cells and membranes

Question 1

“you better not be a phospholipid when i get there”
me:

Answer 1

o (polar heads)
|| (nonpolar tails)
||
o
- main lipids that make up the lipid bilayer
- polar heads attract to each other and nonpolar tails attract to each other
- molecule that has a glycerol backbone, two fatty acid chains, and a phosphate-containing group

Question 2

phagocytosis

Answer 2

type of endocytosis in which cell engulfs very big particles, such as food particles or whole cells

Question 3

endocytosis

Answer 3

• active transport in which the cell takes in particles too big to pass through protein channels
• necessary to move big particles

Question 4

pinocytosis

Answer 4

form of endocytosis in which vesicles form around liquids or smaller particles

Question 5

vesicles

Answer 5

membrane-enclosed sacs used for transporting particles within cells

Question 6

hypotonic

Answer 6

solution with a lower solute concentration and higher water concentration than the cytoplasm of the cell

Question 7

hypertonic

Answer 7

solution with a higher solute concentration and lower water concentration than the cytoplasm of the cell

Question 8

isotonic

Answer 8

solution with the same solute concentration and same water concentration as cell cytoplasm

Question 9

exocytosis

Answer 9

• active transport in which the cell gets rid of big substances too big to pass through protein channels
• necessary to move big particles

Question 10

integral proteins

Answer 10

• span the whole thickness of the membrane
• polarity changes along its length
• channel proteins
• imbedded proteins

Question 11

peripheral proteins

Answer 11

• on the cytoplasmic side of membrane
• embedded proteins

Question 12

Does having more unsaturated acids make the membrane more fluid or less fluid?

Answer 12

more

Question 13

cholesterol

Answer 13

regulates the state of matter in the membrane

Question 14

glycolipids/glycoproteins

Answer 14

phospholipids/membrane proteins that have attached sugar chains

Question 15

channel proteins

Answer 15

allows small polar molecules and ions to pass through the membrane freely by channels to do stuff like produce ATP

Question 16

carrier proteins

Answer 16

allows ions or specific molecules to pass through the membrane to do stuff like nerve impulse conduction by changing shape

Question 17

cell recognition proteins

Answer 17

glycoproteins that do stuff like help immune system cells recognize what cells are a part of the organism

Question 18

receptor proteins

Answer 18

• has a shape that allows only specific molecules to bind to it
• the binding causes the protein to change its shape and therefore activate a cellular response

Question 19

Why is the plasma membrane called a fluid mosaic?

Answer 19

different molecules in the membrane move freely in the lipid bilayer

Question 20

What are the differences between prokaryotic and eukaryotic cells?

Answer 20

PROKARYOTIC (ex. bacteria)
- no nucleus
- few organelles
- simple structure
- prokaryotic organisms are unicellular
- smallest cell type
EUKARYOTIC (ex. protists, fungi, plants, animals)
- has a nucleus
- many organelles
- complex structure
- can be uni or multicellular

Question 21

What are the differences between plant and animal cells?

Answer 21

PLANT CELLS
- has cell wall for structural support
- has chloroplasts for photosynthesis
- has large vacuoles for water storage
ANIMAL CELLS
- has centrioles (each composed of 9 microtube triplets)
- has lysosomes

Question 22

What is the reason for having channel proteins/carrier proteins/protein pumps/etc.?

Answer 22

• polar substances/ions cannot go through the nonpolar tails because they have charge and most of the membrane is nonpolar (like the nonpolar tails of phospholipids are for example)
• large molecules can’t fit

Question 23

Why is most of the membrane hydrophobic?

Answer 23

bc of the tails (i think)