Vocabulary Ch3

Front 1

Active Transport

Back 1

form of transport across the cell membrane that requires input of cellular energy

Front 2

Amphipathic

Back 2

a molecule that exhibits a difference in polarity between its two ends, resulting in a difference in water solubility

Front 3

Anaphase

Back 3

third stage of mitosis (and meiosis), during which sister chromatids separate into two new nuclear regions of a dividing cell

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Anticodon

Back 4

consecutive sequence of three nucleotides on a tRNA molecule that is complementary to a specific codon on an mRNA molecule

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Autolysis

Back 5

breakdown of cells by their own enzymatic action

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Autophagy

Back 6

lysosomal breakdown of a cell's own components

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Cell Cycle

Back 7

life cycle of a single cell, from its birth until its division into two new daughter cells

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Cell Membrane

Back 8

membrane surrounding all animal cells, composed of a lipid bilayer interspersed with various molecules; also known as plasma membrane

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Centriole

Back 9

small, self-replicating organelle that provides the origin for microtubule growth and moves DNA during cell division

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Centromere

Back 10

region of attachment for two sister chromatids

Front 11

Centrosome

Back 11

cellular structure that organizes microtubules during cell division

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Channel Protein

Back 12

membrane-spanning protein that has an inner pore which allows the passage of one or more substances

Front 13

Checkpoint

Back 13

progress point in the cell cycle during which certain conditions must be met in order for the cell to proceed to a subsequence phase

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Chromatin

Back 14

substance consisting of DNA and associated proteins

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Chromosome

Back 15

condensed version of chromatin

Front 16

Cilia

Back 16

small appendage on certain cells formed by microtubules and modified for movement of materials across the cellular surface

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Cleavage Furrow

Back 17

contractile ring that form around a cell during cytokinesis that pinches the cell into two halves

Front 18

Codon

Back 18

consecutive sequence of three nucleotides on an mRNA molecule that corresponds to a specific amino acid

Front 19

Concentration Gradient

Back 19

difference in the concentration of a substance between two regions

Front 20

Cyclin

Back 20

one of a group of proteins that function in the progression of the cell cycle

Front 21

Cyclin-dependent kinase (CDK)

Back 21

one of a group of enzymes associated with cyclins that help them perform their functions

Front 22

Cytokinesis

Back 22

final stage in cell division, where the cytoplasm divides to form two separate daughter cells

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Cytoplasm

Back 23

internal material between the cell membrane and nucleus of a cell, mainly consisting of a water-based fluid called cytosol, within which are all the other organelles and cellular solute and suspended materials

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Cytoskeleton

Back 24

"skeleton" of a cell; formed by rod-like proteins that support the cell's shape and provide, among other functions, locomotive abilities

Front 25

Cytosol

Back 25

clear, semi-fluid medium of the cytoplasm, made up mostly of water

Front 26

Diffusion

Back 26

movement of a substance from an area of higher concentration to one of lower concentration

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Diploid

Back 27

condition marked by the presence of a double complement of genetic material (two sets of chromosomes, one set inherited from each of two parents)

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DNA polymerase

Back 28

enzyme that functions in adding new nucleotides to a growing strand of DNA during DNA replication

Front 29

DNA replication

Back 29

process of duplicating a molecule of DNA

Front 30

Electrical Gradient

Back 30

difference in the electrical charge (potential) between two regions

Front 31

Endocytosis

Back 31

import of material into the cell by formation of a membran-bound vesicle

Front 32

Endoplasmic Reticulum (ER)

Back 32

cellular organelle that consists of interconnected membrane-bound tubules, which may or may not be associated with ribosomes (rough type or smooth type, respectively)

Front 33

Exocytosis

Back 33

export of a substance out of a cell by formation of a membrane-bound vesicle

Front 34

Exon

Back 34

one of the coding regions of an mRNA molecule that remain after splicing

Front 35

Extracellular Fluid (ECF)

Back 35

fluid exterior to cells; includes the interstitial fluid, blood plasma, and fluid found in other reservoirs in the body

Front 36

Facilitated Diffusion

Back 36

diffusion of a substance with the aid of a membrane protein

Front 37

Flagellum

Back 37

appendage on certain cells formed by microtubules and modified for movement

Front 38

G0 phase

Back 38

phase of the cell cycle, usually entered from the G1 phase; characterized by long or permanent periods where the cell does not move forward into the DNA synthesis phase

Front 39

G1 phase

Back 39

first phase of the cell cycle, after a new cell is born

Front 40

G2 phase

Back 40

third phase of the cell cycle, after the DNA synthesis phase

Front 41

Gene

Back 41

functional length of DNA that provides the genetic information necessary to build a protein

Front 42

Gene expression

Back 42

active interpretation of the information coded in a gene to produce a functional gene product

Front 43

Genome

Back 43

entire complement of an organism's DNA; found within virtually every cell

Front 44

Glycocalyx

Back 44

coating of sugar molecules that surrounds the cell membran

Front 45

Glycoprotein

Back 45

protein that has one or more carbohydrates attached

Front 46

Golgi Apparatus

Back 46

cellular organelle formed by a series of flattened, membrane-bound sacs that functions in protein modification, tagging, packaging, and transport

Front 47

Helicase

Back 47

enzyme that functions to separate the two DNA strands of a double helix during DNA replication

Front 48

Histone

Back 48

family of proteins that associate with DNA in the nucleus to form chromatin

Front 49

Homologous

Back 49

describes two copies of the same chromosome (not identical), one inherited from each parent

Front 50

Hydrophilic

Back 50

describes a substanc eor structure attracted to water

Front 51

Hydrophobic

Back 51

describes a substance or structure repelled by water

Front 52

Hypertonic

Back 52

describes a solution concentration that is higher than a reference concentration

Front 53

Hypotonic

Back 53

describes a solution concentration that is lower than a reference concentration

Front 54

Integral Protein

Back 54

membrane-associated protein that spans the entire width of the lipid bilayer

Front 55

Intermediate Filament

Back 55

type of cytoskeletal filament made of keratin, characterized by an intermediate thickness, and playing a role in resisting cellular tension

Front 56

Interphase

Back 56

entire life cycle of a cell, excluding mitosis

Front 57

Interstitial Fluid (IF)

Back 57

fluid in the mall spaces between cells not contained within blood vessels

Front 58

Intron

Back 58

non-coding regions of a pre-mRNA transcript that may be removed during splicing

Front 59

Isotonic

Back 59

describes a solution concentration that is the same as a reference concentration

Front 60

Kinetochore

Back 60

region of a centromere where microtubules attach to a pair of sister chromatids

Front 61

Ligand

Back 61

molecule that binds with specificity to a specific receptor molecule

Front 62

Lysosome

Back 62

membrane-bound cellular organelle originating from the Golgi apparatus and containing digestive enzymes

Front 63

Messenger RNA (mRNA)

Back 63

nucleotide molecule that serves as an intermediate in the genetic code between DNA and protein

Front 64

Metaphase

Back 64

second stage of mitosis (and meiosis), characterized by the linear alignment of sister chromatids in the center of the cell

Front 65

Metaphase Plate

Back 65

linear alignment of sister chromatids in the center of the cell, which takes place during metaphase

Front 66

Microfilament

Back 66

the thinnest of the cytoskeletal filaments; composed of tubulin subunits that function in cellular movement and structural support

Front 67

Microtubule

Back 67

the thickest of the cytoskeletal filaments, composed of tubulin subunits that funciton in cellular movement and structural support

Front 68

Mitochondrion

Back 68

one of the cellular organelles bound by a douple lipid bilayer that function primarily in the production of cellualr enery (ATP)

Front 69

mitosis

Back 69

division of genetic material, during which the cell nucleus breaks down and two new, fully functional, nuclei are formed

Front 70

Mitotic Phase

Back 70

phase of the cell cycle in which a cell undergoes mitosis

Front 71

Mitotic Spindle

Back 71

network of microtubules, originating from centrioles, that arranges and pulls apart chromosomes during mitosis

Front 72

Multipotent

Back 72

describes the condition of being able to differentiate into different types of cells within a given cell lineage or small number of lineages, such as a red blood cell or white blood cell

Front 73

Mutation

Back 73

change in the nucleotide sequence in a gene within a cell's DNA

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Nuclear Envelope

Back 74

membrane that surrounds the nucleus; consisting of a double lipid-bilayer

Front 75

Nuclear Pore

Back 75

one of the small, protein-lined openings found scattered throughout the nuclear envelope

Front 76

Nucleolus

Back 76

small region of the nucleus that functions in ribosome synthesis

Front 77

Nucleosome

Back 77

unit of chromatin consisting of a DNA strand wrapped around histone proteins

Front 78

Nucleus

Back 78

cell's central organelle; contains the cell's DNA

Front 79

Oligopotent

Back 79

describes the condition of being more specialized than mulitpotency; the condition of being able to differentiate into one of a few possible cell types

Front 80

ORganell

Back 80

any of several different types of membrane-enclosed specialized structures in the cell that perform specific functions for the cell

Front 81

Osmosis

Back 81

diffusion of water molecules down their concentration gradient across a selectively permeable membrane

Front 82

Passive Transport

Back 82

form of transport across the cell membrane that does not require input of cellular energy

Front 83

Peripheral Protein

Back 83

membrane-associated protein that does not span the width of the lipid bilayer, but is attached peripherally to integral proteins, membrane lipids, or other components of the membrane

Front 84

Peroxisome

Back 84

membrane-bound organelle that contains enzymes primarily responsible for detoxifying harmful substances

Front 85

Phagocytosis

Back 85

endocytosis of large particles

Front 86

Pinocytosis

Back 86

endocytosis of fluid

Front 87

Pluripotent

Back 87

describes the condition of being able to differentiate into a large variety of cell types

Front 88

Polypeptide

Back 88

chain of amino acids linked by peptide bonds

Front 89

Polyribosome

Back 89

simultaneous translation of a single mRNA transcript by multiple ribosomes

Front 90

Promoter

Back 90

region of DNA that signals transcription to begin at that site within the gene

Front 91

Prophase

Back 91

first stage of mitosis (and meiosis), characterized by breakdown of the nuclear envelope and condensing of the chromatin to form chromosomes

Front 92

Proteome

Back 92

full complement of proteins produced by a cell (determined by the cell's specific gene expression)

Front 93

Reactive Oxygen Species (ROS)

Back 93

a group of extremely reactive peroxides and oxygen-containing radicals that may contribute to cellular damage

Front 94

Receptor

Back 94

protein molecule that contains a binding site for another specific molecule (called a ligand)

Front 95

Receptor-Mediated Endocytosis

Back 95

endocytosis of ligands attached to membrane-bound receptors

Front 96

Ribosomal RNA (rRNA)

Back 96

RNA that makes up the subunits of a ribosome

Front 97

ribosome

Back 97

cellular organelle that functions in protein synthesis

Front 98

RNA Polymerase

Back 98

enzyme that unwinds DNA and then adds new nucleotides to a growing strand of RNA for the transcription phase of protein synthesis

Front 99

S phase

Back 99

stage of the cell cycle during which DNA replication occurs

Front 100

Selective Permeability

Back 100

feature of any barrier that allows certain substances to cross but excludes others

Front 101

Sister Chromatid

Back 101

one of a pair of identical chromosomes, formed during DNA replication

Front 102

Sodium-Potassium Pump

Back 102

membrane-embedded protein pump that uses ATP to move Na+ out of a cell and K+ into the cell

Front 103

Somatic Cell

Back 103

all cells of the body excluding gamete cells

Front 104

Spliceosome

Back 104

complex of enzymes that serves to splice out the introns of pre-mRNA transcript

Front 105

Splicing

Back 105

the process of modifying a pre-mRNA transcript by removing certain, typically non-coding regions

Front 106

Stem Cell

Back 106

cell that is oligo-, multi-, or pleuripotent that has the ability to produce additional stem cells rather than becoming further specialized

Front 107

Telophase

Back 107

final stage of mitosis (and meiosis), preceding cytokinesis, characterized by the formation of two new daughter nuclei

Front 108

Totipotent

Back 108

embryonic cells that have the ability to differentiate into any type of cell and organ in the boy

Front 109

Transcription

Back 109

process of producing an mRNA molecule that is complementary to a particular gene of DNA

Front 110

Transcription Factor

Back 110

one of the proteins that regulate the transcription of genes

Front 111

Transfer RNA (tRNA)

Back 111

molecules of RNA that serve to bring amino acids to a growing polypeptide strand and properly place them into the sequence

Front 112

Translation

Back 112

process of producing a protein from the nucleotide sequence code of an mRNA transcript

Front 113

Triplet

Back 113

consecutive sequence of three nucleotides on a DNA molecule that, when transcribed into an mRNA codon, corresponds to a particular amino acid

Front 114

Unipotent

Back 114

describes the condition of being committed to a single specialized cell type

Front 115

Vesicle

Back 115

membrane-bound structure that contains materials within or outside of the cell