Chapter 1: The Cell in Health and Illness

Vocabulary flashcards covering key cellular structures, organelles, and processes from the lecture notes.

Plasma membrane

Barrier between the external and internal cell environments; semi-permeable; fluid movement can lead to edema or dehydration.

Glycoproteins

Proteins with carbohydrate chains; antigens involved in self vs non-self recognition and in allergies, autoimmune diseases, transplant rejection, and transfusion reactions.

Sodium-Potassium Pump

Active transport moving 3 Na+ out and 2 K+ into the cell; requires ATP.

Resting membrane potential

Voltage difference across the plasma membrane established and maintained by pump activity.

Mitochondria

Organelles for energy production; more mitochondria in highly active tissues; site of aerobic metabolism and free radical formation.

Aerobic metabolism

Glucose is oxidized to pyruvate and enters the Krebs cycle; net yield about 34 ATP; requires oxygen.

Anaerobic metabolism

Oxygen is unavailable; glucose is converted to pyruvate then lactic acid; net yield about 2 ATP and potential pH change.

Mitochondrial DNA

Distinctive DNA inherited maternally; enables study of maternal heritage.

Lysosomes

Small organelles with digestive enzymes; autolysis (cell death) and heterolysis (digestion of foreign material); Tay-Sachs disease involves lysosomal enzyme deficiency.

Autolysis

Cell death caused by lysosomal enzyme activity within the cell.

Heterolysis

Digestion of foreign material by lysosomal enzymes.

Tay-Sachs disease

Lack of lysosomal enzymes leading to ganglioside accumulation.

Proteasomes

Degrade proteins and polypeptide chains; increased activity associated with cancer cachexia.

Peroxisomes

Break down free radicals and very long-chain fatty acids; dysfunction (e.g., adrenoleukodystrophy) leads to fatty acid buildup in the nervous system.

Adrenoleukodystrophy

Dysfunctional peroxisomes causing accumulation of long-chain fatty acids in the nervous system.

Endoplasmic Reticulum (ER)

Network of tubules; smooth ER synthesizes lipids, rough ER synthesizes proteins; ER stress linked to cancer, obesity, and diabetes.

ER stress

Cellular stress related to the endoplasmic reticulum; implicated in cancer, obesity, and diabetes.

Ribosomes

Ribosomal RNA (rRNA)–containing particles; some attached to rough ER; sites of protein synthesis.

Golgi apparatus

Processes, packages, and secretes proteins; receives proteins from the ER; stores hormones in secretory vesicles until release (e.g., ACTH, insulin).

Secretory vesicles

Vesicles formed from the ER-Golgi system that carry substances to be secreted by the cell.

ACTH

Adrenocorticotropic hormone; synthesized as a preprohormone, processed to a prohormone, then to a hormone; stored in secretory vesicles until release.

Insulin

Hormone stored in secretory vesicles; example of a hormone processed and secreted via the secretory pathway.

Preprohormone

Initial synthesized form of a hormone that moves to the ER for processing.

Prohormone

Intermediate form transported to the Golgi; processed into the active hormone.

Hormone

Secreted regulatory protein produced by secretory vesicles after processing.

Nucleus

Contains genetic material (DNA); site of genetic information storage.

DNA

Deoxyribonucleic acid composed of nucleotides; Purines (adenine, guanine) and Pyrimidines (cytosine, thymine); semi-conservative replication by DNA polymerase.

Purines

Adenine and guanine; two-ring nucleobases in DNA.

Pyrimidines

Cytosine and thymine; single-ring nucleobases in DNA.

Transcription

DNA is transcribed into messenger RNA (mRNA).

Translation

mRNA is translated into an amino acid sequence; ribosomes and transfer RNA (tRNA) are involved; codon specifies a sequence.

Codon

Three-nucleotide sequence in mRNA that codes a specific amino acid (as noted in the lecture: three-nucleotide code for a specific nucleotide/amino acid in context).