HUBS1403 Lecture 6: Lecture 6- cells
Cells
Body Fluid Compartments
- Intracellular fluid: 2/3 total water volume
- Extracellular fluid: 1/3 total water volume and includes:
o Interstitial fluid – lies in between circulatory system an cells – 75% of ECF
o Plasma – liquid matrix of blood – 25% of ECF
Compartments are separated by membranes
- Plasma membrane (phospholipid bilayer) in between cells
- Tissue membranes eg pericardial membrane around heart
Cells
• Are the building blocks of all plants and animals
• Come from the division of pre-existing cells - cannot be created from nothing
• The smallest units that perform all vital physiological functions
Classification of Cells
• Two general classes of cells in the human body
o Sex cells
• Aka reproductive cells, germ cells, gametes
• Sperm cells and oocytes
o Somatic cells
• All other cells
• Cells are composed of:
o Nucleus
o Cytoplasm
• Cytosol
• Membrane bound organelles
• Inclusions
• Protein fibres
o Cell membrane
Cell Membrane structure
• Lipid bilayer - phospholipids
o hydrophilic head
o Hydrophobic tails
• Number of proteins
o Integral proteins traverse the entire width of the membrane - port for ions or other
molecules to move into or out of the cell
o Receptor proteins - able to bind to signalling molecules outside the cell
o Glycoprotein
o Peripheral proteins - don’t pass through membrane but associated with other proteins -
shape and movement of cell can be stabilised
Cell membrane Proteins
Two major classes of membrane proteins
• Integral proteins
o Part of the membrane structure
o May span width of membrane 1x or more
o Aka transmembrane proteins
o >>> peripheral proteins
• Peripheral proteins
Document Summary
Extracellular fluid: 1/3 total water volume and includes: Interstitial fluid lies in between circulatory system an cells 75% of ecf: plasma liquid matrix of blood 25% of ecf. Cells: are the building blocks of all plants and animals, come from the division of pre-existing cells - cannot be created from nothing, the smallest units that perform all vital physiological functions. Classification of cells: two general classes of cells in the human body, sex cells, aka reproductive cells, germ cells, gametes. Sperm cells and oocytes: somatic cells, all other cells, cells are composed of, nucleus, cytoplasm, cytosol, membrane bound organelles, protein fibres. Lipid bilayer - phospholipids hydrophilic head: hydrophobic tails, number of proteins. Integral proteins: part of the membrane structure, may span width of membrane 1x or more, aka transmembrane proteins, >>> peripheral proteins, peripheral proteins, pound to inner or outer surface, easily removed.