Chapter 3 Anatomy & Physiology

Front 1

Cells

Back 1

Smallest living units in the human body

Front 2

Microscopy

Back 2

Study of objects using a microscope

Front 3

Cytology

Back 3

Study of cellular structure & function

Front 4

Somatic Cells

Back 4

Body cells

Front 5

Sex Cells

Back 5

Germ cells, reproductive cells

Sperm in males

Oocytes in females

Front 6

Plasma Membrane

Back 6

Cell membrane, the cell's outer boundary consists of a phospholipid bilayer

Front 7

Phospholipid Bilayer

Back 7

The cell membrane - phospholipid molecules in two layers with the hydrophilic heads at the membrane surface and the hydrophobic tails on the inside, account for most of the surface area of the plasma membrane but only 42% of the weight, Proteins ~55% of weight, Carbohydrates ~3% of weight

Front 8

Integral Proteins

Back 8

Proteins embedded within the plasma membrane

Front 9

Transmembrane Proteins

Back 9

Proteins that span the width of the plasma membrane one or more times

Front 10

Peripheral Proteins

Back 10

Bound to inner or outer surface of plasma membrane

Front 11

Anchoring Proteins

Back 11

Proteins that attach the plasma membrane to other structures and stabilize its position

Front 12

Recognition Proteins

Back 12

Identifiers - often glycoproteins, cells of the immune system recognize other cells as normal or abnormal based on these proteins

Front 13

Enzymes

Back 13

Proteins that catalyze reactions in extracellular fluid or cytosol

Front 14

Receptor Proteins

Back 14

Proteins sensitive to the presence of ligands, may trigger changes in cell activity

Front 15

Carrier Proteins

Back 15

Bind solute and transport them across the plasma membrane (may require ATP)

Front 16

Channel Proteins

Back 16

Integral proteins containing a channel/pore that forms a passageway completely through the plasma membrane

Front 17

Gated Channels

Back 17

Channel proteins that can open or close to regulate the passage of substances

Front 18

Rafts

Back 18

Areas where certain integral and peripheral proteins are always confined

Front 19

Glycocalyx

Back 19

Layer of carbohydrate portions of complex molecules that extends beyond the outer surface of the plasma membrane

Functions in lubrication and protection, anchoring and locomotion, specificity in binding, and recognition

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Cytoplasm

Back 20

The material between the plasma membrane and membrane that surrounds the nucleus

Contains the cytosol, organelles, inclusions

Front 21

Cytosol

Back 21

The intracellular fluid, a mixture of water and various dissolved and insoluble materials in which organelles and inclusions are suspended

Front 22

Organelles

Back 22

Internal structures of cells that perform most of the tasks that keep a cell alive and functioning normally

Front 23

Non-Membranous Organelles

Back 23

Not completely enclosed by membranes

Cytoskeleton, centrosome (centrioles), ribosomes, proteasomes, cellular extensions (microvilli, cilia, flagella)

Front 24

Membranous Organelles

Back 24

Organelles that are isolated from the cytosol by phospholipid membranes

Endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, mitochondria

Front 25

Inclusions

Back 25

Masses of insoluble materials in the cytoplasm

Stored nutrients (glycogen, lipid droplets)

Pigment granules (melanin)

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Sodium/Potassium Concentrations in Cytosol vs. Extracellular Fluid

Back 26

Higher sodium concentration in extracellular fluid

Higher potassium concentration in cytosol

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Cytoskeleton

Back 27

Serves as the cell's skeleton

Internal protein framework that gives the cytosol strength & flexibility

Front 28

Microfilaments

Back 28

Smallest cytoskeletal structure (~5nm diameter) made up of the protein actin

Anchor the cytoskeleton to integral proteins of the plasma membrane

Determine consistency of cytosol

Front 29

Intermediate Filaments

Back 29

Intermediate in size between microfilaments and microtubules (~9 to 11nm diameter)

Protein composition varies among cell types, insoluble in watery medium

Most durable of the cytoskeletal elements, strengthens the cell, helps maintain its shape, stabilizes the position of organelles, stabilizes the position of the cell

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Microtubules

Back 30

Largest of the cytoskeletal components (~25nm in diameter) Hollow tubes built from the globular protein tubulin, extend outward into the periphery of the cell from the centrosome

Forms from aggregation of tubulin molecules growing out from centrosome, persists for a while then disassembles

Forms the main portion of the cytoskeleton, gives cell strength, maintains its shape, anchors the positions of major organelles, assists in cell movement, monorail system for movement of materials in the cell, distribute duplicated chromosomes during cell division by forming the spindle apparatus

Front 31

Microvilli

Back 31

Small, non-motile, finger-like projections of the plasma membrane that greatly increase the surface area of the cell

Found in cells that are actively absorbing materials such as cells lining the digestive tract

Have extensive connections with the cytoskeleton

Core of microfilaments stiffens each microvillus and anchors it to the terminal web

Front 32

Centrosome

Back 32

A region of cytoplasm located next to the nucleus, the microtubule-organizing center of animal cells, the heart of the cytoskeletal system, surrounds a pair of cylindrical structures called centrioles which lie perpendicular to each other, with microtubules forming 9 groups with three in each group, with no central microtubules, called 9 + 0 array

Front 33

Cilia

Back 33

Fairly long, slender extensions of the plasma membrane, can be motile or nonmotile

Front 34

Primary Cilium

Back 34

Single, non-motile cilium found in cells in a variety of tissues, similar to 9+0 array organization of centrioles

Acts as a signal sensor, detecting environmental stimuli and coordinating activities such as embryonic development and homeostasis at the tissue level

Front 35

Motile Cilia

Back 35

Multiple motile cilia found on cells lining the respiratory tract & reproductive tracts

Nine pairs of microtubules surround a central pair (9+2 array)

Anchored to central basal body just beneath the cell surface (9+0 array)

Beat rhythmically to move fluids or secretions across the cell surface, move oocytes and sperm through reproductive tract

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Flagellum

Back 36

A whip-like extension of the plasma membrane

Same 9+2 microtubule organization as motile cilia but are much longer

Only human cell with a flagellum is sperm (only 1 per cell)

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Ribosome

Back 37

Organelle responsible for protein synthesis, made of proteins and rRNA

Two subunits: small ribosomal subunit and large ribosomal subunit

Front 38

Free Ribosomes

Back 38

Scattered throughout cytoplasm, proteins they manufacture directly enter cytosol

Front 39

Fixed Ribosomes

Back 39

Temporarily bound to rough endoplasmic reticulum, proteins they manufacture enter the ER where they are modified and packaged for use or secreted from the cell

Front 40

Proteasomes

Back 40

Organelles that contain protein-digesting (proteolytic) enzymes called proteases

Front 41

Endoplasmic Reticulum

Back 41

Network of intracellular membranes continuous with the nuclear envelope

Front 42

Smooth Endoplasmic Reticulum

Back 42

No fixed ribosomes, involving in synthesis of lipids, fatty acids, carbohydrates, absorbs and stores ions, detoxifies or inactivated drugs

Front 43

Rough Endoplasmic Reticulum

Back 43

Contains fixed ribosomes, synthesizes, modifies, and packages proteins

Front 44

Golgi Apparatus

Back 44

Organelle typically consisting of 5 or 6 flattened membranous discs called cisternae

Modifies and packages secretions such as hormones or enzymes for release from the cell, adds or removes carbohydrates to or from proteins, renews or modifies the plasma membrane, packages special enzymes with vesicles (lysosomes) for use in the cytoplasm

Front 45

Lysosomes

Back 45

Vesicles produced by the Golgi Apparatus that provide an isolated environment for potentially dangerous chemical reactions

Contain digestive enzymes that break organic polymers into monomers

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Peroxisomes

Back 46

Smaller than lysosomes and carry different enzymes

Creates by the growth and subdivision of existing peroxisomes

Generates hydrogen peroxide (potentially dangerous free radical) from breakdown of fatty acids and other organic compounds

Catalan breaks down the hydrogen peroxide into oxygen and water

Front 47

Mitochondria

Back 47

Produce energy in the form of ATP molecules

Double membrane, outer membrane surrounds the organelle, inner membrane contains numerous folds called cristae surrounding the fluid contents (matrix)

Contain their own DNA (mtDNA)

Front 48

Glycolysis

Back 48

Break down of glucose molecule into two molecules of pyruvate in the cytosol

Front 49

Citric Acid Cycle

Back 49

AKA Krebs Cycles or Tricarboxylic Acid Cycle - breaks down pyruvate after it is absorbed into mitochondria into CO2 and H

Front 50

Aerobic Respiration

Back 50

AKA Cellular Respiration - type of ATP production in the mitochondria that requires oxygen

Produces about 95% of ATP needed in cell

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Membrane Flow

Back 51

AKA membrane trafficking, continuous movement and exchange of membrane segments

Front 52

Nucleus

Back 52

Usually largest and most conspicuous structure in cell, stores all information needed to direct protein synthesis in DNA

Most cells only contain one nucleus but skeletal muscle cells contain many and red blood cells do not have a nucleus

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Nuclear Envelope

Back 53

Double membrane that encloses contents of nucleus separating them from the cytosol, layers separated by narrow perinuclear space, nuclear envelope continuous with ER

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Nuclear Pores

Back 54

Openings in the nuclear envelope that regulate transport of material such as RNA and proteins

Front 55

Nucleoplasm

Back 55

AKA Karyolymph - the fluid portion of the nucleus

Front 56

Nuclear Matrix

Back 56

Network of fine filaments that provides structural support to the Nucleus and may be involved in regulation of genetic activity

Front 57

Nucleoli

Back 57

Dark-staining areas of the nucleus, transient organelles that synthesize ribosomal RNA (rRNA) and assemble ribosomal subunits which enter the cytoplasm through the nuclear pores

Composed of RNA, enzymes, and histones, form around portions of DNA that contain instructions for producing ribosomal proteins and RNA when those instructions are being carried out

Front 58

Nucleosome

Back 58

DNA strands wound around histones that allow for large amounts of DNA to be packaged into a small space

Determine which information is available

Front 59

Chromatin

Back 59

Fine filaments of nucleosome chains that are loosely coiled in cells that are not dividing

Front 60

Chromosomes

Back 60

Distinct structures resulting from tightly coiled nucleosome chains in cells preparing to divide

Front 61

Triplet Code

Back 61

Sequence of three nitrogenous bases that code for a single amino acid

Front 62

Gene

Back 62

Functional unit of heredity, sequence of nucleotides in a DNA strand that specifies which amino acids are needed to produce a specific protein

Front 63

Protein Synthesis

Back 63

Assembling of functional polypeptides in the cytoplasm

Front 64

Gene Activation

Back 64

Portion of DNA molecule containing the gene is uncoiled and the histones are temporarily removed allowing the gene to be read

Front 65

Promotor

Back 65

Special region of DNA at the start of each gene signaling the start of the gene

Front 66

Transcription

Back 66

The synthesis of RNA from a DNA template

Front 67

Messenger RNA (mRNA)

Back 67

RNA transcribed from DNA that carries the information needed to synthesize proteins

Front 68

Coding Strand

Back 68

DNA strand that contains the triplets that specify the sequence of alibi acids in the polypeptide

Front 69

Template Strand

Back 69

DNA strand that contains the complementary triplets that will be used as a template for mRNA production

Front 70

RNA Polymerase

Back 70

Enzyme that binds to the promoter of a gene on the template strand that promotes hydrogen bonding between nitrogenous bases between the nucleotides on the template strand and nucleotides in the nucleoplasm, and strings together nucleotides by covalent bonding

Front 71

Codon

Back 71

Three nucleotide sequence that codes for a specific amino acid in DNA and RNA

Front 72

RNA Processing

Back 72

Immature mRNA (pre-mRNA) contains many triplets not needed in protein synthesis

Noncoding introns get snipped out, Coding exons are spliced together, creating a much shorter, functional mRNA strand

Front 73

Intron

Back 73

Noncoding intervening segments of mRNA

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Exon

Back 74

Coding segments of mRNA

Front 75

Translation

Back 75

The formation of a linear chain of amino acids (a polypeptide) using the information from an mRNA strand

Front 76

Transfer RNA (tRNA)

Back 76

Binds and delivers a specific type of amino acid during translation

Front 77

Anticodon

Back 77

Base sequence complementary to the mRNA codon that indicates the type of amino acid carried by the tRNA

Front 78

Initiation

Back 78

Translation begins as mRNA binds to small ribosomal subunit at the start codon, tRNA binds to mRNA, then a large ribosomal subunit binds to create a functional ribosome

Front 79

Elongation

Back 79

Translation continues as amino acids are added one by one as ribosome moves along mRNA strand

Front 80

Termination

Back 80

End of Translation - Elongation ends when the ribosome reaches the stop codon, the polypeptide chain is release, the ribosomal subunits separate, the mRNA strand is freed.

Front 81

Permeability

Back 81

The property of the plasma membrane that determines precisely which substances can enter or leave the cytoplasm

Front 82

Impermeable

Back 82

A membrane through which nothing can pass

Front 83

Freely Permeable

Back 83

A membrane through which any substance can pass

Front 84

Selectively Permeable

Back 84

Permeability permits the free passage of some materials and restricts the passage of others

Front 85

Diffusion

Back 85

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

Front 86

Concentration Gradient

Back 86

Difference between high and low concentrations if a substance

Potential energy gradient

Front 87

Electrochemical Gradient

Back 87

Net result of the chemical and electrical forces acting on an ion

Front 88

Membrane Channels

Back 88

Small passageways through the plasma membrane created by transmembrane proteins

Front 89

Leak Channels

Back 89

Membrane channels that are always open and allow ions to pass across the plasma membrane

Front 90

Osmosis

Back 90

The net diffusion of water across a membrane

Front 91

Osmotic Pressure

Back 91

An indication of the force with which pure water moves into a solution as a result of its solute concentration

Front 92

Hydrostatic Pressure

Back 92

Pressure resulting from pushing against a fluid

Front 93

Aquaporins

Back 93

Membrane channels allowing the free passage of water molecules

Front 94

Osmolarity

Back 94

Osmotic concentration - the total solute concentration in an aqueous solution

Front 95

Tonicity

Back 95

The effects of various osmotic solutions on a cell

Front 96

Isotonic

Back 96

Equal solute (osmotic) concentration

Does not cause an osmotic flow of water into or out of a cell

Front 97

Hypotonic

Back 97

Lower solute (osmotic) concentration

Water flows into a cell, causing it to swell up and eventually burst

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Hypertonic

Back 98

Higher solute (osmotic) concentration

Water flows out of the cell, causing it to shrivel up

Front 99

Crenation

Back 99

The shrinking of cells due to a hypertonic solution

Front 100

Carrier-Mediated Transport

Back 100

Integral proteins bind specific ions or organic substrates and carry them across the plasma membrane

Can be active or passive

Front 101

Vesicular Transport

Back 101

Involves moving materials within small membranous sacs (vesicles)

Always an active process

Front 102

Symport Mechanisms

Back 102

Cotransport, common carrier protein (symporter) transports two different molecules or ions through a membrane in the same direction

Front 103

Antiport Mechanism

Back 103

Countertransport, carrier protein (antiporter) transports two different molecules or ions through a membrane in opposite directions

Front 104

Facilitated Diffusion

Back 104

Passive transport across the plasma membrane through a carrier protein

Front 105

Active Transport

Back 105

A high-energy bond (ATP) provides energy needed to move ions or molecules across the membrane

Front 106

Ion Pumps

Back 106

Actively transports the cations sodium, potassium, calcium, and magnesium across the plasma membrane

Some cells also transport iodide, chlorine, and iron ions

Front 107

Exchange Pump

Back 107

Occurs when a countertransport (antiporter) mechanism moves ions

Front 108

Primary Active Transport

Back 108

Process of pumping solute against a concentration gradient using the energy from ATP

Front 109

Sodium-Potassium Exchange Pump

Back 109

Exchanges intracellular sodium ions for extracellular potassium ions

Maintains high extracellular sodium concentration and high intracellular potassium concentrations

1 ATP --> 3 sodium ejected from cell, 2 potassium absorbed into cell

Front 110

Secondary Active Transport

Back 110

Transport mechanism itself does not require energy, but the cell often needs to expend ATP at a later time to preserve homeostasis.

Concentration gradient for one substance provides the driving force needed by the carrier protein to transport the second substance

Front 111

Endocytosis

Back 111

Extracellular materials packaged in vesicles at the cell surface and imported into the cell

Front 112

Endosomes

Back 112

Vesicles created during endocytosis

Front 113

Receptor-Mediated Endocytosis

Back 113

Produces vesicles that contain a specific target molecule in high concentrations

Front 114

Clathrin-Coated Pits

Back 114

Inwardly depressed areas of the plasma membrane that contain receptors and high concentrations of the protein clathrin on their cytoplasmic surface

Front 115

Caveolae

Back 115

Small flask-shaped indentations in the plasma membrane

Front 116

Pinocytosis

Back 116

Cell drinking, formation of endosomes filled with extracellular fluid

No receptors involved, not very selective

Front 117

Phagocytosis

Back 117

Cell eating, produces endosomes called phagosomes containing solid objects that may be as large as the cell itself

Performed only by specialized cells (such as macrophages) such as macrophages that protect tissues by engulfing bacteria, cell debris, or other abnormal materials

Front 118

Pseudopodia

Back 118

Cellular extensions that surround an object and their membranes fuse to form a phagosome

Front 119

Exocytosis

Back 119

A vesicle formed inside the cell fuses with the plasma membrane, releasing its contents into the extracellular fluid

Front 120

Transcytosis

Back 120

Endocytosis produces vesicles on one side of the cell that are discharged through exocytosis on the opposite side of the cell

Front 121

Membrane Potential

Back 121

Positive and negative charges are held apart by the plasma membrane, causing a potential difference across a plasma membrane

Front 122

Resting Membrane Potential

Back 122

The membrane potential in an unstimulated, undisturbed cell

Ranges from about -10mV to -100mV

Front 123

Cell Division

Back 123

Form of cellular reproduction, a single cell divides to produce a pair of daughter cells

Front 124

Apoptosis

Back 124

The genetically controlled death of cells

Front 125

Interphase

Back 125

The stage of the cell life cycle between mitotic divisions where a cell performs its normal functions

Front 126

DNA Replication

Back 126

Duplication of DNA

Front 127

DNA Helicase

Back 127

Enzyme that unwinds the DNA strands and disrupts the hydrogen bonds between the bases

Front 128

DNA Polymerase

Back 128

Enzyme that promotes bonding between nitrogenous bases of the DNA strand and the complementary DNA nucleotides and links the nucleotides with covalent bonds

Front 129

DNA Ligase

Back 129

Splice together DNA segments on the lagging strand of DNA

Front 130

M Phase

Back 130

Includes mitosis and cytokinesis

Front 131

Mitosis

Back 131

Duplication of the chromosomes in the nucleus and their separation into two identical sets in the process of somatic division

Front 132

Cytokinesis

Back 132

The division of the cytoplasm during mitosis producing two daughter cells

Front 133

G0 Phase

Back 133

Cell in this phase is not preparing for division and is performing all of the other functions appropriate for that cell type

Front 134

G1 Phase

Back 134

A cell that is ready to divide first enters this phase during which the cell makes enough mitochondria, cytoskeletal elements, endoplasmic reticula, Golgi apparatus membranes, and cytosol for two functional cells

Front 135

G2 Phase

Back 135

Phase devoted to last-minute protein synthesis and to the completion of centriole replication

Front 136

Prophase

Back 136

Phase begins when the chromatin condenses, and chromosomes become visible as single structures under a light microscope

Front 137

Spindle Fibers

Back 137

Array of microtubules that extend between centriole pairs

Front 138

Astral Rays

Back 138

Smaller microtubules that radiate into cytoplasm

Front 139

S Phase

Back 139

DNA replication takes places during this phase

Front 140

Chromatid

Back 140

Each copy of a chromosome

Front 141

Centromere

Back 141

Each chromatid is connected to its duplicate copy at this point

Front 142

Kinetochores

Back 142

Protein-bound areas of the centromere that attach to spindle fibers forming chromosomal microtubules

Front 143

Metaphase

Back 143

Begins as the chromatids move to a narrow central zone called the metaphase plate, ends when all the chromatids are aligned in the plane of the metaphase plate

Front 144

Anaphase

Back 144

Begins when the centromere of each chromatids pair splits and the chromatids separate, two daughter chromatids are pulled toward opposite ends of the cell along the chromosomal microtubules

Front 145

Telophase

Back 145

Each new cell prepares to return to the interphase state, nuclear membranes reform, nuclei enlarge, chromosomes gradually uncoil

Front 146

Cytokinesis

Back 146

The division of the cytoplasm into two daughter cells, beginning with the formation of the cleavage furrow

Front 147

Mitotic Rate

Back 147

Frequency of cell division can be estimated by the number of cells in mitosis at any time

Front 148

Stem Cells

Back 148

Undifferentiated cells that maintain cell populations through repeated cycles of cell division

Front 149

M-Phase Promoting Factor (MPF)

Back 149

Also known as maturation-promoting factor

Internal trigger that promotes cell division

Front 150

Cyclin

Back 150

Levels climb as cell life cycle proceeds, when levels get high enough, MPF appears in the cytoplasm and mitosis starts

Front 151

Growth Factors

Back 151

Natural body substances derived from food that can stimulate the division of specific types of cells

Hormones, peptides, nutrients

Front 152

Repressor Genes

Back 152

Genes that inhibit cell division

Front 153

p53

Back 153

Protein that binds to DNA that activates a gene that directs the production of growth-inhibiting factors in the cell

Front 154

Telomeres

Back 154

Terminal segments of DNA that protect the ends of the chromosome from damage during mitosis

Front 155

Telomerase

Back 155

Enzyme that repairs telomeres that is active in early life but becomes active by adulthood

Activating telomerase is a key step in the development of cancer

Front 156

Tumor

Back 156

Neoplasm, a mass or swelling produced by abnormal cell growth and division

Front 157

Benign Tumor

Back 157

Cells usually remain within the tissue where it originated and seldom threatens the individual's life

Front 158

Malignant Tumor

Back 158

Cells no longer respond to normal controls and do not remain confined within the epithelium or a connective tissue capsule and spread to surrounding tissues

Front 159

Invasion

Back 159

Spreading of tumor cells to other tissues

Front 160

Cancer

Back 160

An illness that results from the abnormal proliferation of any of the cells in the body characterized by mutations that disrupt normal cell regulatory controls and produce potentially malignant cells

Front 161

Oncogenes

Back 161

Mutated genes involved in cell growth, differentiation, or division

Front 162

Mutagens

Back 162

Agents that cause a mutation (change in DNA)

Front 163

Carcinogens

Back 163

Cancer-causing agents

Front 164

Metastasis

Back 164

The spread of the cancer to other areas, malignant cells break out of the primary tumor and invade the surrounding tissue

Front 165

Angiogenesis

Back 165

The growth of new blood vessels

Front 166

Cellular Differentiation

Back 166

Development of specific cellular characteristics and functions that are different from the original cell

Front 167

Induced Pluripotent Stem (iPS) Cells

Back 167

Ability to take a person's stem or somatic cells and create new cells or neurons to treat disease such as Parkinsin's