Cells shapes and sizes ___
Cells shapes and sizes VARIES

Most human cell sizes are ___ µm (micrometer) in diameter.
Most human cell sizes are 10-15 µm (micrometer) in diameter.
Egg cells (very large) are ___ in diameter
Egg cells (very large) are 100 µm in diameter
Muscle cells can be ___ cm long
Muscle cells can be 30 cm long
Nerve cells can be ___ meter(s) long
Nerve cells can be 1 meter long
Cell growth ____ volume more than surface area
Cell growth INCREASES volume more than surface area
Plasma (cell) membrane is _____ ______, surrounds ____ and ______ entry/exit - on perimeter of the cell
Plasma (cell) membrane is SELECTIVELY PERMEABLE, surrounds CELL, and REGULATES entry/exit - on perimeter of the cell
The cytoplasm is the ___ ____ of the cells
The cytoplasm is the INNER CONTENTS of the cells
What are the 3 things located in the cytoplasm?
98% of molecules in plasma membrane are ____.
The other 2% are ____.
98% of molecules in plasma membrane are LIPIDS (mostly phospholipids).
The other 2% are PROTEINS.
What 3 things can phospholipids be?
How are amphiphilic molecules arranged?
In bilayer
What way do hydrophilic phosphate heads face?
Towards the water
Where are hydrophobic tails directed towards?
Towards the center
What way do phospholipids drift from place to place?
Laterally
What keeps membrane fluid in phospholipids?
Movement
What 2 other lipids are molecules in the plasma membrane?
What are glycolipids?
1/2 sugar and 1/2 lipids - contribute to glycocalyx
What are the 2 membrane proteins?
What are transmembrane proteins?
Proteins that cross over from one side to other side in membrane (go from ECF to ICF).
What are peripheral proteins?
Proteins that are between the plasma membrane and the ICF.
What are the functions of the membrane protein?
(Channel protein - gate constantly open and allows solutes to pass into and out of cell & gated channel - gate that opens and closes to allow solutes through only at a certain time, something has to happen to let it through)

What are second messenger systems?
Receptors and enzymes working together in a way that they create a second messenger system and it’s a way of signaling for a change to occur inside the cell
What are glycocalyx?
Unique fuzzy coat external to plasma membrane