Structure, composition and function of a cell membrane

Question 1

Parts of a fluid mosaic model

Answer 1

carbohydrate chain, external surface membrane, phospholipid bilayer, glycoprotein, protein molecule, hydrophobic tail, internal surface membrane

Question 2

Terms of fluid - Mosaic in a cell membrane

Answer 2

Fluid: proteins float in a sea of phospholipids
Mosaic: made of many different parts (the membrane is a double layer of phospholipid molecules)

Question 3

Phospholipids

Answer 3

Hydrophilic phosphate heads (likes water) and hydrophobic tails (hates water)

Can form lipid bilayers because of their amphiphilic (both hydrophilic and hydrophobic regions) characteristics

Question 4

Semi-permeable

Answer 4

Marker proteins identify cells as yours, keeping them safe from attack by white blood cells.
Channel proteins allow certain large stuff to move in & out of the cell (like a doorway).
Receptor proteins allow the cell to respond to its environment by letting know what’s out there.

Question 5

Passive: diffusion, osmosis, facilitated diffusion (diffusion through a membrane protein)

Answer 5

Active: active transport (through a membrane protein), endocytosis, exocytosis

Question 6

endocytosis = moving particles into the cell by wrapping membrane around it and pinching it off inside.

Answer 6

Exocytosis = moving particles out of the cell by wrapping membrane around it and joining that membrane with the cell membrane to spill the contents out of the cell

Question 7

Prokaryotes came 1st, have no nucleus or other organelles with membranes, and are smaller. (Only bacteria are prokaryotes today.) Both types of cells have DNA (ribosome, cell membrane) and do normal cell processes.

Answer 7

Eukaryotes came 2nd, bigger, nucleus (other organelles with membrane), animals