physiology TBL (1)

Note

Introduction to Cell (Pages 3-4)

  • Cells are the fundamental unit of life and the basic building blocks of life.

  • The study of cells is called histology.

  • Cells can be unicellular or multicellular.

  • The first cells were observed by Robert Hooke in 1665.

Functions of Cell (Pages 5-6)

  • Cells can detect and respond to changes in their environment.

  • Cells can absorb fluids and substances through the cell membrane for growth, repair, and energy.

  • Cells can use oxygen and food substances to release energy.

  • Cells can discharge waste materials.

  • Cells can increase in size and reproduce by dividing.

  • Some cells have the power of movement.

Subcellular Structures (Page 7)

  • Major structures present in a cell include the cell membrane, cytoplasm and its organelles, and the nucleus.

Cell/Plasma Membrane (Page 8)

  • The cell membrane is a thin, flexible, and elastic outermost structure that envelops the cell.

  • It is composed of a combination of lipid bilayer, phosphates, and proteins.

Nucleus (Page 9)

  • All body cells have a nucleus, except for mature erythrocytes.

  • The nucleus contains the genetic material in the form of DNA.

  • It is surrounded by a separate membrane called the nuclear membrane.

  • The nucleus is referred to as the "control center" of the cell.

Cytoplasm and its Organelles (Page 10)

  • The cytoplasm is a thick, gel-like semitransparent fluid found in the cell.

  • It contains various organelles that perform specific cell functions.

Mitochondria (Page 14)

  • Mitochondria are known as the "powerhouse of the cell."

  • They are responsible for energy production through aerobic respiration.

  • They are found in large numbers in cells that require a lot of energy, such as liver and muscle cells.

Ribosomes (Page 15)

  • Ribosomes are tiny granules composed of RNA and protein.

  • They synthesize proteins within the cell from amino acids.

Endoplasmic Reticulum (Page 16)

  • The endoplasmic reticulum is an extensive series of interconnecting membranous canals in the cytoplasm.

  • There are two types: smooth and rough.

  • Smooth ER synthesizes lipids and steroid hormones and is involved in drug detoxification.

  • Rough ER is studded with ribosomes.

Golgi Bodies (Page 17)

  • Golgi bodies are responsible for the export of products from the cell.

  • They receive proteins, modify them, sort them, and package them for storage or transport.

Lysosomes (Page 18)

  • Lysosomes are small membranous vesicles derived from the Golgi.

  • They are involved in the process of phagocytosis and digestion of foreign material.

  • Lysosomes can also digest unwanted cells in a process called cell suicide.

Functions of Cell Organelles (Pages 19-20)

  • The cell membrane controls the passage of molecules in and out of the cell.

  • Mitochondria are responsible for energy production and thermogenesis.

  • Ribosomes are the site of protein synthesis.

  • The endoplasmic reticulum is involved in protein synthesis and fatty acid unsaturation.

  • Golgi bodies are involved in packaging and synthesis of carbohydrates.

  • Lysosomes are responsible for engulfing and digesting worn-out components and foreign substances.

References (Page 21)

  • Champee, P.C., Harvey, R.A., Ferrier, D.R. Biochemistry. 2013. 6th Edition. Lippincott Williams Wilkins.

  • Michele Liberman Marks Allan Colleen Smith. Mark's Essentials of Medical Biochemistry - A Clinical Approach. 2014. 2nd Edition Lippincott Williams Wilkins.