Module 3: Structures

Question 1

It contains the Phospholipid, Membrane proteins, Carbohydrate chain, cholesterol, membrane proteins.

Answer 1

Cell Membrane

Question 2

Also known as cellular
membrane or plasma
membrane

Answer 2

Biological Membrane

Question 3

The cell membrane______________ the
cell from the outside
environment.

Answer 3

Separates and protect

Question 4

______________ from the cell membrane that
surrounds a cell.

Answer 4

Outermost envelope

Question 5

Two layers of
phospholipids
arranged backto-
back which
covers the cell.

Answer 5

Lipid Bilayer

Question 6

Cell takes in macromolecules by
forming vesicles from the plasma
membrane

Answer 6

Endocytosis

Question 7

Transport vesicles migrate to the
membrane, fuse with it, and
release their contents outside the
cell

Answer 7

Exocytosis

Question 8

Requires the input of energy from the cell.

Answer 8

Active Transport

Question 9

Uses ATP and protein pumps to transport
molecules against the concentration
gradient (low to high concentrations).

Answer 9

Active Transport

Question 10

Sodium-potassium pump
* Cell to cell communication (synapses)
* Action potentials
* Nervous system functions

Answer 10

Active Transport

Question 11

Channel proteins have a hydrophilic
channel that certain molecules or ions can use as a tunnel.

Answer 11

Passive Transport

Question 12

Channel proteins called aquaporins
facilitate the passage of water

Answer 12

Passive Transport

Question 13

Carrier proteins bind to molecules and
change shape to shuttle them across the membrane.

Answer 13

Passive Transport

Question 14

the control of
solute concentrations and water
balance, is a necessary adaptation for
life in such environments.

Answer 14

Osmoregulation

Question 15

A protist, which is
hypertonic to its pond water
environment, has a contractile
vacuole that acts as a pump.

Answer 15

Paramecium,

Question 16

is the ability of a surrounding solution to cause a cell to gain or lose water

Answer 16

Tonicity

Question 17

Solute concentration is the same as that inside the cell; no net
water movement across the plasma membrane

Answer 17

Isotonic solution

Question 18

Solute concentration (high to low) is greater than that inside
the cell; cell loses water

Answer 18

Hypertonic solution

Question 19

Solute concentration is less than that inside the cell; cell
gains water

Answer 19

Hypotonic solution

Question 20

Solute that moves from high to low concentrations

Answer 20

Diffusion

Question 21

Solvent moves from low to high concentrations

Answer 21

Osmosis

Question 22

Occurs without the input of cellular
energy. High concentration to low concentration

Answer 22

Passive Transport

Question 23

1. Simple diffusion (i.e. oxygen).
2. Facilitated diffusion
   * Channel mediated
   * Carrier Mediated

Answer 23

Passive Transport

Question 24

Transport of biomolecules does what? (Three answers)

Answer 24

• Selectively permeable
• Regulate what enters and
  exits the cell.
• Facilitating the transport
  of materials needed for
  cell activities.

Question 25

Physically separates the intracellular components of the cells from the extracellular environment.

Answer 25

Protection of cells

Question 26

Bound either to proteins (forming glycoproteins) or to lipids (forming glycolipids). Plays a key role in cell recognition and protection. Found on the outside surface of cells.

Answer 26

Carbohydrates

Question 27

* Maintains the structural integrity of the cell. * Regulates the fluidity of cell membranes.

Answer 27

Cholesterol

Question 28

* Extrinsic membrane protein * Loosely associated with the membrane surface. * Either on the extracellular or cytoplasmic surface. * Connected to the polar head of the lipid bilayer. * Hydrophilic in nature.

Answer 28

Peripheral Membrane Proteins

Question 29

* Type of integral membrane protein. * The protein itself is not in contact with the membrane. * Anchored on the cell membrane through covalent binding to a lipid molecules. * i.e. glycosyl-phosphatidylinositol or GPI anchored proteins.

Answer 29

Lipid-Anchored Membrane Proteins

Question 30

- Made by Singer and Nicolson in 1972 - No consistent pattern or arrangement; just like a mosaic - Cell membrane has proteins that are partially embedded

Answer 30

Fluid Mosaic Model

Question 31

- Forms basic structure of membrane - Acts as barrier

Answer 31

Phospholipid Bilayer

Question 32

- Manage passage of required molecules - Facilitate communication within cell’s environment

Answer 32

Membrane Proteins

Question 33

3 adaptations of cell membrane

Answer 33

Hot environment, Cold environment, Extremely salty environments

Question 34

(Cell membrane - cellular communication) - Neurotransmitter-mediated signaling - Allow neurons to transmit signals through chemicals

Answer 34

Chemical Synapses

Question 35

(Cell membrane - cellular communication) Direct electrical coupling - Allow neurons to transmit signals through electricity

Answer 35

Electrical Synapses

Question 36

- Intrinsic membrane protein - Permanently embedded in membrane - Connected to nonpolar head of lipid bilayer - Hydrophobic - ie. transmembrane and transport proteins

Answer 36

Integral Membrane Protein

Question 37

Where membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid.

Answer 37

tight junctions

Question 38

(anchoring junctions) Junction that fasten cells together into strong sheets

Answer 38

Desmosomes

Question 39

(communicating junctions) Junctions that provide cytoplasmic channels between adjacent cells

Answer 39

Gap junctions

Question 40

Neighboring cells in tissues, organs, or organ systems often adhere, interact, and communicate through direct physical contact

Answer 40

Cell Junctions

Question 41

ECM is made up of _____ such as collagen, proteoglycans, and fibronectin

Answer 41

glycoproteins

Question 42

ECM proteins bind to _______ in the plasma membrane called integrins

Answer 42

receptor proteins

Question 43

Microtubules control the beating of _____ and ______ microtubule-containing extensions that project from some cells

Answer 43

flagella and cilia

Question 44

are the thickest of the 3 components of the cytoskeleton

Answer 44

Microtubules

Question 45

(actin filaments) are the thinnest components

Answer 45

Microfilaments

Question 46

are fibers with diameters in a middle range

Answer 46

Intermediate filaments

Question 47

encloses the nucleus, separating it from the cytoplasm

Answer 47

Nuclear envelope

Question 48

is a double membrane; each membrane consists of a lipid bilayer

Answer 48

Nuclear membrane

Question 49

is located within the nucleus and is the site of ribosomal RNA (rRNA) synthesis

Answer 49

nucleolus