Cell Structure (Ch. 3)

Question 1

• Boundary of the cell
• Phospholipid bilayer
• Described by “Fluid Mosaic Model”
• Selectively permeable
• Includes proteins + lipids + carbohydrates

Answer 1

Plasma membrane

Question 2

“Inside the cell”

Answer 2

Intracellular

Question 3

“Outside the cell”

Answer 3

Extracellular

Question 4

The intracellular environment made up of cytosol and organelles

Answer 4

Cytoplasm

Question 5

Fluid between cells in the body

Answer 5

Interstitial fluid

Question 6

Site for binding of a chemical messenger on the plasma membrane; “docking station”

Answer 6

Receptor molecules

Question 7

Allow for cell recognition; important for the immune system to recognize invaders

Answer 7

Marker molecules

Question 8

• Proteins and lipids with carbohydrates (sugars) stuck to them
• Act as receptor and marker molecules in the plasma membrane

Answer 8

Glycoproteins and glycolipids

Question 9

• Any kind of movement through a plasma membrane that uses no energy

Answer 9

Passive transport

Question 10

• Any kind of movement through a cell membrane that requires energy (ATP)
• May move solutes against their concentration gradient (i.e. from low to high)

Answer 10

Active transport

Question 11

Dissolved substance in a solution

Answer 11

Solute

Question 12

Liquid in a solution

Answer 12

Solvent

Question 13

From higher to lower concentration

Answer 13

Concentration gradient

Question 14

Net movement of a substance along its concentration gradient

Answer 14

Diffusion

Question 15

• Diffusion of a dissolved substance (solute) along its concentration gradient;
• Occurs when membrane is permeable to the solute

Answer 15

Dialysis

Question 16

• Diffusion of water along its concentration gradient
• Occurs when membrane is NOT permeable to the solute

Answer 16

Osmosis

Question 17

• Equal (balanced) concentration of solutes between two solutions (i.e. between intracellular and extracellular)
• No net movement occurs

Answer 17

Isotonic

Question 18

• A solution that contains a higher concentration of solutes (in comparison)
• A cell put in this solution with SHRINK (if its membrane is not permeable to the solute)

Answer 18

Hypertonic

Question 19

• A solution that contains a lower concentration of solutes (in comparison)
• A cell put in this solution may burst or LYSE (if its membrane is not permeable to the solute)

Answer 19

Hypotonic

Question 20

• A type of passive transport in which a moving stream of liquid (e.g. the blood stream) flows over a membrane, and only particles small enough to fit through tiny holes in the membrane get through.

Answer 20

Filtration

Question 21

A type of passive transport in which substances diffuse, but with the help of “carrier” molecules

Answer 21

Facilitated diffusion

Question 22

A tiny “bubble” of membrane, filled with material for transport.

Answer 22

Vesicle

Question 23

• Extracellular material pushes up against the plasma membrane of a cell until part of the membrane caves in and surrounds it
• Allows for particles too large to fit through the plasma membrane to enter the cell in the form of vesicles

Answer 23

Endocytosis

Question 24

• A cell wraps itself around something solid, like an invading bacteria, until the invader becomes completely surrounded (“eaten”)

Answer 24

Phagocytosis

Question 25

• A cell wraps itself around a drop of solution, like digested food sloshing around in the intestines, and “drinks” it inside of itself

Answer 25

Pinocytosis

Question 26

• Vesicles formed inside the cell fuse with the plasma membrane and dump their contents outside of the cell boundary

Answer 26

Exocytosis

Question 27

• Gooey stuff organelles float around in
• Includes: Fluid (A solution of dissolved ions and a colloid of suspended molecules) and cytoplasmic inclusions

Answer 27

Cytosol

Question 28

Maintains cell shape and allows certain cells to move (e.g. sperm)

Answer 28

Cytoskeleton

Question 29

• Temporary additions to the cell (e.g. nutrients not yet used up or waste products not yet expelled)

Answer 29

Cytoplasmic inclusions

Question 30

• Organelle bound by a double membrane
• Glucose is broken down to create ATP

Answer 30

Mitochondria

Question 31

• The folds in the inner membrane of the mitochondria
• Contain enzymes for the Electron Transport System

Answer 31

Cristae

Question 32

• The space between the folds of the inner membrane of a mitochondria
• Contains enzymes for the Citric Acid Cycle

Answer 32

Matrix

Question 33

• Organelles with NO membrane of their own
• Composed of two small “sub-units” joined together
• Synthesize proteins
• May be either free-floating (make proteins for use by the cell) or attached to the RER (make proteins for export)

Answer 33

Ribosomes

Question 34

• A series of membrane-bound channels and sacs directly connected to the cell nucleus
• Synthesizes lipids such as phospholipids to replace lost plasma membrane

Answer 34

Smooth endoplasmic reticulum (SER)

Question 35

• Membrane-bound channels and sacs that are “studded” with ribosomes
• Manufactures proteins for out-of-cell use

Answer 35

Rough endoplasmic reticulum (RER)

Question 36

• Organelle that modifies, packages, and distributes lipids and proteins inside of vesicles meant for exocytosis from the cell
• A stack of flattened, membranous sacs that recieves lipids and proteins from the SER and RER and prepares them for export.

Answer 36

Golgi apparatus

Question 37

• Membrane-bound organelles produced by the golgi apparatus
• Filled with digestive enzymes
• Used to break down food, and also to commit “suicide” in an old or defective cell

Answer 37

Lysosome

Question 38

• A large centrally located membrane-bound organelle
• Contains DNA
• The site of RNA synthesis
• Contains a nucleolus

Answer 38

Nucleus

Question 39

• A dense patch of the nucleus made up of RNA
• Synthesizes the “sub-units” that eventually make up ribosomes

Answer 39

Nucleolus