Test3 Chap 10

• self-feeders
• sustain themselves without eating anything derived from other living beings.
• produce their organic molecules from CO2 and other inorganic raw materials obtained from the environment.

• obtain their organic material by the second major mode of nutrition - “other-feeding”
• Almost all heterotrophs, including humans, are completelydependent, either directly or indirectly, on photoautotrophs for food, O2, by product of photosynthesis

• the tissue in the interior of the leaf where chloroplasts are found
• mesophyll cell has 30 -40 chloroplasts

pores where Carbon dioxide enters the leaf, and oxygen exits

dense fluid inside envelope of 2 membranes

• made up of sacs, suspended in stroma
• grana- stack of thylakoids

the green pigment that gives leaves their color, resides in the thylakoid membranes of the chloroplast.

• 6 CO2  + 12 H2O + Light energy → C6H12O6 +  6 O2 + 6 H2O
• 6 CO2  6 H2O  Light energy → C6H12O6  6 O2

• reverse of cellular respiration
• 2 steps: Light Reaction & Calcin Cycle

• The Splitting of Water:
• The chloroplast splits water into hydrogen and oxygen.
• van Niel hypothesized that plants split H2O as a source of electrons from hydrogen atoms, releasing O2 as a by-product.
• Light carries  electrons across to ATP synthase(energy boost)
• NADPH, a source of electrons as “reducing power” that can be passed along to an electron acceptor, reducing it, and ATP are produced

• endergonic
• electrons increase in potential energy as they move from water to sugar

• acceptor of the electrons and hydrogen ions from water by light
• 1 more phosphate group than NAP+
• use solar power to reduce NADP+ to NADPH by adding a pair of electrons alongwith an H+.

light reactions also generate ATP, using chemiosmosis to power the addition of a phosphate group to ADP

• Take place in Thylakoid
• The Splitting of Water:
• The chloroplast splits water into hydrogen and oxygen.
• van Niel hypothesized that plants split H2O as a source of electrons from hydrogen atoms, releasing O2 as a by-product.
• Light carries  electrons across to ATP synthase(energy boost)
• NADPH, a source of electrons as “reducingpower” that can be passed along to an electron acceptor, reducing it, and ATP are produced

carbon fixation - carbon into organic reducesthe fixed carbon to carbohydrate by the addition ofelectrons with help  of the NADPH and ATP produced by the light reactions.

• Energy(NADPH + ATP) + CO2 -> Glucose
• Take place in Stroma

• electromagnetic spectrum - a nanometer (for gamma rays) to more than a kilometer (forradio waves)
• visible light - 380 nmto 750 nm in wavelength
• Photons - act like objects in that each of them has a fixed quantity of energy
• GXUIMR- (VPBGYR)

• light-harvesting complex : consists of various pigment molecules (which may include chlorophyll a,chlorophyll b, and carotenoids) bound to proteins.
• Absorb light energy by chlorophyl a
• PS II - 680nm
• PS I - 700nm

flow of electrons through the photosystems and other molecularcomponents

• - happens in Calvin Cycle
• -Only ATP is produced
• - NO NADPH or O2

• Carbon Fixation
• Reduction
• Regerneration of CO2
• Produce PGAL (Phosphoglyveralderyde) / G3P(Glyceraldhyde 3 Phosphate)

(Rubisco) : attach ribulose bisphosphate(Rubp) to CO2 -> split to 2 PGAL (3 C)

3PGAL + P(From ATP) -> 1.3 biphosphoglycerate (G3P) _> Glucose

five molecules of G3P are rearranged by the last steps ofthe Calvin cycle into three molecules of RuBP

Calvin cycle consumes total of 9 ATP nad 6 NADPH

• rubisco adds O2 to the Calvin cycle instead of CO2. Peroxisomes and mitochondria rearrange and split this compound, releasing CO2
• produce no ATP but consumes it

mesophyll cells: enzyme PEP add CO2 to PEP -> CO2 -> 4 carbon group -> bundle sheath cell -> CO2 release  -> Calvin Cyc;e

• Ex: Pineapple
• open their stomata during the night  to take CO2 and close them during the day, just the reverse of how other plants behave
• CAM, C4, andC3 plants all eventually use the Calvin cycle to make sugarfrom carbon dioxide.