Lecture 7

Question 1

Electron carriers

Answer 1

NADH (reduced form): carries electrons and is a good electron donator

NAD+ (O2 form): doesn’t carry electrons and is a good electron acceptor

FADH2 (reduced form): carries electrons and is a good electron donator

FAD (O2 form): doesn’t carry electrons and is a good electron acceptor

Question 2

Cellular respiration

Answer 2

involves many oxidation-reduction reactions. the breakdown of glucose to CO2 is an oxidation reaction. Molecule that are oxidised lose electrons and hydrogen. Carbon is more electron poor in the form of CO2 than glucose. Molecules that are reduced gain electrons and hydrogen.

Question 3

Autotrophs

Answer 3

produces energy from inorganic sources. Photosynthesis –> sugar–>cell resp–>energy

Question 4

Heterotrophs

Answer 4

Consumes other organisms, converts energy from food to usable energy (cellular resp)

Question 5

light reactions

Answer 5

starts in chlorophylls which capture energy from sun. They work in an antenna complex to funnel sun energy to reaction centre via resonance energy transfer. when it reaches the reaction centre, non-cyclic photophorylation occurs

Question 6

non-cyclic photophorylation

Answer 6

at ground state receives energy from the antenna pigments which raises an electron to a higher orbital, allowing it to be donated and thus, moves thermodynamically downhill through a series of proteins down an electron transport chain. The electron’s energy is used to pump protons from the stroma into the lumen of the chloroplast. Them, H arrives to another chlorophyll at a different reaction centre. Another hit of light occurs from theantenna pigmnts is raised up to an even higher redox potential and then is used to convert NADP+ to NADPH which row now has reductive power. The electron is replaced by splitting water at the first reaction centre. O2 is released as waste.

Question 7

thylakoid

Answer 7

contains the chloroplasts. has high SA to increase light absorption

Question 8

thylakoid lumen

Answer 8

separated from stroma of chloroplast to separate reactions

Question 9

ATP synthase

Answer 9

high conc of H+ in lumen vs low H+ conc. In stroma due to H2O splitting. Conc gradient moves H+ into stroma via ATP synthase and while they do this, they phosphorylate ADP to ATP.