Energy definition= First law of thermodynamics = Energy is lost as heat with each conversion process

Photosynthesis converts the energy from the sun into ATP, which drives formation of simple sugars Cells metabolize the sugars to harness the energy for cellular work. Fig 6.3

ATP: Adenosine Triphosphate

= phosphorylation = Can be regenerated: Fig 5.7

How is ATP generated? Electron transfer chains:

Enzymes = catalysts (speed up chemical reactions) Lower the amount of energy required for a reaction to proceed. How they work: –Help substrates get together –Orient the substrates in position to favor the reaction

Fig 5.8

Fig 5.9

Photosynthesis - overview = Plants, algae (protists), cyanobacteria, phtyoplankton Plants are primary producers – produce organic molecules from CO 2 & H 2 O

Fig 7.3

Chloroplast anatomy Thylakoid membranes – Stroma –

Photosynthesis - overview 6CO 2 + 6H 2 0 C 6 H 12 O 6 + 6O 2 2 interdependent pathways: 1.Light reactions – 2.Calvin cycle – carbon fixation

Fig 7.4

Light What is light?? Wavelength = distance between peaks in wave Only visible light drives PSN: 380 to 750nm

Pigments = substances that absorb visible light Chlorophyll a – Accessory pigments – absorb light energy & transfer it to chlorophyll a –Chlorophyll b, carotenoids

Photosystems = Fig 7.9

Step of the light reactions 1.Photosystem absorbs light, splitting water into H+, electrons, and O 2. 2.Further light absorption by the photosystem kicks the electrons up to an excited state. 3.Excited electrons are passed along an electron transport chain (proteins in the thylakoid membrane) 4.Energy released at every step of electron transport used to drive ATP synthesis 5.Further light absorption by a second photosystem kicks the electrons up to another excited state, passing the electrons off to generate NADPH.

Fig 7.12

Fig 7.11

The Calvin Cycle =

Fig 7.14

Figs. 6.5&6.6

Fig 6.4

Aerobic Respiration = Summary equation: C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O 3 Steps: 1.Glycolysis

Steps 2 & 3 occur in the mitochondria

Fig. 6.7

2. Krebs cycle Electrons and protons (H + ) are released in the reactions & carried to step 3 by NAD + & FAD (coenzymes – electron carriers)

Fig 6.11.

3. Electron transfer chain & ATP formation NADH & FADH 2 transfer their electrons to series of trans-membrane proteins in the inner mitochondrial membrane

Fig 6.12

Fig 6.13

Anaerobic respiration (Fermentation) Bacteria, fungi living in O 2 -poor environments (wetlands) 2 steps: 1.Glycolysis –

Step 2: Lactic acid fermentation- Or Alcoholic fermentation –

Fig 6.15

Yeast