3.4

Question 1

cytoskeleton (def)

Answer 1

network of protein filaments and cylinders that:

structurally support a cell
determine its shape
organize its contents
direct the movement of materials w/in the cell
contribute to movements of the cell as a whole

Question 2

cytoskeleton is composed of…

Answer 2

microfilaments
intermediate filaments
microtubules

Question 3

microfilaments (def)

Answer 3

thin filaments
made of protein actin

crucial role in:
embryonic development
muscle contraction
immune function
wound healing
cancer metastasis
cell migration

Question 4

intermediate filaments (def)

Answer 4

thicker and stiffer than microfilaments

give cell:
its shape
resist stress
participate in junctions that attach cells to their neighbors

Question 5

microtubules (def)

Answer 5

cylinders made of 13 parallel strands called protofilaments

each protofilament is a long chain of tubular (globular proteins)

radiate from area of cell called centrosome

hold organelles in place
form bundles that maintain cell shape and rigidity
act like monorail tracks

Question 6

organelle (def)

Answer 6

internal structure of a cell that carries out specialized metabolic tasks

Question 7

membranous organelles (def)

Answer 7

organelles surrounded by membranes

Question 8

membranous organelles (examples)

Answer 8

nucleus
mitochondria
lysosomes
peroxisomes
endoplasmic reticulum
Golgi complex

Question 9

organells w/o membranes (examples)

Answer 9

ribosomes
proteasomes
centrosomes
centrioles
basal bodies

Question 10

nucleus (def)

Answer 10

largest organelle
contains cell’s chromosomes –> genetic control center of cell activity

Question 11

anuclear (def)

Answer 11

cells that don’t have a nucleus

ex.
mature red blood cells are anuclear

Question 12

multinuclear (def)

Answer 12

cells that have multiple nuclei

ex.
skeletal muscle cells, liver cells, bone-dissolving cells

Question 13

nuclear envelope (def)

Answer 13

double membrane that encloses nucleus

Question 14

nuclear pores (def)

Answer 14

pores in nuclear envelope
regulate molecular traffic thru the envelop
holds the 2 membrane layers together

Question 15

nuclear lamina (def)

Answer 15

a web of intermediate filaments
densely fibrous zone
inside the nuclear envelop

Question 16

nucleoplasm (def)

Answer 16

material inside nucleus

includes chromatin and nucleoli

Question 17

chromatin (def)

Answer 17

fine threadlike matter of DNA and protein
part of nucleoplasm in nucleus

Question 18

nucleoli (def)

Answer 18

mass where ribosomes are produced
part of nucleoplasm in nucleus

Question 19

endoplasmic reticulum (def)

Answer 19

system of interconnected channels called cisterns
enclosed by a unit membrane

Question 20

rough endoplasmic reticulum (def)

Answer 20

cisterns are parallel, flattened sacs
covered in ribosomes
cisterns of RER are continuous w/ cisterns of SER

Question 21

smooth endoplasmic reticulum (def)

Answer 21

cisterns are more tubular, branch more extensively, and lack ribosomes
cisterns of SER are continuous w/ cisterns of RER

Question 22

rough ER (function)

Answer 22

synthesizes steroids and lipids
detoxifies alcohol and other drugs
manufactures nearly all membranes of the cell

produces phospholipids and proteins of the plasma membrane
synthesizes large amounts of protein

Question 23

smooth ER (function)

Answer 23

present in cells that engage extensively in detoxification (liver and kidney cells)

abundant in cells of the testes and ovaries that synthesize steroid hormones

Question 24

what is function of nucleolus?

Answer 24

ribosome production

Question 25

the Golgi complex packages cellular products that will be exported from the cell into which structures?

Answer 25

secretory vesicles

Question 26

organelle comprised of stacked cistern that synthesize carbs

Answer 26

golgi complex

Question 27

skeletal and cardiac muscle cells store calcium in extensive networks of which organelle?

Answer 27

smooth ER

Question 28

lysosome (def)

Answer 28

membrane-bound organelle that contains a mixture of enzymes that function in digesting forming matter, pathogens, and expired organelles

Question 29

where are proteins, such as enzymes, that are to be secreted form the cells produced?

Answer 29

ribosomes on ER

Question 30

which organelle adds carb groups to proteins produced at the ER?

Answer 30

Golgi

Question 31

which organelle contains enzymes needed to neutralize free radicals, detoxify alcohol, other drugs, and blood-borne toxins?

Answer 31

peroxisome

Question 32

a cell uses organelles called ___ to get rid of nonfunctional proteins

Answer 32

proteasomes

Question 33

___ are the organelles that digest and dispose of worn-out mitochondria and other organelles by a process called autophagy

Answer 33

lysosomes

Question 34

what are small granules of RNA and protein that provide a site for protein synthesis?

Answer 34

ribosomes

Question 35

mitochondria has a ___ unit membrane

Answer 35

double

Question 36

the Golgi complex packages cellular products that will be exported from the cell into which structures?

Answer 36

secretory vesicles

Question 37

centrosome (def)

Answer 37

comprised of 2 centrioles

Question 38

which organelle participates in cell division?

Answer 38

centrioles

Question 39

the membrane-bound organelle that contains enzymes and oxygen used to oxidize organic material is the ___

Answer 39

peroxisome

Question 40

which are not essential to cell survival?

Answer 40

inclusions

Question 41

most of a cell's proteins are broken down by which organelles?

Answer 41

proteasomes

Question 42

which of the following are components of nucleotides?

Answer 42

nitrogenous bases phosphate gropus sugars (ribose or deoxyribose)

Question 43

cytosine is a ___ that binds with ___

Answer 43

pyrimidine that binds w/ guanine

Question 44

adenine is a ___ that binds with ___

Answer 44

purine that binds w/ thymine

Question 45

thymine is a ___ that binds with ___

Answer 45

pyrimidine that binds w/ adenine

Question 46

guanine is a ___ that binds with ___

Answer 46

purine that binds w/ cytosine

Question 47

the pyrimidines are ___ and ___

Answer 47

thymine and cytosine

Question 48

the purines are ___ and ___

Answer 48

adenine and guanine

Question 49

basal bodies and the axonemes of flagella and cilia originate from which non-membranous organelles?

Answer 49

centrioles

Question 50

inclusions (def)

Answer 50

accumulated cell products such as glycogen granules, pigments, and fats

Question 51

a cell uses organelles called ___ to get rid of nonfunctional proteins

Answer 51

proteasomes

Question 52

adenine and thymine form ___ hydrogen bonds w/ each other

Answer 52

2

Question 53

cytosine and guanine form ___ hydrogen bonds w/ each other

Answer 53

3

Question 54

in the nucleus, DNA is complexed w/ proteins to form a fine filamentous material called ___

Answer 54

chromatin

Question 55

a centromere holds ___ together

Answer 55

sister chromatids

Question 56

which is a characteristic of RNA?

Answer 56

contains nitrogenous bases A, U, C, G it leaves the nucleus and can be found in the cytoplasm it plays an important role in the production of proteins

Question 57

DNA (characteristics): contains a sugar called ___ contains nitrogenous bases ___ consists of ___ nucleotide chains (___ helix) it functions in the ___ it codes for ___

Answer 57

sugar called deoxyribose nitrogenous bases A, T, C, G 2 nucleotide chains (double helix) functions in the nucleus codes for synthesis of RNA and protein

Question 58

RNA (characteristics): contains a sugar called ___ contains nitrogenous bases ___ consists of ___ nucleotide chain it functions in the ___ it carries ___

Answer 58

sugar called ribose nitrogenous bases A, U, C, G 1 nucleotide chain functions mainly in cytoplasm carries out the instructions in DNA

Question 59

centromere (def)

Answer 59

where 2 sister chromatids are joined together