Unit 5: Organizing Principles

Question 1

Cell Theory

Answer 1

1. All organisms are made up of cells
2. The cell is the fundamental unit of life
3. Cells come from preexisting cells

Question 2

Amphiphatic

Answer 2

Molecules with both hydrophilic and hydrophobic regions

Question 3

Micelles

Answer 3

Lipids with bulky heads and a single hydrophobic fatty acid tail that are wedge shaped and get packed into spherical structures

Question 4

Bilayer

Answer 4

Lipids with less bulky head groups and two hydrophobic tails

Question 5

Liposomes

Answer 5

Enclosed bilayer structures that spontaneously form when phospholipids are in water at neutral pH

Question 6

Fluid

Answer 6

Membrane lipids that are able to move in the plane of the membrane

Question 7

Cholesterol

Answer 7

A major component of animal cell membranes

Question 8

Lipid Rafts

Answer 8

Lipids that assemble into defined patches

Question 9

Transporters

Answer 9

Move ions or other molecules across the membrane

Question 10

Channels

Answer 10

Allow movement of molecules through them

Question 11

Carriers

Answer 11

Facilitate movement

Question 12

Receptors

Answer 12

Allow the cell to receive signals from the environment

Question 13

Enzymes

Answer 13

Catalyze chemical reactions

Question 14

Anchors

Answer 14

Attach to other proteins that help to maintain cell structure and shape

Question 15

Integral Membrane Proteins

Answer 15

Permanently associated with cell membranes and cannot be separated from the membrane without destroying the membrane itself

Question 16

Peripheral Membrane Proteins

Answer 16

Temporarily associated with the lipid belayer through weak noncovalent interactions

Question 17

Transmembrane Proteins

Answer 17

Span the entire lipid bilayer and are composed of two hydrophilic regions and one hydrophobic region

Question 18

Fluid Mosaic Model

Answer 18

The lipid bilayer is a fluid structure that allows molecules to move within the membrane is is composed of lipids and proteins

Question 19

Plasma Membrane

Answer 19

The boundary that defines the space of the cell, separating its internal contents from the surrounding environment

Question 20

Cell Wall

Answer 20

Maintains the shape and internal composition of cells

Question 21

Homeostasis

Answer 21

The active maintenance of a constant environment

Question 22

Selective Barrier

Answer 22

Allows some molecules to move in and out freely; it lets others in and out under certain conditions; and it prevents other molecules from passing through at all

Question 23

Diffusion

Answer 23

The random movement of molecules

Question 24

Facilitated Diffusion

Answer 24

When a molecule moves by diffusion through a membrane protein and bypasses the lipid bilayer

Question 25

Aquaporins

Answer 25

Allows water to flow through the plasma membrane more readily by facilitated diffusion

Question 26

Osmosis

Answer 26

The diffusion of water

Question 27

Active Transport

Answer 27

The movement of substances against a concentration gradient

Question 28

Primary Active Transport

Answer 28

Active transport that requires the chemical energy of ATP

Question 29

Electrochemical Gradient

Answer 29

The charge and chemical gradients

Question 30

Secondary Active Transport

Answer 30

The movement of a coupled molecule driven by the movement of protons and not ATP