So, genetically the cross from the pea plants is as follows:

P     AA   X    aa

F1    All of the plants are Aa.  So the cross for the F2 generation is Aa   X    Aa


F2   Punnet Square   

     A          a

A  AA     Aa

a   Aa     aa


Which yields a 3:1 Ratio   Tall:Dwarf.



TERMS

GENE- A location on a DNA molecule that codes for a General Trait (Plant Height Gene)
ALLELES - Different forms of the same gene.   (A and a)
PHENOTYPE - the "physical appearance" of an organism. (Tall and Dwarf)
GENOTYPE - the genetic makeup of an organism.  3 basic ones:
1. HOMOZYGOUS DOMINANT - when both alleles are dominant (AA)
2. HOMOZYGOUS RECESSIVE - when both alleles are recessive (aa)
3. HETEROZYGOUS - the alleles in a pair are different.  (Aa)

Product law- the provavility of 2, or more, independant events occurring together, is the product of each of those events occurring alon.

Sum law- When there is more than 1 combination of ways for an event to occur, the probability is the sum of those ways.

Is there only 1 way for this to happen?
Yes-Multiply
No- I.O. of all the combos- multiply each one-Add the combos together

I. The Monohybrid Cross
Parental (P)               true-breeding tall blant  x   true-breeding dwarf


1st Filial(F1)   All Tall       Tall  x  Tall


2nd Filial(F2)                        Tall: Dwarf   3:1 (75%) (25%)
( Interbreeding of f1's)


Key
A=Tall
a= Dwarf

A+a
Aa* Aa

October 16, 2012 AP Bio Notes

(Heads up! Qu-est: Oct. 23, 2012)

Step by step through Electron Transport Chain CONTINUED...

        3. The 3 Protein Complexes use the power of the electrons to pump protons into the INTER MEMBRANE SPACE creating a Proton Gradient. The Protons diffuse back through ATP SYNTHASE to power the synthesis of 32 more ATP's.
                 *(0 NADH, 0 FADH2, 36 ATP, 6 CO2, 6 H20)

The electrons bond w/ protons to O2 forming H20.
                 4e- + 4H+ + 02 => 2 H20 
Without O2 as an electron acceptor, everything that happens in a MITOCHONDRIA stops. 

II. Anaerobic Respiration: Respiration in the absence of 02

    A. Other electron acceptors used by bacteria.
        1. Methanogens: use CO2 as their terminal electron acceptor (TEA) and give off Methane (CH4)
        2. Sulfur Bacteria: use SO4 as their TEA and give off H2S (Hydrogen Sulfide)

    B. Fermentation: cycle glycolysis in order to keep making 2 ATP's per glucose.
        In order for this to happen: a cell must regenerate NAD because when NAD runs out, the reactions that recover the 2 lost ATP's and then add 2 more, cannot happen.
        1. Lactic Acid Fermentation: happens when eukaryotic cells run out of oxygen. Our cells convert pyruvate into lactic acid and this step regenerates NAD+. 
        2. Alcohol Fermentation: yeasts. When they run out of O2, convert Pyruvate to Acetaldehyde (losing a Co2) and then they reduce it to Ethanol regenerating NAD+.
                 (example: Beer)


 

October 15

     B. Pyruvate Oxidation
               1.  Pyruvate enters the mitochondria into the Inter-membrane Space.
               2. It is then converted into Acetyl Co-A.  This strips off a carbon and it leaves as C02 and two electrons leave and bond to NADH. (4 NADH, 2 ATP, 2 CO2)
     C. The Krebs Cycle
              1. Acetyl CoA enters the Mitochondria matrix. This chemical bonds to a four carbon starter, to make a six carbon product.
              2. The six carbon compound breaks down into a 5 carbon compound and CO2 and this also generates a NADH. (6 NADH, 2 ATP, 4 CO2) TWO OF EVERYTHING IS HAPPENING BECAUSE WE STARTED WITH A GLUCOSE
             3. The five carbon compound is broken down into a four carbon and CO2. An ATP is generated and another NADH. (8 NADH 4ATP 6 CO2)
            4.  Four Carbon molecule is now oxidized further, into the starting material.  This yeilds one more NADH and on FADH2.  (10 NADH, 2 FADH2, 4 ATP, 6 CO2)
                                 2e + 2 H + FAD---------->FADH2
     D. The Electron Transport Chain-Series of Cytochrome embedded in the Inner Mitochondrial membrane that contain three protein complexes I, II, and III that act as proton pumps.
             1. NADH donates its electrons to PC I (Protein Complex I) and their energy is used to pump protons from the Mitochondrial Matrix into the Inter-Membrane Space.  They continue on to PC II and PC III which do the same.
             2. FADH2 donates its electrons to PC II and PC III.
             3. This creates a proton gradient where protons flow back through ATP Synthase, to make approximately 32 more ATP from 1 Glucose. (0 NADH, 0 FADH2, 36 ATP, 6 CO2, 6 H2O )
           4. The electrons are "accepted" by O2 and H20 is the product.
                      4H + 4e + O2---------->2H2O

Cellular Respiration:

Cellular respiration: the harvesting of energy from the breakdown of organic molecules produced by plants (glucose)
Overall Process-
Glucose + Oxygen--(energy is given off to form 36 ATP)-- Carbon Dioxide + Water 
C6H12O6 + 6O2--(energy)--- 6CO2 + 6H2O
2 Stages to Cell Respiration-
A. Glycolysis- The beginning stages of the breakdown of glucose
     -Occurs in the Cytoplasm
     1. Glucose is phosphorylated- requires 2 ATP's (-2 ATP)
          -Changes glucose into Fructose
     2. Fructose is broken down into 2 3-C molecules, then each of these molecules is broken down into                  Pyruvates
          - 2 electrons are given off of each
          - 2 ATP's formed from each
          -Net yield of energy from glycolysis
          - requires NO oxygen to perform
         

10/8/12

VII. Photorespiration- BAD. When plant cells close their stomata and the result is that CO2 can't get in, O2 can't get out, and O2 is "fixed" into the Calvin Cycle, not CO2. No Glucose, cell and eventually plant death is the result.
Plants that live in hot, dry conditions have developed C4 Photosynthesis- when CO2 is fixed onto a 4- Carbon compound. 2 types:
     A. C4 Plants- take in CO2 opportunistically into Mesophyll cells, where it is fixed onto a 4- Carbon compound. This 4- Carbon compound is moved into a bundle-sheath cell where it gives off its CO2 to the Calvin Cycle. Concentrates glucose only in these cells. Examples: sugarcane, corn
     B. CAM Plants-(cactus, pineapple) Open their stomata at night and store it in a C4 compound and then strip the CO2 off of it when needed and the CO2 enters the Calvin Cycle. All this happens in Mesophyll cells.

C3 Photosynthesis 10/5/12

*Got grade reports and have them signed by 10/8/12

VII. Other types of Photosynthesis.
Most plants are C3 plants

(Note: If a plant cell ONLY wants to make ATP, it can recycle the electrons that have used their energy to pump protons back to PS II. This is called Cyclic Photophosphorylation)

F. The energy depleted electrons now reach Photosystem I (PS I). PS I boosts the energy level in the electrons even higher and they are passed down a 2nd electron transport chain (also made of cytochromes) and eventually make their way onto NADPH (accepts electrons).

 




Equation: (NADP+) + (H+) + (2e-) = NADPH
(2 excited electrons)

VII. Light Independent Reactions-The Calvin Cycle-building Glucose. Also known as C3 Photosynthesis. Happens in the stroma of the chloroplasts (inside outer membrane, outside of the thylakoid)

Takes six turns of the cycle to make one molecule of glucose