Cellular Respiration: Krebs Cycle, Electron Transport, and Fermentation
Krebs Cycle
The Krebs cycle is the common pathway in all aerobic cells for the complete oxidation of carbohydrates, fats, and proteins. It can also be the starting point of biosynthetic reactions. This is because there are intermediate metabolites, which may go to the cytosol and act as anabolic precursors. In this sense, we say that the Krebs cycle is amphibolic. The process involves the complete oxidation of acetyl-CoA, which is excreted as carbon dioxide. The e-/H+ obtained in the successive oxidations
Read MoreSmooth Muscle, Striated Muscle, and Heart Function
Smooth Muscle Cells
Smooth muscle cells are the simplest of the three muscle types.
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Aspect
- Smooth muscle cells are fusiform, elongated, with sharp ends and an enlarged central portion with an elongated nucleus.
- Most are 5-20 µm in diameter (and up to 200 µm in the gravid uterus), and their length can vary between 20 µm and 1 mm or more (e.g., in the gravid uterus).
- These descriptions are of isolated cells, as they usually form narrow beams and homogenous bundles, making it difficult to see their
Photosynthesis and Cellular Respiration: Mechanisms and Structures
Electron Carriers in the Photosynthetic Electron Transport Chain
The electron carriers involved in the electron transport of the photosynthetic system (Photosynthetic Electron Transport Chain) are:
- Plastoquinone (PQ)
- Functions as a mobile electron carrier between Photosystem II (PSII) and the Cytochrome b6f complex.
- Cytochrome b6f complex
- A multi-subunit protein complex that facilitates electron transfer from Plastoquinone to Plastocyanin and contributes to the proton gradient.
- Plastocyanin (PC)
- A copper-
Human Circulatory and Excretory Systems: Function and Health
1. The Internal Environment
The internal environment is the set of extracellular fluid found inside an organism. In humans, the internal environment is composed mainly of interstitial plasma and circulating fluids: blood and lymph.
- Interstitial Plasma: Originates from the blood that has been filtered through the thin walls of capillaries.
- Lymph: A liquid that forms from interstitial plasma circulating through the lymph vessels.
2. The Blood Circulatory System
Blood Vessels
- Arteries: Carry blood from the
RNA: Structure, Function, and Types in Protein Synthesis
Ribonucleic Acid (RNA)
Ribonucleic acid (RNA) is a nucleic acid comprising a chain of ribonucleotides. It is present both in prokaryotes and eukaryotes and is the only genetic material of certain viruses (virus RNA). The cellular RNA is linear and single-stranded, but in the genome of some viruses, it is double-stranded.
Cellular organisms use RNA in different roles. The molecule directs the intermediate stages of protein synthesis. DNA cannot act alone, and RNA is used to transfer this vital information
Read MoreCellular Processes and Biological Kingdoms: An In-Depth Look
Photosynthesis: How Plants Make Food
Photosynthesis is the process by which plants make their own food. It is based on the ability of plants to transform the sun’s energy into chemical energy stored in the bonds of certain molecules. Through this process, different lifestyles we see on Earth are possible. This process takes place in beings that have the pigment chlorophyll, located in specific cell organelles. The keepers of chlorophyll are green vegetables and some bacteria. In green plants, the
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