Lect 2-3 Cell Anatomy (Plasma Membrane)

Question 1

What are the two types of cells

Answer 1

Sex Cells
Somatic Cells

Question 2

A cell can divided into two areas _____

Answer 2

Cytoplasm
Plasma Membrane

Question 3

The Cytoplasm can be separated into _____

Answer 3

Cytosol
Organelles

Question 4

Cytosol

Answer 4

Intracellular Fluid within cells

Question 5

Organelles

Answer 5

Intracellular Structures
Some have membranes while others do not

Question 6

Plasma Membrane Function

Answer 6

• Physical Barrier
• Regulates Exchange of material
• Maintains homeostasis corresponding to extracellular fluid
• Cell to Cell Communication

Question 7

Components of Plasma Membrane

Answer 7

Phospholipids
Protein Channels
Glycolipids
Sterols

Question 8

Phospholipids and their role

Answer 8

Bilayer with hydrophilic heads and hydrophobic tails

Question 9

Phospholipid Outer Layer Contains

Answer 9

Glycocalyx which is made up of
Glycolipids and
Glycoproteins

Question 10

Glyco means ____

Answer 10

Sugar –> Water Soluble –> Found on the outer layer which is exposed to water

Question 11

Cholesterol Role

Answer 11

Found in phospholipid bilayer around the tails, used to stabilize plasma membrane

Question 12

What two types of proteins are related to the cell membrane

Answer 12

Peripheral Proteins
Attached to either inner/outer layer of membrane

Integral
Embedded into the membrane
Can form gates/channels

Question 13

Glycolipids Function

Answer 13

Makes part of glycocalyx
Can act as receptor

Question 14

Glycolipids Location

Answer 14

Found on outer layer of membrane

Question 15

Passive Processes (Membrane Permeability)

Answer 15

Diffusion
Osmosis
Facilitated Diffusion

Question 16

Diffusion

Answer 16

Molecules move down concentration gradient
(High–>Low)
Does not require energy

Question 17

Diffusion (Substances involved)

Answer 17

Small inorganic molecules and ions
Gases
Lipid Soluble Material (Can cross membrane)

Question 18

Osmosis

Answer 18

Diffusion of water
Dictated by concentration and pressure gradient

Question 19

Hypertonic Solution

Answer 19

Higher osmolarity

Solution has high solute = Cell has low solute
–>Cell has high water conc.

Water flows out of cell down conc. gradient
Cell shrinks

Question 20

Hypotonic Solution

Answer 20

Low Osmolarity

Solution has low solute = Cell has high solute
–> Cell has low water conc.

Water flows into cell down conc. gradient
Cell grows

Question 21

Facilitated Diffusion

Answer 21

Diffusion with help, follows conc. gradient doesn’t need energy

Bidirectional

Question 22

Facilitated Diffusion (Substances Involved)

Answer 22

Organic Molecules like Glucose and Amino Acids
Polar –> Hydrophilic
Lipophobic and can not cross membrane

Question 23

Active Transport

Answer 23

Uses exchange pumps to actively transport solutes regardless of concentration gradient
Unidirectional

Question 24

Phagocytosis

Answer 24

Active process where Vesicles bring in solid particles into the cell

Useable by specialized cells

Question 25

Pinocytosis

Answer 25

Active process where vesicles bring in Small particles into the cell Water and Small molecules Usable by all cells

Question 26

Exocytosis

Answer 26

Release of intracellular material (usually waste) into the extracellular area Uses ATP and Ca2+

Question 27

Phagocytosis Process

Answer 27

Phagosome + Lysosome = Lysosome (Phagolysosome) (Occurs in Golgi apparatus) Useful material diffuses into cytosol Waste is ejected through exocytosis

Question 28

Crossing the Membrane (Non-Polar)

Answer 28

Lipophilic, O2, CO2, Fatty Acids All cross the membrane easily

Question 29

Crossing the Membrane (Polar Molecules)

Answer 29

Diffuse slowly/not at all Requires transport through ion channel/mediated transport

Question 30

What drives electrochemical gradient

Answer 30

Large Positive Charge on one side is attracted by the Large Negative Charge on the other

Question 31

What are Microvilli

Answer 31

Extensions of the plasma membrane that can absorb material from extracellular fluid

Question 32

How do Microvilli move? Why?

Answer 32

Bends back and forth Helps to circulate extracellular fluid Helps to absorb nutrients