Chapter 2 Flashcards
(85 cards)
What are the two major parts of cells?
The nucleus and cytoplasm
How is the nucleus separated from the cytoplasm?
By a nuclear membrane
What is the protoplasm?
The different substances that make up the cell. Composed of mainly five substances
Which cells are not mainly comprised of water?
Fat cells
In what concentration are most cells comprised of water?
70-85%
What are important ions in cells?
Potassium, magnesium, phosphate, sulfate, bicarbonate and smaller quantities of sodium, chloride and calcium.
After water, what is the most abundant substance in most cells?
Proteins
How much do protein constitute of the cell mass?
10-20%
In what two types can proteins be divided?
Structural proteins and functional proteins
What is the common property of lipids?
They are soluble in fat solvents
What are two important lipids?
Phospholipids and cholesterol
How much of the body mass do phospholipids and cholesterol constitute?
2% of the body mass
What is another name for triglycerides?
Neutral fats
What are adipocytes?
Fat cells
How much of the cell mass do triglycerides constitute in cells?
95%
What is glycogen?
Stored carbohydrate in the cell, it is an insoluble polymer of glucose
How much of the cell’s energy release from nutrients would cease immediately without the presence of mitochondria?
95%
What is the function of lipids in membranes?
Provide a barrier that impedes movement of water and water-soluble substances from one cell compartment to another
How thick is the cell membrane (plasma membrane)?
7.5 - 10 nanometers
What is the composition of the cell membrane?
55% proteins, 25% phospholipids, 13% cholesterol, 4% other lipids and 3% carbohydrates
Of which 3 main types of lipids is a basic lipid bilayer composed?
Phospholipids, sphingolipids and cholesterol
Which end of a phospholipid is hydrophilic (water soluble)?
Phosphate end
Which end of a phospholipid is hydrophobic (fat soluble)?
Fatty acid portion
What are water soluble substances?
Ions, glucose and urea