Photosynthesis and Cellular Respiration Unit

what kind of reaction is the process of harvesting chemical energy

catabolic

energy flows into ecosystem through ______ and leaves as _______

photosynthesis/heat

fermentation

partial degradation of sugars without oxygen present

REDOX reactions

combination of reduction and oxidation in reaction

cellular respiration

process where glucose is broken down to create ATP

reducing agent

substance losing electrons

oxidizing agent

substance recieving electrons

reduced means having _______ potential energy why?

greater/bc gaining gained electrons bring their energy with them

4 stages of aerobic cellular respiration

• glycolysis

• pyruvate oxidation

• Kreb’s/citric acid cycle

• oxidative phosphorylation, ETC, and chemiosmosis

substrate-level phosphorylation

enzyme trasnfers phosphate group from substrate molecule to ADP instead of inorganic phosphate

in cellular respiration what happens to carbons

released as CO2

where does substrate level phosphorylation happen

as pyruvate is broken down to CO2

oxidative phosphorylation

NADH and FADH2 relay electrons extracted from food to ETC

cytochromes

electron carrier proteins that deliver electrons from ubiquinone to oxygen ho’s iron atom accepts donated electron

chemiosmosis

energy stored in hydrogen ion concentration gradient is released as they travel through membrane allowing for ATP synthesis

where does aerobic cellular respiration occur in prokaryotic organisms

cytoplasm or cell membrane

purpose of fermentation

rejuvenates NAD+ supply for glycolysis

facultative anaerobe

organisms that generate ATP with fermentation or respiration

what macromolecule provides the most energy and why

lipids/fatty acids because they provide acetyl CoA directly feeding the citric acid cycle

_______ stimulates cellular respiration and ______ inhibits it why

ADP/ATP/bc surplus of product (ATP) inhibits production through feedback inhibition

carbon fixation

initial incorporation of carbon into organic compounds

2 parts of photosynthesis

• light reactions

• calvin cycle

absorption spectrum

3 curves show the wavelengths of light best absorbed by three types of chloroplast pigments

action spectra

effectiveness of different wavelengths at providing energy for photosynthesis

what happens to chlorophyll when hit by light

chlorophyll absorbs photon of light and electron gets excited and jumps to a higher orbital providing higher potential energy

photosystem

reaction enter with light-harvesting complexes

light-harvesting complex

pigment molecules bound to proteins

reaction center

protein complex two special chlorophyll a molecules and a primary electron acceptor molecule

primary electron acceptor

molecule that receives the electron from a chlorophyll starting ETC

cyclic electron flow

electrons take path via only PSI cycling back from Fd to cytochrome complex and to chlorophyll (no NADPH or O2 release but ATP generated)

calvin cycle

anabolic process building sugars from small molecules and storing energy in bonds

carbon fixation

incorporation of CO2 by attachment to five carbon sugars that become unstable 6 carbon sugars and split to 2, 3 carbon sugars

reduction

3 carbon sugars recieve phosphate group from ATP and reduced by 2 electrons from NADPH storing more potential energy

regeneration

3 ATP used to rearrange 5 G3P into 3 RuBP

photorespiration

when not enough CO2 enzyme Rubisco combines 5c RuBP with O2 making 4c OAA and CO2

CAM plants

plants that open their stomata at night and close during day to consrve water and prevent the entrance of CO2/at night take up CO2 and incorporate into molecules

noncyclic electron flow in photosynthesis steps (8)

1. photon strikes chlorophyll exciting electron (PSII)

2. electron taken by primary electron acceptor

3. H2O broken via enzyme during photolysis releasing 2 electrons (replacing lost electrons in chlorophyll molecules) and O that combines with another O releasing O2

4. excited electron passes through PSII and PSI via ETC

5. electron fall produces energy from ATP synthesis

6. photon strikes chlorophyll exciting electron (PSI) and passing it on creating a hole that is filled by de-energized electrons that reach the end of first ETC

7. exciting electrons passed down second ETC through protein Fd

8. NADP+ reductase transfers electrons from Fd to NADP+ reducing to NADPH with 2 electrons

where does glycolysis occur

cytosol

what initial investment does glycolysis need

2 ATP

glycolysis flow chart

6c glucose → 2, 3c PGAL → 2, 3c pyruvate

net gain of ATP during glycolysis

2 ATP

pyruvate decarboxylation definition and flow chart as well as byproducts

process between glycolysis and Kreb’s cycle

3c pyruvate → 3c Acetyl + CoA → Acetyl CoA

CO2 and NAD+ → NADH

Kreb’s cycle/citric acid cycle location, flowchart, and byproducts

mitochondria matrix

2c Acetyl CoA + 4c oxaluacetic acid → 6c citric acid → 5c keto gluterate → 4c succinate → extra step → extra step → 4c oxaluacetic acid + →

CO2, NAD+ → NADH, ATP and FADH2

what happens to CoA

enzyme reused

location of Electron Transport System

inner mitochondrial membrane

oxylated phosphorylation

ADP+P→ATP

fermentation flowchart and byproducts

glycolysis → pyruvate → 2c acetyldehyde (or just 2 lactate) → reduced to ethanol

| _________________/

NADH → NAD+ + electron/

CO2, ADP→ATP

photosynthesis equation and where it is taken up or released

6CO2+6H2O→C6H12O6+6O2

CO2 through stomata to leaves

H2O through roots through xylem tissue

C6H12O6 moved by phloem tissue

O2 released through stomata

central atom in chlorophyll

Magnesium (Mg)

primary pigment

chlorophyll a

accessory pigments

absorb different light and transfer energy to chlorophyll a

examples of accessory pigments

chlorphyll b

carotenoids

phycobilins

xanthophyll

2 photosynthesis steps

light dependent reaction and light independent reaction (Calvin Cycle)

light dependent reaction

converts light energy to ATP and NADH

Calvin Cycle/Light Independent Reaction

energy from ATP and NADPH to PGAL and NADH

label

non-cyclic phosphorylation

normal photosynthesis with 2 PS

PSII→ETC(Qui,Cyt,Pc)→PSI→ETC(Fd, FNR)→NADPH

cyclic phosphorylation

when NADPH not produced due to lack of NADP+ electrons at the end of ETCI get sent back through maintaining H+ ion gradient and continuing ATP synthesis

PSI→ETC(Qui, Cyt, Pc)→PSII

label chloroplast

label thylakoid

photosystem

proteins that have chlorophyll embedded to allow for light absorption

enzyme complex

enzyme on PSII that uses light energy to split H2O into 2H+ 2electrons and O

H+ increases concentration

2electron go into PSII to replace excited electrons

O combined with O and released as O2

photolysis

light energy used to split H2O

photosynthesis steps (6)

1. PSII chlorophyll absorbs light and electrons in lipid head get excited and jump to protein in ETC 1 that pulls H+ into lumen

2. electron jumps to next protein pulling H+ into lumen

3. electron loses enery as it jumps

4. at PSI light absorbed and electrons excited and jump into ETC 2

5. electron reaches FnR (ferredoxin NADP reductase) which combines NADP with the electrons and to balance out takes up H+ making NADPH

6. electrons that travel down ETC 2 replaced with low energy electrons from PSII traveling down ETC 1

chemiosmosis

H+ ion concentration gradient causes H+ move down ATP synthase allowing for ADP+P→ATP

photophosphorylation

light energy used to add phosphate group to ADP making ATP

why do ETC proteins pull in H+

electrons from photosystems make proteins slightly negatively charged attracting positively charged H+ when electrons move one the H+ is released on the opposite side of the protein

which electrons replace electrons in PSI

low charge electrons from ETC 1

ETC 2 components

ferredoxin and ferredoxin NADP reductase

calvin cycle/light independent reaction

process occurs in stroma using CO2, ATP, and NADPH producing PGAL and then glucose

3 steps of calvin cycle

carbon fixation, reduction, regeneration

carbon fixation flow chart

5c molecule RuBP + 3 Rubisco carboxylase + 3 1c CO2 → 3 6c unstable intermediate → 6 3c PGA

reduction flow chart

6 3c PGA → 6 3c PGAL

NADPH → NADP+

regeneration

6 3c PGAL → 5 3c PGAL → ATP and 3 5c RuBP

1 3c PGAL → glucose

C3 plants

usual carbon fixation

C4 plants

additional step PEPcarboxylation in addition to usual carbon fixation

PEPcarboxylation and flow chart

done by pepcarboxylase

3c PEP + CO2 → 4c OAA → 4c malate

where is PEPcarboxylation done

in mesophyl cells

CAM plants

make crassulacean acid and break down for CO2

temporal separation of carbon fixation

stomata open during night

chemiosynthesis

H2S and H2O is broken down (alternate pathway to make organic molecules)

aerobe

needs O2

Anaerobe

no need for O2

facultative

can survive for shrot period of exposure

obligate

need to exposed at all time

what kind of molecule is pyruvate

acid

cellular respiration step by step (14)

1. in cytosol 6c glucose is broken down to 2 3c PGAL with the help of 2 ATP molecules

2. as 3c PGAL is oxidized to 3c pyruvate NAD+ picks up the electron and makes NADH and 2 ATP are produced with the excess energy from the oxidation (glycolysis)

3. 3c pyruvate moved to mitochondria matrix

4. enzyme pyruvate dehydrogenase complex removes a carbon from 3c pyruvate and it is released as CO2 and NAD+ is reduced to NADH

5. the 2c Acetyl product is combined with Coenzyme A creating Acetyl CoA (pyruvate decarboxylation)

6. 2c Acetyl CoA is combined with 4c OAA making 6c Citric Acid

7. CoA leaves to be reused with Acetyl in pyruvate decarboxylation

8. 6c Citric Acid oxidized to 5c ketoglutarate with 1 carbon released as CO2 and NAD+ reduced to NADH

9. 5c ketogluterate oxdized to 4c succinate with 1 carbon released as CO2 and NAD+ reduced to NADH

10. 4c succinate is oxidized to make 4c OAA which is used again combining with 2c acetyl reducing FAD to FADH2 and phosphorylating ADP to ATP (Kreb’s cycle)

11. electrons from FADH2 and NADH travel down ETC in the inner mitochondrial membrane

12. FAD and NAD+ go back to Kreb’s cycle

13. as electrons travel H+ pumped into intermembrane space (ETC)

14. due to gradient H+ pass through ATP synthase generating ATP (chemiosmosis)