The Endocrine System: Hormones and Their Functions
Endocrine System
Pituitary Gland
1. Anterior Lobe (Adenohypophysis)
- Gonadotropin Hormone: Regulates the gonads.
- Thyrotropin Hormone: Regulates the thyroid.
- Somatotropin Hormone: Influences growth and carbohydrate metabolism. (Hypersecretion: Gigantism; Hyposecretion: Dwarfism)
- Adrenocorticotropin Hormone: Stimulates hormone production in the adrenal cortex.
- Prolactin Hormone: Various functions related to reproduction and lactation.
2. Pars Media (Intermediate Lobe)
- Melanocyte-Stimulating Hormone (MSH): Controls
Eukaryotic Cell Nucleus: Structure and Function
The Nucleus: Center of Eukaryotic Cell Control
The nucleus is the central control center of the eukaryotic cell. It contains the majority of cellular DNA and genetic information for almost every gene function.
Morphology and Composition
In animal cells, the nucleus is typically spherical, while in plant cells, it tends to be more irregular in shape. The nucleus contains the majority of cellular DNA within the eukaryotic cell. DNA molecules vary in size, each forming a chromosome. The nucleus also contains
Read MoreDNA Tertiary Structure and RNA Types & Functions
Advantages of DNA Tertiary Structure
- Reduces the overall length of the DNA molecule, allowing it to fit within cellular compartments.
- Facilitates DNA replication. Its clockwise winding (dextrorotatory) structure is efficiently unwound by enzymes that typically work in a counter-clockwise (levorotatory) manner.
Some organisms possess non-coding DNA fragments, known as supernumerary DNA.
DNA Structure Types and Packing
- Single-stranded DNA (ssDNA): Composed of a single nucleotide chain.
- Double-stranded DNA
Cell Division: Mitosis and the Cell Cycle Explained
The Cell Cycle: A Detailed Explanation
Role Play: This is the period of time from when a cell divides until it gives rise to other cells, encompassing all processes within that timeframe.
Interface: The Longest Stage
The interface is the longest stage, featuring the cell nucleus and consisting of three phases:
G1 Phase
During this stage, mRNA synthesis, and therefore protein synthesis, takes place. The cell contains a Diplosoma. Towards the end of this phase, there’s a point of no return, called the
Read MoreDental Office Infection Control
Cross-contamination: Occurs from patient to patient via medical staff or the instruments used. The chain of infection is influenced by key factors that determine the spread of disease through contact between the infectious agent and a susceptible host. Opportunistic Pathogens: Pathology results when the body’s defenses are reduced. Antiseptic: Chemical disinfection of the skin, mucosa, or other tissues using an antiseptic. Antiseptics inactivate substances that inhibit bacterial growth. Disinfection:
Read MoreCellular Respiration and Photosynthesis: Processes and Energy Conversion
Glycolysis
Catabolic process converting glucose to pyruvate, yielding 2 electrons. The following stages occur:
- Phosphorylation of Glucose: Glucose is phosphorylated by hexokinase.
- Isomerization: Glucose 6-phosphate is isomerized to fructose 6-phosphate by isomerase.
- Phosphorylation of Fructose 6-Phosphate: Fructose 6-phosphate is phosphorylated by phosphofructokinase, requiring ATP to produce fructose 1,6-bisphosphate.
- Cleavage of Fructose 1,6-Bisphosphate: Fructose 1,6-bisphosphate is cleaved by aldolase