Ch 3: Note sheet 1

Question 1

Number of cells in the adult human body

Answer 1

70 trillion cells

Question 2

Measurement for cells

Answer 2

Micrometers

Question 3

Main parts of cells

Answer 3

1) cell membrane
2) nucleus
3) cytoplasm
4) inclusions

Question 4

Does a “typical” cell exist?

Answer 4

No, all cells vary in size, shape, structure, etc

Question 5

Inclusions

Answer 5

groups of chemicals in cells; different chemicals for different cells

Question 6

Cell Membrane

Answer 6

Surface membrane that separates the external environment from the internal environment

Question 7

Selectively Permeable

Answer 7

only certain things can go through

Question 8

Signal Transduction

Answer 8

allows cells to receive and respond to incoming messages
link to cells and the BODY’S internal environment

Question 9

Cell Membrane Composition

Answer 9

-Bilayer of phospholipid molecules and embedded proteins
-some carbohydrates, cholesterols, glycolipids
-there are approx. 50 lipids for every one protein

Question 10

Phospholipids

Answer 10

lipids that contain phosphorus

Question 11

“Heads”

Answer 11

water-soluble phosphate groups form the outer surface (hydrophilic)- polar molecule

Question 12

“Tails”

Answer 12

water-insoluble fatty acid chains that make up the interior of the membrane (hydrophobic)- nonpolar

Question 13

Due to the oily nature of the inner membrane…

Answer 13

lipid-soluble substances pass easily (oxygen, co2, steroids)
water-soluble molecules do NOT pass easily (amino acids, sugars, proteins, ions)

Question 14

Membrane Proteins

Answer 14

many different types providing specialized functions

Question 15

Integral protein

Answer 15

extends from the ECF to ICF
-provide routes into and out of the cell for smaller molecules and ions
-bind to specific molecules that trigger responses in the cell
-provide pores for water molecules to enter

Question 16

Peripheral protein

Answer 16

does not extend all the way through, remains at the surface
-many peripheral proteins are enzymes and take part in signal transduction pathways
-act as “cellular adhesion molecules”

Question 17

Cellular adhesion molecules

Answer 17

allow certain cells to touch or bind
-important as cells cluster to form tissue
-also mark the cells of an individual as “self”