Cellular Respiration: Krebs Cycle, Electron Transport Chain
Krebs Cycle
The Krebs cycle is the oxidation of the acetyl group of acetyl-CoA to CO2, while reducing NAD and FAD. These reduced coenzymes are subsequently reoxidized by the respiratory chain, generating ATP. It consists of a series of eight enzymatically catalyzed reactions that occur in the mitochondrial matrix:
- Acetyl-CoA condenses with oxaloacetate to yield citrate, a tricarboxylic acid.
- Citrate is converted to isocitrate.
- Oxidative decarboxylation of isocitrate yields alpha-ketoglutarate, forming
Cell Biology: Discoveries, Theory, and Cell Types
Key Discoveries in Cell Biology
Robert Brown’s Contribution
What was the contribution of Robert Brown?
He discovered the cell nucleus through his studies of plant cells by staining the cells.
Johannes Purkinje’s Contribution
What was the contribution of Johannes Purkinje?
He identified the viscous substance (protoplasm) within cells where cell components could move.
The Cell Theory
Scientists Who Established the Cell Theory
- Scheiden Mathias (botanist): All plants are composed of plant cells.
- Schwann Theodor
Proteins, Enzymes, and Nucleic Acids
Proteins
Proteins are organic compounds composed of C, H, O, N, and S. They are large polymers made of smaller units called amino acids, which are joined by peptide bonds. The union of 1 to 12 amino acids gives rise to an oligopeptide, 12-100 forms a polypeptide, and more than 100, or if their molecular weight exceeds 5000 g/mol, constitutes a protein.
Biological Importance: Proteins are the most abundant organic compounds in cells. Their importance lies in the enormous quantity of functions they
Read MoreBacterial Cell Structures: Morphology and Functions
Living Preparations
Wet Mount
- Add a drop of the culture, and cover it with a glass slide.
- Benefits:
- It’s fast.
- Cells are alive, and you can see them in their natural shape.
- Can examine their behavior.
- Disadvantages:
- Hard to detect cells/characteristics.
- Covering the glass can damage larger cells, contaminate the observer’s fingers, dry out, and also become anoxic.
Staining
- Increases contrast and sometimes size.
- Before staining, we must let it dry and fix it. That way, the sample does not get washed off.
- Positive
Minerals, States of Matter, Kingdoms, and Species
Minerals, Liquids, Solids, Mixtures and More
Mineral: A naturally occurring substance, solid, that stems from a formula according to a predetermined chemical composition and specific conditions of pressure and temperature.
Mohs Scale:
- Talc
- Gypsum
- Calcite
- Fluorite
- Apatite
- Orthoclase
- Quartz
- Topaz
- Corundum
- Diamond
Liquids: They are easier to manipulate than gases. It’s easy to transfer them from one container to another. They don’t have their own form; they take the form of the container that contains them. Their
Read MoreEmbryonic Body Cavity Development
Body Cavities, Mesentery, and Diaphragm
The Embryonic Body Cavity
The intraembryonic coelom becomes the embryonic body cavity, which gives rise to three coelomic body cavities during Week 4:
- Pericardial cavity
- Two pericardioperitoneal canals
- Peritoneal cavity
These cavities are lined with mesothelium: a parietal wall and a visceral wall covered with mesothelium. The peritoneal cavity is connected to the extraembryonic coelom at the navel. The pericardial cavity opens to the pericardial-peritoneal canals.
Read More