Lyons Nsu-Phs4904 The Cell Ch 3

Front 1

basic unit of structure & function, a highly organized molecular factory

Back 1

cell

Front 2

all cells have a _____

Back 2

plasma membrane (pm)

Front 3

subcellular structures are also known as ______

Back 3

organelles

Front 4

the physiology of our organs & systems derives from the __________ of the cells of which they are composed

Back 4

complex functions

Front 5

cells can be divided into 3 principle portions:

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1- plasma membrance (pm), 2- cytoplasm & organelles, & 3-nucleus

Front 6

the pm aka cell membrane (cmb) are primarily composed of _______&______

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phospholipids & mb proteins

Front 7

the pm has 3 specific functions:

Back 7

1-selective permeability, 2-form & seperation (movement), & 3-communication (betw. intra/extra cellular)

Front 8

the aquaneous content of a cell inside the pm but outside the nucleus is called ____

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cytoplasm

Front 9

the aquaneous part of the cytoplasm is called ______

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cytosol

Front 10

_______, (excluding the nucleus), are subcellular structures within the cytoplasm that perform specific functions.

Back 10

organelles

Front 11

the largest organelle:

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nucleus

Front 12

the nucleus contains the _____ & the ______.

Back 12

DNA, nucleoli

Front 13

the fluid mosaic model consists of a _____ on the outside & a _______ center

Back 13

phospholipid bilayer, hydrophobic

Front 14

what is restricted from passing through the phospholipid bilayer? _____, _____, &_______

Back 14

water, charged ions, & other water soluble (polar) substances

Front 15

what can pass through the phospholipid bilayer easily?

Back 15

small molecules, lipid soluble substances, CO2, O2, steriod hormones, drugs, alcohol.

Front 16

the ______ directs the cells activities

Back 16

nucleus

Front 17

mb proteins can be either ____ or _____

Back 17

peripheral, integral

Front 18

_____ proteins are only partically embedded in one face of the mb

Back 18

peripheral

Front 19

______proteins span from 1 side of the mb to the other

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integral

Front 20

the fluid mosiac model is dynamic. 2 parts of the fm model are free to move laterally: ____ & ___

Back 20

phospholipids & proteins

Front 21

the heads of the lipid bilayer are ____ & facing _____. The tails are ____ & facing _____

Back 21

1- polar, outward. 2- nonpolar hydrocarbons, center

Front 22

the mb proteins serve a variety of functions. name 5:

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1-support, 2-transport (of molecules across mb), 3-enzymatic (control of chm rxns), 4-receptors & signaling (hormones & regulatory molecules), & 5-cell id (antigens)

Front 23

glycoproteins & glycolipids are __________ attached to the _____ side of the mb

Back 23

mb carbohydrates, extracellular

Front 24

certain _____ on the pm of rbc's serve as antigens that determine blood type

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glycolipids

Front 25

some _____ have negative charges which affect the interactions betw. cells, & also betw. the mb & regulatory molecules

Back 25

mb carbohydrates

Front 26

can the cytoskeleton change shape?

Back 26

yes

Front 27

_____ is the process in which the pm furrows inward

Back 27

endocytosis

Front 28

pinocytosis is:

Back 28

non specific form of endocytosis. pm invaginates, mb fuses, & sm vesicle containing ECF pinches off & enters cell. allows cell to engulf macromolecules & proteins

Front 29

this process involves a small mb patch where specific molecules in extracellular environment must bind specific receptor proteins in the pm before mb invaginates & vesicle pinches off:

Back 29

receptor mediated endocytosis

Front 30

golgi packages secretory vesicles that fuse with the pm & release into extracellular environment. This is called _____

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exocytosis

Front 31

is cytosol a homogenous solution?

Back 31

no, it is a highly organized structure

Front 32

the latticework of microfilaments & microtubules is said to function as a ________

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cytoskeleton

Front 33

what protein moves along filaments of actin like a molecular motor for muscle contraction?

Back 33

myosin

Front 34

can the cytoskeleton move or is it rigid?

Back 34

it is not rigid. it can move quite rapidly and reorganize

Front 35

what are the molecular motors that move along microtubules called?

Back 35

kinesin & dynein

Front 36

does exocytosis increase or decrease the mb surface area?

Back 36

increase

Front 37

the railway within the cell is known as _____

Back 37

cytoskeleton

Front 38

the protein fibers in the cytoplasm surrounding the organelles are called ______ & _______

Back 38

microfilaments, microtubules

Front 39

nerve endings release neurotransmitters by a process called ____.

Back 39

exocytosis

Front 40

the ______ & _____ aid the cell in movement

Back 40

microfilaments & microtubules (cytoskeleton)

Front 41

this organelle contains a hydrolytic enzyme mixture inside & is responsible for the digestive system of the cell:

Back 41

lysosomes

Front 42

multitudes of peroxisomes be found in this organ:

Back 42

liver

Front 43

what enzyme prevents excessive accumulation of H2O2?

Back 43

catalase (within peroxisomes)

Front 44

3 ways lysosomes receive the wastes?

Back 44

1-fuse with food vacuoles of phagosomes, 2-endocytosis, & 3-autophagosome within the cell

Front 45

what is apoptosis & which organelle is responsible for it?

Back 45

autolysis (suicide), lysosomes, a break in lysosome mb would release digestive enzymes & destroy the cell

Front 46

this organelle (other than nucleus) has its own mb & is separate from other organelles in the cytoplasm:

Back 46

lysosomes

Front 47

which organelle is most important for the function in liver & kidney cells?

Back 47

peroxisome

Front 48

peroxisome

Back 48

this organelle is responsible for oxidation of toxic molecules which forms H2O2 (hydrogen peroxide)

Front 49

a process that destroys worn out organelles & proteins so they can be replaced is called_____

Back 49

autophagy

Front 50

why are lysosomes mb bound?

Back 50

because their hydrolytic digestive enzyme mixture inside would destroy the cell

Front 51

all cells in the body, (except for rbc's), have 100-1000's organelles called _____

Back 51

mitochondria

Front 52

common theory: ______ evolved from bacteria, which then invaded human/animal host, & so far has remained in a state of symbiosis

Back 52

mitochondria

Front 53

"protein factories" of the cell

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ribosomes

Front 54

what is the structure of a ribosome composed of?

Back 54

2 subunits (30S & 50S) composed of Rrna & proteins

Front 55

describe the inner & outer mb of mitochondria

Back 55

inner mb characterized by cristae & an outer mb is smooth

Front 56

the space betw. 2 subunits of ribosomes accommodate ____, needed to bring aa (amino acids) to growing polypeptide chain.

Back 56

Trna

Front 57

Rrna has enzymatic function for many of rxns required for protein synthesis. These enzymes are called____

Back 57

ribozymes

Front 58

what are cristae & where are they located?

Back 58

folds/shelves of the inner mb of mitochondria that project into the matrix (central area)

Front 59

which organelle contains its own separate DNA (not human) & can self replicate?

Back 59

mitochondria

Front 60

this tiny 25nM organelle can be found attach to ER, nuclear envelope, or free in cytoplasm, & is composed of 2 subunits:

Back 60

ribosome

Front 61

why do rbc's lack mitochondria?

Back 61

because mitochondria would use up all of the O2 that the rbc's carry

Front 62

most cells contain a system of membranes known as (granular)_____ or (agranular)____

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ER (endoplasmic reticulum) or RER (rough-containing ribosomes)

Front 63

this organelles consists of a stack of several flattened sacs (like pacakes) with cisternae within each sac

Back 63

golgi complex/apparatus

Front 64

3 duties the agranular ER (SER) is responsible for:

Back 64

1-steroid hormone production, 2-steroid & drug inactivation, 3-stores calcium in striated muscle cells (for contraction)

Front 65

the golgi has 2 sides. the___ faces the ER, & the ___faces the pm

Back 65

cis, trans

Front 66

_____ in liver cells has enzymes that inactivate steroid & drugs by converting them to more water-soluble, less active forms, which can be more easily excreted by the kidneys.

Back 66

SER (smooth ER)

Front 67

the hollow cavities within the golgi flattened sacs are called:

Back 67

cisternae

Front 68

this organelle is abundant in cells that are active in protein syn. & secretion, (such as many exocrine & endocrine glands)

Back 68

RER

Front 69

An abundance of SER be found in _____ cells & _____ cells.

Back 69

liver cells & muscle cells

Front 70

vesicles from ER enter the ____, which are then modified & packaged in vesicles before budding off & traveling to their destination

Back 70

golgi

Front 71

over time, if a patient uses a drug, tolerance will increase, which is accompanied by growth of _____ , & thus an increase of enzymes which inactivate the drug.

Back 71

agranular ER

Front 72

most cells have _____ nucleus'

Back 72

1

Front 73

what is the nuclear envelope composed of?

Back 73

an inner & outer mb fused together by nuclear pore complexes

Front 74

these cells have many nuclei:

Back 74

skeletal muscle cells

Front 75

how is cargo transported into & out of the nucleus?

Back 75

complex process- requires transport protein & energy (active carrier mediated transport)

Front 76

transport of specific proteins from cytoplasm into nucleus serve as regulation of _______ by hormones

Back 76

gene expression

Front 77

what is the structure of nuclear pore complexes?

Back 77

rivets-hold inner & outer mb of nuclear envelope together, has nuclear pores

Front 78

movement of RNA & protein through nuclear pores is selective. Why?

Back 78

to protect the DNA in nucleus.

Front 79

how many nuclei do rbc's have?

Back 79

none

Front 80

what is the central opening of the nucleus called?

Back 80

nuclear pore

Front 81

transport of _____ out of the nucleus, where it is formed is required for gene expression

Back 81

RNA

Front 82

what is gene expression?

Back 82

transcription & translation

Front 83

this term can refer to all of the genes in a particular individual or all of the genes in a particular species:

Back 83

genome

Front 84

each gene codes for _____ proteins

Back 84

many

Front 85

the region of DNA within nucleoli that codes (thru RNA) for protein is a called a _____

Back 85

gene

Front 86

the Human Genome Project 1990; how many different genes do humans have?

Back 86

25,000

Front 87

the ______ contains the DNA & code for MRNA

Back 87

nucleoli

Front 88

where is RNA formed?

Back 88

in the nucleus

Front 89

this term has been coined to refer to all of the proteins produced by the genome:

Back 89

proteome

Front 90

each cell produces ______ proteins

Back 90

100,000+

Front 91

the ratio of _____ to ____ is 25,000:100,000+

Back 91

genes to proteins

Front 92

the proteome is cell type specific. what does this mean?

Back 92

Some of the genome is inactive. Also diff. cell types produce specific proteins that vary according to hormones/ signaling. i.e. neurons produce proteins that are not produced by a liver cell & vice versa.

Front 93

what is deoxyribose nucleic acid?

Back 93

DNA

Front 94

what is a nucleotide?

Back 94

5 carbon sugar, phosphate group, & a nitrogenous base

Front 95

Cytosine pairs with _____

Back 95

Guanine

Front 96

_____ are joined by complimentary base pairing & is twisted to form a double helix

Back 96

nitrogenous bases ADCG

Front 97

Which hydrogen bonds are strongest? Adenine & Thymine? Or Guanine & Cytosine?

Back 97

Guanine & Cytosine

Front 98

what is DNA composed of?

Back 98

4 diff nucleotide subunits that contain nitrogenous bases Adenine Guanine Cytosine & Thymine

Front 99

what is the backbone if DNA composed of?

Back 99

5 carbon sugar & phosphate group

Front 100

RNA nucleotides contain _____, whereas DNA nucleotides contain Thymine

Back 100

Uracil

Front 101

Adenine pairs with _____

Back 101

Thymine

Front 102

what is the threadlike material that makes up the chromosomes?

Back 102

chromatin

Front 103

what is a nucleosome?

Back 103

2 turns of DNA (146 base pairs) wrapped around a core of histone spools

Front 104

histones

Back 104

proteins that make up much of the protein content of chromatin

Front 105

when chromatin is active in genetic transcription (RNA syn.) & loose, it is in a form called _____

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eurochromatin

Front 106

the non-dividing cell (G, S, & G2) is in a part of its life cycle called ______

Back 106

interphase

Front 107

how is chromatin made?

Back 107

the DNA combines with protein

Front 108

what is heterochromatin?

Back 108

highly condensed chromatin that is inactive & condensed

Front 109

_____ are positively charged, organized to form spools, & are the basis of nucleosomes

Back 109

histones

Front 110

what does the G1 phase involve?

Back 110

centrioles duplicate

Front 111

what phase in interphase is DNA (46 chromosomes) replicated in?

Back 111

S phase (synthesis)

Front 112

in ____ phase, chromosome condenses & the cell double checks the duplicated chromosomes for error

Back 112

G2

Front 113

the cell cycle consists of:

Back 113

G1, S, G2, Mitosis, & Cytokinesis

Front 114

what does mitosis consist of?

Back 114

prophase, metaphase, anaphase, & telophase

Front 115

how long do hair & skin (epithlial cells) take to cycle?

Back 115

not long, about 2 weeks

Front 116

how long do nerve & muscle cells take to cycle?

Back 116

they do not divide. they are growth arrested

Front 117

deregulations in cells are implicated in _______

Back 117

cancers

Front 118

____ & ______are a group of proteins that might cause uncontrolled cell division as occurs in cancer.

Back 118

cyclins & cyclin dependent kinesis