Membrane and Cell Transport

Question 1

what does the plasma membrane do?

Answer 1

The plasma membrane surrounds all cells and physically separates the cytoplasm

Question 2

what is the phospholipid bilayer?

Answer 2

-an extremal surface lined with hydrophilic polar heads
-nonpolar, hydrophobic, fatty acid tails sandwiched in between

Question 3

fluid mosaic model

Answer 3

describes the plasma membrane as a phospholipid bilayer in which proteins are imbedded.

Question 4

6 functions of membrane proteins

Answer 4

• channel proteins
  -carrier proteins
  -cell recognition proteins
  -receptor proteins
  -enzymatic proteins
• junction proteins

Question 5

what does selectively permeable mean?

Answer 5

allows some substances to move across the membrane but not all

Question 6

describe concentration gradient

Answer 6

when molecules move from an area of high concentration to an area of low concentration

Question 7

what does the primary cell wall contain?

Answer 7

Contains cellulose fibrils and Non cellulose substances that allow the cell to stretch when growing

Question 8

what does the secondary cell wall consist of?

Answer 8

consists mainly of cellulose microfibrils and lignin

Question 9

living cells are connected by narrow, membrane-lines ?

Answer 9

plasmodesmata

Question 10

what are the 2 primary external feature of animal cells?

Answer 10

1.) extracellular matrix
2.) junctions between cells

Question 11

what are the 3 types of junctions between cells?

Answer 11

adhesion, tight, and gap junction

Question 12

what is the process in which particles spread out evenly in an available space?

Answer 12

diffusion

Question 13

how do ions and polar molecules cross membranes?

Answer 13

By facilitated diffusion
-also known as passive transport

Question 14

Diffusion of water across a differentials permeable membrane is called?

Answer 14

Osmosis

Question 15

What are the effects of osmosis?

Answer 15

Osmosis can affect the size and shape of cells
Hypotonic-cells sweet, burst
Hypertonic-shriveled cells

Question 16

Where do molecules move during active transport?

Answer 16

Molecules move against their concentration gradient

Question 17

Where does the energy used during active transport come from?

Answer 17

The mitochondria (ATP)

Question 18

Proteins engaged in active transport

Answer 18

Pumps

Question 19

Phagocytosis vs pinocytosis

Answer 19

Phagocytosis- large particle
Pinocytosis- liquid or small particle

Question 20

What is a selective, highly efficient form of endocytosis?

Answer 20

Receptor-mediated endocytosis

Question 21

How are membrane proteins transported across membranes

Answer 21

Vesicles

Question 22

The transport of macromolecules out of a cell in a vesicle is called?

Answer 22

Exocytosis

Question 23

The transport of macromolecules into a cell in a vesicle is called?

Answer 23

Endocytosis