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Ch 9: Cellular Respiration and Ch 10: Photosynthesis - Coggle Diagram
Ch 9: Cellular Respiration and Ch 10: Photosynthesis
Catabolic Pathways
ATP Production
fermentation is a partial degradation of sugars that occurs without oxygen
fermentation must use alternate mechanisms to regenerate NAD+, like pyruvate
aerobic respiration is when oxygen is consumed as a reactant along with organic fuel
anaerobic respiration is using other substances other than oxygen as reactants
cellular respiration includes both aerobic and anaerobic processes
Oxidation and Reduction
redox reactions are chemical reactions involving the complete or partial transfer of one or more electrons from one reactant to another
oxidation is the loss of electrons from one substance
reduction is the addition of electrons to a substance
reducing agent is the electron donor in a redox reaction
oxidizing agent is the electron acceptor in a redox reaction
NAD+ and Electron Transport Chain
energy releases from fuel must be controlled, cells release energy from glucose gradually
glucose is broken down in a series of reaction where electrons are removed from glucose
H+ atoms are passed to electron carriers like NAD+
NAD+ becomes NADH when it gains electrons and protons
the electron transport chain is located in the inner mitochondrial membrane/plasma membrane and shuttles electrons down a series of redox reactions
Stages of Cellular Respiration
Glycolysis
glycolysis refers to sugar splitting, glucose a 6-carbon sugar is split into 2 3 carbon sugars
these smaller sugars are then oxidized and their remaining atoms rearranged to form two molecules of pyruvate
energy investment phase is where the cell actually spends ATP
during the pay off stage ATP is produced by substrate-level phosphorylation and is reduced to NADH by electrons released from the oxidation of glucose
the net energy from this process per glucose molecules is 2 ATP plus 2 NADH
Pyruvate Oxidation
pyruvate is first converted to a compound called acetyl coenzyme A, or acetyl CoA
pyruvate’s carboxyl group (-COO-), already somewhat oxidized and thus carrying little chemical energy, is now fully oxidized and given off as a molecule of CO2
the remaining two-carbon fragment is oxidized and the electrons transferred to NAD+ storing energy in the form of NADH
coenzyme A (CoA) is attached via its sulfur atom to the two-carbon intermediate, forming acetyl CoA
Oxidation Phosphorylation
4 ATP produced directly by substrate-level phosphorylation during glycolysis and the citric acid cycle to the many more molecules of ATP generated by oxidative phosphorylation
cytochromes are an iron-containing protein that is a component of electron transport chains in the mitochondria and chloroplasts
ATP synthase is the enzyme that makes ATP from ADP and inorganic phosphate, ATP synthase works like an ion pump running in reverse
chemiosmosis is energy stored in the form of a hydrogen ion gradient across a membrane is used to drive cellular work such as the synthesis of ATP
chemiosmosis is an energy-coupling mechanism that uses energy stored in the form of an gradient across a membrane to drive cellular work
Fermentation
alcohol fermentation is glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD-plus and releasing carbon dioxide
Fermentation consists of glycolysis plus reactions that regenerate NAD+ by transferring electrons from NADH to pyruvate or derivatives of pyruvate
lactic acid fermentation is glycolysis followed by the reduction of pyruvate to lactate, regenerating NAD plus with no release of carbon dioxide
obligate anaerobes, carry out only fermentation or anaerobic respiration
equation= C6H12 O2 +6CO2 +6H2O+ATP
Light Energy
Chloroplasts
all green parts of a plant have chloroplasts, but the leaves are the major sites of photosynthesis in most plants
they are found mainly in the cells of the mesophyll, the tissue in the interior of the leaf
stomata is a pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant
chlorophyll, the green pigment that gives leaves their color, resides in the thylakoid membranes of the chloroplast
Sunlight
wavelength is the distance between the crests of electromagnetic waves
the electromagnetic spectrum is the entire range of radiation
visible light is ranging in wavelength from about 380 nm to about 740 nm.
photons is when light behaves as though it consists of discrete particles
Light Receptors
substances that absorb visible light are known as pigments
if a pigment is illuminated with white light, the color we see is the color most reflected or transmitted by the pigment
spectrophometer is an instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution
absorption spectrum is a graph plotting a pigment’s light absorption versus wavelength
Photosynthesis
Light Dependent Reaction
occurs in the thylakoid membrane
requires continuous supply of light energy
H2O is converted into O2
light energy is converted into ATP and NADPH
Calvin Cycle
akes place in the stroma
does NOT require light
uses ATP and NADPH to make glucose
Carbon Fixation
1 molecule of CO2 combines with RUBP (5-carbon acceptor), this then makes a compound that then splits into 2 molecules of 3-PGA (made of 3 carbons
reaction is catalyzed by the enzyme rubisco
RUBP-ribulose 1, 5-Biphosphate; G3P- Glyceraldehyde-3-Phosphate
Reduction
ATP and NADPH are used to convert 3-PGA into G3P
each molecule of 3-PGA receives a phosphate from ATP to make a 3-carbon intermediate molecule
this intermediate molecule then receives 2 electrons from NADPH and loses one of its phosphate groups making G3P
equation= 6CO2 + 6H2O → C6H12O6 + 6O2