BIOL 190 Unit 4

radiant energy → chemical energy

chemical energy passed through food web

energy from sunlight

energy from chemical compounds

carbon from CO2

carbon from organic compounds

too high energy for long-term storage

• only lasts a few seconds

allosteric binding on enzymes

halts production

C6H12O6 + 6O2 → 6CO2 + 6H2O + energy (ATP)

direct generation of ATP

electron carrier energy way of generating ATP

paired reduction and oxidation reactions

helpers in redox reactions

• capture and pass on electrons generated in chemical reactions

• ex:

  • NADP+/NADPH

  • NAD+/NADH

  • FAD+/FADH2

stores energy in C-C bonds

carry electrons

temporary energy storages

short-term energy

wanted

breaks glucose (6C) into 2 pyruvate (3C)

happens in cytoplasm

a- prime glucose with phosphates using 2 ATP

b- cleave into two 3C molecules

c- 2 NADH + 4ATP generated per glucose

generates some ATP

evolved before O2 in atmosphere

2 pyruvate, 2 NADH, 2 ATP

breaks 1/3 remaining carbons after glycolysis

happens in mitochondrial matrix

a- removes CO2

b- generates NADH

c- attach 2C to Co-A → acetyl CoA

breaks remaining C bonds and stores energy

happens in mitochondrial matrix

a- add 2C (acetyl-CoA) to 4C (oxalocetate) → 6C (citrate)

b- regenerate 4C; make 2 CO2, ATP, and NADH

c- rearrange 4C; make NADH and FADH2

4 ATP, 10 NADH, 2 FADH2

6 CO2

primary electron acceptor in oxidative respiration

donates electrons to generate ATP

transfers energy of electrons into ATP

occurs in inner mitochondrial membrane

a- NADH and FADH2 pass electrons to pump H+ ions into intermembrane space

b- all electrons end by splitting O2 to form H2O

• O2 = final electron acceptor

c- H+ ions drive ATP synthase to form ATP

each NADH = 3 ATP

each FADH2 = 2 ATP

eukaryotes used aerobic bacteria (now mitochondria) to use O2

• efficient energy use allowed multicellular life to emerge

36 eukaryotes, 38 prokaryotes

• 2 ATP used to enter mitochondria in eukaryotes

29 ATP

6CO2 + 6 H2O + energy → C6H12O6 + 6O2

requires light

photons → ATP and NADPH (electron storage)

no light required

ATP and NADPH → sugare

1st in bacteria

• used H2S (oxygen toxic)

oxygen revolution

• cyanobacteria pump out oxygen into atmosphere

endosymbiosis of cyanobacteria = chloroplasts

absorbs violet-blue and red

absorb blue and orange

absorb blue-green

used to collect energy

many chloroplasts involved

electron dislodged with energy from photon

water split to replace electrons

• O2 generated

ATP is generated from H+ gradient set up in thylakoid

NADP+ = final electron acceptor

synthesis of ATP

electrons returned to use elsewhere

used in bacteria

PSII

• generates O2 by grabbing electrons from water

• sends electrons to PSI

• pumps H+ for ATP synthesis

PSI

• takes electrons from PSII

• sends electrons to NADPH

PSII → B6-f complex pumps protons into thylakoid → PSI → electrons put on NADP+ to store energy as NADPH

used energy from light reactions to convert CO2 into glucose

occurs in chloroplast stroma

most abundant enzyme

uses energy to create carbon bonds

wasteful reaction

causes photorespirtation

1- fix the carbon

• RuBP + CO2 → 2-3 C

2- reduce the carbon

• 2 3C processed using energy using ATP and NADPH

  • gives rise to 6C glucose

3- regenerate RuBP

• 3C generate RuBP using ATP

move reaction in space to reduce photorespiration

• calvin cycle occurs in different spot of chloroplast

  • mesolphyll cells fix CO2 into 4C product and more to Bundle Sheath Cells

move reaction in time to reduce photorespiration

• calvin cycle at different time

• open stromata at night and grab CO2

  • no light reaction = no O2 production = less change of photorespiration

• closes stromata during day and release high CO2