DNA Structure, Function, and Amino Acid Properties
DNA: Structure and Function
DNA is a linear polymer composed of a pentose, a phosphate, and a nitrogenous base, which can be A, T, C, or G.
Primary Structure
The primary structure is the sequence of nucleotides linked by phosphodiester bonds. These links are established between the phosphate radical located in the 5′ carbon of one nucleotide and the OH radical in the 3′ carbon of the next nucleotide. A DNA strand has two free ends: the 5′ phosphate and the 3′ attached to a hydroxyl. These chains of
Read MoreHuman Genome: Understanding DNA, GMOs, and Genetic Diseases
Universal Statement on the Human Genome and Human Rights
The human genome is the basis of the fundamental unity of all members of the human family and the recognition of their inherent dignity and diversity. In a symbolic sense, the genome is the heritage of humanity.
- Each individual is entitled to respect for their dignity and rights, regardless of their characteristics.
- That dignity makes it imperative not to reduce individuals to their genetic characteristics and to respect the uniqueness of each
Human Biology: Nutrition, Cells, Tissues, Health, and Disease
Nutrition
Nutrition involves incorporating environmental matter and energy into cells to reproduce, replace damaged structures, and move. Waste products are urine and CO2. The following systems are involved: digestive, respiratory, circulatory, and excretory. Nutrition is not the same as digestion.
Organic Molecules
Organic molecules are made of atoms of carbon, oxygen, nitrogen, and phosphorus, and some contain sulfur. They can be very large and complex.
Inorganic Molecules
Inorganic molecules are much
Read MorePassive Immunity Transfer and Hypersensitivity Reactions in Animals
Passive Transfer of Immunity
A) Type of Placentation:
- Humans and Primates: Hemochorial placentation, maternal blood is in contact with the fetal trophoblast. There are only 2 layers of cells separating the maternal and fetal blood circulation. This allows the passage of IgG. At the time of birth, the newborn has an IgG titer similar to the mother’s.
- Dogs and Cats: Endotheliochorial placentation, the fetal chorionic epithelium is in contact with the endothelium of maternal capillaries. There are 3 cell
Cellular Responses and Nutrition: Metabolism, Movement, and Growth
Cellular Responses
At the molecular level, responses are varied, as all metabolic processes in cells occur as responses to stimuli. Cell behavior can be categorized into three types of responses:
Secretion
Beta cells and other specialized cells have a regulated secretion rate, controlled by specific couriers. Molecules are stored in secretory vesicles until a signal (e.g., calcium levels) triggers their release.
Proliferation and Cell Development
- If a cell receives survival signals, it renews its structures
Hematological Disorders: Causes and Diagnostic Tests
Pernicious Anemia: Causes and Lab Findings
Pernicious anemia is a type of megaloblastic anemia caused by vitamin B12 deficiency, primarily due to autoimmune destruction of gastric parietal cells, leading to a lack of intrinsic factor (IF). Intrinsic factor is necessary for vitamin B12 absorption in the ileum. In addition to IF antibodies, some individuals produce antibodies against the B12-IF complex, further impairing B12 absorption. This results in defective DNA synthesis in erythroid precursor
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