Cellular respiration inputs and outputs chart

Cellular respiration inputs and outputs chart

Cellular respiration and the mighty mitochondria

Pyruvate molecules formed at the end of glycolysis are transported into mitochondria, which are sites of cellular respiration, in eukaryotic cells. Aerobic respiration can proceed if oxygen is sufficient. Pyruvate is converted to a two-carbon acetyl group in mitochondria (by removing a molecule of CO2), which is picked up by a carrier compound called coenzyme A (CoA), which is made from vitamin B5. Acetyl CoA is the result of this reaction. (See Example 4.17). The cell can use acetyl CoA in a number of ways, but its primary function is to transport the acetyl group derived from pyruvate to the next step in the glucose catabolism pathway.
In eukaryotic cells, the citric acid cycle, like the conversion of pyruvate to acetyl CoA, occurs in the mitochondrial matrix. The citric acid cycle, unlike glycolysis, is a closed system: The pathway’s final step regenerates the compound that was used in the first step. The cycle’s eight steps are a series of chemical reactions that result in the production of two carbon dioxide molecules, one ATP molecule (or an equivalent), and reduced forms (NADH and FADH2) of NAD+ and FAD+, which are essential coenzymes in the cell. Since the NADH and FADH2 formed must transfer their electrons to the next pathway in the system, which will use oxygen, this is called an aerobic pathway (oxygen-requiring). This transition does not take place if oxygen is not available.

Glycolysis trick – how to remember glycolysis

We discussed the various types of nutrients your body requires and how it breaks them down into chemical components that your body can use in Part 1 of our Energy & Metabolism overview. Now it’s time to explore how the body uses glucose to produce ATP, one of biology’s most essential molecules.
Now comes the fun part, if you were following the arcade metaphor from the previous paragraph. You’ve broken down the $20 (polysaccharide) into a bunch of $1 bills (glucose), and you’re ready to get your hands on some gleaming gold tokens to play games with!
Despite appearances, glucose is not energy in and of itself. Glucose energy is passed to a molecule known as ATP (adenosine triphosphate). When it comes to powering your cells’ functions, ATP is the real deal—the it’s arcade token you’ll need to play skee-ball, Tetris, or Pacman. The accumulated energy is released as ATP is broken down into ADP.
ATP is involved in muscle contraction, nerve impulse propagation, ion and molecule transfer through cell membranes, and a number of anabolic reactions including protein and lipid assembly in your body. Even to make more ATP, you need ATP.

Photosynthesis and the teeny tiny pigment pancakes


Photosynthesis inputs and outputs

The Krebs cycle, also known as the tricarboxylic acid (TCA) cycle or the citric acid cycle, is a sequence of chemical reactions that produces energy by oxidizing acetate.

Photosynthesis and respiration

Hans Krebs, who was responsible for elucidating the majority of the pathway, discovered it in 1937.

How to remember glycolysis in 5 minutes ? easy glycolysis

In eukaryotic cells, this process takes place in the matrix of the mitochondrion.

Krebs cylcle trick how to remember krebs cycle forever

This reaction takes place in the cytosol of prokaryotic cells, with the proton gradient for ATP production occurring through the cell’s surface (plasma membrane) rather than the mitochondrion’s inner membrane.

Photosynthesis vs. cellular respiration comparison

Two ATP are generated for this step of cellular respiration since one ATP is produced per turn of the cycle (two cycles total).

Photosynthesis: crash course biology #8

(To reflect the Krebs cycle’s total output for each glucose molecule that undergoes glycolysis, inputs and outputs were multiplied by two.)
As acetyl-CoA (2-carbon molecule) and oxaloacetate (4-carbon molecule) combine to form citrate, the Krebs cycle starts (6-carbon molecule).
Citrate is first converted to cis-aconitate, which is then converted to isocitrate.
One of the carbon atoms breaks off and is released as CO2 after this step.
At this point in the cycle, a NAD+ molecule is also reduced to NADH (as the isocitrate dehydrogenase enzyme is active).
We lose another carbon atom in the form of CO2 as alpha-ketoglutarate (5-carbon molecule) is formed, and another NADH molecule is made, this time in the presence of the alpha-ketoglutarate dehydrogenase complex (multiple enzymes present).

Cellular respiration inputs & outputs

The cytoplasm of the cell is where anaerobic respiration or glycolysis takes place. It does not need any oxygen, as the name implies. We break glucose into two smaller molecules called pyruvate at this stage. We gain two ATP molecules and two NADH molecules as a result of this process.
This is the point at which cellular respiration begins. When oxygen is present in the cells, pyruvate molecules join the mitochondria, where they begin a long chain of reactions that produces 34-36 ATP molecules. Although this may seem like a lot, cellular respiration is actually a very inefficient process as compared to the two produced by glycolysis. During these reactions, 60 percent of the energy contained in glucose is lost as heat.
When we follow pyruvate into the mitochondrial matrix, a small Co-enzyme called CoA binds to the pyruvate molecule, converting it to Acetyl Co-A. The extra energy released by the molecule is absorbed by a NAD+ molecule, which converts it to NADH.
The kerb cycle and glycoloysis have been leading up to this stage. At this stage, we combine the 10 NADH and 2 FADH molecules to make 32 ATP molecules. This happens in the folds of the mitochondrial membrane (Cristae).