Download Unit 2 Test Review

SBI4U – Gr.12 University Biology
Mr. S. DeBoer
Unit 2 Test Review
Chapter 2: Cellular Respiration
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Difference between photoautotrophs, chemoautotrophs, heterotrophs
Difference between aerobic respiration and anaerobic respiration
Difference between obligate aerobes, facultative anaerobes, obligate anaerobes
Overall reaction of cellular respiration: Glucose + Oxygen  CO2 + H2O + ATP-energy
o Why is the above reaction misleading?
What is the difference between substrate-level phosphorylation of ATP and oxidative
phosphorylation of ATP? How does this connect to the stages of C.R.?
Know all the diagrams of the four stages of C.R.
Stage 1: Glycolysis
o Glucose  2 ATP’s used  2 phosphates put on  Converted to Fructose 
Split apart into 2 G3P’s  2 NADH’s produced from NAD+  4 ATP’s produced 
End with 2 Pyruvates
o Glycolysis occurs in the cytoplasm outside of the mitochondria
o Overall energy yield: 2 NADH and 2 ATP
Stage 2: Pyruvate Oxidation
o 2 Pyruvates enter the Mitochondria  CO2 is removed  NAD+ is reduced to
NADH  Coenzyme A is added  Results in 2 Acetyl CoA’s
o Overall energy yield: 2 NADH
Stage 3: The Kreb’s Cycle
o Acetyl CoA enters the cycle  Combined with Oxaloacetate  Forms Citric Acid
 Loses 2 CO2  3 NAD+ reduced to NADH  1 FAD reduced to FADH2 
carbon compound converted back to Oxaloacetate to receive another Acetyl CoA
o Occurs in the matrix of mitochondria
o Overall energy yield (per glucose): 6 NADH, 2 FADH2, 2ATP
Stage 4: Electron Transport Chain and Chemiosmosis
o NADH and FADH2 travel to the inner mitochondrial membrane and give up their
extra 2 electrons (which always travel in pairs) to the first (NADH) or second
(FADH2) protein embedded in the membrane. These electrons travel along all
the proteins in the ETC (in order of increasing electronegativity) from NADH
dehydrogenase  Ubiquinone  Cytochrome b-c1 Complex  Cytochrome c 
Cytochrome oxidase complex. Proteins 1,3 and 5 use the free energy from the
passing electrons to pump H+ ions into the intermembrane space. The final
electron acceptor at the end of the ETC is O2 which takes H+ ions and is
converted to H2O. The H+ gradient created is then used as an energy gradient to
assist the production of ATP via ATP synthase.
o Overall energy yield (per glucose): 32 ATP (theoretical)
You should also know the related pathways of energy production – how does the body
use other molecules, like proteins and lipids, to gain energy? How is this related to
Cellular Respiration?
SBI4U – Gr.12 University Biology
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Mr. S. DeBoer
Know ethanol and lactic acid fermentation and when and why they are used, and by
whom?
Chapter 3: Photosynthesis
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What is chlorophyll? What is a pigment molecule? What are some other pigments in
plant leaves? Why do the leaves change colour in the fall?
What are cyanobacteria, and how are they related to chloroplasts of eukaryotic cells?
What creatures are all able to perform photosynthesis?
How does the anatomical structure of leaves and stomata, and the process of
transpiration, aid photosynthesis?
Explain the structure of chloroplasts.
Know all the diagrams of the 3 stages of Photosynthesis.
Stage 1: Capture of light (Photoexcitation)
o Occurs in the thylakoid membrane inside the chloroplasts
o Energy from a photon of light hits Photosystem I or Photosystem II and the
energy is bounced around the various pigment molecules until reaching the
reaction centre, always a chlorophyll a molecule. This centre chlorophyll a
releases an excited electron to a primary electron acceptor, which passes the
excited electron on to the first electron transport chain of the thylakoid
membrane.
Stage 2: Electron Transport Chain and Chemiosmosis
o Excited electron is passed through the first series of embedded membrane
proteins Plastoquinone  Cytochrome b6-f Complex  Plastocyanin. Along the
way, the free energy from the moving electron is used to pump 4 H+ from
outside to inside the thylakoid, per 2 electrons (which travel in pairs always).
o Then the electron, now depleted of free energy, reaching Photosystem I which
gives it an energy boost by capturing another photon of light. The electron, reexcited, moves through Ferrodoxin to NADP reductase, which reduces NADP+ to
become NADPH.
o The electrons lost at the beginning (Photosystem II) are replenished by the
splitting of H2O at the Z-protein: 2H2O  4H+ + O2 + 4 eo The pumped H+ form an energy gradient, just like in C.R., and this is used to
assist the production of ATP via ATP synthase.
Stage 3: The Calvin Cycle
o Occurs in the stroma of the chloroplasts
o 3CO2 is taken in by stomata and added to 3RuBP via the enzyme Rubisco to form
6 PGA’s. 6ATP’s are used up to phosphorylate the PGA’s, and 6 NADPH’s are
oxidized to form NADP+, eventually creating 6 G3P’s. 5 of these are used to
resynthesize RuBP, while the 6th leaves the Calvin Cycle and is used to create
carbohydrates, primarily Glucose, Sucrose, and Starch (storage).
What advantage do C4 and CAM plants have over C3 plants? Why?
How does sun vs. shade effect plants with regards to photosynthesis?
Be able to compare and contrast the processes of photosynthesis and cellular
respiration.