Chapter 4: General Features of Cells

Question 1

prokaryotes

Answer 1

simple cell structure, no nucleus

Question 2

eukaryotes

Answer 2

more complex cells, DNA enclosed within membrane-bound nucleus, internal membranes from organelles

Question 3

cytoplasm

Answer 3

contained within plasma membrane (everything found within the cell)

Question 4

cytosol

Answer 4

everything outside the cell organelles but inside the plasma membrane

Question 5

nucleoid region (bacteria)

Answer 5

where DNA is located

Question 6

ribosome

Answer 6

synthesizes proteins, not an organelle

Question 7

cell wall

Answer 7

provide support and protection

Question 8

glycocalyx (bacteria)

Answer 8

traps water, gives protection, helps evade the immune system

Question 9

appendages (bacteria)

Answer 9

pilli (attachment), flagella (movement)

Question 10

organelles

Answer 10

membrane-bound compartments, each has unique structure and function

Question 11

variety

Answer 11

shape, size, and organization of cells vary considerably

Question 12

chloroplast

Answer 12

site of photosynthesis

Question 13

central vacuoles

Answer 13

site that provides storage and regulation of cell volume

Question 14

cell wall

Answer 14

structure that provides cell support

Question 15

cytoskeleton

Answer 15

network of three types of protein filaments: microtubules, intermediate filaments, actin/microfilaments

Question 16

microtubules

Answer 16

hollow and composed of protein tubulin; functions in cell shape, organization of organelles, intracellular cargo movement, cell mobility

Question 17

intermediate filaments

Answer 17

twisted filaments and can be composed of different proteins; function in cell shape, cell strength, anchoring of cell, nuclear membrane

Question 18

actin/microfilaments

Answer 18

spiral-shaped composed of intertwined strands of actin; function in cell shape, cell strength, muscle contraction, cell movement, cytokinesis in animal cells

Question 19

cytokinesis

Answer 19

step in cell division when a cell splits into two

Question 20

motor proteins

Answer 20

use ATP as a source of energy for movement

Question 21

motor protein movement

Answer 21

1. carries cargo along filament
2. motor protein remains fixed, filament moves
3. motor protein and filament remain fixed, filament bends

Question 22

flagella

Answer 22

usually longer than cilia, present singly or in pairs

Question 23

cilia

Answer 23

often shorter than flagella, tend to cover all or part of the cell surface

Question 24

propagation of a bend

Answer 24

flagella/cilia movement begins at the base and moves toward the tip

Question 25

endomembrane system

Answer 25

enclosing the nucleus, endoplasmic recticulum, golgi apparatus, lysosomes, vacuoles, and plasma membrane

Question 26

nuclear envelope

Answer 26

double-membrane structure enclosing nucleus, outer membrane is continuous with ER membrane

Question 27

nuclear pores

Answer 27

provide passageways into the nucleus

Question 28

chromosomes

Answer 28

composed of DNA and proteins

Question 29

chromatin

Answer 29

complex of DNA and proteins

Question 30

euchromatin

Answer 30

loosely distributed, transcriptionally active

Question 31

heterochromatin

Answer 31

densely packed, transcriptionally inactive

Question 32

nuclear matrix

Answer 32

filamentous network, organizes chromosomes

Question 33

nucleolus

Answer 33

where ribosome assembly occurs

Question 34

endoplasmic recticulum

Answer 34

network of membranes that form flattened, fluid-filled tubules or cisternae

Question 35

ER lumen

Answer 35

single compartment created by the ER membrane

Question 36

rough endoplasmic recticulum

Answer 36

studded with ribosomes, involved in protein synthesis and sorting

Question 37

smooth endoplasmic recticulum

Answer 37

lacks ribosomes, detoxification, carbohydrate metabolism, calcium balance, synthesis, and modifications of lipids

Question 38

golgi apparatus

Answer 38

stack of flattened membrane-bound compartments

Question 39

vesicles

Answer 39

transport materials in the cell

Question 40

pulse-charge experiments

Answer 40

used by George Palade to trace the path of radioactive proteins

Question 41

lysosomes

Answer 41

contain acid hydrolase that promotes hydrolysis, breaks down carbohydrates, nucleic acids, and lipids

Question 42

autophagy

Answer 42

recycling of worn-out organelles through endocytosis

Question 43

central vacuoles

Answer 43

used for storage and support in plants

Question 44

contractile vacuoles

Answer 44

used to expel excess water in protists

Question 45

phagocytic vacuoles

Answer 45

used for degradation in protists and white blood cells

Question 46

perozisomes

Answer 46

catalyze certain reactions that break down molecules by removing hydrogen or adding oxygen

Question 47

catalase

Answer 47

breaks down dangerous hydrogen peroxide into water and oxygen

Question 48

plasma membrane

Answer 48

boundary between the cell and extracellular environment

Question 49

membrane transport

Answer 49

in and out of the cell with selective permeability

Question 50

cell signaling

Answer 50

using receptor

Question 51

semiautonomous organelles

Answer 51

mitochondria and chloroplasts

Question 52

mitochondria

Answer 52

primary role is to make ATP, also involved in the synthesis, modification, and breakdown of several types of cellular molecules

Question 53

mitochondrial matrix

Answer 53

inner folded part that allows for more reactions to make ATP

Question 54

chloroplasts

Answer 54

perform photosynthesis

Question 55

photosynthesis

Answer 55

capture light energy and use some of that energy to synthesize organic molecules like glucose

Question 56

thalakoid membrane

Answer 56

surrounds the compartment where photosynthesis occurs

Question 57

evidence of mitochondria and chloroplasts being descended from bacteria

Answer 57

different ribosomes, contain circular DNA, similar structure to bacteria

Question 58

protein sorting

Answer 58

how eukaryotic proteins are sorted to the right destination

Question 59

co-translational sorting

Answer 59

begins in cytosol during translation, ER signal sequence binds signal recognition particle (SRP) and associates with ER channel - for: ER, golgi apparatus, lysosomes, vacuoles, plasma membrane, and secreted proteins

Question 60

post-translational sorting

Answer 60

synthesized in cytosol and taken up by target organelles; short amino acid sequence directs the protein to its target where its taken up from the cytosol -for: nucleus, mitochondria, chloroplasts, and peroxisomes