Protein Synthesis, Genetics, and Male Reproductive Anatomy

Vocabulary practice flashcards covering protein synthesis, genetic disorders, cellular adaptation, and the anatomical and hormonal aspects of the male reproductive system.

Unexplained weight loss

A potential symptom of cancer characterized by dropping $10$ or more pounds without changes in diet or exercise.

Keratin

A hardening, protein-based substance found in structures such as nails.

Gene

The genetic code required by a cell to make a protein, serving as a blueprint for protein synthesis.

Essential amino acids

Amino acids that cannot be synthesized by the body and therefore must be consumed in the diet.

Nonessential amino acids

Amino acids that do not need to be consumed in the diet because the body, such as the liver, can synthesize them.

Transcription

The first step of protein synthesis, occurring in the nucleus, in which a DNA gene is read and copied onto messenger RNA (mRNA).

Translation

The step in protein synthesis where messenger RNA is read with transfer RNA (tRNA) to assemble amino acids into a protein chain.

Codon

A three-nucleotide sequence on mRNA that codes for a specific amino acid, a start signal, or a stop signal.

AUG

The start codon that signals the ribosome to begin protein synthesis.

UAA

A stop codon that signals the termination of the amino acid sequence during protein synthesis.

PKU (Phenylketonuria)

A metabolic disorder caused by the lack of an enzyme needed to break down phenylalanine, resulting in acid accumulation that destroys brain neurons if not detected and managed with a specialized diet.

Hypertrophy

An increase in cell size without undergoing mitosis, commonly occurring in muscle cells in response to physical stress or growth hormone.

Atrophy

The shrinking of cells from large to small, representing the opposite of hypertrophy and commonly seen in underused muscles.

Testes

The paired male reproductive organs responsible for producing sperm and secreting testosterone.

Epididymis

A sack-like structure located on top of each testis where sperm are stored.

Vas deferens (Ductus deferens)

The long tubular structure that transports sperm and semen from the epididymis toward the ejaculatory duct and urethra.

Vasectomy

A male sterilization procedure in which the vas deferens is cut on both sides, cauterized to form scar tissue, and stapled to block sperm from leaving the body.

Tubal ligation

The female equivalent of a vasectomy, involving cutting and tying off the fallopian tubes to prevent fertilization.

Scrotum

The pouch of skin that houses the testes and maintains their temperature at approximately $95\text{ degrees Fahrenheit}$ ($95^\circ\text{F}$) to ensure fertility.

Orchiopexy

A surgical procedure performed to move undescended or hidden testes from the pelvic cavity down into the scrotum.

Spermatogonia

Cells residing in the seminiferous tubules throughout a male's lifetime that contain $46$ chromosomes and undergo meiosis to produce sperm.

Meiosis

The cell division process that reduces the chromosome number in germ cells from $46$ chromosomes in spermatogonia to $23$ chromosomes in mature sperm cells.

Luteinizing hormone (LH)

An anterior pituitary hormone stimulated by GnRH that targets interstitial cells in the testes.

Follicle-stimulating hormone (FSH)

An anterior pituitary hormone stimulated by GnRH that targets sustentacular cells in the testes to secrete androgen-binding proteins.

Acrosome

The cap located on the head of a sperm cell that contains digestive enzymes required to penetrate the membrane of an egg during fertilization.

Midpiece

The central section of a sperm cell that contains numerous mitochondria to provide energy for movement.