Monday, March 2, 2015

Muscle Contraction

http://doctorprodigious.wordpress.com

Photosynthesis

http://youtu.be/g78utcLQrJ4


Chloroplasts: Site where it occurs in Eukaryotes.

Thylakoid Membrane: Where the light reaction occurs

Granum: Stack of Thykaloids

Stroma: liquid in chloroplasts between Thykaloids where the Calvin Cycle occurs.

2 STEPS:
  1. Light Reactions: In Thylakoid membrane.  Water & light produce NADPH, ATP & 02 (waste).
  2. Calvin Cycle (a.k.a. Dark Reactions): In the Stroma.  Energy transfers where CO2 enters and Glucose comes out.
Essentially, PSII, Cyt B6f and PSI take electrons from light and put it through an electron transport chain.  (Protons are pumped into the inside of the Thylakoid called the Lumen).  ATP Synthase finishes the proton pumping process to make ATP.  Then ATP leaves and goes in the Stroma to the Calvin Cycle.  Waste Product: O2

Calvin Cycle: 5C molecule RUBP combines with CO2 through the leaf stromata, breaks into 2 3C molecules.  ATP adds energy in G3P to make useable sugars (sucrose, glucose, fructose and etc).

Problem: Photorespiration: occurs when we do not have enough CO2.  O2 jumps in and uses RuBisCo and makes junk (bad in all C3 plants).

Hot environments, CAM plants (pineapple)--only open stomata at night to avoid water loss.  Store CO2 in malic acid & enters the Calvin Cycle as they need it.  Stomatas can be closed during the day.  C4 (i.e corn) plants make 4C Oxalate which then moves to the bundle sheath cells, introduce CO2 to enter the Calvin Cycle.  Don't have to wait for CO2 to fuse in.

Cellular Respiration

http://youtu.be/Gh2P5CmCC0M

Respiration: Breaks down food to make ATP or energy in the Mitochondria.  Requires oxygen.

Bacteria use their outer membrane.

Aerobic Respiration: Respiration  in the presence of Oxygen

Anaerobic Respiration: (Turbo button) Respiration without Oxygen and leaves lactic acid (pain).

Heterotrophs (Animals, Fungi): convert organic compounds (food) in the presence of Oxygen to create ATP (energy) & Carbon Dioxide (CO2).

Autotrophs (Plants, Algae): Converts Carbon Dioxide to Oxygen

3 STEPS:
  1. GLYCOLYSIS: (In cytoplasm) Glucose (6c) converted to Pyruvate (two 3C & 2ATP &NADH)
    1. Pyruvate diffuses into the Mitochondria where it is converted to acetyl CoA (2 C molecule to enter Krebs Cycle & gives off CO2).
  2. KREBS CYCLE: AcetyleCoA gives of 2 ATO & CO2.  Adds energy to NADH and FADH2. 
  3. ELECTRON TRANSPORT CHAIN: NADH and FADH2 transfer eletrons to this series of proteins to pump protons to the inner membrane space.  By products are combined here to produce water.  Produces 32 to 34 ATP in this last step.  ATP Synthase (in this ETC) : as every proton goes through, it converts ADP to ATP.
Anaerobic Problem: In Glycolysis, protons are given to NAD+  to make NADH  and uses up all the NAD+ so glycolysis breaks down and stops.

Solution:

Lactic Acid Fermentation: Glycolysis goes to form Pyruvate and then Lactate (which makes more NAD+ to recycle NADH).   This what builds up the toxin lactic acid.  O2 will remove it eventually.

Alcoholic Fermentation works the same, and makes Ethyl alcohol instead of Lactate.

Enzymes

https://www.youtube.com/watch?v=ok9esggzN18&list=TLyNRr49wGDQU

Enzymes: chemicals that speed up a reaction but are not consumed.  (It is a chemical catalyst that reduces the activation energy needed to start the reaction.)

Catalase: A protein enzyme that breaks down hydrogen peroxide in Eukaryokes.

Active Site: The part of the enzyme where substrates go into to let the reaction go.  (The hole in the key hole of the door).

Substrate: (The key to open the door of reaction).

Activation: Cofactors (inorganic i.e. Heme group {iron} in blood) & Coenzymes (organic, thymine/Vitamin B1--or other vitamins).

Inhibition: Competitive and Allosteric

Activation: adding something to an enzyme to make it work, or turned on by DNA regulation