+6+24= 38
where does oxidative phosphorylation occur
inner mitochondrial membrane/ on cristae
oxidative phosphorylation
Generally wth is it
Steps (6)
Transfer of electrons along a series of electron carriers generates ATP in electron transport chain
Reduced NAD (NADH) is oxidised to NAD and releases hydrogen ions to the electron transport chain and returns to the Krebs cycle
Electrons are carried along a chain of electron carriers in a series of redox reactions
Released energy is used to pump protons from the matrix to intermembrane space by active transport, creating a diffusion gradient
Chemiosmosis: protons diffuse back into matrix via pores with protein channels and ATP synthase
Energy is released which is used for ADP + Pi -> ATP
Oxygen is the terminal electron acceptor which forms water
why is anaerobic respiration important
regenerates NAD for more glycolysis to produce ATP
anaerobic respiration in animals
each pyruvate accepts 2H from 2NADH to form lactic + 2NAD
reversible reaction, transported via blood to be conveted to glucose in the liver
anaerobic respiration in plants
each pyruvate loses 1CO2 and accepts H from NADH to form ethanol + CO2 + NAD
irreversible reaction
Absorption spectra
the range of different wavelengths of light a photosynthetic pigment can absorb
Action spectra
compares rate of photosynthesis with the wavelength of light
where does the light dependent reaction occur
thylakoid membrane of the chloroplasts
cyclic phosphorylation
Light hits chlorophyll in PS1 and excites an electron to leave chlorophyll molecule
Electron is picked up by an electron acceptor and passed along electron carriers to produce ATP
Electron returns to chlorophyll molecule
non-cyclic phosphorylation
Water molecule splits by photolysis releasing electrons to chlorophyll
Light hits chlorophyll in PS2 and excites an electron to leave chlorophyll molecule
Electron is picked up by an electron acceptor and passed along electron carriers to produce ATP
PS1 receives the electron which is excited by light again
Electron is picked up by an electron acceptor and passed along electron carrier to be picked up by another electron acceptor (NADP)
NADP takes up H+ from water molecule to form NADPH
photolysis of water
in chloroplast
H2O -> H+ + OH-
H+ used to reduce NADP
4OH- -> O2 + 2H2O + 4e
oxygen as a waste product
electrons restore chlorophyll to original state
where does the light independent reaction occur
stroma in chloroplasts
light independent reaction
CO2 diffuses into the plant via stomata and fixes with 5C ribulose bisphosphate (RuBP) using ribulose bisphosphate carboxylase (RUBISCO) enzyme to form a 6C compound
6C compound splits into two 3C GP
GP is reduced to form 3C glyceraldehyde 3-phosphate (GALP)
H involved is from NADPH and energy required comes from ATP which were produced in the LDR
Some GALP synthesises a 6C β-glucose molecule by condensation
what happens to glucose synthesised in photosynthesis (4)
May pass into the glycolysis pathway to provide energy in the form ATP and acetyl coA which is used to synthesise fatty acids
May be converted to sucrose for transport or starch for storage
Straight polymer cellulose formed by glycosidic bonds between C1 and C4
what happens to GALP synthesised in photosynthesis (3)
Some GALP synthesises a 6C β-glucose molecule by condensation
Some GALP combines compounds from respiration with nitrates from the soil to form parts of amino acids
Some GALP regenerates into 5 C RuBP for the first step of the cycle
