Human Reproductive Biology: Glands, Hormones, and Fertilization
Glands: Classification and Function
Glands are organs composed of specialized cells that manufacture and secrete substances. Glands can be classified into two main types:
Endocrine Glands
Such as the pituitary or thyroid, these glands produce substances called hormones that are released directly into the blood.
Exocrine Glands
Such as the salivary glands and liver, these glands discharge their secretions outside the body or into the digestive tract and are therefore not part of the endocrine system.
Hormones:
Read MoreCore Concepts in Biochemistry: Metabolism, Genetics, and Disorders
Proteins: Structure and Function
Proteins are complex molecules made up of amino acids. They perform various functions in the body, such as:
- Structural support (e.g., collagen)
- Enzymatic activity (e.g., lactase)
- Transport (e.g., hemoglobin)
- Defense (e.g., antibodies)
Classification of Proteins
- Based on Structure:
- Fibrous proteins (e.g., collagen)
- Globular proteins (e.g., enzymes, antibodies)
- Based on Function:
- Enzymes
- Hormones
- Structural proteins
- Transport proteins
- Defense proteins
The Urea Cycle
The urea cycle
Read MoreFundamentals of Microscopy Techniques and Cell Theory
History of Optical Microscopy
Key Milestones
- 1611: Johannes Kepler suggests how to construct a compound microscope.
- 1655: Robert Hooke publishes Micrographia, introducing the concept of the cell.
- In parallel, Antonie van Leeuwenhoek built more than 200 microscopes (simple magnifying glasses).
Early Optical Microscopy Pioneers
Robert Hooke (1655)
In 1655, Robert Hooke observed a piece of cork under his self-built microscope. He used the word cell to describe the small, closed compartments he noted.
Antonie
Read MoreDNA Replication and RNA Transcription in Prokaryotes and Eukaryotes
DNA Replication in Prokaryotes
In bacteria, in addition to the main DNA molecule, there are small circular DNA molecules called plasmids. These plasmids may or may not replicate simultaneously with the main chromosome using a similar mechanism. All plasmid DNA introduced into bacteria must possess a replication origin sequence to be multiplied by the replication machinery.
Eukaryotic DNA Replication Complexity
In eukaryotes, the rate of replication of nuclear DNA is more complex than in bacteria for
Read MoreComparative Anatomy: Digestion, Circulation, and Homeostasis
Primitive Digestion: Intracellular Systems
The Porifera (sponges) are primitive organisms that lack true tissues or organs. They perform the digestion of food particles in specialized cells called choanocytes. Food, carried by water, penetrates through pores. The beating of the flagellum pushes water toward the collar, and food is captured by endocytosis. The resulting vacuole fuses with digestive enzymes from lysosomes. Undigested waste is expelled by exocytosis (intracellular digestion).
The primary
Read MoreCardiovascular System Anatomy: Blood Vessels and Heart Structure
Blood Vessels: Structure and Labeling
Figure 1: Blood Vessel Anatomy
Instruction: Complete the labels of Figure 1 using the following terms: venules, capillaries, valves, arterioles, artery, vein.
Answer Key: A: Artery, B: Arterioles, C: Capillaries, D: Venules, E: Valves, F: Vein
Figure 2: Blood Vessel Cross-Section
Instruction: Complete the labels of Figure 2 using the following terms: vein, capillary, artery (you will need to use some terms more than once).
Answer Key: A: Artery, B: Vein, C: Capillary,
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