2. Cells and Organelles

Question 1

What is the function of the nucleus?

Answer 1

Contains DNA; coordinates cell activities like protein synthesis and reproduction

Question 2

What structure contains genetic material in prokaryotes?

Answer 2

Nucleoid

Question 3

What is the function of the rough endoplasmic reticulum?

Answer 3

Synthesizes and stores proteins; has ribosomes attached

Question 4

What is the function of the smooth endoplasmic reticulum?

Answer 4

Synthesizes lipids and steroid hormones for export

Question 5

What is the function of the nucleolus?

Answer 5

Site of ribosome (rRNA) synthesis

Question 6

What occurs in the cytoplasm?

Answer 6

Metabolic activities of the cell occur here; includes organelles

Question 7

What is the function of the Golgi apparatus?

Answer 7

Modifies and packages proteins (e.g., glycosylates polypeptides)

Question 8

What is the function of lysosomes?

Answer 8

Break down nutrients, bacteria, and cell debris; involved in apoptosis

Question 9

What is the function of mitochondria?

Answer 9

Makes ATP, site of fatty acid catabolism; has its own circular DNA and ribosomes

Question 10

What do peroxisomes do?

Answer 10

Break down substances; common in liver and kidney

Question 11

What are vacuoles?

Answer 11

Membrane-bound vesicles that move materials inside the cell

Question 12

What are ribosomes made of and what do they do?

Answer 12

Made of rRNA; synthesize proteins

Question 13

What does the cytoskeleton do?

Answer 13

Maintains cell shape and aids in movement

Question 14

What are microtubules and what are they composed of?

Answer 14

Composed of tubulin; support and mobility

Question 15

What is the function of centrioles?

Answer 15

Develop spindle fibers for cell division

Question 16

What is the function of cilia and flagella?

Answer 16

Movement of the cell

Question 17

What do intermediate filaments do?

Answer 17

Maintain cell shape

Question 18

What are microfilaments made of and what is their function?

Answer 18

Composed of actin; used for cell motility

Question 19

What is the function of the extracellular matrix?

Answer 19

Provides mechanical support and binds adjacent cells (most abundant component is collagen)

Question 20

What are plant-specific organelles?

Answer 20

Cell walls and plastids (e.g., chloroplasts for photosynthesis)

Question 21

What are traits of prokaryotes?

Answer 21

No nucleus, single circular DNA, 70S ribosomes, peptidoglycan cell walls, flagellin-based flagella

Question 22

What are the properties of the phospholipid membrane?

Answer 22

Allows small, uncharged, hydrophobic molecules to pass freely

Question 23

What is passive transport?

Answer 23

Movement down a gradient without ATP

Question 24

What are types of passive transport?

Answer 24

Simple diffusion, osmosis, dialysis, plasmolysis, facilitated diffusion, countercurrent exchange

Question 25

What is active transport?

Answer 25

Movement against a gradient using ATP

Question 26

What is the role of cholesterol in the membrane?

Answer 26

Regulates membrane fluidity

Question 27

What is the function of channel proteins?

Answer 27

Allow passage of hydrophilic, polar, or charged substances

Question 28

What are ion channels?

Answer 28

Voltage-, ligand-, or mechanically-gated channels for ions

Question 29

What are porins?

Answer 29

Less specific channels for ions and polar molecules

Question 30

What do carrier proteins do?

Answer 30

Change shape to move specific molecules across the membrane

Question 31

What is phagocytosis?

Answer 31

Endocytosis of undissolved (solid) material

Question 32

What is pinocytosis?

Answer 32

Endocytosis of dissolved (liquid) material

Question 33

What is receptor-mediated endocytosis?

Answer 33

Pinocytosis involving ligands binding to specific receptors

Question 34

What is an anchoring junction?

Answer 34

Includes desmosomes; connects two cells

Question 35

What is a tight junction?

Answer 35

Encircles a cell; prevents passage of materials (e.g., in digestive tract)

Question 36

What is a gap junction?

Answer 36

Narrow tunnels between animal cells allowing ion/small molecule passage

Question 37

What do transport proteins do?

Answer 37

Use ATP for active transport or assist in facilitated diffusion (e.g., Na+/K+ pump)

Question 38

Hypertonic

Answer 38

Higher solute concentration, explodes (lysed)

Question 39

Isotonic

Answer 39

Equal solute concentration

Question 40

Hypotonic

Answer 40

Low solute concentration, shrinks