• Photosynthesis Vs Cellular Respiration
  
  
  Similarities
  ·         ATP is a key molecule in each
  ·         They both occur in organelles
  ·         G-3-P is formed in both processes- In Glycolysis (cell respiration) and in Calvin cycle (photosynthesis)
  ·         Both rely on movement of electrons for operation
  ·         Both use electron transport chains in production of ATP
  ·         Both use chemiosmosis to generate ATP
  
  
  
  
  Differences
  
  
  Photosynthesis
  • Needs light
  • Uses energy
  • Happens in the chloroplast
  • Reactants: Water + Carbon Dioxide
  • Products: Glucose + Oxygen
  • Processes: The light dependent reaction and  light independent reaction.
  • ATP Synthase: H+ gradient across thylakoid membrane into stroma. High H+ concentration in the thylakoid lumen
  • Final electron acceptor: oxygen
  • Electron source: Glucose, NADH+, FADH2
  VS
  
  
  Cellular Respiration
  • Does not need light
  • Produces energy
  • Happens in the mitochondria
  • Reactants: Glucose + Oxygen
  • Products: Water + Carbon Dioxide
  • Processes: Glycolysis: breaking down of sugars, Krebs Cycle: occurs in mitochondria; requires energy, Electron Transport Chain: converts O2 to water.
  • ATP Synthase: H+ proton gradient across the inner mitochondria membrane into matrix. High H+ concentration in the intermembrane space.
  • Final Electron acceptor: NADP+ (forms NADPH )
  • Electron Source: Oxidation H2O at PSII
  • Produces a net yield of 36 ATP
  
  
  
  

Photosynthesis

Photosynthesis Notes

PHOTOSYNTHESIS

Light-Dependent Reaction

1.Photosynthesis - the production of glucose and oxygen from carbon dioxide and water using light energy trapped by chlorophyll.

2.The process of Photosynthesis involves a lot of redox reactions. Redox = Reduction (Gain an electron) and Oxidation (Lose an electron).

3.PSII acquire electrons from water after it receives light energy from the sun. Photolysis is the process where the sun's energy is required to break apart water into hydrogen and oxygen. (680mm)

4.Electrons are passed on from PSII to PQ; PSII is oxidized and PQ is reduced.  PQ is a helper protein, assists B6F in opening a proton pump channel.

5.In PQ, a gate forms which allows the inflow of hydrogen.

6.Electrons move from PQ to b₆f; PQ is oxidized and b₆f is reduced. b₆f pumps protons across thylakoid membrane from stroma to the thylakoid lumen.

7.PS1 receives light energy (700mm) before it receives electrons from b6f; PSI is reduced and b6f is oxidized.

8.Electrons are passed on from PSI to Fd; PSI is oxidized and Fd is reduced. Electrons are transported from Fd to FNR; Fd is oxidized and FNR is reduced.

9.Electrons are passed on from FNR to NADP; FNR is oxidized and NADP is reduced. A hydrogen proton then bonds with NADP to form NADPH.

10.    Chemiosmosis -chemicals pass through a semi-permeable membrane from a high to low concentration gradient. This allows hydrogen to leave the structure. ADP (along with A) attaches to ATP synthase. After another phosphate joins this association, ATP is formed and hydrogen can exit the structure.

Light Independent Reaction

1.Calvin Cycle- the chemical process that helps to convert potential energy from ATP and NADPH into potential energy stored in glucose. (occurs in the stroma)

2. CO2 reacts with RUBP to form unstable 6 Cintermediate

3.The reaction of CO2 + RUBP is calatlyzed by the enzyme RuBP carboxylase – rubisco

4.  CO2 + RuBP => unstable 6 carbon intermediate 2 molecules of PGA (3 phosphoglycerate)

5.Converting PGA to Glyceraldehyde phosphate (G3P) requires the addition of energy released by ATP and NADPH – (this is the same ATP and NADPH that were just produced in the Light Dependent Reactions)

6. Glyceraldehyde 3 Phospate (G3P) 

◦ Can be used to produced glucose = Potential energy stored in chemical bonds of glucose 

◦ Can be used to make RUBP = Converting G3P to RUBP requires the input of energy from ATP (also created by the light dependent reactions)

7.   3 RuBP are catalyzed in a single Calvin cycle. 6 PGAs = 6 BPGs = 6 G3Ps. 

8.Through a series of reactions, 5 of the G3Ps formed are recycled to form RuBP to initiate another Calvin Cycle.

9.The last G3P leaves the cycle.

10. This means that it requires two cycles to create one glucose.

Pig Dissection

Fetal Pig Dissection

On April 27 and 28, our biology class had the opportunity to do a 2-day fetal pig dissection. The dissection helped the class to visually and interactively study the organs. 

Before Dissection

DAY 1

For the first part, we dissected the lower part of the pig which mainly consists the digestive and reproductive organs. Here is the list of organs that we found:

1. Liver - produces bile(a substance needed to digest fats) , filters and processes blood as it circulates the body.

2. Gallbladder (behind the liver) - store and concentrate bile

3. Stomach- temporary storage of food and liquids, production of digestive juices, emptying the mixture into the small intestine

4. Spleen- acts as a filter for blood as part of the immune system

5. Pancreas - secretes enzymes to small intestine to further break down food, produces the hormone insulin and glucagon to maintain the homeostasis of glucose levels.

6. Small Intestines- 90% of food digestion and absorption (nutrients and minerals).

7. Kidneys- extract waste from blood, form urine

8. Testis - the pig was a male after finding this scrotal sacs containing the testis which produces sperm and the hormone testosterone.

DAY 2
On the 2nd part of the dissection, we examined the upper part of the pig and we found these organs:

1. Heart- pumps blood through the body.

2. Lungs - bring oxygen to body and remove carbon dioxide

3. Trachea and Larynx- airways passages to the lungs

4. Thyroid - releases T3 and T4, hormones that are essential for body growth, metabolism and development.

For the last part, we attempted to examine the brain and the eyeball.

Cutting Skull

Brain- part of the central nervous system that controls the body, receives, analyzes and stores information.

Cutting Eyeball

Eyes- responsible for vision.

After Dissection

Additional Information:

Amniotic Fluid- clear, slightly yellowish fluid within the amniotic sac that surrounds the baby pig.