Chapter 3 Flashcards
1
Q
About how many cells are there in the human body?
A
75 trillion
2
Q
What is differentiation?
A
When cells specialize.
*As a result of differentiation, cells vary in size and shape due to their unique function.
3
Q
What is a composite cell, and what are its major parts?
A
Also called a "typical cell". Major parts include: • Nucleus • Cytoplasm • Cell membrane
4
Q
What is a cell membrane (plasma membrane) and what is its function?
A
- Outer limit of the cell (phospholipid bilayer)
* Controls what moves in and out of the cell which is also known as selective permeabilitly
5
Q
What are the characteristics of a phospholipid bilayer?
A
- Water-soluble “heads” form surfaces (hydrophilic)
- Water-insoluble “tails” form interior (hydrophobic)
- Permeable to lipid-soluble substances
6
Q
What does cholesterol do to the membrane?
A
stabilizes it
7
Q
What proteins are found in the membrane?
A
- Receptors
- Pores, channels and carriers
- Enzymes
- CAMS
- Self-markers
