review for photosynthesis

Since we have already done photosynthesis, and our test  is upcoming,  i  find those information pretty much useful for us to review, hopefully what i have posted could be helpful for us. Anyways, let me talk about what i have found.


So basically Photosynthesis is the process of converting light energy to chemical energy. This process occurs in plants and some algae. Plants use light energy, CO₂, and H₂O to make sugar. This process takes place in the chloroplasts of the leaves.

the photosythesis are composed of two major parts, the Light Reactions and the Calvin Cycle Reactions which is also known as the dark reaction.

Light Reactions

The energy from the sun is captured by photosynthetic pigments of the chloroplast and is transferred along a series of proteins and iron-sulfur containing compounds along the thylakoid membranes of the chloroplast; the net result is the formation of high-energy compounds such as ATP and NADPH. Water molecules are split during the transfer of light energy along the membranes. Oxgyen is produced as a result of this water-splitting event.

Calvin Cycle Reactions
In the reactions of the Calvin Cycle, chemical energy held within ATP and NADPH are used to convert carbon dioxide into sugars through a series of enzymatic reactions. In the initial step of the Calvin Cycle, carbon dioxide reacts with a five-carbon compound, ribulose bisphosphate (RuBP), in a reaction that is catalyzed by the enzyme RuBP carboxylase/oxygenase ("RuBisco"). The first stable product of this reaction is a three-carbon compound known as phosphoglycerate (PGA). Energy captured in the light reactions in form of ATP and NADPH is used to convert PGA into glyceraldehyde 3-phosphate (G3P) which can be converted to other organic compounds, or using energy from ATP, some is converted into RuBP to continue the cycle. The Calvin cycle reactions occur in the stroma of the chloroplasts.

hopefully this would be helpful for us.

review for cellular respiration

It has been a while for me to write my blog,every time there is something busy for me to do when i was trying to write my blog, anyways, so here it is, i'm gonna breifly talk about the cellular respiration which i leant in my class, also is also an important opportunity for me to review for the coming test.

Cellular respiration is the process by which the chemical energy of "food" molecules is released and partially captured in the form of ATP.

We can divide cellular respiration into three metabolic processes: glycolysis, the Krebs cycle, and oxidative phosphorylation. Each of these occurs in a specific region of the cell.

1. Glycolysis occurs in the cytosol.
2. The Krebs cycle takes place in the matrix of the mitochondria.
3. Oxidative phosphorylation and the electon transport chain is carried out on the inner mitochondrial membrane.

In the absence of oxygen, respiration consists of two metabolic pathways: glycolysis and fermentation. Both of these occur in the cytosol.

 

 

 

 

 

 

 

 

 

In glycolysis, the 6-carbon sugar, glucose, is broken down into two molecules of a 3-carbon molecule called pyruvate. This change is accompanied by a net gain of 2 ATP molecules and 2 NADH molecules.

 

 

 

 

The Krebs cycle occurs in the mitochondrial matrix and produce the largest amount of energy among cellular respiration.Pyruvate is transported into the mitochondria and loses carbon dioxide to form acetyl-CoA, a 2-carbon molecule. When acetyl-CoA is oxidized to carbon dioxide in the Krebs cycle, chemical energy is released and captured in the form of NADH, FADH₂, and ATP.

 

 

The electron transport chain (ETC) consists of a series of molecules, mostly proteins, embedded in the inner mitochondrial membrane. It allows the release of the large amount of chemical energy stored in reduced NAD⁺ (NADH) and reduced FAD (FADH₂). The energy released is  in the form of ATP.