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
Read More

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 More

DNA 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
Read More

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 More

Dental 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 More

Cellular Respiration and Photosynthesis: Processes and Energy Conversion

Glycolysis

Catabolic process converting glucose to pyruvate, yielding 2 electrons. The following stages occur:

  1. Phosphorylation of Glucose: Glucose is phosphorylated by hexokinase.
  2. Isomerization: Glucose 6-phosphate is isomerized to fructose 6-phosphate by isomerase.
  3. Phosphorylation of Fructose 6-Phosphate: Fructose 6-phosphate is phosphorylated by phosphofructokinase, requiring ATP to produce fructose 1,6-bisphosphate.
  4. Cleavage of Fructose 1,6-Bisphosphate: Fructose 1,6-bisphosphate is cleaved by aldolase
Read More